Helicops boitata MORAES-DA-SILVA, CECÍLIA AMARO, SALES-NUNES, STRÜSSMANN, TEIXEIRA, ANDRADE, SUDRÉ, RECODER, RODRIGUES, CURCIO, 2019
Can you confirm these amateur observations of Helicops boitata?
|Higher Taxa||Colubridae (Dipsadinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Synonym||Helicops boitata MORAES-DA-SILVA, CECÍLIA AMARO, SALES-NUNES, STRÜSSMANN, TEIXEIRA, ANDRADE, SUDRÉ, RECODER, RODRIGUES, CURCIO 2019|
Helicops boitata — NOGUEIRA et al. 2019
|Distribution||Brazil (Mato Grosso)|
Type locality: Transpantaneira Road (16o25’21.18’’S, 56o40’12.64’’W; 124 m above sea level), municipality of Poconé, Mato Grosso state, Brazil
|Types||Holotype: UFMT-R 11940, adult male, collected on May 1st 2016 by F.F. Curcio; M. Teixeira Jr., R. Recoder and V. Sudré (Fig. 5).|
|Diagnosis||Diagnosis. Helicops boitata differs from all other congeners for presenting the unique combination of the following characters: (1) dorsal scale rows 25/25/21, with moderate keels throughout the whole body length, slightly stronger on posterior one-third of trunk; (2) low ventral counts (113, male); (3) moderate subcaudal counts (68, male; tail tip missing); (4) subcaudal keels absent, moderate keels present on tail dorsals; (5) supralabials 10/10, 4th–6th contacting orbit; (6) infralabials 12/13; (7) intergenials absent; (8) nasal entire; (9) two preoculars; (10) two postoculars; (11) temporals 1+3; (12) maxillary teeth 20+2; (13) hemipenis strongly bilobed, noncalyculate, hemicapitate with a shallow capitular groove, lobes ornamented with circular spinulate transverse folds, body elongate, nearly twice as long as lobes, ornamented with enlarged lateral spines and small spicules in the central area of asulcate face; (14) dorsum greenish copper brown, with one vertebral and two lateral chain-like rows composed of dark spots, ventrally flanked by a continuous light orange paraventral stripe, and (15) venter light brown, with two irregular stripes composed of light orange rounded spots along the lateral margins of ventrals that converge towards midline of the ventral surface of tail, ending at level of 38th subcaudal.|
Comparisons. The most relevant features that distinguish Helicops boitata from other congeners refer to the presence of entire nasal plate and the general color pattern. An entire nasal plate occurs only in H. nentur, H. petersi, and H. yacu (but see Remarks for comments on H. petersi). The presence of entire cloacal plate in the holotype of H. boitata (see Description of the holotype) appears as exclusive to the new species in the genus, although we concede that our restriction to one single specimen renders the uniqueness of this feature dependent on further sampling. For this reason, we decided to exclude the condition of the anal plate from our diagnosis until new specimens come to clarify this issue.
Regarding color pattern, there are no other Helicops species with a ventral pattern similar to the one of Helicops boitata, with a light brown venter ornamented by vivid orange rounded spots forming irregular ventral stripes (Figs. 2, 4). The dorsal pattern in life is also unique; no other congener exhibits the chain-like vertebral and lateral spot rows combined with the continuous paraventral light orange stripe, eliminating any possibility of misidentification. Dorsal patterns documented in Helicops taxa are mostly composed of alternated spots/blotches (H. danieli, H. gomesi, H. hagmanni, H. leopardinus, H. pastazae, H. petersi, H. polylepis, H. scalaris, and H. yacu), with a lower number of representatives with a uniform dorsum (H. nentur and H. tapajonicus), dorsal bands (H. angulatus, H. apiaka), or stripes (H. carinicaudus, H. infrataeniatus, H. modestus, and H. trivittatus) (see Costa et al. 2016).
The elongate and slender hemipenial lobes promptly distinguish Helicops boitata from H. angulatus, H. apiaka, H. carinicaudus, H. danieli, H. gomesi, H. infrataeniatus, H. leopardinus, H. modestus, H. polylepis, and H. tapajonicus (vs. short or globose hemipenial lobes); the presence of enlarged lateral spines on the hemipenial body distinguishes the new species from H. hagmanni, H. infrataeniatus, H. leopardinus, H. modestus, H. tapajonicus, and H. trivittatus (vs. enlarged lateral spines absent); the elongate and slender hemipenial body distinguishes the new species from H. angulatus, H. apiaka, H. carinicaudus, H. danieli, H. gomesi, H. infrataeniatus, H. leopardinus, H. modestus, H. polylepis, and H. tapajonicus (vs. globose or cylindrical hemipenial body); an hemicapitate hemipenis with a shallow capitular groove distinguishes the new species from H. angulatus, H. apiaka, H. carinicaudus, H. danieli, H. gomesi, H. pastazae, H. polylepis, and H. tapajonicus (vs. hemipenis bicapitate with a deep capitular groove); the absence of reduced hook-shaped calcified spines dispersed through the central area of the asulcate face distinguishes the new species from H. hagmanni, H. infrataeniatus, H. leopardinus, H. modestus, H. pastazae, H. tapajonicus, and H. trivittatus, in which such structures are present.
