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1

Barnes, Thomas C., Claudia Junge, Steven A. Myers, Mathew D. Taylor, Paul J. Rogers, Greg J. Ferguson, Jason A. Lieschke, Stephen C. Donnellan i Bronwyn M. Gillanders. "Population structure in a wide-ranging coastal teleost (Argyrosomus japonicus, Sciaenidae) reflects marine biogeography across southern Australia". Marine and Freshwater Research 67, nr 8 (2016): 1103. http://dx.doi.org/10.1071/mf15044.

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Population structure in marine teleosts is often investigated to aid conservation and fisheries management (e.g. to assess population structure to inform restocking programs). We assessed genetic population structure of the important estuary-associated marine fish, mulloway (Argyrosomus japonicus), within Australian waters and between Australia and South Africa. Genetic variation was investigated at 13 polymorphic microsatellite markers. FST values and Bayesian estimates in STRUCTURE suggested population differentiation of mulloway within Australia and confirm strong differentiation between South Africa and Australia. The 12 Australian sample sets fell into one of four spatially separated genetic clusters. Initially, a significant signal of isolation-by-distance (IBD) was evident among Australian populations. However, further investigation by decomposed-pairwise-regression (DPR) suggested five sample sets were influenced more by genetic-drift, rather than gene-flow and drift equilibrium, as expected in strong IBD cases. Cryptic oceanographic and topographical influences may isolate mulloway populations from south-western Australia. The results demonstrate that DPR is suitable to assess population structure of coastal marine species where barriers to gene flow may be less obvious than in freshwater systems. Information on the relative strengths of gene flow and genetic drift facilitates a more comprehensive understanding of the evolutionary forces that lead to population structure, which in turn informs fisheries and assists conservation management. Large-bodied predatory scale-fish may be under increasing pressure on a global scale, owing to a variety of anthropogenic reasons. In southern Australia, the iconic sciaenid A. japonicus (mulloway, jewfish or kob) is no exception. Despite the species supporting important fisheries, much of its ecology is poorly understood. It is possible that a greater understanding of their genetic population structure can help ensure a sustainable future for the only southern Australian sciaenid.
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2

Sewell, Kim B., i Robert J. G. Lester. "Stock composition and movement of gemfish, Rexea solandri, as indicated by parasites". Canadian Journal of Fisheries and Aquatic Sciences 52, S1 (1.08.1995): 225–32. http://dx.doi.org/10.1139/f95-530.

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The parasite fauna of gemfish, Rexea solandri, from seven areas off southern Australia, was examined for evidence of isolated gemfish populations. Canonical multivariate analyses of data on larval nematodes (Anisakis spp. and Terranova sp.), cestode plerocercoids (Hepatoxylon trichiuri and Nybelinia sp.), acanthocephalans (Rhadinorhynchus sp. and Corynosoma sp.), and a hemiuroid digenean from a total of 763 gemfish showed that the parasite faunas of fish from eastern Australia were similar except for a sample taken off New South Wales at the end of the spawning season whose affinities are unknown. Fish from South Australia had similar parasite faunas to those collected from eastern Australia, suggesting that fish from the eastern and western Bass Strait belong to the same stock. Fish collected from the Great Australian Bight were distinct from the southern and eastern fish. Differences in parasite fauna were detected between samples taken within the spawning season and those taken from the same locations outside the spawning season, presumably a result of the spawning migration.
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3

Ayres, Renae M., Vincent J. Pettigrove i Ary A. Hoffmann. "Genetic structure and diversity of introduced eastern mosquitofish (Gambusia holbrooki) in south-eastern Australia". Marine and Freshwater Research 63, nr 12 (2012): 1206. http://dx.doi.org/10.1071/mf11279.

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The closely related eastern mosquitofish (Gambusia holbrooki) and western mosquitofish (Gambusia affinis) have been introduced into many countries and collectively represent the most widely distributed freshwater fish in the world. We investigated genetic patterns associated with the spread of G. holbrooki in its introduced range in south-eastern Australia, by sampling 60 G. holbrooki populations (n = 1771) from major regions where G. holbrooki was initially introduced into Australia, and characterising the genetic diversity and population structure of G. holbrooki, using five polymorphic nuclear microsatellite loci and sequences from two mitochondrial genetic markers. Results were compared with published data on American and European Gambusia samples and historical records. Low microsatellite diversity and strong population genetic structuring were found within G. holbrooki in south-eastern Australia. Observed heterozygosity and allelic richness declined regionally in the order Sydney, Brisbane, Canberra, Melbourne and Adelaide. Microsatellite variation in Australia was reduced compared with native populations. Two mitochondrial DNA haplotypes of G. holbrooki were found; one was common, whereas the other was detected in one Sydney population and one Melbourne population. Cytochrome b sequence diversity was reduced compared with native and European ranges, and sequences were identical to two haplotypes previously identified. Microsatellite diversity of G. holbrooki in south-eastern Australia validates historical records of its spread, beginning north and moving south. Mitochondrial sequencing confirms that G. holbrooki is present in Australia, but the origins of Australian G. holbrooki populations remain unclear.
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4

Shamsi, S., A. Stoddart, L. Smales i S. Wassens. "Occurrence of Contracaecum bancrofti larvae in fish in the Murray–Darling Basin". Journal of Helminthology 93, nr 05 (18.07.2018): 574–79. http://dx.doi.org/10.1017/s0022149x1800055x.

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AbstractThere is a paucity of information on the diversity and occurrence of freshwater fish parasites in Australia. This study investigates the distribution and occurrence of a parasitic nematode of the genusContracaecumin freshwater fish from south-eastern Australia. Fish (n= 508) belonging to nine species and eight families were collected from eight wetlands associated with the Murrumbidgee River floodplain in the southern Murray–Darling Basin and subjected to laboratory examination. Third-stage nematode larvae were found in eight of the nine fish species. The exception was the fly-specked hardeyhead (Craterocephalus stercusmuscarum), although only one specimen of this species was examined. Nematode larvae were identified asContracaecum bancroftiusing a combined morphological and molecular approach. The parasite was most prevalent in weather loach (Misgurnus anguillicaudatus; 34.8%) and Australian smelt (Retropinna semoni; 21.4%), followed by carp (Cyprinus carpio; 9.5%), of which the former and latter are non-native species.Contracaecumprevalence differed between locations, with Two Bridges having the highest number of infected fish. This may be due to the higher number of suitable host species collected at these localities.Contracaecumspp. are parasites with low host specificity that have also been reported in Australian marine fish, humans and piscivorous birds. The high parasite prevalence in the two abundant non-native fish species in the region suggests that they act as a suitable host for this endemic parasite, resulting in the increase in the parasite population. It would be interesting to study host–parasite interactions in this area, especially if introduced fish populations declined dramatically in the attempt to eradicate them or control their population.
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5

Maclaine, Alicia, Wytamma T. Wirth, Donald T. McKnight, Graham W. Burgess i Ellen Ariel. "Ranaviruses in captive and wild Australian lizards". FACETS 5, nr 1 (1.01.2020): 758–68. http://dx.doi.org/10.1139/facets-2020-0011.

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Ranaviral infections have been associated with mass mortality events in captive and wild amphibian, fish, and reptile populations globally. In Australia, two distinct types of ranaviruses have been isolated: epizootic haematopoietic necrosis virus in fish and a Frog virus 3-like ranavirus in amphibians. Experimental studies and serum surveys have demonstrated that several Australian native fish, amphibian, and reptile species are susceptible to infection and supported the theory that ranavirus is naturally circulating in Australian herpetofauna. However, ranaviral infections have not been detected in captive or wild lizards in Australia. Oral-cloacal swabs were collected from 42 wild lizards from northern Queensland and 83 captive lizards from private collections held across three states/territories. Samples were tested for ranaviral DNA using a quantitative PCR assay. This assay detected ranaviral DNA in 30/83 (36.1%) captive and 33/42 (78.6%) wild lizard samples. This is the first time molecular evidence of ranavirus has been reported in Australian lizards.
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6

Ward, R. D., i N. G. Elliott. "Genetic population structure of species in the South East Fishery of Australia". Marine and Freshwater Research 52, nr 4 (2001): 563. http://dx.doi.org/10.1071/mf99184.

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A summary is given of allozyme, mitochondrial DNA and microsatellite data for commercially important species (13 fish and 7 shellfish) in Australia’s South East Fishery, including contiguous waters and the Tasman Sea. For most fish species, genetic population differentiation was limited and in about half the studies was non-detectable. Striking population differentiation was recorded for gemfish. For fish species, on average only 2–3% of the total genetic variation could be attributed to population differentiation within southern Australian waters. In shellfish, ~5% of variation arose from population differences. The reduced differentiation of fish populations may be due to a longer larval period and greater adult mobility. Although there was evidence that the Tasman Sea acts as a barrier to gene flow, with most fish species showing significant differences between Australia and New Zealand, the degree of differentiation was small (only ~2%). The limited genetic differentiation obserred for most species is attributable to the lack of major oceanographic and environmental barriers to gene flow, together with influential current systems; it necessitates large sample sizes for good genetic tests. However, significant genetic stock structuring is apparent for several fish and shellfish species – particularly for coastal species, where isolation by distance may explain some of the data. Any evidence for genetic stock structure must be factored into plans for sustainable management.
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7

Islam, Md Rakeb-Ul, Daniel J. Schmidt, David A. Crook i Jane M. Hughes. "Patterns of genetic structuring at the northern limits of the Australian smelt (Retropinna semoni) cryptic species complex". PeerJ 6 (3.05.2018): e4654. http://dx.doi.org/10.7717/peerj.4654.

