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Aim: The study was conducted to describe the morphology and morphometry of nematode worm in the stomach of Xenochrophis piscator snake macroscopically and microscopically using light and scanning electron microscopy (SEM). Materials and Methods: The sample was 40 nematode worms that have been collected from 60 snakes which slaughtered at snake slaughterhouses in Sidoarjo, Indonesia. The worms (10 male and 10 female) were stained with carmine, and the others were sent to Indonesian Science Institute for ultrastructure observation by SEM. Some of the female worms were immersed in physiological NaCl and incubated to collect the worm eggs. Results: Nematode worm in this study had three lips with almost the same size and it had papillae, so it was included in ascaridoid. The mouth of ascaridoids has three lips, the dorsal bearing two large outer papillae and the each lateroventral with one papilla. The body length and width of the male worm were 70-105 mm and 0.92 1.32, respectively, with head diameter of 0.22-0.28 mm. Dorsal and ventrolateral lips almost have the same size that was 0.10-0.12×0.11-0.13 mm. The length of interlabia was 0.06-0.08 mm, esophagus was 3.21-4 mm, tail was 0.17-0.23 mm, and spicule was 2.12-3.36 mm. The body length and width of the female worm were 85-130 mm and 1.28-1.71 mm, respectively. The head diameter was 0.29-0.38 mm. Dorsal and ventrolateral lips almost have the same size that was 0.13-0.16×0.15-0.19 mm. The interlabial length was 0.08-0.10 mm, esophagus was 3.04-4.67 mm, and tail was 0.22-0.31 mm. The distance of the vulva from the anterior edge was 56-88 mm with an average of 67.35 mm. The eggs have conspicuously pitted with length 0.08-0.09 mm and width 0.07-0.08 mm. Conclusion: Based on the characteristics of morphology and morphometry, the ascaroid worms found on X. piscator snake from Sidoarjo, Indonesia, were O. piscatori. Keywords: carmine, Ophidascaris piscatori, scanning electron microscopy, Sidoarjo Indonesia, Xenochrophis piscator snake

Checkered Keelback, Xenochrophis piscator, was found to inhabit aquatic, semi-aquatic, terrestrial and fossorial habitats. The average body weight of Checkered Keelback was 233 ± 107.25 g. The average weight of the consumed food by each animal was 10.28 ± 6.78 g, which was 4.41% of their body weight. A total of 23 food items were found in the stomachs of 40 snakes. All the food items were animal food, but three categories of accidental food items were found in the stomachs. Based on food contents the snake fed mainly on arthropods (56.52%), fish (26.80%) and amphibians (17.39%). The consumption of food varied seasonally, being much less in winter compared to summer and rainy seasons but the per cent frequency of occurrence of insects in relation to the total number of food items was more or less the same in all seasons. Insects belonged to 14 families under seven orders, mostly harmful to agriculture, fish ponds, gardens and human residences.Bangladesh J. Zool. 44(1): 153-161, 2016

The checkered keelback is also known as Asiatic water snake and is common species of non-venomous snake known to occur in India. The present study report the occurrence of Ascaridia galli infection in a checkered keelback snake, which was found dead near Veterinary College hostel premises. The post-mortem examination of the snake revealed catarrhal exudate without ingesta in the stomach and showed gastric ulcerations with edema. Large numbers of round worms were packed in the lumen of small intestine with petechial haemorrhages and necrotic enteritis. The nematode parasites were recovered and processed for identification. Based on morphological characters, the worms were identified as A. galli and the intestinal contents of the snake showed A. galli eggs.

Species diversity of reptiles is much higher in Sundarban than in other mangrove ecosystems in India. Presently snakes are declining in Sundarban due to habitat loss caused by tremendous population pressure. Besides, irresponsible killing to avoid snakebite both from poisonous and nonpoisonous varieties is another reason for the gradual declining snake population. According to an intensive household survey in 35 villages in Sundarban, about 22 species (five poisonous and 17 non-poisonous) of snakes have been identified and there appears to have been a general decline in densities. On the contrary, a large number of people are bitten and die from snakebite every year with 0.57 and 0.34 vulnerability and mortality rate per 10,000 people, respectively. The two most commonly observed poisonous species are the common krait, Bungarus caeruleus (51 %) and common cobra, Naja naja (40 %), and that of non-poisonous varieties are the Ptyas mucosus (41 %), Typhlina bramina (34 %), Xenochrophis piscator (12 %), and Amphiesma stolata (10 %). Apart from killing of snakes out of fear; habitat loss, unscientific handling of snakes by snake catchers and charmers, and netting by fisherman contributes to snake mortality to a large extent; 72 % killed snakes are of poisonous varieties, 60 % of which are B. caeruleus, the most venomous snake in Sundarban. This paper is an attempt to highlight some of the important conservation efforts like the introduction of snake firms, alternative employment channels for the snake charmers and catchers, and mass awareness campaign through panchayet (village level governing body) and local NGOs.

