Academic literature on the topic 'Microhylid frog species'

A wide range of frogs produce skin poisons composed of bioactive peptides for defence against pathogens, parasites and predators. While several frog families have been thoroughly screened for skin-secreted peptides, others, like the Microhylidae, have remained mostly unexplored. Previous studies of microhylids found no evidence of peptide secretion, suggesting that this defence adaptation was evolutionarily lost. We conducted transcriptome analyses of the skins of Phrynomantis bifasciatus and Phrynomantis microps, two African microhylid species long suspected to be poisonous. Our analyses reveal 17 evolutionary related transcripts that diversified from to those of cytolytic peptides found in other frog families. The 19 peptides predicted to be processed from these transcripts, named phrynomantins, show a striking structural diversity that is distinct from any previously identified frog skin peptide. Functional analyses of five phrynomantins confirm the loss of a cytolytic function and the absence of insecticidal or proinflammatory activity, suggesting that they represent an evolutionary transition to a new, yet unknown function. Our study shows that peptides have been retained in the defence poison of at least one microhylid lineage and encourages research on similarly understudied taxa to further elucidate the diversity and evolution of skin defence molecules.

The Painted Rice Frog, Microhyla picta Schenkel, is one of the least studied species among narrow-mouthed frogs of the genus Microhyla. To date it is known only from Vietnam, where it is distributed mostly in eastern coastal areas in central and southern parts of the country (Nguyen et al. 2009; Nguyen & Hoang 2013). The species was also found in Con Dao archipelago (Poyarkov & Vassilieva 2011). No data are available on the ecology and reproductive biology of the species, and its larval morphology is also not described. Microhyla frogs are widespread and numerous in terrestrial ecosystems and microhylid tadpoles are known to play an important role in the aquatic communities of temporary waterbodies of monsoon ecosystems in Southeast Asia (Heyer 1973; Vassilieva et al. 2017). The ability to identify microhylid tadpoles in the field is pertinent for biodiversity and ecological studies. We provide a description of larvae of M. picta from various areas in southern Vietnam.

A new species of microhylid frog of the genus Gastrophrynoides is described from Gunung Besar Hantu, in the state of Negeri Sembilan, adding a new generic record to the family Microhylidae of Peninsular Malaysia and an additional species to the previously monotypic genus Gastrophrynoides. This new species can be distinguished from its only congener, G. borneensis by having an immaculate, grayish brown dorsum (instead of a spotted one); a longer snout (2.6–3.0 vs. 2.0–2.5 times diameter of eye); and a single, large, oval outer metacarpal tubercle beneath the hand (instead of smaller, paired, rectangular outer metacarpal tubercles in G. borneensis).

We describe a new species of frog in the microhylid genus Micryletta Dubois, 1987 from Northeast India based on molecular and morphological evidence. The new species, formally described as Micryletta aishani sp. nov., is phenotypically distinct from other congeners by a suite of morphological characters such as brown to reddish-brown dorsum; dorsal skin shagreened with minute spinules; snout shape nearly truncate in dorsal and ventral view; a prominent dark streak extending from tip of the snout up to the lower abdomen; ash-grey mottling along the margins of upper and lower lip extending up to the flanks, limb margins and dorsal surfaces of hand and foot; tibiotarsal articulation reaching up to the level of armpits; absence of outer metatarsal tubercles; and absence of webbing between toes. Phylogenetic relationships within the genus are inferred based on mitochondrial data and the new taxon is found to differ from all the recognised Micryletta species by 3.5–5.9% divergence in the mitochondrial 16S rRNA. The new species was found in the states of Assam, Manipur, and Tripura, from low to moderate elevation (30–800 m asl) regions lying south of River Brahmaputra and encompassing the Indo-Burma Biodiversity Hotspot. The discovery validates the presence of genus Micryletta in Northeast India based on genetic evidence, consequently confirming the extension of its geographical range, westwards from Southeast Asia up to Northeast India. Further, for nomenclatural stability of two previously known species, Microhyla inornata (= Micryletta inornata) and Microhyla steinegeri (= Micryletta steinegeri), lectotypes are designated along with detailed descriptions.