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Freshwater fishes often exhibit high genetic population structure due to the prevalence of dispersal barriers (e.g., waterfalls) whereas population structure in diadromous fishes tends to be weaker and driven by natal homing behaviour and/or isolation by distance. The Australian smelt (Retropinnidae:Retropinna semoni) is a native fish with a broad distribution spanning inland and coastal drainages of south-eastern Australia. Previous studies have demonstrated variability in population genetic structure and movement behaviour (potamodromy, facultative diadromy, estuarine residence) across the southern part of its geographic range. Some of this variability may be explained by the existence of multiple cryptic species. Here, we examined genetic structure of populations towards the northern extent of the species’ distribution, using ten microsatellite loci and sequences of the mitochondrial cytbgene. We tested the hypothesis that genetic connectivity among rivers should be low due to a lack of dispersal via the marine environment, but high within rivers due to dispersal. We investigated populations corresponding with two putative cryptic species, SEQ-North (SEQ-N), and SEQ-South (SEQ-S) lineages occurring in south east Queensland drainages. These two groups formed monophyletic clades in the mtDNA gene tree and among river phylogeographic structure was also evident within each clade. In agreement with our hypothesis, highly significant overallFSTvalues suggested that both groups exhibit very low dispersal among rivers (SEQ-SFST= 0.13; SEQ-NFST= 0.27). Microsatellite data indicated that connectivity among sites within rivers was also limited, suggesting dispersal may not homogenise populations at the within-river scale. Northern groups in the Australian smelt cryptic species complex exhibit comparatively higher among-river population structure and smaller geographic ranges than southern groups. These properties make northern Australian smelt populations potentially susceptible to future conservation threats, and we define eight genetically distinct management units along south east Queensland to guide future conservation management. The present findings at least can assist managers to plan for effective conservation and management of different fish species along coastal drainages of south east Queensland, Australia.
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8

Kelly, E., i S. Gibson-Kueh. "The haematology of six species of native catfish from northern Australia". Australian Journal of Zoology 63, nr 5 (2015): 293. http://dx.doi.org/10.1071/zo15040.

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Haematology has the potential to be a valuable tool in determining the health status of wild fish populations and wider ecosystem health. However, limited haematological data are available for wild Australian fish species, and the interpretation and nomenclature of leukocytes is variable and inconsistent in fish. The morphology and cytochemical reactions of erythrocytes, thrombocytes and leukocytes of 189 wild eel-tailed catfish (Tandanus tandanus), Wet Tropics tandan (Tandanus tropicanus), Hyrtyl’s tandan (Neosilurus hyrtlii), black catfish (Neosilurus ater), lesser salmon catfish (Neoarius graeffei), and silver cobbler (Neoarius midgleyi) are described. Erythrocytes, thrombocytes, lymphocytes, monocytes and heterophils in all six species are morphologically similar to those reported in other Siluriformes. Basophils and eosinophils are rarely reported in fish; however basophils were observed in peripheral blood smears of T. tropicanus and N. ater, and eosinophils were observed in N. graeffei. Periodic acid Schiff positive granular leukocytes were observed in N. graeffei, N. midgleyi, N. ater and T. tandanus. This is the first report on the leukocyte morphology and cytochemistry of any native Australian catfish species, and provides useful baseline data for future assessments of fish health and ecosystem integrity in Australia.
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9

Ovenden, J. R., i R. W. White. "Mitochondrial and allozyme genetics of incipient speciation in a landlocked population of Galaxias truttaceus (Pisces: Galaxiidae)." Genetics 124, nr 3 (1.03.1990): 701–16. http://dx.doi.org/10.1093/genetics/124.3.701.

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Abstract Galaxias truttaceus is found in coastal rivers and streams in south-eastern Australia. It spawns at the head of estuaries in autumn and the larvae spend 3 months of winter at sea before returning to fresh water. In Tasmania there are landlocked populations of G. truttaceus in a cluster of geologically young lakes on the recently glaciated Central Plateau. These populations have no marine larval stage and spawn in the lakes in spring. Speciation due to land locking is thought to be a frequent occurrence within Galaxias. To investigate the nature of the speciation event which may be occurring within lake populations of G. truttaceus we studied the mitochondrial DNA (mtDNA) and allozyme diversity of both lake and stream populations. Using the presence or absence of restriction sites recognized by 13 six-base restriction endonucleases, we found 58 mtDNA haplotypes among 150 fish collected from 13 Tasmanian and one south-east Australian mainland stream populations. The most parsimonious network relating the haplotypes by site loss or gain was starlike in shape. We argue that this arrangement is best explained by selection upon slightly beneficial mutations within the mitochondrial genome. Gene diversity analysis under Wright's island model showed that the populations in each drainage were not genetically subdivided. Only two of these stream haplotypes were found among the 66 fish analyzed from four lake populations. Despite the extreme lack of mtDNA diversity in lake populations, the observed nuclear DNA heterozygosity of 40 lake fish (0.10355) was only slightly less than that of 82 stream fish (0.11635). In the short time (3000-7000 years) that the lake fish have been landlocked, random genetic drift in a finite, stable-sized population was probably not responsible for the lack of mtDNA diversity in the lake populations. We infer the lake populations have probably experienced at least one, severe, but transitory bottleneck possibly induced by natural selection for life-history characters essential for survival in the lacustrine habitat. If speciation is occurring in the landlocked populations of G. truttaceus, then it may be driven by genetic transilience.
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10

Faulks, Leanne K., Dean M. Gilligan i Luciano B. Beheregaray. "Phylogeography of a threatened freshwater fish (Mogurnda adspersa) in eastern Australia: conservation implications". Marine and Freshwater Research 59, nr 1 (2008): 89. http://dx.doi.org/10.1071/mf07167.

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Phylogeography is a field that has the potential to provide an integrative approach to the conservation of threatened species. The southern purple spotted gudgeon, Mogurnda adspersa, is a small freshwater fish that was once common and widely distributed throughout south-eastern Australia. However, habitat alteration has dramatically reduced the size and the range of Murray–Darling Basin populations, which are now classified as endangered. Here patterns of genetic structure and evolutionary history of M. adspersa in southern Queensland and the Murray–Darling Basin are elucidated using three regions of the mitochondrial DNA, the ATPase 6 and 8 and the control region. Murray–Darling Basin populations are characterised by lineages with highly localised endemism, very low genetic diversity and restricted gene flow. Phylogenetic reconstructions show that Murray–Darling Basin populations comprise a monophyletic clade that possibly originated by range expansion from the coast around 1.6 million years ago. It is proposed that the divergent Murray–Darling Basin clade is of high conservation priority and requires separate management. The present study further exemplifies the role of drainage rearrangement in driving evolutionary diversification in Australian freshwater fishes, an historical process with profound implications for conservation management.
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Appleford, P., T. A. Anderson i G. J. Gooley. "Reproductive cycle and gonadal development of Macquarie perch, Macquaria australasica Cuvier (Percichthyidae), in Lake Dartmouth and tributaries of the Murray - Darling Basin, Victoria, Australia". Marine and Freshwater Research 49, nr 2 (1998): 163. http://dx.doi.org/10.1071/mf97012.

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The gonadal development, reproductive cycle and growth of Macquarie perch, Macquaria australasica Cuvier, in Lake Dartmouth and selected tributaries of the Murray–Darling River Basin in south-eastern Australia were evaluated. Gonadosomatic index (GSI) and histological analysis were used to determine gonadal development and age and size at first maturity in the resident Lake Dartmouth population. GSI analysis was also used to determine age and size of Macquarie perch at first maturity in the inflowing Mitta Mitta River and other riverine populations within the Goulburn River catchment. Males appeared slightly smaller at first spawning than females at all sites; both sexes were fully mature at four years of age. Differences in size at first maturity were found between the lake and river populations; both males and females of river populations tended to mature at a much smaller size than the fish resident in the lake. Spawning occurred around November. Ovarian and testicular development in this species follows a pattern similar to that of other native Australian percichthyids. The implications for management of recreational fisheries based on minimum size regulations is discussed in relation to site-specific differences in growth rates and size of first maturity of fish.
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Crook, David A., Paul Reich, Nick R. Bond, Damien McMaster, John D. Koehn i P. Sam Lake. "Using biological information to support proactive strategies for managing freshwater fish during drought". Marine and Freshwater Research 61, nr 3 (2010): 379. http://dx.doi.org/10.1071/mf09209.

