Clelia plumbea ( Wied-Neuwied 1820 )

Scott Jr., Norman J., Giraudo, Alejandro R., Scrocchi, Gustavo, Aquino, Aida Luz, Cacciali, Pier & Motte, Martha, 2006, THE GENERA BOIRUNA AND CLELIA (SERPENTES: PSEUDOBOINI) IN PARAGUAY AND ARGENTINA, Papéis Avulsos de Zoologia (São Paulo) 46 (9), pp. 77-105 : 92-93

Clelia plumbea ( Wied-Neuwied 1820)

Coluber plumbeus Wied-Neuwied, 1820: Type locality: Between Cabo Frio and Rio São João, Brazil

Clelia clelia plumbea ; Bailey, 1970: Misiones, Argentina

Clelia clelia plumbea ; Abalos & Mischis, 1975: Argentina

Clelia clelia ; Acosta et al., 1994: Misiones, Argentina.

Clelia clelia clelia ; Duré Rodas, 1995: Eastern Paraguay

Clelia clelia ssp. (part.); Chebez, 1996: Misiones, Argentina

Clelia clelia (part.); Aquino et al., 1996: Paraguay

Clelia plumbea ; Zaher, 1996; Asunción, Paraguay (incorrect locality)

Clelia plumbea ; Giraudo & Scrocchi, 2002: Argentina

Clelia plumbea ; Giraudo, 2002: Northeastern Argentina

Taxonomic History – It is difficult to say if the earlier workers on Paraguayan-Argentinean snakes had specimens of C. plumbea that they did not distinguish from Boiruna or C. clelia . The first explicit recognition of the taxon in the area was Bailey (1970), who considered it a subspecies of C. clelia . He did not explain the large area of apparent overlap between C. clelia clelia and C. c. plumbea in southern Brazil and eastern Argentina. Zaher (1996) cleared up that confusion by recognizing that C. plumbea was a valid species. He recorded a specimen from Asunción, Paraguay; however the locality is probably incorrect.

Abalos & Mischis (1975) first recorded the species from Argentina, but its presence was not acknowledged again until Giraudo (2002) and Giraudo & Scrocchi (2002) recognized it in northeastern Argentina.

Diagnosis – Adult C. plumbea differ from Boiruna in having dark pigmentation only on the outer lateral tips of the ventral scales; Boiruna has posterior ventrals that are completely covered with dark pigmentation. They may be distinguished from C. clelia by the higher number of ventrals (Appendix 4, Fig. 4 ) and by the straight line (dentate in C. clelia ) on the tips of the ventrals demarking the change between the dark dorsal color and the ivory venter ( Fig. 1 ; Giraudo, 2002). The smallest species ( C. bicolor , C. quimi ) also have fewer ventrals. Ventral counts for the intermediate-sized form, C. rustica , overlap slightly with counts for C. plumbea (Appendix 4, Fig. 4 ).

Clelia plumbea tends to have a smaller loreal than the other species ( Fig. 2B ); it was the only species that occasionally lacked a loreal when it was fused with either the posterior nasal or the prefrontal (Appendix 3). In all but one specimen, the loreal was absent or only contacted the second supralabial; in one specimen, the loreal touched supralabials 2 and 3 on both sides of the head. In B. maculata and C. rustica , about half of the loreals contacted one scale and half touched two supralabials; in the rest of the species the loreal always had a joint suture with two or even three supralabials.

Hatchling C. plumbea are colored like C. clelia , with a red body, white venter and nape band, and a black dorsal head and neck spot (photograph in Giraudo, 2002; Fig. 10 ). Ontogentic color changes proceed as in C. clelia . They lack the dark dorsal stripe of B. maculata and C. bicolor , and are not uniformly colored like hatchling C. rustica .

Description – Giraudo (2002) has the only description of C. plumbea from the study area. Clelia plumbea may be longest species of Clelia ; in our collection, the shortest and longest were 435 mm and 2300 mm total length. Zaher (1996) recorded a female with a total length of 2585 mm. There is probably no significant difference in length between the sexes (t-test; P>0.07), although the largest specimens are usually females.

Clelia plumbea has a relatively high number of ventrals (215-240) and subcaudals (69-90; Appendix 4, Fig. 4 ). They usually have 7 supralabials on each side (Appendix 1). The relatively small loreal is discussed in the Diagnosis above.

The hemipenis of C. plumbea entirely lacks enlarged spines (Appendix 2, Zaher, 1996 with photograph, 1999).

Adults are very similar in color to C. clelia , with a dark gray or black dorsum and ventral scales that are mostly ivory with dark tips. A dark zigzag is usually present along the suture where the pairs of subcaudals meet. The supraoculars are dusky and there may be some melanin on the infralabials and mental. Like some related species, specimens may be irregularly spotted with white. We see no differences between the coloration and ontogeny of coloration of juvenile C. clelia and C. plumbea ; see the former description and Giraudo (2002) for details.

Distribution – Although Bailey (1970) recognized the presence of Clelia plumbea in Misiones Province, Argentina, Zaher (1996) had the first published report of a specimen from the study area. However, the Instituto Butantan specimen (IB 10100) from “Assunción” is almost certainly an incorrect locality. All of the other records from the study area are in the wet Atlantic forests close to the Parana River ( Fig. 12 ).

Figures

FIGURE 1. Comparison of the patterns of dorsal color incursion on the tips of the ventrals in Clelia clelia (INALI 1685, lower) and C. plumbea (MNHNP 3059, upper). Notice the relatively straight border in the latter compared to the toothed pattern in C. clelia.

FIGURE 2. Diagrams of the lateral head squamation in Boiruna and Clelia. A) C. clelia (MNHNP 3840); B) C. plumbea (MNHNP 3059); C) Boiruna maculata (MNHNP 7674); D) C. bicolor (MNHNP 2616); E) C. rustica (FML 2766).

FIGURE 4. Distribution of ventral counts in female and male Boiruna and Clelia from Paraguay and Argentina.

FIGURE 10. Juvenile Clelia plumbea. INALI 387, Aristóbulo del Valle, Misiones Province, Argentina. Photo by A. Giraudo.

FIGURE 12. Geographic distribution of Clelia clelia (squares) and C. plumbea (filled circles) in Argentina and Paraguay.