Clelia rustica ( Cope 1878 )

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 46 (9), pp. 77-105 : 94-95

Clelia rustica ( Cope 1878)

Oxyrhopus rusticus Cope, 1878 [1877]: Type locality: Argentina

Oxyrhopus rusticus ; Boulenger, 1896: Argentina

Oxyrhopus rusticus ; Berg, 1898; Argentina

Oxyrrhopus maculatus ; Boettger, 1898: Buenos Aires, Argentina

Oxyrrhopus rusticus ; Boettger, 1898: Buenos Aires, Argentina

Oxyrhopus rusticus ; Koslowski, 1898: Argentina

Pseudoboa rustica ; Serié, 1921: Argentina

Pseudoboa rustica ; Serié, 1936: Argentina

Pseudoboa rustica ; Saporiti, 1946: La Pampa, Argentina

Pseudoboa rustica ; Amaral, 1925: Tucumán, Argentina

Clelia rustica ; Bailey 1970: Argentina

Clelia rustica ; Abalos & Mischis, 1975: Argentina

Clelia rustica ; Gallardo, 1976: Buenos Aires, Argentina

Clelia rustica ; Gallardo, 1977: Buenos Aires, Argentina

Clelia rustica ; Laurent & Terán, 1981: Tucumán, Argentina

Clelia rustica ; Miranda et al., 1983: Buenos Aires, Argentina

Clelia rustica ; Halloy and Laurent, 1984: Northern Argentina

Clelia rustica ; Cei, 1986: Argentina

Clelia rustica ; Scrocchi & Viñas, 1990: Argentina

Clelia rustica ; Cei, 1993: Argentina

Clelia rustica ; Chebez, 1996: Misiones, Argentina

Clelia rustica ; Zaher, 1996: Argentina

Clelia rustica ; Giraudo & Arzamendia, 1997a: Mendoza, Argentina

Clelia rustica ; Giraudo & Arzamendia, 1997b: Santa Fe, Argentina

Clelia rustica ; Leynaud & Bucher, 1999: Gran Chaco, Argentina and Paraguay

Clelia rustica ; Cabrera, 2001: Interior Argentina

Clelia rustica ; Giraudo & Scrocchi, 2002: Argentina

Clelia rustica ; Giraudo, 2002: Northeastern Argentina

Clelia rustica ; Arzamendia & Giraudo, 2002: Santa Fe, Argentina

Clelia rustica ; Scolaro, 2005: Patagonia.

Taxonomic History – After Cope (1878) described C. rustica from Argentina, it was discovered in southern Brazil and Uruguay, but all of the records from “ Paraguay ” are suspect, as we have seen no specimens from the country. It almost certainly occurs in southeastern Paraguay, and Bertoni (1914) may have observed it, but Schouten (1931, 1937) and Gatti (1955) seemed to be simply copying Bertoni. The C. rustica record in Aquino et al. (1996) is based on a specimen that has been reidentified as B. maculata . This publication is probably the source of the erroneous Paraguayan Chaco record in Leynaud & Bucher (1999), showing the errors that can be made by uncritically using museum lists without examining the specimens.

Diagnosis – The reticulate dorsal color pattern and olive ground color can distinguish all specimens of C. rustica , except the rare unicolor exceptions, from the other species treated here ( Fig. 13). Hatchlings may lack the pale nuchal collar that is present in all of the other species. In contrast to C. bicolor and C. quimi , C. rustica usually has 7 supralabials (Appendix 1). The snout is short, and the loreal scale often touches the first supralabial, a condition seen only rarely in Boiruna and not at all in the other species (Appendix 3).

Many or all of the various records of C. rustica from Paraguay are probably based on specimens of Boiruna with a rustica -like reticulate pattern on the sides of the body. True C. rustica have a uniform dorsal pattern ( Fig. 13), and lack the broad dark dorsal stripe present in these Boiruna .