A new diminutive species of microhylid frog (genus Microhyla) is described from the Matang Range, Sarawak, Malaysian Borneo. The new species is an obligate of the pitcher plant, Nepenthes ampullaria, breeding in senescent or mature pitchers, and is Old World’s smallest frog and one of the world's tiniest: adult males range between SVL 10.6– 12.8 mm (n = 8). The new species is diagnosable from congeners in showing dorsum with low tubercles that are relatively more distinct on flanks; a weak, broken, mid-vertebral ridge, starting from forehead and continuing along body; no dermal fold across forehead; tympanic membrane and tympanic annulus absent; Finger I reduced to a nub proximal to Finger II in males; toe tips weakly dilated; phalanges with longitudinal grooves, forming two scale-like structures; webbing on toe IV basal; toes with narrow dermal fringes; inner and outer metatarsal tubercles present; and dorsum brown with an hour-glass shaped mark on scapular region. Miniaturization and reduced webbing may be the result of navigation on the slippery zone of pitchers, situated below the peristome.

We analyzed the diet composition, endoparasites and sexual size dimorphism of the microhylid frog Chiasmocleis capixaba (Microhylidae) from a "mussununga" habitat in the municipality of Nova Viçosa, southern Bahia state, Brazil. All the 119 specimens analyzed were collected in a single night of heavy rainfall. Females (mean snout-vent length = 15.7 + 3.0 mm) were significantly larger than males (mean snout-vent length = 13.2 + 2.1 mm), and specimens of both sexes were smaller than those of a conspecific population previously reported in Aracruz, state of Espírito Santo state. The diet of C. capixaba was dominated by mites, ants and collembolans. Seventy-nine frogs (66.4% of the total) were infected by helminths, all belonging to a single species, Cosmocerca ornata, an intestinal nematode parasite.

A new species of microhylid frog Microhyla kodial sp. nov. from the west coast of India is described in this paper. It is distinct from all described species of Microhyla occurring in South and Southeast Asia as revealed by a combination of morphological, molecular and acoustic characters. The new species is characterized by absence of lateral body stripe, tuberculated dorsal skin surface, absence of webbing between fingers, presence of basal webbing between toes and absence of dorsal marginal groove on finger and toe disc. Each male advertisement call lasts for 0.11–0.42 s and is comprised of 2–7 pulses with a dominant frequency of 3.3–4.2 kHz. The breeding season is short, limited to the rainy season (June to September) and the females lay up to 300 eggs per clutch. A molecular phylogenetic tree constructed using the mitochondrial 16S rRNA gene shows that M. kodial sp. nov. is closely related to the M. achatina group from Southeast Asia. The uncorrected genetic divergence between the new species and its closest congeners M. heymonsi, M. mantheyi, M. borneensis and M. orientalis were 7.3–7.6 %, 7.5–7.8%, 7.8–8.1% and 8.1–8.4% respectively. At present, this species is known only from the type locality, a highly disturbed urban and industrialized area which needs conservation intervention.

