Atropoides indomitus, Smith & Ferrari-Castro, 2008

Smith, Eric N. & Ferrari-Castro, Jorge A., 2008, A new species of jumping pitviper of the genus Atropoides (Serpentes: Viperidae: Crotalinae) from the Sierra de Botaderos and the Sierra La Muralla, Honduras, Zootaxa 1948 (1), pp. 57-68 : 59-66

Atropoides indomitus sp. nov.

( Figs. 1–4 )

English name: Indomitable jumping pitviper

Atropoides mexicanus: Espinal et al. (2001: 103 , 106); Wilson et al. (2001: 116, 123, 137, 141, 149, part); Marineros (2000: 143, in part, citing Espinal et al. [2001]); Campbell and Lamar (2004: 281–282, in part, added distribution from previous citations)

Atropoides occiduus Honduras: Castoe et al. (2005: 884, 888, 891, 894, 895)

Holotype. The University of Texas at Arlington ( UTA) R-52952, an adult male from near the edge of Quebrada de Botaderos, Montaña de Botaderos, Departamento de Colón, Honduras, 670 m (l 5°26’03.4” N 86°08’37.3” W), collected between 17 and 22 May 2002 by J. A. Ferrari-Castro. Original number ENS 10964.

Paratype. United States National Museum ( USNM) 337487, an adult female from Hacienda Terrero Blanco , Departamento de Olancho , Honduras, ca 1200 m (l 5°12’ N 86°42’ W), collected during September 1993 by Damian Almendarez for J. R. McCranie. Original number LDW 10340 .

Diagnosis. A relatively small terrestrial pitviper (female and male 549 and 573 mm TL, respectively) in which the tail comprises 13.7% of the TL in the single known male and 10.9% in the single known female. There are 0–1 nasorostrals, 8–10 intersupraoculars that are distinctly keeled, 23–24 interrictals that are also keeled, 10–11 supralabials, 11–12 infralabials, 140 ventrals, 37–41 subcaudals (first divided), 24–25 dorsal scale rows at midbody, 26–32 lateral body blotches, and 5–6 tail blotches.

Atropoides indomitus can be distinguished from all other known species of Atropoides , except A. picadoi from Costa Rica and adjacent Panama, by having more ventral scales, 140 compared to a maximum of 130, 136, 135, and 116 in males, and 135, 138, 137, and 119 in females of A. mexicanus , A. nummifer , A. occiduus , and A. olmec respectively. Additionally, A. indomitus differs from A. mexicanus , a potentially sympatric species, in having a single scale between the prelacunal and second supralabial (vs. 2 or 3), a single or no nasorostral (vs. 2–4), the rostral apex reaching the canthal ridge, and the postorbital stripe including temporal rows 2 and 3 at midlength (vs. 3 and 4; see Campbell and Lamar 2004: 276, Fig. 91). It differs from A. nummifer , occurring on the slopes of the Sierra Madre Oriental of Mexico, in having the postocular stripe extending up to five scales behind the rictus (vs. usually ending at the ultimate infralabial or no more than two to three scales behind the rictus), in having the anterior two thirds of the body venter nearly immaculate or just finely stippled at the midline (vs. multiple dark ventrolateral blotches extending more than 1/4 the width of the ventrals into the midline), and in having the underside of the tail with some dark pigment, paler towards tip and near vent (vs. nearly completely black in most specimens). Atropoides indomitus can be distinguished further from A. occiduus in having a subocular spot that does not contact the orbit of the eye (vs. contacting orbit), a postorbital stripe including only the last three temporal scales of the first row, with only the posterior one or two scales more than half pigmented (vs. covering completely or almost completely three or more temporal scales of the first row), in having the dark spot below the pit small and only encompassing the prelacunal and anterior part of the postlacunal and the edge of the contiguous foveals (vs. large and encompassing also most of the contiguous foveals and usually even part of supralabials 2 and 3), in having a high number of supralabials, 10–11 (vs. 8–10), in having a high number of subcaudals, 37–40 (vs. 24–36, for both males and females), and in having a nearly immaculate venter or with only slight mid-ventral stippling on the anterior two thirds of the body (vs. multiple dark ventrolateral blotches extending more than 1/4 the width of the ventrals into the midline, a checkered pattern, or at least some heavy mottling on the anterior half of the body). The new species differs from A. olmec by possessing a rostral that reaches the canthal ridge (vs. terminating well below the ridge), one or no nasorostrals (vs. 1–3, 3 being most common), a single scale between the second supralabial and the prelacunal (vs. 2–3), and a high number of subcaudals, 37 in males and 28 in females (vs. 25–33 in males and 25–30 in females). Atropoides indomitus differs from A. picadoi in being smaller (573 mm maximum known TL vs. reaching> 750 mm [ Campbell and Lamar 2004]), having 50% or more of the last third of the venter of the body pale (vs. very dark posterior third of body venter, more than 50% melanized), the underside of the tail more than 50% pale (vs. adults with all or most of the tail black), the postorbital stripe covering more than 50% in only one or two scales from the first temporal row, completely only the ultimate, at most (vs. 3–4 and the last two usually completely melanized). Atropoides indomitus has fewer ventral scales than most of its congeners, 140 (vs. 138-155), the female has fewer subcaudals (28 vs. 30–37), whereas the male subcaudal count of 37 overlaps only with that of A. picadoi (34–40).

