Leptophis liocercus ( Wied, 1824 )

Albuquerque, Nelson Rufino De & Fernandes, Daniel S., 2022, Taxonomic revision of the parrot snake Leptophis ahaetulla (Serpentes, Colubridae), Zootaxa 5153 (1), pp. 1-69 : 28-32

Leptophis liocercus ( Wied, 1824)

( Fig. 11E–F , 16–17 )

Coluber liocercus Wied, 1824: 665 . Holotype male (AMNH 3531; examined). Type locality: “Cabo Frio, Paraiba, Marica, Saquarema, Araruama, Ponta Negra, Lagoa Feia, and Espírito Santo ” [southeastern Brazil]; restricted by Albuquerque et al. (2022) to the state of Rio de Janeiro, Brazil (see also Vanzolini & Myers 2015: 44 for comments on the type locality and type series of C. liocercus ).

Dendrophis liocercus — Schlegel 1837 (in part): 124. Holotype unknown. Type locality: “ Martinique jusqu‘au Brésil et au Chilé ”.

Leptophis flagellum Andersson, 1901: 13 . Holotype female (under number 1981) in the Royal Museum of Stockholm (specimens subsequent transferred to Naturhistoriska riksmuseet) (fide Hoge 1959: 77). Type locality: “Brasilia”. According to Sven Kullander (pers. com., 18 April 2017), there is no specimen of Leptophis with that number catalogued as Leptophis flagellum in the collections of NRM.

Leptophis liocercus — De Witte 1930: 3; Amaral 1977: 78; Torres-Carvajal & Téran 2021: 6.

Thalerophis richardi liocercus — Oliver 1948: 232.

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

Leptophis ahaetulla liocercus — Peters & Orejas-Miranda 1970: 162; Amaral 1977: 78; Tipton 2005: 161; Bérnils, Almeida, Gasparini, Srbek-Araujo, Rocha & Rodrigues 2014: 201.

Leptophis ahaetulla — Argôlo 2004: 176 (in part); Pontes & Rocha 2008: 66 (in part).

Diagnosis. Leptophis liocercus can be distinguished from its congeners by the following unique combination of character states: (1) head scales slightly edged with black and with no black spots; (2) adult color pattern with no dark dorsal bands; (3) dorsum unstriped, dark bluish green, with dorsal coloration changing gradually to light brown or darker brown toward tail, with scales narrowly edged with black; (4) keeled dorsal scales, except first dorsal row on each side; keels of dorsal scales slightly black, usually present on midbody and posterior region of adult males; (5) no loreal scale; (6) ventrals 150–169 in males, 151–173 in females; (7) subcaudals 149–167 in males, 144–173 in females; (8) dorsal scales of tail with no keels; (9) maxillary teeth 21–24; (10) TL/SVL: 95% CI = 0.656 –0.685 (n = 51); (11) small spines at first basal row of hemipenial body; (12) asulcate side of hemipenis similar to sulcate side.

Comparisons. Leptophis liocercus differs from all members of the L. ahaetulla complex by the combination of head scales slightly edged with black and with no black spots ( Figs. 16A , 17A ) (vs. head scales not or heavily edged with black and with black spots); dorsum unstriped, metallic green anteriorly ( Fig. 16C , 17B ) (vs. dorsum striped, not metallic green anteriorly), with dorsal coloration changing gradually to Olive Yellow (117) (vs. light brown or darker brown in preservative) toward tail ( Fig. 17B ) (vs. dorsal coloration not changing gradually to olive yellow, light brown or darker brown toward tail), with dorsal scales narrowly edged with black ( Fig. 17B ) (vs. dorsal scales not edged with black). Further, it is distinguished from the occasionally sympatric L. dibernardoi by having supracephalic scales slightly edged with black ( Figs. 16A , 17 ) (vs. not edged with black). It differs from L. occidentalis by the lower number of ventrals in males—95% CI = 156.9–159.5 and females 159.3–162 (vs. 164.9–166.9 and 167–169.9, respectively) and by higher values of TL/SVL—95% CI = 0.656 –0.685 (vs. 0.600 –0.626) ( Table 2).

