Helicops cyclops Cope, 2020

Murphy, John C., Muñoz-Mérida, Antonio, Auguste, Renoir J., Lasso-Alcalá, Oscar, Rivas, Gilson A. & Jowers, Michael J., 2020, Evidence for cryptic diversity in the Neotropical water snake, Helicops angulatus (Linnaeus, 1758) (Dipsadidae, Hydropsini), with comments on its ecology, facultative reproductive mode, and conservation, Amphibian & Reptile Conservation (e 261) 14 (3), pp. 138-155 : 146

Helicops cyclops Cope , sp. nov.

Scales in nineteen rows, strongly keeled everywhere, including the first row. Two pairs genials; occipitals short and wide, long as frontal. Head exceedingly short, mouth wide as the length of the rounded lip margin Superior labials eight, fourth scarcely entering orbit by its upper corner (by its whole extremity in H. angulatus ), the fifth, sixth and seventh narrow and high. Prefrontals broad as long (much broader than long in H. angulatus ). Orbitals 1–2, nearly meeting below orbit. Temporals 2 |1 | 3 (1 | I | 3 in H. angulatus ). Loreal plate wide as high, (higher than wide in H. angulatus ). Tail 0.33 total length, slender (less than 0.25, H. angulatus ). Gastrosteges 124, anal 1-1; urosteges 89. Light yellowish brown, with twentysix transverse deep brown rhombs across the back which terminate at the second row of scales, being separated from the back ventral cross-bar, which is opposite each, by a longitudinal yellow band. This band is not distinct between the spots. Belly strong yellow with jet black cross bars, which are on more than two gastrosteges. Tail black spotted below. A brown cross-band between the eyes Length 27.5 inches. From Bahia, Brazil. Mus. Academy, from Dr. Otho Wucherer. This species is at first sight much like the H. angulatus but differs variously as above. In coloration the spots in the latter are always continued into the ventral cross-bars, and not interrupted as in H. cyclops .

At this writing, there are too many unknowns to make further taxonomic adjustments. As further molecular and morphological information becomes available on the type specimens ( Table 1) of the species which has been placed in the synonymy of Helicops angulatus , the species and nomenclature will undoubtedly change again.

Facultative reproduction. The Trinidad and Venezuela populations are known to be oviparous ( Mole 1924; Gorzula and Señaris 1998; Boos 2002; Ford and Ford 2002; Natera et al. 2015). One of the authors (JCM) collected a clutch of eight eggs laid in a terrestrial nest under pieces of wood and tin in November 2013. The eggs contained near full-term embryos. When combined with the February oviposition dates reported by Ford and Ford (2002), it seems likely this species reproduces yearround in Trinidad.

We also followed up on Boos’ (2001) story of viviparity in a Trinidad specimen. Boos (recently deceased) attributed the story to Alan Rodriguez, an avid Trinidad snake enthusiast. One of the authors ( RJA) interviewed him, but Rodriguez did not remember much about the incident related to Boos (2001), which took place about 1980. However, he reported that while searching for snakes on 15 March 2011, he observed a female Helicops angulatus giving birth in a drain with about 20 cm of water. The observations were made in a semi-urbanized area of Sangre Grande, Trinidad. He observed actively moving young dispersing, but several others present in the drain were stillborn. Thus, he saw this phenomenon twice (once in ~1980 and in 2011) .

Curiously, Cunha and Nascimento (1981) found eggs (7–20) in 12 females from Brazil (Leste do Pará), but these authors also state that embryos were present in a single specimen. A comment in Martins and Oliveira (1998) by L.J. Vitt suggested this could be an error. Yet, according to the new evidence, it is plausible that the female examined by Cunha and Nascimento (1981) had fully developed embryos.

A related observation in the viviparous Helicops scalaris from the Lake Maracaibo basin ( Barros et al. 2001) involved post-partum females depositing what appeared to be shell remains (Barros, pers. comm. 2020). In discussing the reproduction mode in this species, Natera et al. (2015) stated it is “vivipara lecitotrófica” (i.e., embryos receive nutrients from the yolk); and they also mentioned two females which gave birth to 21 and 22 young, in addition to a female with nine eggs in middevelopment (probably referring to developing embryos). Table 2 compares the 20 known species of Helicops for basic meristic traits and reproductive modes.