The tadpole of Pleurodema nebulosum Burmeister (Anura: Leiuperidae)

Abstract

The genus Pleurodema Tschudi currently contains fourteen species, ten of them occurring in Argentina (Faivovich et al. 2012). However, Pleurodema nebulosum presents a wide altitudinal and latitudinal geographic range and is only distributed in arid areas of western Argentina, from Catamarca to Río Negro province (Ferraro & Casagranda 2009, Frost 2011). The external morphology was described for the tadpoles of most species of Pleurodema, but the external larval morphology of P. nebulosum was only briefly described by Fernández (1927) and Cei (1980). The aim of this work is to provide a detailed redescription of the external larval features of Pleurodema nebulosum. The tadpoles were collected in February 2010 from temporary ponds in Sarmiento department, San Juan province (31.9143S; 68.4934W; altitude: 580 m). The tadpoles were anesthetized after capture and immediately fixed in 10 % buffered formalin. The description was based on 10 specimens at stage 37 of development (Limbaugh and Volpe 1957, as modified by Gosner 1960), some tadpoles were reared until metamorphosis was complete for species identification. We recorded 17 morphometrical variables: Total length (TL), Body length (BL), Tail length (TAL), Maximum body height (MBH), Maximum tail height (MTH), Tail muscle height (TMH), Dorsal fin height (DFH), Ventral fin height (VFH), Maximum body width (MBW), Body width at nares (BWN), Tail muscle width (TMW), Eye diameter (E), Interorbital distance (IOD), Internarial distance (IND), Eye-nares distance (END), Snout-narial distance (SND) and Oral disc width (ODW). Measurements were taken under a stereomicroscope with digital caliper (0.01 mm precision). Terminology and measurements followed Lavilla and Scrocchi (1986), Altig and McDiarmid (1999) and Grenat et al. (2009). The specimens were deposited in the herpetological collection of Fundación Miguel Lillo (FML 24837), Tucumán, Argentina. The morphological measurements are in millimeters (mm) and are presented as mean ± standard error and [minimum – maximum].