Leptophis urostictus ( Peters, 1873 )

Albuquerque, Nelson Rufino De & Fernandes, Daniel S., 2022, Taxonomic revision of the parrot snake Leptophis ahaetulla (Serpentes, Colubridae), Zootaxa 5153 (1), pp. 1-69 : 50-52

Leptophis urostictus ( Peters, 1873)

( Figs. 22C–D , 33–34 )

Ahaetulla urosticta Peters, 1873: 606. Holotype female (ZMB 7786; not examined). Type locality: “ Bogotá ” (4°38‘57 N, 74°3‘ 46W, 2812 m asl) [ Colombia]; later corrected to “Choco area, Western Colombia ” by Mertens (1973: 144) who stated that “The typical land designated to Leptophis ahaetulla urostictus is definitely the Choco area, west of Bogota; Bogota was just the place from which the snake, whose collector was a Mr. Ribbe, departed on its journey to Berlin. In Bogota there are apparently no Leptophis species at all because of its altitude...” (our translation).

Leptophis urostictus —Amaral 1929c: 162; Dunn 1944: 79; Torres-Carvajal & Téran 2021: 6.

Leptophis occidentalis chocoensis Oliver 1942: 15 . Holotype male (UMMZ 55528; examined). Type locality: El Río Condoté [Condoto], Camp Peña Lisa, Choco, Colombia (5°06’N, 76°42’W, 100 m asl); Daniel 1949: 311.

Thalerophis richardi chocoensis — Oliver 1948: 227.

Leptophis ahaetulla [chocoensis]— International Commission of Zoological Nomenclature 1958: 270.

Leptophis ahaetulla chocoensis — Peters & Orejas-Miranda 1970: 162; Pérez-Santos & Moreno 1988: 210.

Leptophis ahaetulla urostictus — Mertens 1973: 143; Tipton 2005: 162.

Leptophis ahaetulla — Wallach et al. 2014: 372 (in part).

Diagnosis. Leptophis urostictus can be distinguished from its congeners by the following unique combination of character states: (1) head scales narrowly edged with black and with no black spots; the presence of a broad black postocular stripe, occupying half or nearly all of anterior temporal and lower posterior temporal; (2) adult color pattern with no dark dorsal bands; (3) dorsal scale rows V to XI, before scale row reduction from 15 to 11, greenish blue in adults; (4) keeled dorsal scales, except first dorsal row on each side; keels on rows III to XII heavily black (more prominent on the paravertebral scales and less prominent in the rows below and at vertebral row); (5) no loreal scale; (6) ventrals 160–168 in males, 153–166 in females; (7) subcaudals 172–181 in males, 164–180 in females; (8) dorsal scales of tail with no keels; (9) maxillary teeth 22–23; (10) TL/SVL: 95% CI = 0.635 –0.663 (n = 11); (11) moderately enlarged spines at first basal row of hemipenial body; (12) asulcate side of hemipenis similar to sulcate side.

Comparisons. Leptophis urostictus differs from all members of the L. ahaetulla complex by having dorsal keels on rows III to XII heavily black (more prominent on rows V–VII on each side, and less prominent on rows II–IV and at vertebral row), before the reduction to 11 dorsal scale rows ( Figs. 33–34 ) (vs. dorsal keels not black or slightly black on these rows).

Variation and sexual dimorphism. Largest male SVL 1081 mm, TL 696+ mm and largest female SVL 890 mm, TL 620 mm; ventrals 160–168 in males (163.4 ± 3.3, n = 7), 153–166 in females (162.8 ± 4.1, n = 8); subcaudals 172–181 in males (176.5 ± 6.4, n = 2), 164–180 in females (174.7 ± 5.5, n = 7); supralabials 9 (n = 15), and only two specimens with 8 on left side, with fourth–fifth (75.9%, n = 88), and fifth–sixth (24.1%, n = 28) bordering orbit; infralabials 9–12 (10.5 ± 0.8, n = 170), with first 6 (66.7%, n = 20), first 5 (30.0%, n = 9), and first 7 (3.3%, n = 1) contacting first chin shields; preocular 1 (n = 15); postoculars 2 (n = 14) and a single specimen with 3 on both sides; anterior temporal 1 (n = 15); posterior temporals 2 (n = 15); supracephalic scales of AMNH 107935, a male with 1586 mm in total length (tail incomplete), ornamented with numerous small, irregularly shaped black spots, similar to those found in L. bocourti ; keels more developed in adult males than females and juveniles. Sexual dimorphism was not evident in the average number of ventrals (F = 0.1233; P = 0.7302) and was not tested to subcaudals due to the low number of specimens with intact tails.

