DOI: 10.5061/dryad.s1rn8pkgn
title: Videos of the new specimens of Helicops boitata (Serpentes: Dipsadidae: Hydropsini), with data on morphological variation and behavior

description: We report information on morphological variation and behavior of the
 recently described watersnake Helicops boitata, previously known strictly
 from the holotype. Our data come from five new specimens fortuitously
 found in a private area near the type locality, in the Brazilian Pantanal
 wetlands. The expanded sample revealed polymorphism in at least two
 scalation features assumed as diagnostic of the species (i.e., undivided
 condition of the cloacal plate and nasal scales) and confirmed the
 uniqueness of the ventral color pattern, as well as the divided condition
 of the foremost ventral shields. Besides, as reported for the holotype,
 three individuals collected alive also exhibited harmless behavior when
 handled, a rather unusual feature among snakes of the genus Helicops.
 Other new behavioral observations include a mostly nocturnal activity (in
 contrast with the previous data) and the ability to dig galleries in the
 soft substrate when attempting to escape. The finding of five individuals
 very close to each other suggest aggregations in habitats retaining
 humidity in the dry season of the Pantanal. Low abundance rates and
 possible habitat restrictions might render Helicops boitata particularly
 susceptible to seasonal fire episodes that consume large extensions of the
 wetlands, including dry swamps in which aquatic reptiles find refuge
 during the seasonal droughts.
description: We collected the new specimens of <em>Helicops
 boitata</em> and deposited them in the Coleção Herpetológica do
 Instituto de Biociências da Universidade Federal de Mato Grosso (UFMT-R)
 (see Sabaj 2020). Two snakes freshly killed by the bulldozer were
 collected on 15 (UFMT-R 12520) and 16 (UFMT-R 12521) October of 2019.
 UFMT-R 12520 was found by LVSC belly up (exposing its unique ventral
 pattern) on the bare surface of the soil. UFMT-R 12521 was found the next
 day, dead and deeply injured, together with many individuals of
 <em>Helicops leopardinus </em>(Schlegel, 1837)<em>
 </em>and other three individuals of <em>H. boitata,
 </em>alive and unharmed (UFMT-R 12504, 12505 and 12506)
 When arrived from the field, the alive specimens remained
 provisionally accommodated in a semi-aquatic terrarium to be euthanized
 after three days. The terrarium cube (101 cm length, 51 cm width, 61 cm
 height, Fig. 1) contained quartzitic sand as the main substrate and a
 fragment of peat soil obtained in the collection site with the snakes. The
 sand inside the system exhibited an elevated area of 23 cm high at one of
 the extremities of the cube representing a permanently dry spot. The
 snakes (entangled in the peat fragment, exactly as found in the field)
 were accommodated in this area of the terrarium. The system contained
 nearly 90 L of water attaining a maximum level of 15 cm, as well as
 macrophyte plants [<em>Pistia stratiotes</em> (Araceae) and
 <em>Eichhornia crassipes</em> (Pontederiaceae)] floating on
 the water surface. We attached a clamp black light lamp to the glass wall
 of the cube to provide proper illumination during nocturnal observations.
 From October 17<sup>th</sup> and 19<sup>th</sup>,
 two of us (GVA and SSW) observed the specimens in shifts from 6:00 AM to
 9:00 PM, reporting any events of activity displayed by any of the three
 individuals. At 6:00 PM, we turned off the lights of the lab and turned on
 the black light lamp, keeping nocturnal observations until 9:00 PM, when
 observations were interrupted until the next morning.
description: # Videos of the new specimens of Helicops boitata (Serpentes: Dipsadidae:
 Hydropsini), with data on morphological variation and behavior
 [https://doi.org/10.5061/dryad.s1rn8pkgn](https://doi.org/10.5061/dryad.s1rn8pkgn) ## Description of the data and file structure Data was derived from the following sources: Videos of specimens of Helicops boitata exhibiting the behavior of the species throroughly described in the "Results" section of manuscript entitles "New specimens of Helicops boitata (Serpentes: Dipsadidae: Hydropsini), with data on morphological variation and behavior" The behaviours illustrated in the videos represent some unique displays that deserve objective observation from the readers, beyond the simple text description. These behaviour include harmlessness during manipulation, specimens digging the substrate while fleeing, and specimens swimming and exploring the water in an aquarium. Three videos without mp4 format The first video (S1) shows a specimen in an entirely harmless behavior while handled by one of the authors, in sharp contrast with all other known congenres, that promptly bite when bothered; the second video (S2) shows a specimen in field digging into the substrate immediately after being exposed from its shelter, in an unexpected behaviour for a species belonging to a watersnake genus; finally the third video (S3) shows the individual exploring the aquatic environment of the aquarium, swimming among the macrophyte plants. \|- S1/ \| |- Results \| | |- S1.mp4 \|- S2/ \| |- Results \| | |- S2.mp4 \|- S3/ \| |- Results \| | |- S3.mp4