Leptophis coeruleodorsus Oliver, 1942

Albuquerque, Nelson Rufino De & Fernandes, Daniel S., 2022, Taxonomic revision of the parrot snake Leptophis ahaetulla (Serpentes, Colubridae), Zootaxa 5153 (1), pp. 1-69 : 22-26

Leptophis coeruleodorsus Oliver, 1942

( Figs. 11C–D, 12–14)

Leptophis coeruleodorsus Oliver, 1942: 4 . Male holotype (AMNH 9022; examined). Type locality: Trinidad, British West Indies; restricted to Mt. St. Benedict (10°39’N, 61°23’W, 1300 m asl), Tunapuna, Trinidad by Murphy et al. 2013: 566 ; Boos 2001: 125; Auguste 2019; Torres-Carvajal & Terán 2021: 2.

Leptophis ahaetulla ortoni — Beebe 1946: 34.

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

Leptophis ahaetulla coeruleodorsus — Peters & Orejas-Miranda 1970: 162; Pérez-Santos & Moreno 1988: 205; Kornacker 1999: 98; Tipton 2005: 161; Ugueto & Rivas 2010: 241; Barrio-Amorós et al. 2011: 29.

Leptophis haileyi Murphy, Charles, Lehtinen & Koeller, 2013: 569 . Male holotype ( CAS 245313 ; photograph examined). Type locality: Tobago near Roxborough. New synonym.

Leptophis caeruleodorsus (sic)— Barrio-Amorós & Ortiz 2015: 85.

Diagnosis. Leptophis coeruleodorsus can be distinguished from its congeners by the following unique combination of character states: (1) head scales not edged with black and with no black spots; (2) adult color pattern with no dark dorsal bands; (3) dorsum with two dorsolateral stripes separated from each other by middorsal area about three to nine scale rows wide, at least anteriorly; (4) dorsals keeled, except first dorsal row on each side; keels of dorsals slightly black; (5) no loreal scale; (6) ventrals 144–168 in males, 157–178 in females; (7) subcaudals 141–166 in males, 125–174 in females; (8) dorsal scales of tail with no keels; (9) maxillary teeth 22–24; (10) TL/SVL: 95% CI = 0.632 –0.663 mm (n = 18); (11) small spines at first basal row of hemipenial body; (12) asulcate side of hemipenis similar to sulcate side.

Comparisons. Leptophis coeruleodorsus differs from all members of the L. ahaetulla complex by dorsal color pattern with two dorsolateral stripes at rows 2–4 or 2–5 (occasionally 2–3 or 3–5) ( Fig. 12A–B) separated from each other by middorsal area about three to nine scale rows wide, at least anteriorly (vs. dorsolateral stripes usually absent; if present, separated from each other by vertebral stripe one to one and half scale wide, at least anteriorly). Further, L. coeruleodorsus differs from sympatric L. occidentalis by having dorsal coloration reduced posteriorly, becoming Pale Cinnamon (55) ( Fig. 12C) to bronze in preservative (vs. uniform dorsal coloration; Fig. 29A); preocular black stripe always absent or reduced to black margin on second and third supralabials (vs. preocular black stripe present and always reduced to upper margin on second, third and fourth supralabials); and the lowest number of ventrals in males—95% CI = 158.6–161 and females—162.6–165.2 (vs. 164.9–166.9 and 167–169.9, respectively) ( Table 2).

Variation and sexual dimorphism. Largest male (AMNH 110472) SVL 907 mm, TL 615+ mm and largest female (USNM 15235) SVL 935 mm, TL 588 mm; ventrals 144–168 in males (160 ± 3.9, n = 38), 157–178 in females (164.1 ± 4.7, n = 40); subcaudals 141–166 in males (156.4 ± 9.2, n = 17), 125–174 in females (157.5 ± 10.1, n = 20); supralabials 7–9 (8.3 ± 0.5, n = 140), with fourth–fifth (64.4%, n = 85), fifth–sixth (34.1%, n = 45), or, rarely, third–fourth (1.5%, n = 2) touching orbit; infralabials 9–11 (10.2 ± 0.5, n = 138), with first 5 (73.6%, n = 103) and first 6 (26.4%, n = 37) contacting first chin shields; preoculars 1–2 (1.1 ± 0.3, n = 140); postoculars 2 (n = 69) and a single specimen with 1 on both sides; anterior temporal 1 (n = 70); posterior temporal 1–3 (1.9 ± 0.1, n = 138); keels more developed in adult males than females and juveniles; width of dorsolateral stripes varies from four to five scales wide, at least anteriorly.

