1. Taxonomy, allometry, sexual dimorphism, and conservation of the trans-Andean watersnake Helicops danieli Amaral, 1937 (Serpentes: Dipsadidae: Hydropsini)
- Author
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Citeli, Nathalie, Klaczko, Julia, De-Lima, Anderson Kennedy Soares, de-Carvalho, Mariana, Nunes, Pedro M. Sales, Passos, Paulo, and Brandao, Reuber Albuquerque
- Subjects
Snakes -- Physiological aspects -- Protection and preservation ,Zoology and wildlife conservation - Abstract
The extensive lack of knowledge on the morphological aspects of South American watersnakes includes a poor understanding of phenotypic parameters, intraspecific variation, and conservation of the trans-Andean Helicops species, Daniel's Keelback (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 ontoge-netic 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 watersnake's morphology, intraspecific variation, and distribution. Key words: Daniel's Keelback, ecological niche modeling, Helicops danieli, linear morphometry, hemipenis morphology, intraspecific variation, ontogeny, taxonomy. Le vaste manque de connaissances sur les aspects morphologiques des couleuvres d'eau sud-americaines com-prend une pietre comprehension de parametres phenotypiques, de la variation intraspecifiqueet dela conservation d'une espece transandine d'Helicops (Helicops danieli Amaral, 1937). Nous en presentons un premier portrait multidisciplinaire en utilisant des elements cles (p. ex. morphologie et modelisation de la niche) pour ameliorer l'identification taxonomique de l espece, en plus de decrire des changements de coloration ontogeniques, l allometrie, le dimorphisme sexuel et l etat de conservation de ce serpent peu etudie. Nous modifions d'abord le diagnostic morphologique de H. danieli sur la base de 23 caracteres et relevons que la longueur de la queue des specimens juveniles presente une relation positive avec la crois-sance allometrique et que les jeunes specimens se distinguent des adultes par la presence d un collet nucal blanc. Les femelles sont plus grandes que les males en ce qui concerne la longueur du museau a l'orifice anal, alors que les males ont des queues proportionnellement plus longues et une plus faible croissance de la longueur de la tete. Les secteurs qui con-viennent a l espece se limitent aux regions transandines allant du bassin versant de Magdalena au littoral caribeen, qui pre-sentent aussi de forts degres d impact de l activite humaine. Notre approche multidisciplinaire fournit de nouveaux renseignements sur la morphologie, les variations intraspecifiques et l'aire de repartition de cette couleuvre d'eau sud-americaine. [Traduit par la Redaction] Mots-cles: modelisation de la niche ecologique, Helicops danieli, morphometrie lineaire, morphologie de l'hemipenis, variation intraspecifique, ontogenese, taxonomie., Introduction In general, phenotypic traits are responses to evolutionary forces that drive adaptations to different niches or environmental constraints on nature, thus producing a myriad of morphologies and lifestyles (e.g., [...]
- Published
- 2022
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