Bothrocophias myersi, Gutberlet Jr. & Campbell, 2001

GUTBERLET, JR, RONALD L. & CAMPBELL, JONATHAN A., 2001, Generic Recognition for a Neglected Lineage of South American Pitvipers (Squamata: Viperidae: Crotalinae), with the Description of a New Species from the Colombian Chocó, American Museum Novitates 3316, pp. 1-16 : 8-10

Bothrocophias myersi , holotype ( AMNH 109812 ), 756 mm total length .

larger canthal and by upper preocular posteriorly, longer than high; prefoveals 2/2; subfoveals absent; prelacunal fused to second supralabial; interoculabials 3/3; postfoveals 1/1, longer than high, extending posteriorly beyond posteroventral corner of pit, contacting lower preocular posteriorly and lacunolabial anteriorly; preoculars 3/3; upper preocular longer than high, contributing to canthus; middle preocular much shorter, contacting but not fused to supralacunal; lower preocular tiny, almost excluded from orbit by subocular and middle preocular; suboculars 1/1, each partially divided anteriorly; postoculars 2/2; supralabials 7/7; infralabials 9/9, first infralabial on left side partially fused to mental, first pair of infralabials barely contact each other medially; mental approximately as wide as long; chin shields longer than wide, contacting first four infralabials on each side; gulars between chin shields and first scale on underside of head that is wider than long 4/5; 4 internasals, middle two smallest and partially fused medially; canthals 2/2, anterior canthal distinctly larger, posterior canthal tiny, separating anterior canthal from supraocular; intercanthals 3, immediately posterior to internasals; intercanthals 5, between posterior canthals; intersupraoculars 6; all dorsal head scales, from level of posterior of supraoculars forward, smooth; supraoculars longer than wide but distinctly wider than adjacent intersupraoculars; dorsal scale rows 25–23–19; ventrals 148, ultimate scale in series extending only partially across venter; anal entire; subcaudals 48, all divided; tail spine slightly compressed laterally, curving slightly dorsad, as long as adjacent 3 subcaudals, tip blunt; dorsals extending onto tail spine only slightly farther than subcaudals; dorsal scales of middorsum at midbody twice as long as wide anteriorly, becoming wider posteriorly such that length only slightly exceeds width; dorsal body scales distinctly keeled, keel does not extend to terminus of scale, keels distinctly tuberculate on posterior portion of body; paraventrals smooth over most of body, very weakly keeled posteriorly, similar in size and shape to adjacent dorsals; parasubcaudals weakly keeled anteriorly, smooth posteriorly.

Measurements of holotype (in millimeters): SVL 597, TL 92, EP 1.7, EN 6.7, ED 3.9, HL 30.1, RH 4.3, RW 4.2.

In his field notes, Myers described the col­ or in life of the holotype as follows: ‘‘Dark red­brown, posteriorly turning light bluegray on sides. Pale grayish blue oblique lines from eye, and small spots of same color underneath head. Under head and venter orange, except turning white down center on posterior half of belly.’’ From our inspection of color slides of the holotype ( AMNH 109812 ) taken before preservation, we can add the following: the dorsal coloration is almost uniform, but slightly darker bands are discernible against the red­brown ground color (fig. 3). From the supraoculars forward, the top of the head is dark brown, as is most of the side of the head. The iris appears to be red­brown, paler above .

Color in preservative (70% ethanol after 10% formalin): Dorsal surface of head unpatterned, pale brown to bronze in color; a wide, pale, brown­bronze postocular stripe extending from the posteroventral corner of eye to cover supralabial 7, all but anteroventral corner of supralabial 6, and posterodorsal edge of supralabial 5; pale postocular stripe bordered dorsally by a thin, dark brown stripe, and anteroventrally by a thicker stripe of same dark brown color; most of side of head and rostral dark brown, but with a small triangle of pale brown­bronze occupying anteroventral corner of supralabial 4 and posteroventral corner of supralabial 3; dorsum brown­bronze with a greater amount of dark brown or dark gray coloration laterally; most paraventrals partly dark graybrown and partly cream­colored; no clear pattern discernible on dorsum; tail plain brown dorsally, darker than dorsal body coloration; ventral scales predominantly cream but also with a small amount of brown pigment, mostly concentrated laterally; subcaudals also cream but with slightly more brown pigment than ventrals; ventral surface of head cream but with distinctive coloration on several scales; mental and first 2 infralabials on each side dark brown; 5 infralabials on each side and a total of 8 gular scales containing white spots with irregular dark brown edges.

VARIATION: On each side of the head, specimens of Bothrocophias myersi have 1– 2 prefoveals, 1–2 canthals, 3–4 interoculabials, 1 postfoveal, 3 preoculars, 1–3 suboculars, 1–2 postoculars, 7 supralabials, 8–10 infralabials, and 3–5 gulars between the chin shield and first ventral. Additional variation in features of scalation includes 3–4 internasals, 2–3 anterior intercanthals, 4–7 posterior intercanthals, 3–6 intersupraoculars ( fig. 4 ), 21–26 anterior dorsal scale rows, 21– 23 middorsal scale rows, 16–19 posterior dorsal scale rows, 139–151 ventrals, and 44– 52 divided subcaudals. Coloration is similar in all type specimens, with the exception of one small male (UTA R­21689) with fairly distinct bands on the dorsum. Measurements (in millimeters) for specimens in the type series vary as follows. Males: total length 376– 677, SVL 311–577, tail length 48–100. Females: total length 327–756, SVL 280–655, tail length 47–120. Table 1 summarizes variation within B. myersi .

HEMIPENES: One paratype of Bothrocophias myersi (UTA R­21689) was preserved with its hemipenes everted. The total length of the right hemipenis is equivalent to the length of the first five subcaudals. The lobes bifurcate at a length of two subcaudals from the base, and the sulcus spermaticus divides at a distance approximately one subcaudal from the base. As in most other crotalines, the organ is spinous proximally and calyculate distally. There are 18–20 lateral spines per lobe, including 6–8 that are relatively large (approximately 1 subcaudal in length). Small mesial spines are also present on the proximal half of each lobe. The mesial spines extend as far distally as the lateral spines. The distal half of each lobe is entirely calyculate. Many of the proximal calyces have spinulate walls, but walls of the more distal calyces are smooth.

DISTRIBUTION AND HABITAT: Bothrocophias myersi is known only from the Pacific lowlands (ca. 75–200 m) of Cauca and Valle del Cauca, Colombia. The original habitat in this region consists of very wet rainforest (probably> 5000 mm of rain per year). Myers et al. (1978: 321–324) provided a detailed description and photographs of the habitat at the type locality. This type of habitat formerly occupied lowland areas of southwestern Colombia and adjacent areas in northwestern Ecuador. It is possible that B. myersi occurs (or used to occur) throughout the Chocó region, although we know of no records of this species from Ecuador. Unfortunately, extensive habitat destruction throughout the Ecuadorian Chocó region makes it unlikely that B. myersi currently occurs in that country.

ETYMOLOGY: The specific epithet, a noun in the genitive case, is a patronym in honor of Dr. Charles W. Myers, who collected the new species and who has made many significant contributions to Neotropical herpetology through dedicated work in both the field and laboratory.

Figures

Fig. 4. Bothrocophias myersi, paratype (FMNH 165593), dorsal view of head, head length 35 mm.