Etymology. The specific nomen is derived from the Latin adjective indomitabilis, meaning “that which can not be conquered.” This name is given for two reasons: to honor Hondurans, who maintain a strong spirit, despite extreme hardships, and to credit the project “ Honduras Indomita” that lead to the discovery of this species. Honduras Indomita was started by several Hondurans, non-governmental organizations, the Organización de Rescate y Protección de Reptiles y Anfibios de Honduras (ORPRAH), and the Instituto Hondureño de Turismo (IHT) to spread knowledge and bring pride to Hondurans regarding their natural heritage and resources through communicating and promoting scientific discovery within the country.

Description of holotype and variation. Features of the adult male holotype are followed by variation of the adult female paratype in parentheses. Rostral wider than long, 4.0 x 3.8 mm (4.9 x 3.9), distinctly concave, apex reaching canthal ridge; single nasorostral (none); nasal large, divided above and below naris; one large scale between nasal and upper preocular; subnasals 2/2 (1/1); prefoveals 8/7 (3/5); subfoveals and postfoveals 11/13 (12/8); prelacunal large; sublacunal small; postlacunal elongate; one scale between prelacunal and third supralabial; loreal pit rounded and large, as big as posterior half of nasal, located just below line drawn between center of naris and center of eye; loreals 1/1, contacting upper two preoculars (fused with lower preocular); preoculars 2/2 (1/1), upper preocular large, lower small (fused to loreal); suboculars 5/5 (4/6), first two smaller; two scale rows between third subocular and fourth supralabial; postoculars 6/3 (4/3); supralabials 11/10 (10/10); mental broader than long, 4.6 x 3.5 mm (6.3 x 3.5); infralabials 12/12 (12/11), first contacting at midline; three pairs of chin shields flanking mental groove (2 pairs); anterior chin shield pair about two times longer than second (almost three times) and 1.6 times larger than third (third absent); internasals 2 (3); canthals 3/3, between internasal and supraocular; single supraocular, large and narrow, 6.4/5.8 mm (5.5/6.4); head dorsal scales keeled; scales between first canthals 3 (4); intersupraoculars 8 (11); interrictals 24; 3 (4) pairs of gulars between chinshields and first ventral, no preventral; dorsal scale rows 25–23–19 (26–25–21), keeled, except for paraventral rows; ventrals 140; single anal scale; subcaudals 37 (28), undivided, except first pair; tip of tail elongated, 5.0 mm (4.5), narrow at base, slightly curved upward, a partially fused dorsal capping scale; 14 dentary teeth (including sockets) on right side of holotype.