The hemipenis of C. rustica is spined, not spineless as in C. plumbea , with usually two pairs of intrasulcal spines ( Zaher, 1996); C. clelia and Boiruna never have more than one pair of intrasulcal spines (Appendix 2).

Description – Descriptions of C. rustica can be found in Cope (1878), Achaval (1973), Gallardo (1977), Cei (1986, 1993), Scrocchi & Viñas (1990), Zaher (1996), Achaval & Olmos (1997, 2003), Giraudo (2002), and Carreira et al. (2005). Photographs of adults are in Cei (1993) Achaval & Olmos (1997, 2003), and Scolaro (2005), Halloy and Laurent (1984) and Yanosky (1989a) have the same photograph of a large juvenile, and Giraudo (2002) has a photograph of the venter of a preserved juvenile.

Clelia rustica is middle-sized, being larger than C. bicolor and C. quimi but smaller than Boiruna , C. clelia , and C. plumbea ( Fig. 3). Total lengths of the smallest and largest C. rustica that we observed were 224 mm and 1583 mm, respectively.

Ventral counts for C. rustica (187-224) overlap those of all of the other species except C. bicolor (Appendix 4, Fig. 4). Clelia rustica has a relatively short tail; tail proportions are shorter than those of C. bicolor , C. plumbea , C. quimi , and probably C. clelia ( Fig. 5). The species has a lower range of subcaudal counts (45-69; Appendix 4) than any of the other species considered here.

The hemipenis of C. rustica is illustrated in Zaher (1996). According to him, there are two pairs of intrasulcal spines and 16-17 enlarged spines on each side of the sulcus. We found more variation in our small sample, with fewer extrasulcal spines and 1-3 pairs of intrasulcal spines (Appendix 2).

Juvenile and adult C. rustica are similarly colored. Only the very smallest specimens may have a white collar ( Gallardo, 1977). The dorsal ground color is usually a clear to dark yellowish-olive, with contrasting dark pigment on the bases the scales. The scales on the dorsum of the head may be edged in black. The dark pigment may be quite diffuse and occasional specimens may be almost unicolor ( CENAI 3303, 3063; see Cei, 1993). Ventral scales are more yellow than the dorsal ground color. In contrast to other Southern Cone species of Clelia and Boiruna , where dark pigment invades the ventrals along their lateral and free margins, C. rustica may or may not have black pigment along the bases of the ventrals ( Zaher, 1996). In extreme cases the ventrals may be almost entirely black (photograph of CENAI 3083 in Giraudo, 2002: Plate 6). The large, irregular white patches found in other large pseudoboines are not seen in C. rustica .

Distribution – The first member of the Clelia-Boiruna group to be reported from the area was Cope’s (1878) original description of Oxyrhopus rusticus (now Clelia rustica ) from the Page Expedition to Argentina and Paraguay. Cope’s specimen probably came from present-day Argentina.

Clelia rustica is endemic to the Southern Cone, including Uruguay (Achaval Elena, 2001). It is a temperate forest and steppe species that enters the tropical zone only in the cool Atlantic Forest and the foothills of the Andes in northern Argentina ( Fig. 14). The “ C. rustica ” cited by Yanosky et al., (1996) for Formosa, Argentina is a C. bicolor ( Scrocchi & Giraudo, 2005) . The species is the southernmost member of the genus Clelia ( Marcus et al., 2000) .

A reviewer raised the intriguing possibility that the newly described Clelia langeri ( Reichle & Embert, 2005) from Bolivia might be present among the snakes in northwestern Argentina that we identified as C. rustica . We reexamined 57 specimens of C. rustica in the collection of the Fundación Miguel Lillo ( FML) from the provinces of Jujuy, Salta, and Tucumán. None had the two pairs of loreals and 21 nuchal scale rows that distinguish C. langeri from all other Clelia , and their ventral and subcaudal numbers were much lower than those of C. langeri .