Academic literature on the topic 'Morelia viridis'

Colour polymorphisms are common in nature, but their evolutionary significance and the mechanisms maintaining them sometimes remain poorly understood. Polymorphic green pythons (Morelia azurea and Morelia viridis) are born either red or yellow. Several processes are proposed to maintain such polymorphisms, and the assumption that colour is adaptive predicts that it may be correlated with a series of life-history and/or ecological traits. We examined 1090 green pythons from northern Australia and New Guinea and reveal strong geographic variation in the frequency of juvenile polymorphism. Some variation is explained by known genetic structure among populations, while stochastic processes (e.g. bottlenecks, founder effects) likely explain remaining variation. The yellow juvenile morph occurs in all populations of M. azurea and M. viridis, whereas the red morph occurs only in some populations of M. azurea and at varying frequencies. Yellow and red juveniles did not differ in morph-specific survival, sex ratios, morphology (tail length, head shape and mass) or diet. We discuss our results in relation to several hypotheses relating to maintenance of colour polymorphisms in nature. Although inconclusive, we are reluctant to suggest that colour is non-adaptive, and encourage additional experimental field research on the significance of polymorphism in these taxa.

SUMMARYSarcocystisspp. represent apicomplexan parasites. They usually have a heteroxenous life cycle. Around 200 species have been described, affecting a wide range of animals worldwide, including reptiles. In recent years, large numbers of reptiles have been imported into Europe as pets and, as a consequence, animal welfare and species protection issues emerged. A sample of pooled feces from four confiscated green pythons (Morelia viridis) containingSarcocystisspp. sporocysts was investigated. These snakes were imported for the pet trade and declared as being captive-bred. Full length 18S rRNA genes were amplified, cloned into plasmids and sequenced. Two differentSarcocystisspp. sequences were identified and registered asSarcocystissp. fromM. viridisin GenBank. Both showed a 95–97% sequence identity with the 18S rRNA gene ofSarcocystis singaporensis.Phylogenetic analysis positioned these sequences together with otherSarcocystisspp. from snakes and rodents as definitive and intermediate hosts (IH), respectively. Sequence data and also the results of clinical and parasitological examinations suggest that the snakes were definitive hosts forSarcocystisspp. that circulate in wild IH. Thus, it seems unlikely that the infected snakes had been legally bred. Our research shows that information on the infection of snakes withSarcocystisspp. may be used to assess compliance with regulations on the trade with wildlife species.

The green python (Morelia viridis) is an iconic snake species highly sought after in the pet trade and is the target of illegal collection. Despite their popularity, some important ecological attributes of green pythons remain unknown, making their effective conservation management difficult. Detection-only surveys were conducted throughout the potential range of the green python in Australia, and intensive mark–recapture surveys were conducted in the areas where there have been previous records. In total, 298 green pythons were located in the Iron, McIlwraith and Kawadji–Ngaachi ranges of Cape York, distributed over an estimated area of 2289 km2, where they frequented rainforest habitats and adjacent vine thickets. They were not found in the Lockerbie Scrub or Jardine River Catchment, despite anecdotal records. Green python density was estimated to be 540 km–2 in the Iron Range and 200 km–2 in the McIlwraith Range, where the percentages of adults captured were 56% and 83%, respectively. The differences between abundance and population demographics in the Iron and McIlwraith ranges may be due to differences in prey abundance and the impacts of collection. The results of this study provide baseline data to conservation managers and policy makers for the future conservation management of this species in Australia.

A 10-y-old female green tree python ( Morelia viridis) died of fungal pneumonia caused by Purpureocillium lilacinum, which was confirmed histologically and by PCR and subsequent DNA sequencing. The same fungal species was cultivated from a swab taken from the terrarium in which the snake was housed. Clinical and environmental P. lilacinum isolates were indistinguishable by the typing method applied, strongly suggesting clonal relatedness of both isolates. Because no other underlying predisposing respiratory infection could be detected by virus-specific PCR or histopathology, P. lilacinum was considered a primary pulmonary pathogen in this tree python.