Unresolved phylogenetic relationships within the subfamily Natricinae continue to exist, including the position of the genus Xenochrophis. In the present study, two mitochondrial genes (cytochrome b, 12S rRNA) and one nuclear gene (c-mos) were used to infer the phylogenetic relationships among the members of Natricinae, with a special emphasis on the position of the genus Xenochrophis. Two statistical methods, Maximum Likelihood and Bayesian Inference, were used for phylogenetic reconstruction. Both the mitochondrial and nuclear datasets produced sufficiently resolved and congruent topologies. Our findings placed the genus Xenochrophis within Natricinae consistently with strong nodal support. Findings also revealed a close association between two Indian natricid snakes, Xenochrophis piscator and Xenochrophis schnurrenbergeri. However Xenochrophis vittatus, from Indonesia, does not cluster with the remaining species of Xenochrophis, suggesting a nonmonophyly of this genus. Overall Natricinae was found to be monophyletic because the two genera, Psammodynastes pulverulentus and Amplorhinus multimaculatus, are now known to be members of the Lamprophiidae. This study also finds a close relationship between the endemic species Lycognathophis seychellensis with the African natricids.

It has been documented in some reptiles that fluctuating incubation temperatures influence hatchling traits differently than constant temperatures even when the means are the same between treatments; yet whether the observed effects result from the thermal variance, temperature extremes or both is largely unknown. We incubated eggs of the checkered keelback snake Xenochrophis piscator under one fluctuating (Ft) and three constant (24, 27 and 30 °C) temperatures to examine whether the variance of incubation temperatures plays an important role in influencing the phenotype of hatchlings. The thermal conditions under which eggs were incubated affected a number of hatchling traits (wet mass, SVL, tail length, carcass dry mass, fatbody dry mass and residual yolk dry mass) but not hatching success and the sex ratio of hatchlings. Body sizes were larger in hatchlings from incubation temperatures of 24 and 27 °C compared with the other two treatments. Hatchlings from the four treatments could be divided into two groups: one included hatchlings from the 24 and 27 °C treatments, and the other included hatchlings from the 30 °C and Ft treatments. In the Ft treatment, the thermal variance was not a significant predictor of all examined hatchling traits, and incubation length was not correlated with the thermal variance when holding the thermal mean constant. The results of this study show that the mean rather than the variance of incubation temperatures affects the phenotype of hatchlings.

We collected 20 checkered keelback snakes (Xenochrophis piscator) to study embryonic growth and mobilization of energy and material during incubation. Females laid eggs between late May and late June. The eggs were incubated at 27 degrees C (+/-0.3). One egg from each clutch was dissected at five-day intervals starting at oviposition. The mean incubation length at 27 degrees C was 48.9 days. We identified three phases of embryonic growth or yolk depletion in X. piscator. Phase 1, between oviposition and Day 20, was one of minimal transfer of energy and material from yolk to embryo. Phase 2, between Day 20 and Day 39-40, was characterized by increasingly rapid embryonic growth or yolk depletion. Phase 3, between Day 39-40 and hatching, was characterized by reduced embryonic growth or yolk depletion. Approximately 71% of dry mass, 53% of non-polar lipids and 66% of energy were transferred from the egg contents to the hatchling during incubation. Our data confirm that oviposition is not timed to coincide with the onset of rapid embryonic growth in oviparous squamate reptiles. The greater conversion efficiencies of energy and material from egg to hatchling in snakes can be attributed to their lower energetic costs of embryonic development and greater residual yolk sizes.

An investigation was carried out to study the scale morphology, arrangement and micro-ornamentation in three Indian snakes - Xenochrophis piscator, Naja naja and Eryx johni to understand their role, if any, in regulating locomotion and its use as a taxonomic tool.

Xenochrophis piscator is a snake that often found in Indonesia, particularly in Java Island. Xenochrophis piscator is a non-venomous snake and often used for food, traditional medicine and as pets in Indonesia. Snakes can be infected by different types of parasites which are zoonotic. One of the zoonotic helminth infect snakes is acanthocephalan. Acanthocephalan can be transmitted to humans by ingesting snake products. We investigate the incidence of helminthiasis in X. piscator from snakes collector in Tulangan district, Sidoarjo, East Java. Parasites were collected from X. piscator organs. Identification of parasites was in carmine stain using light microscope for examination. Sixty snakes were observed and sixteen snakes were positively infected by adult acanthocephalan (26.67%). Acanthocephalan was found in mesenterium and fascia of X. piscator. Keyword : Xenochrophis piscator , acanthocephalan, helminthiasis, zoonosis.