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This paper provides an assessment of the biological attributes of fish species in south-eastern Australia and rates their potential risk from the impacts of drought. We used scientific literature and expert opinion to conduct a semiquantitative assessment of attributes considered to influence species resistance and resilience to drought for 15 freshwater fish species found in south-eastern Australia. We also present a conceptual framework to guide management of fish populations during drought. The framework focuses on (1) quantifying spatial variation in the severity of drought impacts on particular habitats (rivers, wetlands etc.), (2) assembling information on drought sensitivities of regionally important species, (3) identifying high risk areas (based on species sensitivity and drought severity), (4) determining and implementing appropriate management actions (pre-emptive, responsive), (5) monitoring outcomes and (6) disseminating information on outcomes. In many regions, historic population declines will serve to exacerbate the impacts of drought, and thus are a major threat to successful recovery from drought. Although we discuss both long-term, pre-emptive planning and short-term, responsive management actions, we contend that a long-term view is required to successfully address the threats posed by drought. Furthermore, although droughts clearly represent a severe disturbance to fish populations, ultimately it is anthropogenic factors that exacerbate drought and constrain recovery pathways (at global, regional and local scales), rather than drought per se. These factors must be addressed if we are to ensure the long-term viability of fish populations in inland aquatic ecosystems.
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Creighton, Colin, Paul I. Boon, Justin D. Brookes i Marcus Sheaves. "Repairing Australia's estuaries for improved fisheries production – what benefits, at what cost?" Marine and Freshwater Research 66, nr 6 (2015): 493. http://dx.doi.org/10.1071/mf14041.

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An Australia-wide assessment of ~1000 estuaries and embayments undertaken by the National Land and Water Resources Audit of 1997–2002 indicated that ~30% were modified to some degree. The most highly degraded were in New South Wales, where ~40% were classified as ‘extensively modified’ and <10% were ‘near pristine’. Since that review, urban populations have continued to grow rapidly, and increasing pressures for industrial and agricultural development in the coastal zone have resulted in ongoing degradation of Australia's estuaries and embayments. This degradation has had serious effects on biodiversity, and commercial and recreational fishing. A business case is developed that shows that an Australia-wide investment of AU$350 million into repair will be returned in less than 5 years. This return is merely from improved productivity of commercial fisheries of a limited number of fish, shellfish and crustacean species. Estuary repair represents an outstanding return on investment, possibly far greater than most of Australia's previous environmental repair initiatives and with clearly demonstrated outcomes across the Australian food and services economies.
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14

Russell, D. J., F. E. Thomson, P. A. Thuesen, T. N. Power i R. J. Mayer. "Variability in the growth, feeding and condition of barramundi (Lates calcarifer Bloch) in a northern Australian coastal river and impoundment". Marine and Freshwater Research 66, nr 10 (2015): 928. http://dx.doi.org/10.1071/mf13269.

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Lates calcarifer supports important fisheries throughout tropical Australia. Community-driven fish stocking has resulted in the creation of impoundment fisheries and supplemental stocking of selected wild riverine populations. Using predominantly tag–recapture methods, condition assessment and stomach flushing techniques, this study compared the growth of stocked and wild L. calcarifer in a tropical Australian river (Johnstone River) and stocked fish in a nearby impoundment (Lake Tinaroo). Growth of L. calcarifer in the Johnstone River appeared resource-limited, with juvenile fish in its lower freshwater reaches feeding mainly on small aytid shrimp and limited quantities of fish. Growth was probably greatest in estuarine and coastal areas than in the lower freshwater river. Fish in Lake Tinaroo, where prey availability was greater, grew faster than either wild or stocked fish in the lower freshwater areas of the Johnstone River. Growth of L. calcarifer was highly seasonal with marked declines in the cooler months. This was reflected in both stomach fullness and the percentage of fish with empty stomachs but the condition of L. calcarifer was similar across most sites. In areas where food resources appear stretched, adverse effects on resident L. calcarifer populations and their attendant prey species should be minimised through cessation of, or more conservative, stocking practices.
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Ellis, Iain M., Daniel Stoessel, Michael P. Hammer, Scotte D. Wedderburn, Lara Suitor i Arkellah Hall. "Conservation of an inauspicious endangered freshwater fish, Murray hardyhead (Craterocephalus fluviatilis), during drought and competing water demands in the Murray–Darling Basin, Australia". Marine and Freshwater Research 64, nr 9 (2013): 792. http://dx.doi.org/10.1071/mf12252.

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Approximately 40% of Australian freshwater fish species are of conservation concern, largely because of the impacts of river regulation, habitat fragmentation and alien fishes. Murray hardyhead is a threatened fish endemic to the southern Murray–Darling Basin in Australia, which has declined significantly in range and abundance since European settlement. Conservation of the species has relied largely on environmental watering of off-channel wetlands where isolated populations persist. This became problematic during recent drought (1997–2010) because of competing demands for limited water, and resentment towards environmental watering programs from communities that themselves were subject to reduced water entitlements. In response, emergency conservation measures prioritised the delivery of environmental water to minimise applied volumes. Captive maintenance programs were established for fish rescued from four genetically distinct conservation units, with varying levels of breeding success. Several translocations of wild and captive-bred fish to surrogate refuge sites were also conducted. Future recovery of the species should secure existing natural and stocked populations and translocate fish to additional appropriate sites to spread risk and reinstate natural pathways for dispersal. The approach to the conservation of Murray hardyhead during extreme environmental conditions provides insights to inform the management of fishes in other drought-prone regions of the world.
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Johnson, MS, DR Hebbert i MJ Moran. "Genetic analysis of populations of north-western Australian fish species". Marine and Freshwater Research 44, nr 5 (1993): 673. http://dx.doi.org/10.1071/mf9930673.

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Allozyme variation was used to investigate the genetic structure of Lutjanus sebae, Lethrinus nebulosus, Lethrinus choerorynchus, and Epinephelus multinotatus, which are components of a multispecies fishery off north-western Australia. Samples of each species were obtained from five or six localities, over a total distance of 1400-2080 km. Allelic variation was found at 13-16 loci in each species. The consistent picture to emerge was one of little genetic subdivision in all four species, with average values of FST ranging from 0.003 in L. sebae to 0.012 in E. multinotatus. Although there was statistically significant variation in allelic frequencies in three of the species, there were no clear geographical groupings of populations. With the possible exception of clinal variation for aldehyde oxidase in E. multinotatus, all heterogeneity of allelic frequencies was within the range that could easily be due to within-generation effects of selection. Thus, the allozyme data are consistent with the view that there are extensive connections of populations over large distances. The electrophoretic study also confirmed that, contrary to suggestions in the literature, L. nebulosus, L. choerorynchus, and Lethrinus laticaudis are reproductively isolated species.
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Shaddick, Kim, Dean M. Gilligan, Christopher P. Burridge, Dean R. Jerry, Kiet Truong i Luciano B. Beheregaray. "Historic divergence with contemporary connectivity in a catadromous fish, the estuary perch (Macquaria colonorum)". Canadian Journal of Fisheries and Aquatic Sciences 68, nr 2 (luty 2011): 304–18. http://dx.doi.org/10.1139/f10-139.

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The estuary perch ( Macquaria colonorum ) represents an important model for assessing how historical changes in coastal geomorphology and current oceanographic and estuarine conditions may have impacted connectivity in a catadromous fish. A fragment of the mitochondrial control region and six microsatellite DNA markers were used to clarify connectivity in 17 populations (n = 354) of estuary perch from the southeast and southern coasts of Australia. The mtDNA data showed a latitudinal disjunction in haplotype frequencies that divided populations into two groups (ΦST = 0.419), in a pattern suggestive of isolation by geographic distance. However, no marked structure or correlation with distance was apparent within each group, a result consistent with microsatellite data that showed high contemporary population connectivity across large distances. This was contrary to expectations that the species would exhibit moderate to strong genetic structure consistent with a one-dimensional stepping stone pattern. Coalescent phylogeographic and population genetic analyses provided support for a historical divergence probably due to the emergence of the Bassian Isthmus in southern Australia. Current connectivity appears to be maintained by both large- and fine-scale oceanographic currents and processes, highlighting the important role of the marine environment for an estuarine resident species.
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Humphries, P. "Life history, food and habitat of southern pygmy perch, Nannoperca australis, in the Macquarie River, Tasmania". Marine and Freshwater Research 46, nr 8 (1995): 1159. http://dx.doi.org/10.1071/mf9951159.

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The reproductive biology, age, growth, food and habitat of Nannoperca australis are described from samples collected from fringing macrophyte beds of the Macquarie River, Tasmania. Comparisons are made with the same species at Narrandera in New South Wales and other nannopercids, mainly in south-western Australia. Nannoperca australis spawned at the end of its first year, predominantly between October and December, inclusive. The peak mean gonadosomatic index of males occurred in August at 8.0 and that of females two months later at 11.5. The largest oocytes, of running-ripe females collected in October and December, were 1.15 mm in diameter. Fecundities ranged from 78 for a 1-year-old 37-mm fish to 679 for a 2-year-old 63-mm fish. Spawning is presumed to occur in the macrophyte habitat, since adults did not emigrate from these areas at this time. Otoliths and length-frequency histograms indicated that populations were dominated by 0+ fish. Amphipods and ostracods predominated in the guts of N. australis and prey items were mostly either benthic invertebrates or plant epifauna. Plankton was consumed by small fish in greater quantities than by larger fish, whereas the opposite was true for benthic and epifaunal prey. Fish were virtually always associated with aquatic macrophytes and almost always with shallow, still water.
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19

Hardy, Christopher M., Mark Adams, Dean R. Jerry, Leon N. Court, Matthew J. Morgan i Diana M. Hartley. "DNA barcoding to support conservation: species identification, genetic structure and biogeography of fishes in the Murray - Darling River Basin, Australia". Marine and Freshwater Research 62, nr 8 (2011): 887. http://dx.doi.org/10.1071/mf11027.