Variation and sexual dimorphism. Largest male SVL 1541 mm, TL 539+ mm and largest female SVL 925 mm, tail 637+ mm; ventrals 150–169 in males (158.3 ± 4.5, n = 35), 151–173 in females (160.8 ± 4.7, n = 39); subcaudals 149–167 in males (158.4 ± 5.9, n = 21), 144–173 in females (157.6 ± 7.2, n = 27); supralabials 6–10 (8.4 ± 0.6, n = 142), with fourth–fifth (54.9%, n = 79), fifth–sixth (43.7%, n = 63), or, rarely, sixth–seventh (1.4%, n = 2) bordering orbit; infralabials 7–11 (10.2 ± 0.7, n = 138), with first 5 (66.2%, n = 90), first 6 (31.6%, n = 43), and first 4 (2.2%, n = 3), contacting first chin shields; preoculars 1–2 (1.0 ± 0.2, n = 146); postoculars 1–3 (2.0 ± 0.2, n = 146); anterior temporal 1 (n = 74); posterior temporal 1–2 (1.9 ± 0.2, n = 146); keels stronger in adult males than females and juveniles; keels present on dorsal scale rows II–XIV (males) and VI–VII (females) before reduction in number of dorsal scales from 15 to 11 rows; keels stronger and darker on midbody and posterior portion of adult males (e.g., CHUNB 6640, CZGB 3160, MHNCI 11553).

In the holotype AMNH 3531 postocular stripes extend up to seven scales posterior to last supralabial on each side ( Fig. 16B ). In the CHUNB 6640 postocular stripe extend up to 12 scales posterior to last supralabial. The specimen CHUNB 6640 (an adult male) has a distinct broad postocular stripe covering the lower and upper postocular, anterior margin of parietal, preocular, postocular, nearly all anterior and posterior temporals, and upper edges of last three supralabials. A female with 608 mm in total length, CHUNB 29019 , is ornamented with bands on anterior and middle portion of the body. Females have more ventrals than males (F 1,74 = 4.5153; P <0.05). No significant difference in subcaudal counts between males and females was observed (F 1,48 = 0.1700; P = 0.6849). The TL / SVL showed no significant difference between females and males (H = 0.1455; P = 0.7029) .

Hemipenial morphology. Five retracted organs examined extend to the level of eighth subcaudals. Four evert- ed hemipenes unilobed and one (CZGB 1149) slightly bilobed, noncapitate; sulcus spermaticus centrolineal, undivided, extending from base to tip of lobe in five organs. Although the hemipenis of CZGB 1149 is slightly bilobed, sulcus spermaticus remains unbifurcated until the apical portion of the organ; basal portion bears numerous smallsized spines, distributed approximately in 5–8 rows encircling the organ; first row bears 5–9 spines; spines in the first row longer than those in other rows (MNRJ 4846), but in three other organs examined (CZGB 1149, MCN 5340 and MZUESC 2002) spines in the fourth row longer than most spines of first row; a hooked spine in the first row adjacent to sulcus spermaticus is the largest hemipenial spine (CHUNB 6640, MNRJ 4846); few minute spinules widely scattered on basal portion, occurring below (MCN 5340) and between (CZGB 1149) first row of spines; these spinules become papillae on the middle portion of hemipenial body, being larger along sulcus spermaticus; small number of calyces ornamented with 6–10 papillae concetrated above most distal row of basal spines; papillae gradually decrease in length toward distal portion of hemipenis and become stouter; distal portion of lobe bears small-sized calyces ornamented with 4–8 or 6–8 fringing papillae; papillate calyces irregularly distributed on distal region of lobe; asulcate side similar to sulcate side ( Fig. 11E–F ).

Coloration in life. Dorsum of the head Light Caribbean Blue (163) or metallic green; body Light Caribbean Blue (163) to metallic green anteriorly, changing gradually to Olive Yellow (117) toward tail; dorsal scales narrowly edged with black; black marks present on keels of dorsal scales; preocular Jet Black (300) stripe always absent or reduced to black margin on second and third supralabials; postocular Jet Black (300) stripe moderately broad, covering lower margin of upper postocular and all of lower postocular, half of anterior temporal and two-thirds of lower posterior temporal; supralabials, infralabials, chin, throat; and venter white. Argôlo (2004, fig. 29) and Pontes & Rocha (2008, pages 66 and 67) illustrated and described the color pattern of L. liocercus (as L. ahaetulla ). Amaral (1977, fig. 35) illustrated a specimen of L. liocercus .

