Leptophis marginatus ( Cope, 1862 )

Albuquerque, Nelson Rufino De & Fernandes, Daniel S., 2022, Taxonomic revision of the parrot snake Leptophis ahaetulla (Serpentes, Colubridae), Zootaxa 5153 (1), pp. 1-69 : 32-36

Leptophis marginatus ( Cope, 1862)

( Figs. 19–21 , 22A–B )

Thrasops marginatus Cope, 1862: 349 . Holotype male ( ANSP 5514 ; examined). Type locality: “ Paraguay ”.

Herpetodryas affinis Steindachner, 1870: 348 . Holotype (no number), sex unknown. Type locality: “ Brazil ”. Illustrated in figures 4 and 5, plate VII of Steindachner (1870).

Leptophis rostralis Lönnberg 1902: 458 . Holotype ( NRM 2249 ; not examined), sex unknown. Type locality: San Miguel (34°32’38 S, 58°42’55 W, 29 m asl), Argentina.

Leptophis argentinus Werner 1903: 384 . Holotype (ZSM 1797/0, lost fide Franzen & Glaw 2007), sex unknown. Type locality: “Rosario (there are 11 entries for Rosario as separate localities in Argentina) Argentinien ” [ Argentina].

Leptophis liocercus — Serié 1915: 573.

Leptophis ahaetulla — Amaral 1925: 18; Freiberg 1939: 6; Griffin 1916: 184 (in part) (Griffin listed four specimens deposited in Carnegie Museum as L. ahaetulla ; the CM 314 is here assigned to L. marginatus ); Marques, Eterovic, Strüssmann & Sazima 2005: 49; Wallach, Williams & Boundy 2014: 372 (in part); Cacciali et al. 2016: 171 (in part).

Leptophis marginatus — Oliver 1942: 10; Cope 1876: 177; Torres-Carvajal & Terán 2021: 2.

Thalerophis richardi marginatus — Oliver 1948: 235.

Leptophis ahaetulla [ marginatus ]— International Commission of Zoological Nomenclature 1958: 163.

Leptophis ahaetulla marginatus — Peters & Orejas-Miranda 1970: 163; Carreira, Meneghel & Achaval 2005: 271; Achaval & Olmos 2007: 117; Tipton 2005: 161; Oliveira et al. 2016: unpaged.

Diagnosis. Leptophis marginatus can be distinguished from its congeners by the following unique combination of character states: (1) head scales edged with black and usually with a small black spot approximately on center of each parietal scale and on outer side of each supraocular; (2) adult color pattern with no dark dorsal bands; (3) dorsal color of anterior body distinct from that of posterior half of body or persisting throughout the length of the body; (4) keeled dorsal scales, except first dorsal row on each side; keels of dorsal scales black; (5) no loreal scale; (6) 152–173 ventrals in males, 154–185 in females; (7) 120–160 subcaudals in males, 121–162 in females; (8) dorsal scales of tail with or with no keels; (9) 21–24 maxillary teeth; (10) TL/SVL: 95% CI = 0.577 –0.596 mm (n = 118); (11) moderately enlarged spines at first basal row of hemipenial body; (12) asulcate side of hemipenis similar to sulcate side.

Comparisons. Leptophis marginatus differs from all members of the L. ahaetulla complex by having head scales edged with black and usually with a small black spot approximately on center of each parietal scale and on outer side of each supraocular ( Fig. 19A–B ) (vs. head scales not edged with black and with no black spots on parietals and supraoculars). Adults of L. marginatus are further distinguished from L. nigromarginatus , L. occidentalis , and L. praestans by showing shorter values of TL/SVL—95% CI = 0.577 –0.596 (vs. 95% CI= 0.640–0.649, 0.600–0.626, and 0.610 –0.660 respectively) ( Table 2).