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Freshwater fish stocks worldwide are under increasing threat of overfishing, disease, pollution and competition from introduced species. In the Murray—Darling Basin (MDB), the largest river system of Australia, more than half the native species are listed as rare or endangered. Active management is required to counteract reduction in population sizes, prevent local extinctions and to maintain genetic diversity. We describe the first comprehensive set of DNA barcodes able to discriminate between all 58 native and introduced species of freshwater fish recorded in the MDB. These barcodes also distinguish populations from those in adjacent basins, with estimated separation times as short as 0.1 million years ago. We demonstrate the feasibility of using DNA fingerprinting of ribosomal RNA (12S and 18S rRNA) genes and mitochondrial DNA control region (mtDNA CR) sequences to identify species from eggs, larvae, tissues and predator gut contents as well as differentiate populations, morphologically cryptic species and hybrids. The DNA barcode resource will enhance capacity in many areas of fish conservation biology that can benefit from improved knowledge of genetic provenance. These include captive breeding and restocking programs, life history studies and ecological research into the interactions between populations of native and exotic species.
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20

THIRUMARAISELVI, Ramakrishnan, i Muthusamy THANGARAJ. "Genetic Diversity Analysis of Indian Salmon, Eleutheronema tetradactylum from South Asian Countries Based on Mitochondrial COI Gene Sequences". Notulae Scientia Biologicae 7, nr 4 (13.12.2015): 417–22. http://dx.doi.org/10.15835/nsb749668.

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Eleutheronema tetradactylum is an important commercial fish species exposed to intense exploitation both in Southeast Asian countries and Northern parts of Australia. Research on the population structure of E. tetradactylum in these coastal waters is substantial in order to ensure sustainable use and appropriate resource management. In this study, genetic variation, diversity and population structure of E. tetradactylum among four FAO fishing areas, along South Asian countries, were evaluated using cytochrome c oxidase subunit I (COI) gene. Totally 30 sequences of COI gene were collected from four FAO fishing areas. Among these 30 individuals, 18 distinct haplotypes were defined. High levels of haplotype diversity (hd = 0.952 ± 0.096) and nucleotide diversity (π = 0.01536 ± 0.00312) were observed in the population within the Bay of Bengal. No haplotype and nucleotide diversity were observed in South China Sea population. Hierarchical analysis of molecular variance (AMOVA) indicated that 0.81% of the genetic variation occurred within the populations, while 7.09% variation occurred among populations. Significant genealogical branches were recognized in North Australian populations (one clade), South China Sea populations (one clade), Arabian Sea and Bay of Bengal populations (one clade) on the neighbor-joining tree. These results suggested that E. tetradactylum populations in FAO fishing areas 51, 57 and 61 have developed different genetic structures. Tests of neutral evolution and mismatch distribution suggest that a population growth of E. tetradactylum may take place in these fishing areas.
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21

McGlashan, D. J., J. M. Hughes i S. E. Bunn. "Within-drainage population genetic structure of the freshwater fish Pseudomugil signifer (Pseudomugilidae) in northern Australia". Canadian Journal of Fisheries and Aquatic Sciences 58, nr 9 (1.09.2001): 1842–52. http://dx.doi.org/10.1139/f01-113.

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Dendritic channel patterns have the potential to isolate populations within drainages, depending on the relative position within the stream hierarchy of the populations. We investigated the extent of genetic subdivision in the Australian freshwater fish Pseudomugil signifer (Kner) (Pseudomugilidae) from two drainages in northern Queensland, Australia, using allozyme techniques. The drainages were adjacent and had similar channel patterns each with two major subcatchments coalesced to an estuarine confluence. Analysis of 30 sites across the two drainages revealed that although there was significant genetic variation among sites in both drainages, this was not between the two subcatchments in either case. This result did not support predictions of the stream hierarchy model (SHM), which would predict higher levels of variation among subcatchments than within them, nor did it suggest that estuarine conditions represent a significant barrier to dispersal in this species. More variation was among sites within each subcatchment. Multidimensional scaling plots revealed that, although most sites within a drainage were similar to one another, outlier sites occurred in each drainage, so correlations between genetic distance and geographic distance were weak. We suggest that the distance between sites and the probability of connectivity between sites may better explain the observed distribution of genetic diversity.
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22

Puckridge, J. T., J. F. Costelloe i J. R. W. Reid. "Ecological responses to variable water regimes in arid-zone wetlands: Coongie Lakes, Australia". Marine and Freshwater Research 61, nr 8 (2010): 832. http://dx.doi.org/10.1071/mf09069.

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In dryland rivers, interactions between flow variability and complex geomorphology expose floodplain wetlands to long-term patterns of flooding and drying and highly variable short-term events. We consider whether the abundance and diversity of fish, macroinvertebrate and zooplankton communities in wetlands of the Coongie Lakes complex are influenced by long-term water regimes. To relate biological changes to changes in water regime, mean values of assemblage indices were ranked and correlated against ranked frequency of drying (i.e. water retention) in each waterbody. As water-retention time increased, fish species diversity (richness, evenness) and disease incidence rose, and fish species dominance and macroinvertebrate abundance decreased. The more mobile species of fish utilised the habitats and food resources provided by newly flooded waterbodies. We conclude that fish populations utilise wetlands with a variety of water regimes, and reductions in the frequency of inundation will decrease fish diversity with sequential losses of less mobile species.
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23

Shams, Foyez, Fiona Dyer, Ross Thompson, Richard P. Duncan, Jason D. Thiem, T. Gabriel Enge i Tariq Ezaz. "Multiple Lines of Evidence Indicate Limited Natural Recruitment of Golden Perch (Macquaria ambigua) in the Highly Regulated Lachlan River". Water 12, nr 6 (7.06.2020): 1636. http://dx.doi.org/10.3390/w12061636.

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Freshwater ecosystems and their associated biota have been negatively impacted by the human development of water resources. Fundamental to restoration activities for target species is an understanding of the factors affecting population decline or recovery. Within Australia’s Murray–Darling Basin, recovery efforts to address the population decline of native freshwater fish include stock enhancement, habitat restoration, and the delivery of environmental water. Essential to guiding future management actions is information to assess the efficacy of these efforts. We undertook a study to investigate whether natural spawning and recruitment, stock enhancement, or a combination of the two is contributing to sustaining populations of golden perch (Macquaria ambigua) in the highly regulated Lachlan River, Australia. Otolith microchemistry and genetic analyses were used as complementary tools to determine the source (hatchery origin or wild-spawned) of existing populations in the catchment. We identified that natural spawning and recruitment was contributing to riverine populations in some years but that populations were heavily reliant on stocking. It was not possible to distinguish hatchery and wild-born fish using genetic tools, highlighting the value of using multiple lines of evidence to establish causal mechanisms contributing to population recovery.
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24

Ovenden, Jennifer R., i Raewyn Street. "Genetic population structure of mangrove jack, Lutjanus argentimaculatus (Forsskål)". Marine and Freshwater Research 54, nr 2 (2003): 127. http://dx.doi.org/10.1071/mf02142.

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Translocations of mangrove jack, Lutjanus argentimaculatus (Forsskål 1775), to increase angling opportunities in artificial impoundments are foreshadowed in Queensland. To evaluate genetic population structure before translocations occur, mangrove jack were collected from three sites on the Queensland coast and from one site on the north-western coast of Western Australia. Allelic variation at four dinucleotide microsatellite loci was high: gene diversity (heterozygosity) ranged from 0.602 to 0.930 and allelic counts from 10 to 24. Genetic differentiation among collection sites was weak: estimates of FST were 0.002 for all four sites, and less (FST = 0.001) across a major biogeographical boundary (the Torres Strait region). Nucleotide sequence from two mitochondrial regions (control, 375 base pairs, and ATPase, 415 base pairs) was obtained from a subset of the Australian and additional Indo-Pacific (Indonesian and Samoan) mangrove jack. Haplotype diversity was high (control region, 33 haplotypes for 34 fish; ATPase region, 13 haplotypes for 56 fish). Phylogenetic analysis of mitochondrial DNA sequence data could not discern a relationship between tree topology and geography. These results suggest that mangrove jack in Queensland, and possibly throughout Australia, experience high levels of gene flow. The artificial gene flow caused by permitted translocations is unlikely to exceed natural levels. Fine-scale ecological matching between donor and recipient populations may increase stocking success, and is important if translocation is needed as a species recovery tool in the future.
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25

Page, Timothy J., Suman Sharma i Jane M. Hughes. "Deep phylogenetic structure has conservation implications for ornate rainbowfish (Melanotaeniidae:Rhadinocentrus ornatus) in Queensland, eastern Australia". Marine and Freshwater Research 55, nr 2 (2004): 165. http://dx.doi.org/10.1071/mf03139.