Measurements. TL 573 mm (549 mm); tail length 79 mm (54 mm); head-length 31.7 mm (38.5); head width 22.4 mm (20.0); neck width immediately behind jaws 9.1 mm (7.8); right fang length from upper lumen to tip 6.5 mm, in holotype.

Color ( Figs. 1–3 ). Holotype in preservative: Dorsum of head and body Vandyke Brown (121) with dorsal and lateral Sepia (119) markings with fine Drab-Gray (119D) to pale Glaucous (80) edges; irregular diffuse markings on top of head; paravertebral neck blotches separated by one scale; first three dorsal blotches paired at midline, first separated by one scale, others joined, rest of dorsal markings forming a zigzag pattern; lateral blotches round; 27 primary lateral blotches (confluent with dorsal blotches or not), approximately 1.5 scales wide; about eight diffuse secondary lateral blotches in interspaces at level between dorsal blotches, restricted to midsection of body, about 1.5 scales wide; six dorsal blotches on tail, last diffuse; tip of tail dark; dark irregular spots occupying edge of ventral scales and part of first dorsal row, located at level between lateral blotches, about one scale wide; eye surrounded by dark pigment; postorbital stripe from posterior border of eye to posteroventral area of head, covering four postocular scales, 2–2.5 temporal scale rows, and more than half of only one or two scales of first temporal row, Glaucous (80) edged above; area below postorbital stripe Pale Horn (92); small dark spot below facial pit, encompassing prelacunal, anterior part of postlacunal and edge of contiguous foveals; subocular spot occupying dorsolateral area of supralabial four and part of adjacent scales; venter pale whitish cream anteriorly, turning Pale Horn (92) towards cloacal area; tail pale whitish cream anteriorly, turning Pale Horn (92) towards tip; venter of anterior part of body immaculate, grading into numerous irregular dark flecks and checks posteriorly; underside of tail paler at midline, particularly towards cloaca and towards tip.

Paratype similar to holotype, differing in having a slightly larger subocular spot occupying one third of supralabials 4 and 5 and scale above their suture; having infralabial spots between infralabials 1 and 2, 5 and 6, and on 8 and edge of its adjacent scales; ventral spots more anteriorly, beginning just behind neck; overall dorsal coloration paler, Cinnamon (123A) with Raw Umber (223) blotches with Sepia (119) edging; 28 dorsal body blotches; 27 lateral primary blotches; secondary lateral blotches through most of body, most displaced above level of primary lateral blotches; 7 tail dorsal blotches.

In life the male holotype had a Deep Vinaceous (4) to Natal Brown (219A) ground color with Sepia (119) to black markings; cream below postocular stripe and edge of dorsal markings; venter pale Pearl Gray (81), whitish rostrally.

Description of hemipenes ( Fig. 4 ). The following description is based on the everted left hemipenis of the male holotype, after removal and preparation. The organ is relatively simple in ornamentation, with relatively undifferentiated spines and calyces; it is bilobed, symmetrical, and centrolineal. The organ is divided, about 27 mm long, and with a very short base, about 2.5 mm to the bifurcation of the sulcus spermaticus. The sulcus extends from the median side of the organ, divides at the mid-base, and extends to the apical tip of each lobe. The folds defining the sulcus spermaticus and the area directly above the point of bifurcation of this structure are thick. Between the levels of bilobation and bifurcation the hemipenis has only very small, keratinized spicules. At the level of bilobation some slightly larger spines are present, <0.3 mm in length, on the lateral surfaces of the organ. Large spines occupy the mid-third of the organ (the proximal half of the lobes) and are absent on the distal half of the lobes. Spines attain a maximum length of approximately 3 mm and have about one third exposed, about 1 mm (two thirds are embedded in the hemipenial tissue and visible through it). These large spines are relatively straight and directed towards the base and sides of the organ. About 70 spines are present on the mid-third of the organ, but being relatively smaller and about twice as numerous on the inside surface of each lobe. The tips of the organ are relatively slender and covered by calyces between 1 mm (proximally) and 0.2 mm (distally) in diameter. Calyces are directed somewhat basally and laterally and extend further towards the base near the sulcus spermaticus. The rims of the calyces are only slightly scalloped.