Variation and sexual dimorphism. Largest male SVL 1054 mm, TL 531 mm and largest female SVL 948 mm, tail 507+ mm; ventrals 152–173 in males (161.1 ± 4.2, n = 88), 154–185 in females (166.5 ± 5.2, n = 89); subcaudals 120–160 in males (141.4 ± 7.8, n = 53), 121–162 in females (141.7 ± 7.9, n = 55); supralabials 6–10 (8.0 ± 0.4, n = 352), with fourth–fifth (90.3%, n = 316), or, rarely, fifth–sixth (9.7%, n = 34) bordering orbit; infralabials 8–12 (10.0 ± 0.5, n = 344), with first 5 (86.9%, n = 299), first 6 (11.4%, n = 39), or, rarely, first 4 (1.7%, n = 6) contacting first chin shields; preoculars 1–2 (1.1 ± 0.3, n = 354); postoculars 2 (n = 177), a single specimen with 3 on right side, another specimen with 1 on left side, and a single specimen with 1 on each side; anterior temporal 1 (n = 177); posterior temporal 1–3 (1.5 ± 0.5, n = 354); keels more developed in adult males than females and juveniles; keels stronger and darker on rows III–XIII before reduction in number of dorsal scales from 15 to 11 rows and III–IX after this reduction.

In the holotype (ANSP 5514) supraoculars and parietals ornamented with two small black spots. In several specimens (including holotype), distinct keels on dorsal scales of the tail posterior to the point of reduction from six to four rows (e.g., BMNH 1971.430, CHUNB 15451, IBSP 49908, MHNCI 10559, ZUEC 2758, ZVC 4401). In the ZUEC 2758 postocular stripes extend to the level of four scales posterior to last supralabial. Six specimens examined: MHNCI 3871, a male with 515 mm in total length, MHNCI 8017, a female with 393 mm in total length, CHUNB 15451, a female with 864 mm in total length, CHUNB 15453, a female with 741 mm in total length, CHUNB 29019, a female with 608 mm in total length, and UFMT 8633, a female with 679 mm in total length (tail incomplete), showed a banded pattern, with bands in the anterior and middle portion of the body, similar to those found in juveniles of L. marginatus (e.g., Lonnberg’s 1902 L. rostralis = L. marginatus ; Giraudo 2001). Females have more ventrals than males (H = 0.1455; P = 0.7029). No significant difference in subcaudal counts between males and females (F 1,108 =0.1193, P = 0.7306) was observed. The TL/SVL showed no significant difference between females and males (H = 0.0467; P = 0.8289).

Hemipenial morphology. Ten retracted organs extend up to seven subcaudals. Everted hemipenis unilobed, noncapitate; sulcus spermaticus centrolineal, undivided, extending from base to tip of lobe; basal portion bears moderately enlarged spines, distributed approximately in 5–7 rows encircling the organ; first row bears 4–5 hooked spines; spines in the first row larger than those of other rows; spine in the first row adjacent to sulcus spermaticus is the largest hemipenial spine; one to three small spinules on basal portion (IBSP 9121, IBSP 37444, IBSP 59556, ZUEC 995), occurring between first row of spines; small spinules absent in basal region of FML 1624 and UFMT 79; large and stout papillae adjacent to sulcus spermaticus, immediately above most distal row of basal spines; these papillae gradually decrease in length toward distal portion of hemipenis though still clearly robust along organ; well-developed calyces ornamented with 9–12 papillae concentrated above most distal row of basal spines; distal portion of lobe ornamented with 6–8 robust papillate calyces (CHUNB 15441, UMMZ 109052), but some organs (FML 1624, IBSP 37444) with distal region nude; asulcate side similar to sulcate side ( Fig. 22A–B ).

Coloration in life. Dorsum of the head Light Emerald Green (142) or Turquoise Green (147); body Yellow- Green (103) or Turquoise Green (147) anteriorly, changing gradually to Opaline Green (106), Olive Yellow (117), or Smoke Gray (266) toward tail, or persisting throughout the length of the body; dorsal scales edged with black. Rows II–III (occasionally the II–IV) in the anterior third of the body Sulphur Yellow (80) or Yellow-Green (103); row I usually suffused with Sulphur Yellow; supracephalic scales edged with black, usually with a small black spot in the center of each parietal scale and in the outer side of each supraocular; preocular Jet Black (300) stripe reduced to black margin on second, third, and fourth (occassionally only the fourth or the fouth and fifith are margined) supralabials; postocular Jet Black (300) stripe usually covers lower edge of upper postocular, upper edge of lower postocular, lower edge of anterior temporal, lower edge or half of lower posterior temporal, and upper edges of last two or three supralabials; portions of supralabials uncovered by pre- and postocular stripes, infralabials, chin and throat white to Light Turquoise Green (146); venter white to Pale Greenish White (97). Marques et al. (2005, pages 36 and 49) illustrated photos of L. marginatus (as L. ahaetulla ). Further, Giraudo (2001, fig. 11) and Carrera (2002, fig. 62) illustrated and described the color pattern of L. a. marginatus .