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The freshwater fish, Rhadinocentrus ornatus Regan, 1914, has a patchy distribution through coastal drainages of Queensland and New South Wales, eastern Australia. Isolated populations of R. ornatus are found on several islands, as well as in a disjunct northern population 350 km from its nearest conspecific population. Deoxyribonucleic acid was extracted and sequenced for the mitochondrial ATPase gene to describe the geographic and genetic subdivision within the species. Four major clades were identified. These clades diverged between two and seven million years ago and so represent long-term divisions and possible units of conservation. There are conservation implications in that the narrow and localised distribution of R. ornatus overlaps with an area of large-scale land clearing, high human population and threats from introduced exotic fish. A particularly high centre of Rhadinocentrus diversity in the Tin Can Bay area of Queensland presents some interesting questions about the evolution of the genus Rhadinocentrus.
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26

Crook, David A., Damien J. O'Mahony, Bronwyn M. Gillanders, Andrew R. Munro, Andrew C. Sanger, Stephen Thurstan i Lee J. Baumgartner. "Contribution of stocked fish to riverine populations of golden perch (Macquaria ambigua) in the Murray–Darling Basin, Australia". Marine and Freshwater Research 67, nr 10 (2016): 1401. http://dx.doi.org/10.1071/mf15037.

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Stocking of native fishes is conducted to augment riverine fisheries in many parts of the world, yet most stocking activities are conducted without empirical information on their effectiveness or impacts. In the Murray–Darling Basin (MDB), Australia, stocking has been underway for several decades to maintain recreational fisheries. We stocked chemically tagged golden perch (Macquaria ambigua) fingerlings in three rivers to determine the proportions of stocked fish within populations of the species. Stocked sites were monitored for up to 5 years in the Murrumbidgee River, Edward River and Billabong Creek and non-stocked sites were monitored in the Murray River. Catch per unit effort of stocked year classes increased substantially in Billabong Creek, with stocked fish contributing 100 (2005), 79 (2006) and 92% (2007). Chemically tagged fish comprised 18–38% of the respective age classes in the Murrumbidgee and Edward rivers and there was little evidence of natural recruitment in the non-stocked Murray River. Tagged fish generally attained the legal minimum size within 4 years and had dispersed up to 60km from the original release location. Our results demonstrate that artificial stocking has the potential to strongly influence the abundance and population structure of golden perch in rivers of the MDB.
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27

Wells, Rufus M. G., John Baldwin i Roger S. Seymour. "Low concentrations of methaemoglobin in marine fishes of the Great Barrier Reef, Australia". Marine and Freshwater Research 48, nr 4 (1997): 303. http://dx.doi.org/10.1071/mf97024.

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Concentrations of methaemoglobin (the oxidized non-functional ferric form of haemoglobin) in the blood of marine fish are poorly documented. Although high concentrations have been reported for fish maintained in captivity, baseline values for wild populations are unknown. Two techniques, the cyanide derivative method and the multiple wavelength method, were used to determine methaemoglobin concentrations in blood samples from 25 species of marine teleosts and elasmobranchs captured on the Australian Great Barrier Reef. Although methaemoglobin generally accounted for less than 2% of total haemoglobin, systematic errors occurred when these two standard methods, developed for mammalian blood, were applied to the blood of some fish species. Most problems arose from reactions of various blood components with the reagents used in the cyanide derivative method. Consequently, the multiple wavelength method generally was more reliable for estimating methaemoglobin in the blood of marine fish. The low methaemoglobin concentrations in fish studied on the Great Barrier Reef indicate high water quality and healthy physiological condition.
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28

Crook, David A., Jed I. Macdonald i Tarmo A. Raadik. "Evidence of diadromous movements in a coastal population of southern smelts (Retropinninae: Retropinna) from Victoria, Australia". Marine and Freshwater Research 59, nr 7 (2008): 638. http://dx.doi.org/10.1071/mf07238.

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Understanding the migratory behaviour of fishes is critical to the conservation and management of fish assemblages in coastal rivers. We analysed the otolith chemical signatures of smelt, Retropinna sp., from inland and coastal populations in mainland south-eastern Australia to determine whether individuals within coastal populations of the species were diadromous. Assessments of otolith chemical composition combined with water chemistry data were used to make inferences about the migration histories of individual fish. A proportion of the smelt collected from the freshwater reaches of a coastal river exhibited diadromous movements, with the majority of fish analysed showing evidence of estuarine or marine occupation as larvae/juveniles and a minority inhabiting freshwater throughout their life histories. A broad range in the daily ages of upstream migration into freshwater (15–106 days) and the timing of these migrations suggest that spawning and migration occur over several months during the summer/autumn period. The results of this study suggest that southern smelts are an ecologically variable taxonomic group and that conservation and management actions should take into account the range of migratory behaviours exhibited both within populations and across regions.
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29

Blackmore, Caroline J., Jennifer R. Ovenden, Toby P. Piddocke i Les Christidis. "Population structure undetectable using genetic markers in Mangrove Jack Lutjanus argentimaculatus from its cool-water range limit in eastern Australia". Australian Zoologist 40, nr 4 (styczeń 2020): 628–35. http://dx.doi.org/10.7882/az.2019.021.

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Failure to consider genetic structure in fish populations when collecting aquaculture broodstock can negatively affect fitness, and hence conservation and management goals. Here we used mitochondrial DNA from the 5’ end of the control region (D-loop) and four microsatellite markers to evaluate population genetic structure in the Mangrove Jack Lutjanus argentimaculatus with a view to guiding broodstock collection at the southern extremity of its east Australian range. There was no evidence of genetic structure within the entire tropical, subtropical and temperate east Australian distribution of L. argentimaculatus. Although this species may exhibit clinal morphological and life-history variation at its southern range limit, we did not detect wide- or fine-scale spatial genetic structure to indicate the presence of non-random evolutionary processes. Broodstock collection of L. argentimaculatus need not be geographically restricted in eastern Australia, but fisheries management should consider variation in life history and recruitment success at the species’ edge.
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30

Wedderburn, Scotte D., Keith F. Walker i Brenton P. Zampatti. "Salinity may cause fragmentation of hardyhead (Teleostei: Atherinidae) populations in the River Murray, Australia". Marine and Freshwater Research 59, nr 3 (2008): 254. http://dx.doi.org/10.1071/mf07205.

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Salinisation in lowland areas of the Murray–Darling Basin, Australia, has had noticeable effects on fish. The endangered endemic Murray hardyhead Craterocephalus fluviatilis is distributed patchily and confined mainly to saline waters (0.4–20 g L–1), whereas the unspecked hardyhead C. stercusmuscarum fulvus has a more continuous distribution but is absent from high salinities (>10). Osmoregulation was compared in these two congeners and an estuarine atherinid, the small-mouth hardyhead Atherinosoma microstoma, over a wide salinity range (0.03–85). All three species are euryhaline, although the osmoregulatory ability of C. s. fulvus falters above ~35 salinity. In low salinity (<1), C. fluviatilis is a better osmoregulator than A. microstoma, but both species tolerate hypersaline conditions (85). These data imply a physiological reason for the predominance of C. fluviatilis in inland saline waters, but the reasons for its absence from freshwater habitats (<0.4) remain unclear. The findings have implications for other freshwater fish, especially populations of closely related species, subjected to the effects of salinisation or other stressors.
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31

Wynne, Felicity J. "Detection of ranavirus in endemic and threatened amphibian populations of the Australian Wet Tropics Region". Pacific Conservation Biology 26, nr 1 (2020): 93. http://dx.doi.org/10.1071/pc19009.

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The amphibian chytrid fungus (Batrachochytrium dendrobatidis) has driven severe amphibian declines in the Australian tropics. These declines have resulted in species extirpations and extinctions, with many surviving in small, highly threatened populations. Despite the fragility of remaining populations, another group of lethal pathogens, ranaviruses, have rarely been investigated among native amphibians. Ranaviruses have previously been associated with fish, reptile and amphibian mortality events in Australia, yet remain poorly understood here, especially among amphibian hosts. Here, quantitative polymerase chain reaction assays were used to detect ranavirus presence from eight of 17 tested sites containing populations of endangered and critically endangered Australian frog species. Although present in these populations, ranavirus seems to be at the lower bounds of detectability of the assay, which makes firm diagnosis at the individual level unreliable. Repeated (n=14) detections of this pathogen, however, are highly indicative of its presence at each area where it was detected. Therefore, these populations are likely often exposed to ranavirus. The results of this study are not characteristic of populations experiencing rapid disease-associated die-offs or declines, but further investigations should be undertaken to examine the potential drivers of these pathogens to predict future emergence and potential threats to endangered Australian amphibians.
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32

Fowler, A. J., G. K. Jones i R. McGarvey. "Characteristics and consequences of movement patterns of King George whiting (Perciformes : Sillaginodes punctata) in South Australia". Marine and Freshwater Research 53, nr 7 (2002): 1055. http://dx.doi.org/10.1071/mf02023.