Habitat, distribution and habits ( Figs. 5–6 ). The holotype of Atropoides indomitus was found during a rainy day, coiled on top of a rock and sheltered below two big boulders at the edge of a stream under the canopy of premontane rainforest. The stream is locally known as Quebrada de Botaderos and the elevation of the locality is 670 m. The paratype comes from Terrero Blanco, Sierra de La Muralla, 1200 m. The area and herpetofauna of this locality is described by Espinal et al. (2001). The vegetation at Terrero Blanco is premontane rainforest, which corresponds to the Very Wet Subtropical Forest Life Zone of Holdridge (1962), the same found in Botaderos. Other pitvipers we collected in the Botaderos Mountains include Bothriechis schlegelii , Bothrops asper , Cerrophidion godmani , and Porthidium nasutum . In the Sierra de La Muralla only Bothriechis schlegelii is known to be sympatric with Atropoides indomitus . The new species may well be allopatric from its congeners. Atropoides mexicanus is so far the only other member of the genus found in Honduras and it has been recorded only from the mountains flanking the Ulúa and Chamelecón river valleys at 0–1300 m, in the departments of Copán, Santa Rosa, Cortés, and western Atlántida and Yoro ( Wilson et al. 2001; Campbell and Lamar 2004). The nearest locality for A. mexicanus is about 100 Km West of Terrero Blanco. More information about Botaderos can be found at http://www.hondurasindomita.com/ (5 June 2006).

Relationships ( Fig. 7 ). The molecular phylogenetic study of Castoe et al. (2005) confirmed the status of Atropoides indomitus as a valid taxon. Castoe et al. (2005) used mitochondrial DNA sequences (1405 bp of the Cyt-b and ND4 genes) to estimate the phylogeny of Atropoides based on all known species and included samples from multiple populations for most species. Their results suggested that A. indomitus (labeled “ A. occiduus- Honduras ” in their paper) is the sister species to A. occiduus . Based on their nucleotide sequence data, they found A. occiduus and A. indomitus to have 5.7% uncorrected pairwise sequence divergence.

Figures

FIGURE 1. Atropoides indomitus, adult male holotype, 573 mm total length, UTA R-52952 (reproduced from UTADC 2059).

FIGURE 2. Lateral aspect of head of Atropoides indomitus, 31.7 mm head-length (male holotype, UTA R-52952, reproduced from UTADC 2058).

FIGURE 3. Venter of Atropoides indomitus (male holotype, UTA R-52952, reproduced from UTADC 2060).

FIGURE 4. Left hemipenis of Atropoides indomitus (male holotype, UTA R-52952), sulcate (A) and asulcate (B) views.

FIGURE 5. Distribution of Atropoides indomitus in north-central Honduras.

FIGURE 6. Type locality of Atropoides indomitus, showing rocks at edge of Quebrada Botaderos where holotype was found, Sierra de Botaderos, Honduras (reproduced from UTADC 2061).

FIGURE 7. Phylogenetic relationship among Atropoides species, showing the position of Atropoides indomitus (adapted from Castoe et al. [2005] with permission). Branch lengths are scaled to genetic distance among sequences, as indicated by the scale bar. The phylogenetic estimate is based on the preferred tree estimated from 1405 bp of mitochondrial DNA (including cyt-b and ND4 genes) using Bayesian Markov chain Monte-Carlo methods, with models of nucleotide substitution partitioned by codon position and by gene region. Bayesian posterior probability support for nodes> 94% are given, and nodes receiving 100% posterior probability are indicated with gray circles.