Species differences are known to exist with reference to LDH profile. A four-band isoenzyme pattern is a feature in most snakes, which is a deviation from the primitive ancestor. The LDH morphic state of two water snakes, Cerberus rhynchops and Xenochrophis piscator belonging to the same family Colubridae was selected for the geneological understanding since one of the species is a known salt tolerant. The study was undertaken to observe the fractions of the key isoenzyme LDH subunit diversity in an evolutionary backdrop.

Three endangered Indian snake species, Python molurus, Naja naja, and Xenochrophis piscator are known to be significantly involved in illegal trade. Effective authentication of species is required to curb this illegal trade. In the absence of morphological features, molecular identification techniques hold promise to address the issue of species identification. We present an effective PCR-restriction fragment length polymorphism method for easy identification of the three endangered snake species, Python molurus, Naja naja, and Xenochrophis piscator. A 431-bp amplicon from cytochrome b gene was amplified using novel snake-specific primers following restriction digestion with enzymes Mbo II and Fok I. The species-specific reference fragment patterns were obtained for the target species, which enabled successful identification of even highly degraded shed skin sample confirming the utility of the technique in case of poor-quality DNA. The assay could be effectively used for forensic authentication of three Indian snake species and would help strengthen conservation efforts.

Recent studies have demonstrated that thermoregulatory behavior occurs not only in posthatching turtles but also in turtles prior to hatching. Does thermoregulatory behavior also occur in the embryos of other reptile and bird species? Our experiments show that such behavior is widespread but not universal in reptile and bird embryos. We recorded repositioning within the egg, in response to thermal gradients, in the embryos of three species of snakes (Xenochrophis piscator, Elaphe bimaculata, and Zaocys dhumnades), two turtles (Chelydra serpentina and Ocadia sinensis), one crocodile (Alligator sinensis), and four birds (Coturnix coturnix, Gallus gallus domesticus, Columba livia domestica, and Anas platyrhynchos domestica). However, we detected no significant thermoregulation by the embryos of two lizard species (Takydromus septentrionalis and Phrynocephalus frontalis). Overall, embryonic thermoregulatory behavior is widespread in reptile as well as bird species but may be unimportant in the small eggs laid by most lizards.

The Asiatic water snake (Xenochrophis piscator) is a small-sized snake and can be found in or near freshwater lakes or rivers. This species is listed in Appendis III of the Convention on International Trade in Endangered Species of Wild Fauna and Flora. We isolated and characterizated 9 polymorphic microsatellite loci in this species to evaluate their population polymorphism using 176 individuals collected from Quanzhou in southern China. These markers revealed a high degree of genetic diversity (20–50 alleles per locus) and heterozygosity (H O ranged from 0.137 to 0.944 and H E ranged from 0.884 to 0.953). No locus exhibited significant deviations from Hardy–Weinberg equilibrium. There was no evidence of linkage disequilibrium among pairs of loci. These microsatellite markers will be useful for future study of gene flow, population structure, and evolutionary history of X. piscator.

Morphological variation was investigated across the entire geographic range of the snakes of the Xenochrophis piscator species group. Our results, based on morphological univariate analyses, show the existence of several well-definedclusters identified as species. Xenochrophis flavipunctatus (Hallowell, 1861) is distinct from X. piscator (Schneider, 1799)and sympatric with it over a large area. Xenochrophis tytleri (Blyth, 1863) is confirmed as the valid combination for thepopulation living on the Andaman Islands. Xenochrophis asperrimus (Boulenger, 1891) is confirmed, with species status,for populations from Sri Lanka. Xenochrophis melanzostus (Gravenhorst, 1807) is accepted, as a distinct species mostprobably endemic to Java. Xenochrophis schnurrenbergeri Kramer, 1977 is confirmed for populations from Nepal,southeastern Pakistan, and northern and eastern India. Tropidonotus sanctijohannis Boulenger, 1891 seems to be amontane colour morph of X. piscator and is not regarded here as valid. The second population of “X. piscator“ on SriLanka is regarded as different from that of the mainland, but it is not named here due to the uncertain relationships amongpopulations of southern India and Sri Lanka. The variation of X. piscator sensu stricto is discussed. All taxa areredescribed on the basis of new material. The history of all synonyms is discussed and neotypes are designated for Hydrus palustris Schneider, 1799, Coluber melanzostus Gravenhorst, 1807 and Amphiesma flavipunctatum Hallowell, 1861. The holotype of Hydrus piscator Schneider 1799 has been rediscovered and is discussed.