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The characteristics of movement of the South Australian population of King George whiting (Sillaginodes punctata) were determined through analysis of tag and recapture records collected from three tagging periods: (i) 1968–1969; (ii) 1978–1985; and (iii) 1986–1987. The characteristics were compared between the northern and southern parts of two large fishery regions, and determined for fish tagged at different sizes and ages. Fish tagged in the northern Gulf St Vincent and Spencer Gulf moved southwards up to several hundred kilometres, but those tagged in the southern areas showed no systematic directional displacement. Most fish tagged were subadults or young, immature adults at 2–4 years of age. Small, young fish did not move far until a considerable period after tagging, whereas some fish >300 mm total length (TL) at tagging moved substantial distances within only a few weeks. Fish movement resulted in a significant ontogenetic habitat shift, from relatively protected shallow waters that support extensive meadows of seagrass, to southern, exposed, deeper waters and rocky reef. As a result of this systematic, directional displacement the age structures of the fishery catches also varied systematically throughout the two regions. In the northern areas these were simple and dominated by the 3+ age class, whereas in the south they were complex and consisted of the 2+ to 17+ age classes. Because the latter were the spawning populations, fish movement is an obligate step in the life history that ultimately results in supplementation of numbers on the spawning grounds. The consequences for fishery management are discussed.
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33

Coleman, R. A., i A. A. Hoffmann. "Digenean trematode cysts within the heads of threatened Galaxiella species (Teleostei : Galaxiidae) from south-eastern Australia". Australian Journal of Zoology 64, nr 4 (2016): 285. http://dx.doi.org/10.1071/zo16004.

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The dwarf galaxias (Galaxiella pusilla) and little galaxias (Galaxiella toourtkoourt) are both threatened freshwater fish from south-eastern Australia. Occasionally populations have been found with enlarged heads associated with the accumulation of ‘white balls’, but the cause of these deformities has not previously been investigated. In this study, histopathology and molecular techniques were employed to identify cysts extracted from the heads of Galaxiella species across six populations. Histopathology and DNA sequences from both mitochondrial (cytochrome c oxidase subunit I) and nuclear (ribosomal internal transcribed spacer 1) regions identified the cysts as metacercariae of Apatemon gracilis (Rudolphi, 1819), a cosmopolitan digenean trematode species. Heavy infestations of trematode metacercariae within Galaxiella populations are of concern due to the potential to cause increased mortality associated with altered behaviour of the fish host that increases the likelihood of predation. Direct mortality from infestations is also possible, but not quantified in this study.
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34

Booth, David J., Nick Bond i Peter Macreadie. "Detecting range shifts among Australian fishes in response to climate change". Marine and Freshwater Research 62, nr 9 (2011): 1027. http://dx.doi.org/10.1071/mf10270.

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One of the most obvious and expected impacts of climate change is a shift in the distributional range of organisms, which could have considerable ecological and economic consequences. Australian waters are hotspots for climate-induced environmental changes; here, we review these potential changes and their apparent and potential implications for freshwater, estuarine and marine fish. Our meta-analysis detected <300 papers globally on ‘fish’ and ‘range shifts’, with ~7% being from Australia. Of the Australian papers, only one study exhibited definitive evidence of climate-induced range shifts, with most studies focussing instead on future predictions. There was little consensus in the literature regarding the definition of ‘range’, largely because of populations having distributions that fluctuate regularly. For example, many marine populations have broad dispersal of offspring (causing vagrancy). Similarly, in freshwater and estuarine systems, regular environmental changes (e.g. seasonal, ENSO cycles – not related to climate change) cause expansion and contraction of populations, which confounds efforts to detect range ‘shifts’. We found that increases in water temperature, reduced freshwater flows and changes in ocean currents are likely to be the key drivers of climate-induced range shifts in Australian fishes. Although large-scale frequent and rigorous direct surveys of fishes across their entire distributional ranges, especially at range edges, will be essential to detect range shifts of fishes in response to climate change, we suggest careful co-opting of fisheries, museum and other regional databases as a potential, but imperfect alternative.
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35

Koster, W. M., D. R. Dawson, J. R. Morrongiello i D. A. Crook. "Spawning season movements of Macquarie perch (Macquaria australasica) in the Yarra River, Victoria". Australian Journal of Zoology 61, nr 5 (2013): 386. http://dx.doi.org/10.1071/zo13054.

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The Macquarie perch (Macquaria australasica) is a threatened fish species that inhabits rivers and impoundments in south-eastern Australia. Previous studies have shown that Macquarie perch in impoundments exhibit synchronised upstream spawning migrations to shallow, fast-flowing habitats in the lower reaches of inflowing streams. There has been little study of movement behaviours of entirely riverine populations of Macquarie perch despite this being the species’ natural habitat. Here, radio-telemetry is used to test the hypothesis that riverine populations exhibit synchronised migrations during the spawning season. Thirty Macquarie perch in the Yarra River, Victoria, a translocated population outside of the species’ natural range, were radio-tagged before the late spring–early summer spawning season and their movements followed over a 10-month period (May 2011 to February 2012). Tagged fish typically occupied restricted reaches of stream (<450 m). Sixteen of the fish undertook occasional upstream or downstream movements (~250–1000 m) away from their usual locations, particularly associated with large flow variations during the spawning season. There was no evidence of synchronised migratory behaviour or movement of multiple fish to specific locations or habitats during the spawning season. Whilst further research over more years is needed to comprehensively document the spawning-related behaviours of riverine Macquarie perch, our study demonstrates that management of riverine populations of this threatened species cannot necessarily be based on the model of spawning behaviour developed for lacustrine populations.
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36

Pusey, Bradley J., i Angela H. Arthington. "Importance of the riparian zone to the conservation and management of freshwater fish: a review". Marine and Freshwater Research 54, nr 1 (2003): 1. http://dx.doi.org/10.1071/mf02041.

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The relationship between freshwater fish and the integrity of the riparian zone is reviewed with special emphasis on the fauna of northern Australia. Linkages between freshwater fish and riparian zone processes are diverse and important. The riparian zone occurs at the interface between terrestrial and aquatic ecosystems and it may, therefore, regulate the transfer of energy and material between these systems, as well as regulating the transmission of solar energy into the aquatic ecosystem. Riparian influences on light quantity, quality and shade in streams are discussed and predictions are made about the likely impacts associated with changes in light quality. Increased rates of transfer of thermal energy between the atmosphere and the aquatic environment in the absence of an intact riparian zone may potentially disrupt reproduction by desynchronizing the thermal regimen from regional factors, such as the flow regimen, as well as having direct effects on mortality rates, body morphology, disease resistance and metabolic rates. Impacts associated with changes in light quality range from increased egg and larval mortality due to increased ultraviolet (UV) B irradiation and a decreased ability to discriminate between potential mates to increased conspicuousness to predators. Increased insolation and proliferation of exotic pasture grasses, an increasing threat in northern Australia, are shown to have a range of impacts, including changes in habitat structure, food-web structure and the facilitation of invasion by exotic fish species. The interception of terrestrial sediments and nutrients by the riparian zone has important consequences for stream fish, maintaining habitat structure, water clarity and food-web structure. Coarse organic matter donated to the aquatic environment by the riparian zones has a large range of influences on stream habitat, which, in turn, affect biodiversity and a range of process, such as fish reproduction and predation. Terrestrial matter is also consumed directly by fish and may be a very important source of energy in some Australian systems and under certain circumstances. Attention to the linkages between fish and riparian systems is essential in efforts to rehabilitate degraded stream environments and to prevent further deterioration in freshwater fish populations in northern Australia.
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Bejder, Lars, Amanda Hodgson, Neil Loneragan i Simon Allen. "Coastal dolphins in north-western Australia: The need for re-evaluation of species listings and short-comings in the Environmental Impact Assessment process." Pacific Conservation Biology 18, nr 1 (2012): 22. http://dx.doi.org/10.1071/pc120022.