Zusammenfassung: Gegenstand und Ziel: Beschreibung des Falls eines Lungenabszesses bei einem Grünen Baumpython (Morelia viridis) mit Diskussion der Differenzialdiagnosen. Ergebnisse: Das seit drei Monaten inappetente Tier wies eine stetig zunehmende, mäßig elastische, nicht verschiebliche Umfangsvermehrung im Bereich des kranialen Körperdrittels auf. Röntgenologisch stellte sich diese etwa auf Herzhöhe gelegene Zubildung als inhomogene Verschattung dar. Nach Eingabe von Kontrastmittel in den Ösophagus per Sonde zeigte sich eine Verdrängung desselben auf Herzhöhe. Sonographisch war keine Flüssigkeitsansammlung nachweisbar, das Gewebe hatte eine inhomogene Textur. Das von einer Kapsel umgebene Gebilde konnte in toto exstirpiert werden und erwies sich als Abszess. Der histologische Befund lautete hochgradige fibrinopurulente Pneumonie. Die mikrobiologische Untersuchung ergab einen hochgradigen Gehalt an Pseudomonas aeruginosa, Morganella morganii und α-hämolysierenden Streptokokken. Entsprechend dem Antibiogramm erhielt die Schlange Enrofloxacin über acht Tage. Die Behandlung führte zur komplikationslosen Heilung. Schlussfolgerung: Wie auch in der Literatur mehrfach beschrieben wird für Reptilien mit Abszess die kombinierte Therapie aus chirurgischem Eingriff und antimikrobieller Therapie nach Antibiogramm empfohlen.

The green python Morelia viridis is a most striking animal. Individuals are born either brick red or bright yellow and both colours change to green as adults. These colours and the remarkable colour change have long made them of interest to biologists and in demand for the pet trade. Despite this interest nothing is known of their distribution, biology or ecology in the wild. Here I address this knowledge gap by presenting results from the first detailed study of the species, at Iron Range on eastern Cape York Peninsula, Australia.¶ Individual growth was described by the von Bertalanffy growth curve, with a maximum predicted size of 1.35 metres snout-vent length. Males matured at 2.4 years and females at 3.6 years, and growth was indeterminate after approximately 12 years. The colour change from yellow to green occurs at 55 centimetres, which corresponds to individuals approximately a year old. There was no sexual dimorphism in adults, however juvenile females had larger heads than juvenile males. Adult sized individuals comprised ~50% of the population.¶ Females had a home range of 6.2 ± 1.9 ha (mean ± SE), which was positively correlated with their snout-vent length. Males adopted a roaming strategy through suitable habitat while juveniles were restricted to areas where more light reached the ground. There was overlap between multiple female home ranges, and between female home ranges and the movement paths of males. There were no differences in the distances moved by males and females of any size, although the variation in movement distances was greater in the dry season than the wet season.¶ Green pythons are obligate ambush predators which eat a variety of prey. They show an ontogenetic shift from invertebrates and terrestrial, diurnal reptiles to birds and terrestrial, nocturnal mammals. This diet change is concurrent with a shift in the time of hunting, and the location and characteristics of ambush sites. Yellow individuals were usually found within ten metres of the ground, while green individuals used the full vegetation strata and were often found in the canopy.¶ The three colour morphs of the green python appear to be adaptive for camouflage rather than intraspecific communication, as conspicuousness of each morph was always greater to a predator than to that of a conspecific. Using advanced light analysis techniques I show that each colour morph is adaptive for camouflage from visually orientated avian predators under different environmental conditions. Yellow and red morphs are half as conspicuous as green individuals would be in locations near the ground where juveniles hunt during the day. Green was the least conspicuous morph in only the canopy, where it was half as conspicuous as either the red or yellow morph. In both leafy and non-leafy sub-canopy environments green individuals were more conspicuous than both yellow and red morphs. Red morphs were least conspicuous in only the non-leafy sub-canopy environment. The conspicuousness of green males decreased with age, but this was not the case with green females. Predation of plasticine models of the three colour morphs showed that red models were ten times more likely to be predated than either green or yellow morphs, however the model colours did not always match the real morph colours.¶ There is a large predicted global distribution in Papua New Guinea, including some offshore islands, however the Australian range is restricted to small areas of eastern Cape York Peninsula. In Australia green pythons occurred in nine regional ecosystems, with most records for the closed semi-deciduous mesophyll vine forest ecosystem. A mark-recapture study at Iron Range captured 101 individuals 147 times over two wet seasons, which equates to a population size of 227 ± 81 individuals in the study area of 51 hectares. Based on the known population structure at this site only 114 (or 50%) of these individuals are adult. Although green pythons have a high density at the one intensely studied site and are predicted to occur over a large geographic area, my data are insufficient to conclude that the species is not vulnerable.