The 25/25/21 dorsal rows of Helicops boitata exceed at least the dorsal formulae of H. nentur (17/17/15), H. carinicaudus (19/17–19/17–19), H. infrataeniatus (17–19/19/17–19), H. angulatus, H. modestus, H. tapajonicus (19/19/17), H. gomesi (19/19/17–19), H. danieli (19/19/19), H. leopardinus (19–20/19/17–19), H. apiaka (21– 23/19–21/19), H. petersi (21/21–23/16), and H. pastazae (23/21–23/19). The only comparable taxa that may possibly exhibit 25 dorsal rows at some region of the trunk are H. hagmanni (27/23–27/23), H. polylepis (23–25/22– 25/19–21), H. scalaris (21-25/19-21/16-19), H. trivittatus (21–25/21–23/21–19), and H. yacu (25–29/25–28/18–20) (Table 4).
According to our definition, Helicops boitata exhibits moderate dorsal keels ̧ similar to the patterns present in H. danieli, H. infrataeniatus, H. leopardinus, and H. trivittatus. Diverge from such a condition the taxa H. angulatus, H. apiaka, H. gomesi, H. hagmanni, H. pastazae, H. petersi, H. polylepis, and H. scalaris (strong dorsal keels), as well as H. modestus, H. nentur, and H. tapajonicus (weak dorsal keels). Prominence of keels vary between weak and moderate in H. carinicaudus (Table 4). Helicops boitata lacks any traces of subcaudal keels, rendering it promptly distinguishable from H. angulatus, H. apiaka, and H. gomesi (prominent subcaudal keels) and H. scalaris (moderate subcaudal keels) (see Table 4). The literature also reports such a feature in H. infrataeniatus (table 1 in Kawashita-Ribeiro et al. 2013:81), but this information is inconsistent and requires revision, as our data on this species reveal no evident subcaudal keels, as also reported by Costa et al. (2016:161, table 3).
Helicops boitata has the highest number of supralabials in the genus (10/10). Our data revealed no more than nine supralabials in all species from which we had primary data, whereas the counts provided in the original descriptions of H. scalaris (nine supralabials) and H. yacu (nine) are also below this limit (Table 4). Literature reports 10 supralabials to H. leopardinus and H. pastazae (Kawashita-Ribeiro et al. 2013; Costa et al. 2016), but we argue that such information deserves checking (see Remarks). The holotype of Helicops boitata has 12/13 infralabials (lateral asymmetry), also reflecting high counts for this character within the genus, only comparable to those from H. apiaka, H. hagmanni, H. petersi, H. yacu (up to 12), H. pastazae, H. polylepis (up to 13), H. trivittatus, and H. scalaris (up to 14). The upper bound of infralabials of the remaining congeners is always below these limits, with counts of up to 11 scales in H. angulatus, H. danieli, H. gomesi, H. infrataeniatus and H. modestus, and up to 10 scales in H. carinicaudus, H. leopardinus, H, nentur, H. pastazae, and H. tapajonicus (Table 4).
Finally, the last relevant character that may help in the distinction of Helicops boitata refers to the two preoculars, similar to H. angulatus, H. carinicaudus, H. hagmanni, H. leopardinus (vs. one or two), and H. trivittatus (vs. two). All other congeners have only one preocular scale (Table 4 in Moraes da Silva et al. 2019).
Diagnosis: see Schöneberg & Köhler 2021 for alternative diagnosis.
|Comment||Habitat: Moraes da Silva et al. 2019 found the holotype at 14:23hs, almost entirely submerged in a flooded area at the margins of the “Transpantaneira”, an unpaved road crossing the northern portion of Pantanal wetlands. This finding suggests that Helicops boitata has diurnal habits, contrasting with other congeners considered nocturnal (H. angulatus and H. polylepis) (Marques et al. 2005). In the Pantanal, at least H. leopardinus may be active during the day and night (Marques et al. 2005). Detecting the specimen became easy because it was exposed to the sun and the water in the collection spot was clear, shallow (up to 30 cm deep), and free from floating aquatic plants that would otherwise obstruct the vision. The collection site corresponds to a tributary of the Bento Gomes River that spreads in the area during the rainy season (from November to February), receding back to the riverbed in the dry season (from June to August) (Cunha & Junk 2009:305). Thus, the collection date reflects the receding period, when flooded areas start to dry out. We visited again the collection site in July of 2018–dry season–and the place still retained water in isolated and very turbid ponds.|
Behavior: The holotype did not bite when manipulated, contrasting with the usually aggressive behavior of most congeners that promptly bite when grabbed (Marques et al. 2005).
Sympatry: Helicops leopardinus.
|Etymology||The specific name is a noun in apposition deriving from the Brazilian Portuguese “boitatá”, as a reference to the folk legend of a giant fire snake that inhabits the Brazilian rivers and protects the forests against man-caused fire. The word has its origins in the native language Tupi (‘Mboi = snake; tatá = fire). It serves also as an allusion to the vivid orange tonality of the ventral pattern, resembling the color of flames.|
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