Why some species are rare while others are common remains a much asked question in ecology. As rare species are generally considered to be most extinction-prone, the importance of answering this question is becoming paramount in order to prioritise conservation efforts and resources to the most threatened species. The difficulty in gaining information on rare species which, by their very nature, are low in numbers and often difficult to detect, are just some of the reasons behind the apparent lack of answers regarding determinants of rarity. To further investigate why some closely related species are rare while others are common, this study examined the ecological differences between rare and common species of microhylid frogs in the Wet Tropics, North Queensland Australia. Eleven species of microhylid frog of the genus Cophixalus and three from the genus Austochaperina are endemic to the region. While some of these species occur across most of the Wet Tropics region, a majority are restricted to single mountain ranges. By comparing the ecological traits of niche breadth, dispersal ability and genetic diversity, in geographically restricted and widespread species, it has provided a more comprehensive understanding of what factors have shaped the patterns of distribution in these species. The niche breadth of microhylid species was measured using climatic and microhabitat variables. Comparisons of climatic niche among species showed that geographically restricted species do have narrower niche than widespread species, i.e. climate variables explaining more variation in species abundance within their range than topography or vegetation. However when microhabitats of species were described in a smaller subset of six species no relationship of niche breadth and range size was found. Geographically restricted or widespread species were either microhabitat specialists or generalist with no clear trend shown. The relationship between diet specialisation and geographic range was also investigated as a measure of species niche breath. Although macroecological theory predicts that species with broad niches should have the largest geographic ranges, I found the opposite: geographically rare species were diet generalists, widespread species were diet specialists. It is argued that this pattern is a product of extinction filtering, whereby geographically rare and therefore extinction-prone species are more likely to persist if they are diet generalists. The dispersal ability and genetic diversity were compared in a subset of three species to determine if these traits explained restricted, intermediate or widespread distributions. Similar levels of dispersal were suggested across all species however, contra to rarity theory, genetic diversity was found to be higher in the restricted and intermediate species than in widespread. It is suggested that historical habitat stability may have maintained greater genetic diversity in restricted species than in widespread species which have recolonised areas from refugia. The population parameters of species geographic range size, local abundance and ubiquity were used to generate a Rarity Index (RI – ranging in values between 0 - 1.7). The RI allowed for the comparison of population parameters (used as three axis of rarity) of each species in three dimensional space. No species were found to be rare on all three axis, that is, if a species is geographically restricted then it compensated by being abundant and/or ubiquitous on the other two axis. In fact no species were found to have RI values below 0.8 which suggests that species with lower values may have been more extinction prone and unable to maintain viable populations over time. It appears that no single ecological trait explains patterns of distribution seen in microhylid frogs. While rare species may be specialist in some ecological traits they compensate by being generalists in other traits, with past history of rainforest expansion and contraction in this region placing strong selection pressure on these species or these traits being left over from previously being more widespread. This may be one of many reasons that geographically restricted and rare species, while considered to be those most prone to extinction, have been able to persist through long geological time periods.

Throughout much of the world, frog populations are declining and some species are disappearing totally. In Australia, several species have become extinct in the past 25 years. This revised and updated guide provides concise accounts of all the known frogs of Australia. There are 230 species within the five native frog families: Hylidae, Limnodynastidae, Microhylidae, Myobatrachidae and Ranidae. Also included are the introduced Cane Toad and nine ‘stowaway’ species that have arrived in Australia. The text for each species includes details of size, status, distribution, habitat, behaviour and advertisement call. Each species is accompanied by a map of Australia showing its known distribution, and a full-colour painted illustration. Closely related frogs are shown in identical poses so that comparisons can be made readily. The introductory section of the book covers frog biology and habitats and includes notes on families and genera.

Throughout much of the world, frog populations are declining, with the survival of many species under threat. In Australia, several species have become extinct in the past 35 years. This second edition of Field Guide to the Frogs of Australia provides fully updated accounts of all the known frogs of Australia. There are 248 species within the five native frog families: Hylidae, Limnodynastidae, Microhylidae, Myobatrachidae and Ranidae. Also included are the introduced Cane Toad and nine ‘stowaway’ species that have arrived in Australia. Each species account includes details of size, status, distribution, habitat, behaviour and advertisement call. Species are beautifully illustrated with full-colour paintings and distribution maps are also included. Closely related frogs are shown in identical poses so that comparisons can be made readily. The introductory section of the book covers frog biology and habitats and includes notes on families and genera.

Throughout much of the world, frog populations are declining and some species are disappearing totally. In Australia, several species have become extinct in the past 25 years. This fully illustrated guide to all the known frogs of Australia provides concise accounts of 227 species within the five main frog families: Hylidae, Limnodynastidae, Microhylidae, Myobatrachidae and Ranidae. It also includes the introduced Cane Toad and provides notes on other ‘stowaway’ species that have arrived in Australia. The text for each species includes details of size, status, distribution, habitat, behaviour and advertisement call. Each species is accompanied by a map of Australia showing its known distribution, and a full-colour painted illustration. Closely related frogs are shown in identical poses so that comparisons can be made readily. The introductory section of the book covers frog biology and habitats and includes notes on families and genera.