Erythrolamprus rochai, Ascenso & Costa & Prudente, 2019

Ascenso, Alexandre C., Costa, João C. L. & Prudente, Ana L. C., 2019, Taxonomic revision of the Erythrolamprus reginae species group, with description of a new species from Guiana Shield (Serpentes: Xenodontinae), Zootaxa 4586 (1), pp. 65-97 : 78-87

Erythrolamprus rochai sp. nov.

Figures 3F , 5C , 7–8

Holotype: Adult male, MPEG 25680 (field number S. NAVIO 095 ), collected by D. Silvano, B. Pimenta and U. Galatti, between September and November 2000, at Urucum region (00°50' N, 51°53' W; ca. 171 m asl), municipality of Serra do Navio, state of Amapá, Brazil ( Fig. 7 ).

Paratype: Adult male, MPEG 25681 (field number S. NAVIO 094 ), same data as holotype .

Diagnosis. Erythrolamprus rochai is distinguished from all congeners by the combination of the following characteristics: (1) dorsal scale rows 17, reducing to 15 rows after midbody; (2) apical pit single; (3) 131–135 ventrals; (4) 56 subcaudals; (5) dorsum of head olive green, extending from anterior third of the body, changing gradually to grayish-brown at midbody, with six to 15 distinct black dorsal bands; (6) upper edges of supralabials with distinctive dark postorbital stripe; (7) belly cream without marks, except for some slight pigmentation on the lateral extremities of ventrals; (8) lateral black spots extending from anterior third of the body, located between 2– 3 th dorsal scale rows, and merged on the posterior third of the body to form a lateral-posterior stripe, which extends to the end of the tail; (9) ventral surface of tail creamish-white without black spots; (10) intrasulcal region with enlarged spines, organized in rows in each lobe, extending from the distal region to the level of bifurcation of branches; (11) medial region of asulcate face of hemipenial body ornamented with extremely elongated spines homogeneously distributed at hemipenial body; (12) sulcus spermaticus bifurcates at the proximal portion of hemipenial body; and (13) small body size (SVL 217–219 mm).

Comparisons. Erythrolamprus rochai shares with species of the Erythrolamprus reginae group the lateral stripe along the posterior region of the body and tail, and dark postorbital line. Among the species of the Erythrolamprus reginae group, E. rochai differs from E. reginae by having a cream belly without spots (vs. cream belly with rectangular black spots), from E. oligolepis by having 17 dorsal scale rows with reduction on the midbody (vs. 15 dorsal scale rows without reduction on the midbody), and from E. zweifeli and E. dorsocorallinus by having an olive green dorsal ground color on anterior third of body gradually changing to grayish-brown (vs. dorsal scales with apical half black). Additionally, E. rochai differs from E. epinephelus epinephelus by having more than 6–15 distinct black dorsal bands on the anterior part of body (vs. having less than five dorsal bands); from E. e. a lbiventris by having dark nuchal collar and dorsum of body olive green with black dorsal blotches (vs. olive green dorsal ground color on anterior third of body without nuchal collar or blotches); from E. e. juvenalis, E. e. pseudocobella, E. e. opisthotaenius, E. e. bimaculatus, E. e. lamonae and E. e. fraseri by having a cream belly without spots (vs. cream belly with rectangular black spots); from E. cobella , E. taeniogaster and E. breviceps by having a cream belly without spots or bands (vs. cream belly with banded pattern); from E. miliaris by having olive green dorsal ground color on anterior third of body gradually changing to grayish-brown (vs. all dorsal scales with apical half black), from E. typhlus and E. poecilogyrus by having 17 dorsal scale rows in the midbody (vs. 19 dorsal scale rows in the midbody); from E. taeniurus by having 131–135 ventral scales without spots (vs. 152–181 ventral scales with dark spots); and from E. pygmaeus by having 22–23 prediastemal maxillary teeth and two conical postdiastemal tooth (vs. eight prediastemal teeth and a lanceolate postdiastemal tooth).

Description of the holotype. Body cylindrical; SVL 217 mm, CL 64 mm (29.5% of SVL); head length 12.2 mm and width 6.1 mm; diameter of ocular orbit 2.5 mm; distance between orbit and rostral shield 3.07 mm; rostral triangular, 2.7 mm wide and 1.6 mm high, visible in dorsal view; internasals two, 1.25 mm length and 1.4 mm wide; prefrontals two, 1.6 mm length and 1.9 mm wide, contacting supraoculars, preocular, loreal, and postnasal; frontal pentagonal, 3.9 mm length, and 1.9 mm wide; parietals two, 4.1 mm length and 3 mm wide; supralabials eight, second and third contacting loreal, fourth to fifth contacting eye, and sixth and seventh higher than remaining supralabials; supraoculars longer than wide; nasal in contact with first two supralabials, internasals, prefrontals, loreal, and rostral; loreal tetragonal, 0.75 mm length and 1.1 mm high, in contact with second and third supralabials, postnasal, prefrontals, and preocular contacting supraocular, prefrontal, nasal, third and fourth supralabials; postoculars two, upper postocular higher than lower; temporals 1+2, anterior longer than upper posterior temporal; symphysial triangular; infralabials nine, first pair in broad contact behind symphysial and first four pairs contacting chinshields; anterior chinshields 2.75 mm long; posterior chinshields 3.6 mm long; smooth dorsal scale rows 17/17/15, reduction at the level of 78/79 th ventrals (right and left); apical pit single; ventrals 135; subcaudals 56; cloacal plate divided; maxillary with 22 conical pre-diastemal teeth, subequal, increasing slightly in length posteriorly; diastema larger than the gap between the three posterior teeth; two postdiastemal teeth twice as large as the last pre-diastemal tooth; dentary teeth 35; palatine teeth 16.