Distribution and natural history. From southeastern Bolivia to the states of Mato Grosso, Goiás and Mato

Grosso do Sul in Brazil, southward through Uruguay and Paraguay into northern Argentina, corresponding to tropical and subtropical moist broadleaf forests, flooded grassland and savannas, tropical and subtropical grassland, savannas, and shrublands, and temperate grassland, savannas, and shrublands ecoregions, as defined by Olson et al. (2001) ( Fig. 18 ).

Albuquerque & Di-Bernardo (2005) recorded a veined treefrog Trachycephalus venulosus Laurenti (= T. typhonius Linnaeus ) in the stomach of an adult female collected in Foz do Iguaçu, Paraná; this snake also contained nine well-developed eggs. IBSP 26764 (SVL 1286+ mm), collected on 28 June 2005, contained 10 well-developed eggs (the tenth, snout-vent direction, measured 33.11 mm).

Remarks. In Oliver’s key (1948), specimens of Thalerophis richardi (= L. ahaetulla ) from southern South America with temporals “usually 1–1” will key out as T. r. marginatus at couplet 11. Herein, 59.1% of the specimens examined for this character (n = 169) have the formula 1–1 on both sides of the head (thus we considered this as a non diagnostic character state). Unlike the temporal formula, few specimens lack black spots on supraocular or parietal scales (e.g., Oliveira et al. 2016). Murphy et al. (2013) indicates some degree of molecular divergence between samples of L. marginatus from Brazil and Paraguay. On the other hand, the monophyly of L. marginatus from Paraguay was strongly supported by Torres-Carvajal & Terán (2021). Alejandro Giraudo kindly sent the first author, on 15 September 2005, a photo of a live specimen ( Fig. 20B ) collected in Santa Fé, Argentina, whose dorsal bright green coloration somewhat resemble those illustrated by Cacciali et al. (2016) and Achaval & Olmos (2007: 117) in Paraguay and Uruguay, respectively, including the dorsal coloration of the head and anterior portion of the body persisting throughout the length of the body in this specimen (as in the holotype, Fig. 21 ), a trait we have not found in some populations of L. marginatus . Additionally, four median rows of dorsal scales of the tail are keeled in this specimen, at least on the anterior portion of the tail. Although Oliver (1948) and Giraudo (2001: 85) stated that dorsal scales of the tail of L. marginatus are devoid of keels, this characteristic can be found in some specimens, including the holotype.

Figures

FIGURE 18. Distribution of Leptophis bolivianus, L. liocercus, L. marginatus, and L. nigromarginatus based upon the material examined.

FIGURE 19. Color patterns and color tones variability of Leptophis marginatus: Male holotype AMNH 5514, SVL 1245 mm, from “Paraguay”. Dorsal (A) and (B) lateral views of the head. Scale bars = 0.5 cm. Photos by N.R. Albuquerque.

FIGURE 20. Color patterns and color tones variability of Leptophis marginatus: (A) IBSP 63731 from the municipality of Presidente Epitácio, state of São Paulo, Brazil; and (B) INALI 969, SVL 1020 mm, a male specimen from province of Santa Fé, Argentina. Note dorsal bright green coloration similar to specimens from Paraguay and Uruguay. Four median rows of dorsal scales of the tail are keeled in this specimen (indicated by the arrow), at least on anterior portion of the tail. Photos by O.A.V. Marques (A) and A.J. Giraudo (B).

FIGURE 21. Color patterns and color tones variability of Leptophis marginatus: Male holotype AMNH 5514, SVL 1245 mm, from “Paraguay”. Note that the dorsal coloration of the head and anterior portion of the body persists throughout the length of the body in this specimen. Photo by N.R. Albuquerque.

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.