Only three banded specimens were examined: AMNH 101309 and AMNH 64478 , two males with 392 and 361 mm in total length, respectively, and MCZ 126381 , a female with 382 mm in total length, which have bands on anterior and middle portion of the body. Females have more ventrals than males (F 1,78 = 17.3932; P <0.01). No significant difference in subcaudal counts between males and females was observed (F 1,37 = 0.1287; P = 0.7223). The TL / SVL showed no significant difference between females and males (F 1,16 = 2.6178; P = 0.1221) .

Hemipenial morphology. Three retracted organs examined extend up to seventh-eight subcaudals. Everted hemipenis unilobed, noncapitate; sulcus spermaticus centrolineal, undivided, extending from base to tip of lobe; basal portion bears small spines distributed in 5–6 rows approximatelly encircling the organ; first row bears 5–7 hooked spines; two spines in the first row adjacent to sulcus spermaticus larger than those in other rows; few spinules widely scattered on basal portion, occurring below first row of spines; lips of sulcus spermaticus beset with tiny spinules until about the level of midsection portion of hemipenial body; calyces ornamented with 6–8 robust papillae concentrated along distal portion of hemipenial body; papillae gradually decrease in number and length toward distal portion of hemipenis; distal portion of lobe bears few papillate calyces irregularly distributed; most central portion of lobe either calyculate (USNM 195127), or nude (MCZ 100651, TCWC 46262); asulcate side similar to sulcate side ( Fig. 11C–D).

Coloration in life. Dorsum of the head Light Grass Green (109); dorsal scales row I (occasionally I–II) in anterior portion of the body (before body scale reduction from 15 to 11) white or Smoky White (261); anterior portion of the body of adults with two Spectrum Yellow (79) or Sulphur Yellow (80) lateral stripes on dorsal scale rows II–III, II–IV, II–V or III–V on each side; these stripes are separated by Light Grass Green (109) middorsal area 3–9 scale rows wide, depending on the region of anterior portion of the body examined and the width of the dorsolateral bands; dorsal coloration reduces posteriorly, becoming Pale Cinnamon (55); keels of dorsal scales slightly black, being more pronounced on paravertebral rows; preocular Jet Black (300) stripe always reduced to upper margin on second, third and fourth supralabials; postocular Jet Black (300) stripe broad covering lower edge of upper postocular, all of lower postocular, two-thirds of anterior temporal, all or nearly all of lower posterior temporal, and upper edge of last three supralabial scales, extending further over two up to eight scales onto nuchal region; supralabials, infralabials, chin, throat and venter white or dirty white. Roze (1966: 173) and Boos (2001: 125) briefly described the color pattern of Leptophis a. coeruleodorsus , whereas Murphy (1997, fig. 136) and Ugueto & Rivas (2010: fig. 102) not only described but also illustrated this color pattern (as L. a. coeruleodorsus ). Campbell & Lamar (2004, fig. 1172) illustrated a specimen from Villavicencio, Meta, Colombia.

Distribution and natural history. Caribbean coast of Venezuela to the islands of Trinidad and Tobago and Llanos region between Venezuela and Colombia and Pantepui areas (see below), corresponding to the tropical and subtropical moist broadleaf forests, tropical and subtropical grassland, savannas, and shrublands; and deserts and xeric shrublands ecoregions, as defined by Olson et al. (2001) ( Fig. 8). In addition, William Lamar (pers. comm., 26 Aug 2015) collected specimens of L. coeruleodorsus in the Llanos of Colombia and in Villavicencio, departament of Meta, which is at the piedmont of the Eastern Cordillera of the Colombian Andes. USNM 562695 was collected at 1390 m at Cerro de La Neblina, Venezuela.

The specimen MHNLS 13595 (SVL 981 mm) contains five well-developed eggs (the first, along head-tail orientation, measured 21.44 mm).

