Cochranella petersi

Guayasamin, Juan M., Cisneros-Heredia, Diego F. & Castroviejo-Fisher, Santiago, 2008, Taxonomic identity of Cochranella petersi Goin, 1961 and Centrolenella ametarsia Flores, 1987, Zootaxa 1815, pp. 25-34 : 26

Status of Cochranella petersi .

Goin (1961) differentiated Hyalinobatrachium petersi from other centrolenid frogs mainly by the absence of vomerine teeth and the presence of extensive webbing between Fingers II–IV. Since its description, the recognition of H. petersi has been debated in various papers. Lynch and Duellman (1973) synonymized H. petersi with H. fleischmanni Boettger , arguing that the extensive webbing observed in H. petersi falls within the variation of H. fleischmanni . Later, Ruiz-Carranza and Lynch (1998) revalidated H. petersi based on specimens from southwestern Colombia and differentiated it from H. fleischmanni by the color of the pericardium (transparent in H. petersi , white in H. fleischmanni ). Cisneros-Heredia and McDiarmid (2007a) considered that Ruiz-Carranza and Lynch (1998) misidentified the Colombian specimens, and later assigned those specimens to H. valerioi ( Cisneros-Heredia & McDiarmid 2007b), who mentioned that the holotype of H. petersi was conspecific with H. fleischmanni but did not take further taxonomic actions. Recent expeditions to the Río Durango area have collected specimens of Centrolene callistommum Guayasamin and Trueb , C. ilex (Savage) , C. litorale Ruiz-Carranza & Lynch , C. prosoblepon (Boettger) , Cochranella albomaculata (Taylor) , C. pulverata (Peters) , C. spinosa (Taylor) , H. aureoguttatum (Barrera-Rodríguez & Ruiz-Carranza) , and H. fleischmanni , but not a single specimen that could be confidently assigned to H. petersi ( Bustamante et al. 2007, QCAZ catalogue, DHMECN catalogue, pers. obs.).

We examined the holotype of Hyalinobatrachium petersi ( Fig. 1 ), which is in a good state of preservation (except for a careless ventral dissection). Although iridophore layers over the visceral peritonea are well preserved, the general color of the specimen (including bones) is olive green. This green coloration, which is also present in several other centrolenid species housed at the BMNH (DFCH and SCF pers. obs.), seems to be a preservation artifact caused by the fluid used at the time by the BMNH.

Morphological traits of the holotype include a slightly sloping snout in lateral profile, traces of cloacal ornamentations, completely transparent parietal peritoneum, white pericardium, white hepatic and gastrointestinal peritonea, an externally bulbous liver (no dissection was done to confirm this character state), extensive webbing between Fingers II–IV, traces of low enameled ulnar and tarsal folds, warts on the upper lip, white (enameled) warts between the tympanum and the arm, and lack of humeral spine and vomerine teeth. The traces of cloacal ornamentations, warts behind the tympanum, and the ulnar and tarsal folds are subtle and were overlooked the first two times the specimen was examined (SCF and DFCH). This led Cisneros-Heredia and McDiarmid (2007b) to suggest it was conspecific with H. fleischmanni . Re-examination of the specimen by DFCH in September 2007 revealed the presence of the mentioned traits. Three male specimens of Cochranella pulverata were found in the BMNH, one of them collected with the holotype of Hyalinobatrachium petersi (BMNH 1902.5.27.25) and the others at a nearby locality (1902.7.29.36–37). They present the same morphological patterns and most preservation effects showed by type of H. petersi , except that the enameled warts and folds are better preserved, they bear vomerine teeth, and they show the normal coloration in preservative of the species. All but one of these characteristics (i.e., absence of vomerine teeth) is present in all Cochranella pulverata examined (Appendix 1). We hypothesize that the absence of vomerine teeth in the holotype of H. petersi can be the result of accidental removal during examination by researchers or previously unnoticed intraspecific variation within C. pulverata . The former option is favored by the condition of another type in the BMNH; the holotype of Hylella parabambae Boulenger (= Centrolene prosoblepon ) that shows no teeth on the right side and two teeth on the left side, but close examination under a dissecting microscope (x40) shows that the areas are strongly damaged and several teeth were broken. Particularly important in associating the holotype of H. petersi with Cochranella pulverata is the presence of enameled warts on the upper lip and below the tympanum, extensive hand webbing, and ulnar and tarsal folds. This combination of traits is absent in all species of Hyalinobatrachium , including those sympatric or from surrounding areas, i.e. H. aureoguttatum , H. chirripoi (Taylor) , H. fleischmanni , and H. valerioi (Dunn) . Based on these observations, we place the name Cochranella petersi Goin, 1961 as a junior synonym of Cochranella pulverata ( Peters, 1873) . Below, we provide a synonymy, diagnosis, and characterization of Cochranella pulverata .

Figures

FIGURE 1. Photographs of preserved specimens of Cochranella pulverata. (A, B) Holotype of Cochranella petersi, BM 1902.5.27.24; (C) dorsal view of KU 116493.