Leptophis cupreus ( Cope, 1868 )

De Albuquerque, Nelson R. & Mcdiarmid, Roy W., 2010, Redescription Of Leptophis cupreus (Cope) (Serpentes, Colubridae), A Rare South American Colubrine Snake, Papéis Avulsos de Zoologia 50 (23), pp. 375-384 : 375-384

Leptophis cupreus ( Cope, 1868)

to as “No. 6666” by Cope in the type description (1868:106). This specimen, originally cataloged as USNM 6666 , was apparently recataloged as ANSP 5202 in the confusion over provenance of specimens in Cope’s possession at the time of his death in 1897 (see later discussion) .

The ventral and subcaudal counts for this specimen are identical to those reported by Cope (1868); other details of scutellation are the same, and the measurements are extremely similar. The coloration is different in several respects from that presented in Cope’s description; however, the specimen has lost all of the stratum corneum, a condition that had begun when Cope described it, and as a result has not retained its original coloration. This specimen is a small female, possibly juvenile, SVL 313 mm, tail length 205 mm, with bands on the anterior and middle region of the body, similar to those found in juveniles of other species of Leptophis (see Oliver, 1948). Head elongate and distinctly broader than neck, narrower than diameter of midbody. Head length from the posterior tip of retroarticular process of the mandible 12.27 mm, 3.9% of SVL. Snout length from tip of snout to anterior margin of orbit 3.80 mm. Rostral wider than high, visible from above. Nasals undivided; right nasal separated from preocular by broad prefrontal contact with second and third supralabials; left nasal separated from preocular by loreal scale. Prefrontals not contacting orbits; prefrontals slightly larger than internasals. Frontal longer than wide, about twice as long as prefrontals.

Thrasops cupreus Cope, 1868 . Proceedings of the Academy of Natural Sciences of Philadelphia 20:96-140. Holotype: ANSP 5202 , collected by James Orton in late 1867. Type-locality: “from the Napo and Maranon ”.

Leptophis cupreus – Boulenger, 1894:109; Werner, 1929:102-103; Peters, 1960:525; Peters & Orcés-V, 1960:139-141; Peters & Orejas-Miranda, 1970:164; Mertens, 1973:144-145; Dixon & Soini, 1977:20, 58; Duellman, 1978:249-250; Dixon & Soini, 1986:6, 75, 114; Pérez-Santos & Moreno, 1988:213-214; Pérez-Santos & Moreno, 1991:219-220; Carrillo de Espinoza & Icochea, 1995:16; Harding, 1995:225; Jorge da Silva & Sites, 1995:895.

Description of holotype ( Figs. 1-2 )

As noted by Malnate (1971), ANSP 5202 corresponds to the holotype of L. cupreus that was referred Single anterior temporal on each side in contact with parietal, postoculars, and sixth, seventh and eight supralabials; two posterior temporal scales, upper reaching the end of parietal on each side. Eye large, horizontal diameter 2.64 mm, pupil round. Single preocular on each side, in contact with frontal. Two postoculars on each side, the upper about three times higher than lower. Two pairs of elongate chin shields separated by mental groove, with posterior pair distinctly more elongate. Mental not touching anterior chin shields. Anal plate divided; 152 ventrals; 137 paired subcaudals (tail complete); scales of vertebral and paravertebral rows slightly larger than those of adjacent rows; supralabials 8/8, 4-5/ 4-5 in contact with orbit; infralabials 10/10, 1- 5 in contact with anterior chin shields; parietals longer than broad and in contact with upper postocular. Dorsal scale rows 15-15-11; keels on dorsal scale rows 2-14 of trunk (reduced and often indistinct on scales of vertebral row), absent on first dorsal rows; dorsal scales of tail without keels. Single apical pit present on all dorsal scales of trunk, except those in first dorsal row. Narrow black ocular stripe along upper margins of second and third supralabials, covering lower postocular, lower edges of anterior and lower posterior temporals, and upper edges of last three supralabials; stripe disappears two scales posterior to last supralabial.

Variation

Additional specimens examined are similar in scutellation to the holotype ( Table 1). The preoculars contact the frontal in eight ( ICN 8382 , MCZ 164915 , USNM 197281 , 211036-38 , 211041-42 ) of 18 specimens examined. The dark postocular stripe extends nine scales posteriorly from the last supralabial as a diffuse black stripe in ICN 8382 ; in other specimens it is shorter and more diffuse (e.g., LACM 45444 , 76811 ) ( Fig. 3 ). ICN 390 , LACM 45444 , MCZ 164915 and USNM 562696 have keels on all dorsal scales of the trunk, except on the first; in some specimens the keels are reduced on scales of the second and fourteenth rows anterior to the reduction from 15 to 11 scale rows and on scales of the vertebral row; dorsal scales on the tail are keeled posterior to the point of reduction. Keels are more prominent in males than females and juveniles, and not visible in a few long preserved specimens. The stratum corneum has been lost in ICN 8379 ; a pale stripe appears at vertebral scale 4 (33 mm from the tip of the snout), borders paravertebral rows at vertebral 18 (78 mm from the tip of the snout), and becomes indistinct at vertebral 27 (110 mm from the tip of the snout). In life, the dorsal color of the Venezuelan specimen ( USNM 562696 ) was coppery tan; the chin and first 15 ventral scales were white and the remainder of the ventrals tan .