Remarks. Prior to its recognition as a distinct subspecies of Leptophis ahaetulla, Oliver (1942) described Leptophis coeruleodorsus from 14 specimens from “ Trinidad, British, West Indies”, plus four specimens from “Milford Bay, Tobago Island, British West Indies”, one specimen from “Macute, Venezuela ”, one specimen from “Río Chico, Venezuela ”, one specimen from “ Venezuela ”, one specimen from “Cariquito, Venezuela ”, and one specimen from “Santa Lucia, Estado Miranda, Venezuela ”. Although Oliver (1942) formally designated specimen AMNH 9022 (now AMNH 209022) as the holotype of L. coeruleodorsus , he did not describe it separately from paratypes. Subsequently, Murphy et al. (2013) described this holotype, restricted the type locality and recognized this taxon as full species, as originally considered by Oliver (1942). Before Murphy et al. (2013), Navarrete et al. (2009) also considered L. coeruleodorsus as full species, but with no further discussion. Due to their phenotypic similarities in body size and color pattern, L. coeruleodorsus was considered a synonym of L. ahaetulla until Oliver’s (1948) revision. The presence of a vertebral stripe 1.0–1.5 scale wide in adults of L. ahaetulla , however, unequivocally distinguishes this taxon from L. coeruleodorsus . On the other hand, based on molecular data, Murphy et al. (2013) reinforced earlier conclusions obtained by Albuquerque (2008), which proposed the elevation of L. a. coeruleodorsus to species level based on a unique combination of phenotypic characters. Further, Murphy et al. (2013) described L. haileyi based on a single male specimen collected in Tobago and the diagnosis of this new taxon was particularly contrasted against Tobago specimens of L. coeruleodorsus by a suite of morphometric, meristic and coloration characters. However, the extensive variation in color pattern and scutellation within and among the widely distributed snakes of the genus Leptophis (see Oliver 1948; Mertens 1973; Albuquerque 2008) was not considered by Murphy et al. (2013), as shown hereafter. According to these authors, L. haileyi is “the only Tobago Leptophis to have a subacuminate snout in profile and the rostral barely visible from above”. However, a subacuminate snout and a rostral barely visible can also be found in preserved specimens of Leptophis coeruleodorsus (paratype USNM 59931 from Trinidad, and paratypes MCZ 11994 –95 from Tobago, Fig. 13A–C; a “normal” rounded snout in Fig. 13D). The “primary temporal in contact with three or four upper labials, including the last” appears to be typical of L. cupreus (see fig. 2 in Albuquerque & McDiarmid 2010), and L. nigromarginatus ( KU 126041 ); the contact between the anterior temporal and four upper labials was either not observed or not investigated herein, but this condition (not illustrated by Murphy et al. 2013) is also not present in L. haileyi . The left side of the head of the holotype of L. haileyi , as well as the right side illustrated by Murphy et al. (2013), contains only three upper labials in contact with the anterior temporal, since an azygous scale prevents contact between the last upper labial and the anterior temporal in the left side ( Fig. 14). The “longitudinal dorsolateral stripes on the anterior body scale rows 2–4” (also not illustrated by Murphy et al. 2013; Oliver’s 1948: 229 “five lower rows on each side” with first row included) is subject to variation because the anterior portion of the body of L. coeruleodorsus is ornamented with dorsolateral stripes on rows 2–4 ( Murphy 1997: 181), 2–4 or 2–5 ( Murphy et al. 2013: 567; and this study), and occasionally 2–3 or 3–5 (this study). Actually, the width of yellow dorsolateral stripes varies from one specimen to another and depends on the portion of the body examined, as in L. ahaetulla (see above). Two of the L. coeruleodorsus illustrated in Fig. 12A–B, for instance, exhibit a dorsolateral stripe at rows 2–5 and 2–3 on the anteriormost portion of body, respectively; in these specimens, the middorsal area is five and nine scales wide on these portions of anterior body, respectively. The “nine upper labials, 2–3–4 at the loreal-prefrontal shield” can also be found in other Leptophis such as L. ahaetulla (MPEG 24491, Fig. 2A–D; note 2–3– 4–5 in Fig. 2C), L. bocourti (USNM 285488 and QCAZ 8023, Fig. 7B; Oliver 1948: plate 19), L. nigromarginatus ( KU 126041 ), L. praestans (UMMZ 74851, Fig. 32), L. urostictus (paratype MCZ 13298 ; Mertens 1973: fig. 4), and Leptophis dibernardoi ( Albuquerque et al. 2022) (CHUFC 2144) . Concerning the “5–6 (upper labials) in the orbit”, these scales enter the orbit in 45 (34.1%) of the specimens of L. coeruleodorsus examined in the present study. Finally, Murphy et al. (2013) claim that “this species can also be distinguished from L. coeruleodorsus by…its proportionally shorter tail. The male holotype has a tail/SVL ratio (0.64) …”. The tail/SVL ratio of L. coeruleodorsus , as presented by Murphy et al. (2013) in their Table 3, falls within the range of the specimens of L. coeruleodorsus from Venezuela and Trinidad. Actually, the tail of L. haileyi would be proportionally shorter only if it is contrasted against the four Tobago male specimens of L. coeruleodorsus examined by Murphy et al. (2013) (see also Table 2). Though the phenotype of individuals varies within the same species over a relatively small geographic area (e.g., the supralabial formula of Ecuadorian L. bocourti and L. bolivianus ), the coloration, meristic and morphometric characters used by Murphy et al. (2013) were not sufficiently diagnosable to consider the Tobago specimen as a new taxon. Therefore, we herein place Leptophis haileyi as a junior synonym of L. coeruleodorsus .

We detected that the type series of Leptophis coeruleodorsus is composite, as the diagnostic two dorsolateral stripes separated from each other by middorsal area, at least anteriorly, and the dorsal coloration reduced posteriorly, are lacking in the Venezuelan paratype USNM 27821. Based on these characters, this specimen is here reidentified as L. occidentalis , one of the four species of Leptophis found in Venezuela.