Hemipenial morphology. Single retracted organ examined extends to the level of seventh subcaudals. Everted hemipenis slightly bilobed, noncapitate; sulcus spermaticus centrolineal, undivided, extending from base to tip of lobe; basal portion bears five moderately enlarged spines in the first row, followed distally by 6 transverse rows of smaller, stout spines encircling the organ; spine in the first row adjacent to sulcus spermaticus larger than others; few spines adjacent to sulcus spermaticus, as an extension of minute spinules present on basal portion; calyces originate above most distal row of basal spines; calyces on distal region developed, uniformly large and ornamented with 6 robust papillae (up to 16 papillae on calyces situated on the middle portion of the organ); papillae gradually decrease in length and number toward distal portion of hemipenial body; distal portion of lobe bears few papillate calyces irregularly distributed; asulcate side similar to sulcate side ( Fig. 22C–D ).

Coloration in life. Dorsum of the head Cinnamon-Drab (50), with supracephalic scales narrowly edged with black; a broad black postocular stripe, occupying lower edge of upper postocular, upper edge of lower postocular, half or nearly all of anterior and posterior temporals, and upper edges of last two or three supralabials; before dorsal scale row reduction from 15 to 11, rows I–IV Cyan (148) whereas rows V–XI Cinnamon-Drab (50); keels on rows III to XII heavily black (more prominent on paravertebral scales and less prominent in the rows below and at vertebral row); supralabials and infralabials white to Light Turquoise Green (146); chin and throat white; venter Pale Cyan (157).

Distribution and natural history. Pacific lowlands of Colombia in the departments of Chocó, Risaralda, Valle del Cauca and Cauca. These snakes were collected up to 480 m asl in the tropical and subtropical moist broadleaf forests ecoregion, as defined by Olson et al. (2001) ( Fig. 8 ).

Remarks. Described subsequently as Leptophis occidentalis chocoensis by Oliver (1942), this taxon was later assigned as a subspecies of L. ahaetulla by Oliver (1948). However, Mertens (1973) suggested the applicability of Peter’s (1873) name Ahaetulla urosticta. As noted by Mertens (1973), the holotype has a maximum of 13 dorsal scale rows, which led Dunn (1944) to consider it as an aberrant specimen, a result of erroneous examination.

Figures

FIGURE 8. Distribution of Leptophis bocourti, L. coeruleodorsus, L. occidentalis, L. praestans, and L. urostictus based upon the material examined.

FIGURE 22. Sulcate (left) and asulcate (right) sides of the hemipenes of Leptophis marginatus (FML 1624) from Puerto Pilcomayo, departament of Pilcomayo, Formosa Province, Argentina (A-B); L. urostictus (AMNH 109753) from Guanguí stream, department of Cauca, Colombia (C-D); L. occidentalis (ANSP 32397), from province of Limón, Costa Rica (E-F); and L. praestans (KU 55716) from El Petén, Guatemala (G-H) sides. Note the first row of moderate-sized spines in the first two species, and the enlarged spines in the latter two species. Scale bars = 0.5 cm. Photos by N.R. Albuquerque.

FIGURE 33. Color pattern and color tones of Leptophis urostictus: Male holotype of L. occidentalis chocoensis (=L. urostictus), UMMZ 55528, SVL 1555 mm, from Condoto River, Chocó, Colombia. Note that the black keels are less prominent at vertebral row (indicated by the arrow). Photo by N.R. Albuquerque.

FIGURE 34. Color pattern and color tones of Leptophis urostictus (AMNN 115932) from the south bank of the San Juan River, department of Risaralda, Colombia. Note the keels on paravertebral scales heavily black (indicated by the arrow) (less prominent in the rows below). Photo by C.W. Myers.