Drymoluber apurimacensis Lehr, Carrillo & Hocking, 2004

Costa, Henrique Caldeira, Moura, Mário Ribeiro & Feio, Renato Neves, 2013, Taxonomic revision of Drymoluber Amaral, 1930 (Serpentes: Colubridae), Zootaxa 3716 (3), pp. 349-394 : 381-384

Drymoluber apurimacensis Lehr, Carrillo & Hocking, 2004

Drymoluber apurimacensis Lehr, Carrillo & Hocking, 2004 . Copeia, 2004, p. 47.

Holotype: Museu de Historia Natural Universidad Nacional Mayor de San Marcos, MHNSM 20672, juvenile female, SVL 206 mm, TL 73 mm, collected by P. Hocking on 15 January 2001, in Abancay (-13.64, -72.88), Abancay Province, Apurimác Department, Peru, 2500 m above sea level (Lehr et al. 2004). Specimen examined by photographs ( Fig. 22 ).

Paratypes: Field Museum of Natural History, FMNH 81542, male, SVL 460 mm, TL 192 mm, collected by C. Kalinowski in September 1953 in Hacienda Palmira (-13.65, -73.38), Huancarama district, Andahuaylas Province, Apurimác Department, Peru, 3300 m above sea level (specimen examined by the senior author; Fig. 23 A); Museum für Tierkunde, Dresden, MTKD 44669, adult female, SVL 653 mm, TL 253 mm, killed by a local farmer in May 2002, in Cconoc (-13.06, -72.64), Abancay Province, Apurimác Department, Peru, 1925 m above sea level (Lehr et al. 2004) (specimen examined by photographs; Fig. 23 B); MHNSM 18647, female, SVL 670 mm, TL 274 mm (Lehr et al. 2004; not examined), MTKD 45192, male, SVL 480 mm, TL 165 mm (Lehr et al. 2004; examined by photographs; Fig. 23 C), MTKD 45193, female, without head, TL 216 mm (Lehr et al. 2004; examined by photographs; Fig. 23 D), all collected by an inhabitant of Cconoc, Abancay Province, Apurimác Department, Peru, 1925 m above sea level (Lehr et al. 2004).

Diagnosis: Drymoluber apurimacensis is distinguished from D. brazili and D. dichrous by the following combination of characters: a) 13-13-13 dorsal scale rows without apical pits; b) 158–164 ventrals in males, 166– 182 in females; c) 84–93 subcaudals in males, 87–91 in females; d) 14–16 maxillary teeth.

Comparisons: Drymoluber brazili has 17-17-15 dorsal scales rows, and D. dichrous has 15-15-15. Apical pits are present in D. brazili and D. dichrous . Drymoluber brazili has 182–200 ventrals in males and 185–202 in females, 109–127 subcaudals in males and 109–126 in females. Drymoluber dichrous is not distinguishable from D. apurimacensis based on ventrals and subcaudals counts, having 157–173 ventrals in males and 160–180 in females, 87–110 subcaudals in males and 86–109 in females. Drymoluber brazili has 19–15 maxillary teeth, and D. dichrous has 19–16.

The only known juvenile of Drymoluber apurimacensis (holotype) has dark crossbands 1–2 scales wide, and pale interspaces 2–3 scales wide. Juveniles of D. brazili have dark crossbands 2–6 scales wide (mean 3.6) and pale interspaces 0.5–5 scales wide (mean 1.6). Juveniles of D. dichrous have dark crossbands 1.5–7 scales wide (mean 3.6) and pale interspaces 0.5–2.5 scales wide (mean 0.8).

The hemipenis of Drymoluber apurimacensis has more calyces than those of D. brazili , smaller spinulate flounces, and no spines in the lobular region. The walls of the sulcus spermaticus tend to be more ornamented, at least in the lobular region, with small jagged papillae. The spines on the asulcate face, mainly the most proximal, are larger than those in some specimens of D. brazili . The hemipenial morphology of D. apurimacensis and D. dichrous is similiar, making inaccurate the differentiation of these species by hemipenial characters.

According to the description by Lehr et al. (2004), Drymoluber apurimacensis has dorsal scales with two apical pits. However, a reexamination of the holotype and four paratypes did not reveal apical pits (H.C. Costa pers. obs.; M. Auer, pers. comm.; C.P. Torres-Castello, pers. comm.). Lehr et al. (2004) also suggested that D. apurimacensis could de distinguished from its congeners based on the temporal formula of 1+2 (1+1/ 1 in the present study), while D. brazili and D. dichrous have temporal formulae of 2+2 (1/1+1/ 1 in the present study). As previously discussed, marked polymorphism of temporal plates characterizes Drymoluber , and the temporal formula 1+1/1 also occurs in D. dichrous and D. brazili , although the 1/1+1/1 formula is more frequent.