Dorsum of head dark brown, extending laterally to upper edges of first six supralabials, with a distinctive postorbital stripe. Prefrontals, internasals, nasals, and rostral shields with cream spot. Anterior region of frontals and medial region of parietals grayish-brown. Darker posterior edge of preoculars contacting orbit. Dark nuchal collar, three or four dorsal rows long. Dorsal region of body olive green, with black dorsal bands (n = 15 bands). First two bands elongated extending to second row of dorsal scales with three or four dorsals of length. Remaining blotches shorter and without defined shape, disappearing in the midbody, with only dark pigmentation at the edges of the dorsals. Two rows of paraventrals cream. Irregular black lateral spots, placed between the second and third dorsal rows of dorsal scale, merging around 111/112 th ventral scale to form a lateral-posterior stripe, located between the second and third dorsal scale rows, and extending to the posterior portion of the tail at the level of 53 th subcaudal. Ventral region of the body and tail cream without spots, except for some slight pigmentation at extremities contacting first row of dorsals ( Fig. 5C ).

Variation. Adult male, MPEG 25681, SVL 219 mm; CL 68 mm (31% of SVL); head length 6.8 mm; distance between orbit and rostral shield 3.3 mm (26% of head length); rostral triangular, 2.8 mm wide and 1.6 mm high; two internasals, 1.4 mm length and 1.6 mm wide; frontal pentagonal, 3.8 mm length, 2.6 mm and 1.7 mm, anterior and posterior width, respectively; two parietals, 4.3 mm length and 3.1 mm wide; loreal tetragonal, 1.2 mm length and 0.85 mm high; anterior chinshields 2.9 mm length (23% of head length); posterior chinshields 3.7 mm length (29% of head length); smooth dorsal scale rows 17, reduction at the level of 86 th /82 nd ventrals (right and left); 131 ventrals, 3/4 preventrals; and maxillary with 23 prediastemal and two postdiastemal teeth; 32 dentary teeth. The other body and cephalic characteristics of paratypes were invariable with respect to the holotype. Internasals, nasals, and rostral shields with cream spot. Six black blotches in dorsal region, of which first three elongated, extending to the third row of dorsals, with a width of three or four rows. Black lateral spots merge into a lateralposterior line located in the level of third dorsal scale row around the 106th/103rd ventrals, extending to posterior portion of tail at the level of 56th subcaudal. Edges of ventrals without dark dots as well as first row of dorsals. Other features show no differences from the description of the holotype.

Hemipenial morphology (everted organ n= 1). Right organ in situ extending to the level of 10 th subcaudal. Fully everted and maximally expanded renders a short and slightly bilobed, non-calyculate and capitulated organ; lobes cylindrical, encircled by two rows of medium-sized spines; apical disks smooth and located on the apex of lobes; sulcus spermaticus bifurcates at proximal portion of hemipenial body, branches with centrifugal orientation extending to apical disks; margins of the sulcus spermaticus bordered by spinules; intrasulcal region with enlarged spines, organized in regular diagonal rows on each lobe, extending from the distal region to the level of bifurcation of sulcus spermaticus branches; hemipenial body covered by several enlarged spines on both sides of the organ; asulcate side with three more conspicuous rows of enlarged spines, extending as far as the bifurcation of the lobes. Hemipenis with inflated regions in the basal region of the sulcus and on both sides of the asulcate surface ( Fig. 3F ).

Etymology. The specific epithet “ rochai ” is a patronym in honor to Reginaldo Augusto Trindade Rocha, laboratory technician at the Laboratory of Herpetology of Museu Paraense Emílio Goeldi, in recognition of his extraordinary work, zeal, and dedication to the herpetological collection of this laboratory over more than three decades. His commitment to this institution and his expert assistance to the curator have been invaluable for scientists, students, and visitors.

Geographic distribution. Erythrolamprus rochai is known only from the type locality. This area is located in a mountain range of central Amapá in the vicinity of the Amapari River, a tributary of the Araguari River ( Fig. 8 ).

Figures

FIGURE 3. Sulcate (left) and asulcate (right) views of the hemipenis of Erythrolamprus reginae (RMNH 42042—A), E. oligolepis (MPEG 23979—B), E. macrosomus (CEPB 2125—C), E. zweifeli (AMNH 137302—D), E. dorsocorallinus (UFAC 129—E), and E. rochai (MPEG 25681—F). Scale Bar = 5 mm.

FIGURE 5. Dorsal and lateral views of head; dorsal, ventral and lateral views of midbody; and ventral and lateral views of tail of Erythrolamprus zweifeli (AMNH 137302—A), E. dorsocorallinus (MZUSP 7362—B), and E. rochai (MPEG 25680 -C). Scale Bar = 10 mm.

FIGURE 7. Dorsal (A) and ventral (B) views of midbody; dorsal (C), ventral (D) and lateral (E) views of head; and lateral view of tail (F) of the holotype of Erythrolamprus rochai (MPEG 25680). Scale Bar = 10 mm.

FIGURE 8. Geographic distribution of the Erythrolamprus reginae species group. White symbols for each species represents literature records; red symbols for each species represents the type localities of each species; the other symbols and colors refer to the specimens examined in first hand.