Hemipenis ( Fig. 4 )

Left retracted organ extends for length of 7 subcaudals. Everted hemipenis single, noncapitate; sulcus spermaticus undivided, intrasulcar surface smooth. Basal region bearing numerous spines, distributed in five rows; first row with six spines; spines on first row larger than those in other rows; two spines adjacent to sulcus largest. Spines arranged irregularly rather than in transverse rows. Few spinules present, occurring in area adjacent to sulcus. Small number of papillate calyces with fringing papillae occurs above fifth row of basal spines; papillae decrease in length and number distally and become stouter, as calyces increase in size. Seven papillae occur on calyces in middle of organ, 6-5 between middle of organ and proximal region of lobe, and 4 in proximal region. Lobe is completely calyculate. Proximal region of lobe has few, irregularly distributed, papillate calyces. Sulcate side is similar to asulcate side.

Dentition

ICN 390 has 25/25 recurved maxillary teeth without a diastema, 15/14 palatine teeth, 26/25 pterygoid teeth, and 29/30 dentary teeth. Maxillary teeth increase in size posteriorly. Last three maxillary teeth are ungrooved and enlarged. One specimen from the Iquitos region has 21 maxillary teeth (Dixon & Soini, 1977).

Ecology

Little is known about the ecology of L. cupreus . Dixon & Soini (1977) collected two specimens in the leaf litter of primary forest at Yanamomo, Peru. USNM 562696 was collected at 1880 m elevation on Cerro de la Neblina, substantially higher than other records of the genus. It was first seen as it searched among the leaf rosettes of Neblinaria celiae , a bizarre plant restricted to the higher elevations of Cerro de le Neblina ( Givnish et al., 1986); presumably the snake was hunting frogs that frequently hide in the leafy rosettes that can hold up to 100 ml of rainwater. According to notes accompanying one specimen (USNM 211042), a frog of the genus Eleutherodactylus (= Pristimantis ) was removed from its stomach. Another specimen (USNM 211038) collected in March, 1956 contained two large ova in the oviduct.

Distribution

Though apparently rare, or at least rarely encountered, L. cupreus appears to be widely distributed. It is known from the southwestern Guayana Highlands of Venezuela and adjacent Colombia (Sierra de La Macarena), the Amazonian lowlands of Ecuador, Colombia and Peru, and from two localities on the Pacific versant of the Andes in Colombia and Ecuador ( Fig. 5).

Diagnosis and comparison with similar species

Leptophis cupreus is distinguished from its congeners by adults having a uniformly copper dorsum ( Fig. 6 ) (vs. dorsum uniformly green, dorsum green with each dorsal scale edged with black, or middorsal area green or bronze contrasting in colour with the posterior area of trunk). The posterior venter is also coppery but slightly darker than the dorsum, and has dark brown and white streaks. Further, L. cupreus differs from the occasionally sympatric L. ahaetulla ahaetulla , L. a. nigromarginatus , L. a. urostictus , and L. riveti (see Oliver, 1948; Albuquerque, 2008, 2009) by the absence of black spots in the center of each parietal scale (vs. present in L. a. nigromarginatus ); scales on dorsal surface of head not edged with black (vs. edged in L. a. nigromarginatus and L. a. urostictus ); dorsum unstriped in adults (vs. two dorsolateral stripes separated from each other by a pale vertebral stripe in L. a. ahaetulla ), adult color pattern without dark oblique bands (vs. with dark bands in L. riveti ); and keels absent on the first dorsal scale rows (vs. keels present on all dorsal scales of trunk in L. riveti ).

Figures

FIGURE 1: Dorsal view of the holotype of Leptophis cupreus (ANSP 5202), a young female specimen (518 SVL) from the “Napo and Maranon”.

FIGURE 2: Dorsal (A) and lateral (B) view of head of the holotype of Leptophis cupreus (ANSP 5202).

FIGURE 3: Leptophis cupreus (LACM 45444).Lateral view of head showing the short and diffuse postocular stripe.

FIGURE 4: Leptophis cupreus. Left hemipenis of ICN 390: (A) sulcate and (B) asulcate sides.

FIGURE 6: Leptophis cupreus. A specimen without locality data photographed at the Valencia Aquarium, Valencia, Venezuela. Courtesy of Marco Natera Mumaw.