Coloration of preserved adults: Three of the four paratypes examined (MTKD 44669, 45192, 45193) have the dorsum covered with old scales of olivre-brown color. The inner layer of scales is light bluish-gray. The labials, gular region and the venter are cream colored. The venter becomes bluish-gray with some cream marks on the posterior 2/3 of the body. Subcaudals are bluish-gray and cream colored.

The coloration of FMNH 81542 is darker; its dorsum is dark-gray, and the venter is cream on the anterior third, becoming gray with cream marks posteriorly. The supralabials are cream with dark upper and lateral edges (the last four scales are almost completely black), and the gular region is cream.

There is no information about the coloration of living adult specimens of D. apurimacensis .

Coloration of preserved juveniles: The only known specimen of D. apurimacensis with juvenile coloration is the holotype (MHNSM 20672). Its dorsum has more than 40 dark crossbands of uniform size (about 1–2 scales wide), which become less visible in the posterior third of the body. The light interspaces are 2–3 scales wide. The gular region and venter are cream to light-gray color. The dark crossbands reach the lateral edges of ventrals. The head has the same color of the juveniles of D. dichrous and D. brazili with a transversal white stripe crossing the parietals. The supralabials are pale colored, with slightly darkened lateral edges.

Coloration of juveniles in life: The holotype had black crossbands, and the interspaces are brown. The venter was light-gray and the head brown with black marks (Lehr et al. 2004).

Hemipenial morphology (n=1) ( Fig. 24 ): Hemipenis single, subcylindrical, not capitate. Sulcus spermaticus single and centrolinear. Lobe with just less than half of the hemipenis length, with papillate calyces (5–10 triangular papillae per calyx). Proximally, the calyces are gradually replaced by spinulate flounces and spines. Body covered by spines arranged in more or less transverse rows (about 60–70 spines in total). Walls of the sulcus spermaticus ornamented at least in the lobular region by jagged papillae and some spinules. These walls are also bordered on both sides by a longitudinal row of eight spines that tend to increase in size toward the proximal region. A hook is present at the end of each of row bordering the sulcus; the right hook is located more proximally than the left. Neither spines nor spinules occur between the left hook and the sulcus spermaticus. There are two lateral spines larger than the hooks left of the sulcus. The asulcate face of the hemipenis is formed by spines arranged in about seven more or less transverse rows (counted from proximal to distal region), with largest spines in the medial rows. The base of the hemipenis is smooth, with some grooves and several sparse spinules.

Variation: When available, data of the paratype MHNSM 18647 given by Lehr et al. (2004) were used. Largest male has SVL 643 mm, TL 253 mm (MTKD 44669); largest female has SVL 670 mm, TL 274 mm (MHNSM 18647; not examined). The tail is 34.4–41.7% of the SVL in males (mean 38.5%; SD=3.75; n=3) and 35.4–40.9% (n=2) in females. For variation in meristic characters, see Table 5.

Geographic distribution: Drymoluber apurimacensis is known from three localities between 1920 and 3300 meters above sea level south of the Apurimác and Pampas Rivers, department of Apurimác, in the Serranía Esteparia ecoregion. The area is characterized by matorral seco and matorral sub-húmedo vegetation (Lehr et al. 2004). Drymoluber apurimacensis probably is endemic to the deep valley of the Apurímac River, which seems to be a significant geographical barrier to the North-south distribution of some Andean taxa (Lehr et al. 2004). Amphibians of the genus Bryophryne (Strabomantidae) , the bird Synallaxis courseni (Furnariidae) and the plant Solanum anomalostemon (Solanaceae) are some species endemic to the Apurímac region (Lehr & Catenazzi 2008; BirdLife International 2009; Knapp & Nee 2009).

Natural history: The holotype was collected under a rock at midday, and the paratype MTKD 45193 had a lizard Euspondylus sp. ( Gymnophthalmidae ) in its stomach (Lehr et al. 2004). Drymoluber apurimacensis is sympatric with the snakes Dipsas peruana , Leptotyphlops sp., Oxyrhopus melanogenys and Tachymenis peruviana (Lehr et al. 2004) .

Figures

FIGURE 22. Holotype of Drymoluber apurimacensis Lehr, Carrillo & Hocking, 2004 (MHNSM 20672). Photo: Claudia P. Torres Gastello.

FIGURE 23. Four of the five paratypes of Drymoluber apurimacensis Lehr, Carrillo & Hocking, 2004. A) FMNH 81542; B) MTKD 44669; C) MTKD 45192; D) MTKD 45193. Photos: Henrique C. Costa (A) and Barbara Bastian (B – D).

FIGURE 24. Hemipenis of Drymoluber apurimacensis, FMNH 81542, Hacienda Palmira, Huancarama district, Andahuaylas Province, Apurimác Department, Peru. A) Sulcate face; B) Asulcate face. Scale bar = 0.5 cm. Photos: Henrique C. Costa.