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LITTLE is known about the distribution, abundance and behavioural ecology of dolphins in the tropical north-west of Australia. This region is remote, and until recently, has had a relatively low human population. Two of Australia’s tropical coastal dolphin species, the Australian Snubfin Orcaella heinsohni and Indo-Pacific Humpback Dolphins Sousa chinensis (“Snubfin Dolphin” and “Humpback Dolphin”, hereafter) are known to occur in the region. Australia-wide, the only scientific publications on these two species come from a few studies from eastern Queensland, where both species live in “populations” of 50–100 individuals (Parra et al. 2006a; Cagnazzi et al. 2009) that are genetically isolated from one another (Parra 2011); have small home ranges; and are found in near-shore areas, typically within 3- 5 km of the coastline (Parra 2006; Parra et al. 2002, 2004, 2006a,b; Cagnazzi et al. 2009). In eastern Australia, both species forage on coastal/estuarine fish and cephalopods, which is further evidence of their reliance on the near-shore environment (Parra and Jedensjö 2009). According to population sizes in Queensland, and the extent of potentially suitable habitat along the north-west coast, the total numbers in Western Australia are likely to be in the low thousands of individuals (i.e., < 5000). The combination of these life-history characteristics may render Snubfin and Humpback Dolphins particularly vulnerable to local extinctions due to human activities such as habitat modification and increased shipping and boating activity (Frankham 2005; O’Grady et al. 2006). In this Essay, we review the current extent of coastal developments in the waters of north-west Australia. Then we discuss the conservation and management implications of this in relation to coastal dolphins, particularly Snubfin and Humpback Dolphins. We also appraise the current, non-targeted methods being used to survey marine mammal populations for environmental impact assessments (EIAs), highlighting their inadequacy for coastal dolphins. Finally, we make recommendations that should improve government decision making processes for the long term conservation of these two species.
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38

Chilcott, Stuart, Rob Freeman, Peter E. Davies, David A. Crook, Wayne Fulton, Premck Hamr, David Jarvis i Andrew C. Sanger. "Extinct habitat, extant species: lessons learned from conservation recovery actions for the Pedder galaxias (Galaxias pedderensis) in south-west Tasmania, Australia". Marine and Freshwater Research 64, nr 9 (2013): 864. http://dx.doi.org/10.1071/mf12257.

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The Pedder galaxias (Galaxias pedderensis) from Lake Pedder, Tasmania, Australia, is one of the world’s most threatened freshwater fish. The flooding of Lake Pedder in 1972 for hydroelectric power generation caused a major change to the ecosystem that initiated an irreversible decline in the Pedder galaxias within its natural range. The flooding inundated another headwater catchment and native and introduced fish from this catchment colonised the impoundment. Numbers of the Pedder galaxias declined markedly as the impoundment matured and as colonising fish proliferated. Surveys in the 1980s confirmed the parlous state of the population, highlighting the need for conservation intervention. Several urgent conservation actions were undertaken to save the species from extinction. Translocation was considered the most important recovery action, given the critically low numbers in the wild. The species is now extinct from its natural range and is known from only two translocated populations. The conservation program, and specifically the translocation recovery action, saved the Pedder galaxias from extinction. The conservation management was extremely challenging since rapidly declining fish numbers needed timely and critical decisions to underpin the future of the fish. Recommendations are provided arising from this case study to guide conservation of freshwater fish in similar circumstances.
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39

Zampatti, Brenton P., i Sandra J. Leigh. "Within-channel flows promote spawning and recruitment of golden perch, Macquaria ambigua ambigua – implications for environmental flow management in the River Murray, Australia". Marine and Freshwater Research 64, nr 7 (2013): 618. http://dx.doi.org/10.1071/mf12321.

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Restoring fish populations in regulated rivers requires an understanding of relationships between hydrology and population dynamics. In the present study, spawning and recruitment of golden perch, Macquaria ambigua ambigua, were investigated in relation to flow in the regulated lower River Murray. All life stages were sampled in three successive years, with peak flows of 8500 (2004–05), 15 000 (2005–06) and 7000 ML day–1 (2006–07). Larvae occurred only in November/December 2005, and young-of-year fish only in early 2006. Counts of daily increments in otolith microstructure indicated spawning in late October/early November 2005. Back-calculated birth years for adults, derived from otoliths and compared with the hydrograph for the preceding 25 years, revealed the dominance of three year classes spawned in association with increased discharge in 2000, 1998 and 1996. In 2007, an additional year class of 1-year-old fish appeared, following spawning in 2005. In each case, strong recruitment followed spring–summer spawning, when peak flows were >14 000 ML day–1 and water temperatures would have exceeded 20°C. Restoration of within-channel flows of 15–25 000 ML day–1 from late spring through summer would promote spawning and recruitment and improve the resilience of golden perch populations in the lower Murray.
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40

Heagney, Elizabeth C., Bronwyn M. Gillanders i Iain M. Suthers. "The effect of parasitism by a blood-feeding isopod on the otolith chemistry of host fish". Marine and Freshwater Research 64, nr 1 (2013): 10. http://dx.doi.org/10.1071/mf12123.

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Otolith chemistry is widely used to discriminate fish stocks or populations, although many of the factors that determine trace-element concentrations within the otolith remain poorly understood. We investigated the effect of a blood-feeding isopod ectoparasite, Ceratothoa sp., on the otolith chemistry of yellowtail scad, Trachurus novaezelandiae. We sampled 65 fish from three subpopulations of T. novaezelandiae from Jervis Bay in south-eastern Australia, and used laser ablation (LA)–inductivelycoupled plasma mass spectrometry (ICPMS) to measure otolith lithium (Li) : calcium (Ca), magnesium (Mg) : Ca, strontium (Sr) : Ca and barium (Ba) : Ca from four consecutive summer and winter growth bands. Otoliths of parasitised fish were characterised by significantly lower Li : Ca and Mg : Ca, and higher Sr : Ca, than those of unparasitised individuals from the same subpopulation. The consistency of trends in otolith chemistry across ablation points and among subpopulations suggests that there is a consistent physiological mechanism through which Ceratothoa parasites affect the otolith chemistry of infected individuals. It is likely that a range of physical, metabolic, chemical and behavioural processes act in concert to influence the otolith chemistry of parasitised fish. Given the ubiquitous distribution of parasites in the marine environment, differential rates of parasitism among fish stocks, populations or migratory contingents may be an important but unappreciated factor driving stock- or population-based differences in otolith chemistry.
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41

Klunzinger, Michael W., Stephen J. Beatty, David L. Morgan, Gordon J. Thomson i Alan J. Lymbery. "Glochidia ecology in wild fish populations and laboratory determination of competent host fishes for an endemic freshwater mussel of south-western Australia". Australian Journal of Zoology 60, nr 1 (2012): 26. http://dx.doi.org/10.1071/zo12022.

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Glochidia (parasitic larvae) of freshwater mussels generally require a fish as a host. Westralunio carteri Iredale, 1934 (Bivalvia : Hyriidae), the only freshwater mussel found in south-western Australia, was listed as Vulnerable, but recently changed to Least Concern (International Union for the Conservation of Nature). Glochidia were found on four alien and seven native species of fish from 18 sites in the South West Coast Drainage Division. On alien fishes, prevalence of glochidia ranged from 0.0 to 41.0% and mean intensity (number of glochidia per infested fish) from 1.0 to 6.0, while on native fishes prevalence was 9.2–90.5% and intensity was 2.3–7.1. Glochidia infestation was greatest on benthic fishes, which may be a consequence of greater encounter rates, but other factors, such as host size, probably also influence glochidia prevalence and intensity. Glochidia were generally restricted to fins of infested fish, and were rarely on gills or the body surface. In the laboratory, four native and one alien fish species were found to be competent hosts for their ability to produce juvenile W. carteri, but two alien fish species were not. The inability of some alien fishes to produce juvenile W. carteri could potentially reduce recruitment success in areas dominated by alien fishes.
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42

Bansemer, C. S., i M. B. Bennett. "Retained fishing gear and associated injuries in the east Australian grey nurse sharks (Carcharias taurus): implications for population recovery". Marine and Freshwater Research 61, nr 1 (2010): 97. http://dx.doi.org/10.1071/mf08362.

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Incidental hooking of Carcharias taurus is a threat to their populations’ recovery on the east coast of Australia. Photo-identification techniques were used to investigate the frequency of hooking at 25 aggregation sites along the east coast of Australia between 2006 and 2008. Of the 673 sharks identified, 113 sharks were identified with signs of 119 incidences of hooking. For sharks with both their left and right flank photographed during a single survey day, up to 29% of females and 52% of males were identified with retained fishing gear or an attributed jaw injury. The largest number of sharks identified (222) were from a year-round aggregation of immature and mature sharks at Fish Rock, New South Wales, Australia. Forty-eight per cent of all sharks identified with retained fishing gear were first identified at this site. Fish Rock, a designated critical habitat for C. taurus, allows most forms of line fishing except fishing with bait or wire trace while anchored or moored. As interactions with fishing gear can result in debilitating disease, morbidity and death, the high incidence of hooked individual C. taurus is considered a key threatening process that is likely to reduce this shark population’s ability to recover.
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43

Jerry, Dean R. "Phylogeography of the freshwater catfish Tandanus tandanus (Plotosidae): a model species to understand evolution of the eastern Australian freshwater fish fauna". Marine and Freshwater Research 59, nr 4 (2008): 351. http://dx.doi.org/10.1071/mf07187.