Distribution and natural history. Specimens examined were collected in localities within the limits of Atlantic Forest and Cerrado domain boundaries, from southern Paraíba to São Paulo at 600 m asl in the tropical and subtropical moist broadleaf forests, and tropical and tubtropical grasslands, savannas and shrublands ecoregions, as defined by Olson et al. (2001) ( Fig. 18 ).

One specimen from Bahia State (MCZ 2989) previously identified by Oliver (1948) as Thalerophis richardi richardi (= L. a. ahaetulla ) contained two Dendropsophus Fitzinger of the Dendropsophus marmoratus Laurenti species group (identified by J. Faivovich in 2006), ingested headfirst. Another specimen (IBSP 46053), collected in Aracaju, Sergipe State, contained one Boana raniceps Cope.

Remarks. Andersson (1901: 14) stated that the holotype of Leptophis flagellum possessed “scales in 15 rows… all smooth, but striated”, an “enlarged vertebral row” and “no dark streak behind the eye”. Except for the absence of a dark streak behind the eyes, which seems to be absent in adult L. praestans (see Remarks below), the available evidence suggests that the holotype of Leptophis flagellum belongs to another genus. Oliver (1948) briefly described the hemipenis of Leptophis liocercus based on retracted organs. According to Oliver (1948), L. liocercus has “four enlarged basal spines; the two on either side of the sulcus are the largest”. However, Oliver did not explicitly indicate the material from which the hemipenes were described. IBSP 9019 (“Estação Cascadura”, Rio de Janeiro) and IBSP 9121 (“Estação Itá ” = Estação Itapina, Espírito Santo), which were used by Oliver (1948) in his description, have four enlarged basal spines, similar to those of L. marginatus . Presumably, these specimens were collected in localities situated near of the train stations of Estação Itapina and Estação Cascadura and sent to Instituto Butantan, as were many other specimens received by this Institute in the 1930’s (see Fonseca 1949). On the other hand, the hemipenes of CZGB 1149 and MZUESC 2002 (both collected in Ilhéus, Bahia) have respectively five and seven spines in the first basal row; in contrast to the organs of IBSP 9019, IBSP 9021 and MBML 130, they possess small spines. Although IBSP 9019 and IBSP 9121 have no spots on parietal scales, these specimens are here assigned to L. marginatus on the basis of hemipenial morphology and dorsal color pattern. IBSP 9019 was severely damaged and faded, so that the original color pattern was absent.

Figures

FIGURE 11. Sulcate (left) and asulcate (right) sides of the hemipenes of Leptophis bolivianus (AMNH 104564) from Estancia Yutiole, department of Beni, Bolivia (A–B); L. coeruleodorsus (TCWC 46262) from municipality of San Fernando de Apure, state of Apure, Venezuela (C–D); L. liocercus (CZGB 1149) from municipality of Ilhéus, state of Bahia, Brazil (E–F). Note that although the hemipenis of CZGB 1149 is slightly bilobed, its sulcus spermaticus remains unbifurcated until the apical portion of the organ; L. nigromarginatus (LPHA 1731) from municipality of Santarém, state of Pará, (G–H); and (TCWC 42177) from Centro Union, departament of Loreto, Peru (I–J). Although the first row of basal spines is small in the four species, the two spines adjacent to sulcus spermaticus are larger than those in other rows. Scale bars = 0.5 cm. Photos by D. Kizirian (A–B) and N.R. Albuquerque (C–J).

FIGURE 16. Color pattern and color tones of Leptophis liocercus: Male holotype AMNH 3531, SVL 1144 mm (incomplete tail), from an unspecified locality in the tropical forests of Brazil. Dorsal (A) and (B) ventral views of the head; dorsal (C) and ventral (D) views of the holotype. Scale bars = 0.5 cm. Photos by N.R. Albuquerque.

FIGURE 17. Color pattern and color tones of Leptophis liocercus: (A) MZUFV 2082, SVL 1594 mm, a female from Linhares, Espírito Santo. Note the head scales slightly edged with black (indicated by the arrow); (B) IBSP 88574, SVL 1072 mm, a female from the municipality of São Mateus, state of Espírito Santo, Brazil. Photos by M.R. Moura (A) and R.D. Moysés (B).

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