Taxonomy, allometry, sexual dimorphism, and conservation of the trans-Andean water-snake Helicops danieli Amaral 1937 (Serpentes: Dipsadidae: Hydropsini).

The extensive lack of knowledge on the morphological aspects of South American water-snakes, includes a poor understanding of phenotypic parameters, intraspecific variation, and conservation of the trans-Andean Helicops species, Helicops danieli Amaral, 1937. For the first time, we provide a multidisciplinary view using key features (e.g., morphology and niche modeling) to improve the taxonomic recognition of this species, as well as describing ontogenetic color changes, allometry, sexual dimorphism, and the conservation status of this poorly studied snake. First, we emended the morphological diagnosis of H. danieli with 23 characters and detected that juvenile tail length is positively related to allometric growth, and that juveniles differ from adults through the presence of the white nuchal collar. Females are larger than males for snout-vent length, whereas males showed proportionally longer tails and smaller head length growth. Suitable areas for H. danieli are restricted to the trans-Andean regions from the Magdalena drainage to the Caribbean coast, which also showed high values of anthropic impacts. Our multidisciplinary approach provided new insights into this South American water snake’s morphology, intraspecific variation, and distribution.

I dropped a big stone on the water snake… Poetic and the Folk Image of a SNAKE

The aim of the article is to reconstruct the linguistic and cultural image of the snake in Polish language and Polish folk culture, functioning within three different but complementary genre-based models: (a) mythological, which echoes are present in belief stories, records of beliefs, and descriptions of practices; (b) biblical (religious), Judeo-Christian, settled in aytiological legends, wedding speeches, religious and historical songs (c) colloquial (common sense), confirmed mainly in colloquial phraseology. In the first model, the snake appears as the guardian of the house and the enclosure, a living creature, friendly to people and animals, whose presence ensures happiness and prosperity; in the second – the serpent is a symbol of evil, sin and Satan; in the third, the most stabilized features of the snake are: wisdom, prudence, but the most of all cunning and sly. The features that emerge especially from the mythological and religious model are the basis for the interpretation of the poetic creation of a snake from Czesław Miłosz’s poem Rue Descartes, in which the lyrical subject combines all evil that has happened to him in his life with in breaking of the ban and just punishment for killing a water snake coiled in the grass.

Sexual dimorphism in the South American water snake Helicops polylepis (Serpentes: Dipsadidae)

Sexual selection, fecundity selection and ecological divergence have been the main explanations proposed for the origin and maintenance of sexual dimorphism. In this study we provide evidence of sexual dimorphism in the South American aquatic snake Helicops polylepis, which is mainly determined by body and head sizes. Males have longer tails and more subcaudal scales, and females have larger body and head and more ventral scales. The sexual dimorphism observed in different morphological characters of H. polylepis occurs in other species of xenodontine snakes and is interpreted as a consequence of sexual selection pressures. Data on growth rates associated with prey availability and female size-related offspring size are necessary to refine our analyzes and test specific hypotheses about the ecological and evolutionary bases of sexual dimorphism in H. polylepis.

SEM study of cephalic region of Tanqua tiara and Tanqua anomala (Nematoda: Gnathostomatidae) from Asansol coal-field area (W.B.) India

From the Asansol region of district Paschim Bardhaman of West Bengal, India two parasitic nematodes belonging to same genus, Tanqua tiara from the stomach of Water monitor lizard, Varanus flavescens and Tanqua anomala from the intesine of Asiatic water snake, Xenochropis piscator were recovered. The Surface structures of head region of both nematodes have been examined with Scanning electron microscope. The mouth region of both species is characterised by presence of two large pseudolabia followed by cephalic bulb. Each pseudolabium bears a pair of submedian cephalic papillae and a lateral amphid. T. tiara has four large cephalic bulbs whereas T. anomala has two large cephalic bulbs. Asansol industrial region is recorded as new geographical area for this parasite.

Facultative Parthenogenesis in a Diamondback Water Snake (Nerodia rhombifer)

Here we describe a case of facultative parthenogenesis in a diamondback water snake (Nerodia rhombifer). An adult female N. rhombifer kept in captivity produced four unfertilized ova, one stillborn and one live neonate in July 2016. The neonates had characteristic abnormalities in morphology and were determined as males, suggestive of a parthenogenetic event. Stillborn and live neonates along with the mother and four unrelated N. rhombifer were genetically screened at twelve microsatellite loci. Results confirmed that the reproductive event represented a case of facultative parthenogenesis. In light of previous reports of facultative parthenogenesis in the genera Nerodia and Thamnophis, these results suggest that this reproductive mode may be a widespread phenomenon in the Natricinae as a whole.