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The geologically complex eastern Australian coastal margin supports the highest taxonomic diversity of freshwater fishes on the continent. However, mechanisms leading to coastal biogeographic patterns are poorly understood. A 399-bp fragment of the hypervariable mtDNA control region was sequenced from populations of eel-tailed catfish (Tandanus tandanus) to determine their phylogeographic structure and to relate this to proposed biogeographic mechanisms and landform evolution. Genetic structure in Tandanus is complex, with haplotypes clustering into three lineages: a phylogenetically distant, northern Queensland clade that is probably a new species; a mid-northern New South Wales clade corresponding to the recently discovered ‘Bellinger’ Tandanus cryptic species; and a third ‘derived’ clade T. tandanus. Phylogenetic analyses suggest that eastern Australian Tandanus originally invaded freshwaters from the coast where volcanic activity in the north and increasing aridity from the Paleocene reduced inter-fluvial connections, causing genetic divergence of northern Queensland and mid-northern New South Wales populations. The haplotypes represented by Murray–Darling drainage T. tandanus were the most derived, indicating that this species originally evolved on the coast and subsequently colonised the Murray–Darling basin. Tandanus in eastern Australia is phylogenetically structured and possibly comprises three species in this region; a pattern potentially shared by other eastern Australian freshwater fishes.
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44

Wedderburn, S. D., i T. C. Barnes. "Piscivory by alien redfin perch (Perca fluviatilis) begins earlier than anticipated in two contrasting habitats of Lake Alexandrina, South Australia". Australian Journal of Zoology 64, nr 1 (2016): 1. http://dx.doi.org/10.1071/zo15083.

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Redfin perch (Perca fluviatilis) introduced to the Southern Hemisphere has contributed to the decline or localised extirpations of native fishes, principally due to predation. It has been widely recorded in the Murray–Darling Basin, south-eastern Australia, since the 1920s but the ecological consequences are largely undetermined. The purpose of this study was to examine the diet of juvenile redfin perch in Lake Alexandrina to assess its potential impacts on native biota in two distinct habitats (channel and lake). We proposed that the broad dietary composition of juvenile redfin perch matches that of its natural range (small decapods and insects). Most juvenile redfin perch with prey items in their guts, however, had consumed native fish. There was variability in the diet of redfin perch between the channel and lake where gudgeons and gobies, respectively, were targeted. Unexpectedly, otolith ageing revealed that the redfin perch were larger and shifted to piscivory at a much younger age compared with populations in its native range. Among other ecological issues, the findings are pertinent to threatened small-bodied fish populations in the Murray–Darling Basin. More broadly, they suggest that a generalist feeding behaviour can lead to the early onset of piscivory in alien fish populations.
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45

Morgan, David L., Simon J. Hambleton, Howard S. Gill i Stephen J. Beatty. "Distribution, biology and likely impacts of the introduced redfin perch (Perca fluviatilis) (Percidae) in Western Australia". Marine and Freshwater Research 53, nr 8 (2002): 1211. http://dx.doi.org/10.1071/mf02047.

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Within Western Australia, Perca fluviatilis is restricted to the south-western corner and is found in the Swan, Murray, Harvey, Collie, Capel, Carbunup, Margaret, Blackwood, Donnelly and Warren river systems. Age data suggest it was released into Big Brook Dam (Warren River) in 1992 or 1993, where it has since played a role in eliminating the native teleosts. Its success here is attributed to a young age at maturity, rapid growth (compared with populations elsewhere), predatory nature, large size (compared with native fish), broad environmental and habitat tolerances, and absence of predators. Gonadal development initiates in late summer, with peak spawning between August and September. Males and females attained maturity in their first and second years, respectively, which is earlier than reported for most Northern Hemisphere populations and can be attributed to their rapid growth here because of the warmer climate. At ages 1, 2, 3, 4 and 5, males, on average, attained 102, 159, 206, 246 and 280 mm total length (TL) and females had attained 104, 166, 228, 290 and 351 mm TL at the respective ages. Diets of fish 50–200 mm TL comprised mainly small aquatic invertebrates, whereas larger fish preyed almost exclusively on decapods, mainly marron (Cherax tenuimanus), and teleosts.
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46

Moore, B. R., D. J. Welch i C. A. Simpfendorfer. "Spatial patterns in the demography of a large estuarine teleost: king threadfin, Polydactylus macrochir". Marine and Freshwater Research 62, nr 8 (2011): 937. http://dx.doi.org/10.1071/mf11034.

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Understanding spatial patterns in demographic parameters of exploited fish species is of critical importance to effective fisheries management. In the present study, patterns in demography of a large, protandrous, estuarine teleost, king threadfin, Polydactylus macrochir, were compared among three estuaries on the eastern coast of Queensland, Australia. Significant variation in age and growth was observed between fish from the Fitzroy River and those from the Mary and Brisbane Rivers, with Fitzroy River fish living longer (22 years v. 10 and 14 years, respectively), reaching a greater asymptotic length (1222-mm fork length (FL) v. 975- and 1047-mm FL, respectively), and attaining greater length-at-ages of 6 years and beyond. No difference in growth was detected between Mary and Brisbane River fish, or in total mortality among any of the sites. Fitzroy River fish were generally found to mature and change sex at greater lengths and ages than those from the Mary and Brisbane Rivers. The observed variability suggests that spatially segregated populations of P. macrochir may respond differently to fishing pressure and highlights the importance of understanding the spatial patterns in demography of exploited estuarine fish populations.
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47

Woods, Ryan J., Jed I. Macdonald, David A. Crook, Daniel J. Schmidt i Jane M. Hughes. "Contemporary and historical patterns of connectivity among populations of an inland river fish species inferred from genetics and otolith chemistry". Canadian Journal of Fisheries and Aquatic Sciences 67, nr 7 (lipiec 2010): 1098–115. http://dx.doi.org/10.1139/f10-043.

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Patterns of dispersal in riverine populations of Australian smelt ( Retropinna semoni ) were examined using otolith chemistry (Mg:Ca, Mn:Ca, Sr:Ca, Ba:Ca) and genetic markers (allozymes, mtDNA, microsatellite DNA). During a period of prolonged low flows, young-of-year smelt were collected from 13 streams within three catchments of the southern Murray–Darling Basin, Australia. Spatial differences in otolith core and edge chemical signatures and high levels of genetic assignment to sampling locations were observed, suggesting that most recruits were retained in natal areas after spawning. Following a subsequent period of hydrological connection, the same cohort was sampled as 1-year-olds. Maximum likelihood estimation using otolith core chemistry data from these fish suggested that retention in natal areas was highly variable between years and a similar, though less pronounced, pattern was evident in genetic assignments. Partitioning of genetic variation among catchments was not significant (FCT < 0.004) and probably reflects disequilibrium between migration and genetic drift due to an historical population expansion (~270 000 years ago). Taken together, otolith chemistry and genetic analyses suggest that contemporary dispersal of smelt within these catchments is relatively restricted and may be mediated by changes in hydrological connectivity.
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48

Rourke, Meaghan L., Helen C. McPartlan, Brett A. Ingram i Andrea C. Taylor. "Biogeography and life history ameliorate the potentially negative genetic effects of stocking on Murray cod (Maccullochella peelii peelii)". Marine and Freshwater Research 61, nr 8 (2010): 918. http://dx.doi.org/10.1071/mf10037.

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Stocking wild fish populations with hatchery-bred fish has numerous genetic implications for fish species worldwide. In the present study, 16 microsatellite loci were used to determine the genetic effects of nearly three decades of Murray cod (Maccullochella peelii peelii) stocking in five river catchments in southern Australia. Genetic parameters taken from scale samples collected from 1949 to 1954 before the commencement of stocking were compared with samples collected 16 to 28 years after stocking commenced, and with samples from a local hatchery that supplements these catchments. Given that the five catchments are highly connected and adult Murray cod undertake moderate migrations, we predicted that there would be minimal population structuring of historical samples, whereas contemporary samples may have diverged slightly and lost genetic diversity as a result of stocking. A Bayesian Structure analysis indicated genetic homogeneity among the catchments both pre- and post-stocking, indicating that stocking has not measurably impacted genetic structure, although allele frequencies in one catchment changed slightly over this period. Current genetic diversity was moderately high (HE = 0.693) and had not changed over the period of stocking. Broodfish had a similar level of genetic diversity to the wild populations, and effective population size had not changed substantially between the two time periods. Our results may bode well for stocking programs of species that are undertaken without knowledge of natural genetic structure, when river connectivity is high, fish are moderately migratory and broodfish are sourced locally.
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49

Ivantsoff, W., i LELM Crowley. "Review of the Australian silverside fishes of the genus Atherinomorus (Atherinidae)". Marine and Freshwater Research 42, nr 5 (1991): 479. http://dx.doi.org/10.1071/mf9910479.

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Previous studies of the genus Atherinomorus suggested that A. lacunosus was one species with a very wide range over the Indian and Pacific Oceans. Morphology (including osteology) and meristics of many populations of Atherinornorus were studied to test this hypothesis. The results indicate that there are two species pairs of Atherinomorus around the coast of Australia. Each of the four species can be distinguished by the combination of meristic and morphological characters. This study was supplemented with an electrophoretic analysis on a limited collection of fish from the western, northern and eastern coasts of Australia.
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50

Stewart, John. "Evidence of age-class truncation in some exploited marine fish populations in New South Wales, Australia". Fisheries Research 108, nr 1 (luty 2011): 209–13. http://dx.doi.org/10.1016/j.fishres.2010.11.017.

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