Description of the Tadpoles of Hyla giesleri and Hyla microps from Southeastern Brazil

Abstract

-The previously unknown tadpole of H. giesleri is described and illustrated based on two populations from Southeastern Brazil, one from Rio de Janeiro State and the other from Espirito Santo State. The tadpole of H. microps is redescribed and illustrated from Rio de Janeiro State and compared with that of H. giesleri. The mean length of tadpoles of H. giesleri in stage 33 varies from 17.9 (Rio de Janeiro State) to 22.5 mm (Espirito Santo State). The mean length in H. microps is 16.9 mm. Tadpoles of H. giesleri have the terminal portion of tail orange (red in H. microps). These species can also be distinguished by other details of their color patterns. Remarkable differences of size and color were found between the two studied populations of H. giesleri. The Hyla parviceps group was defined by Duellman and Crump (1974) and modified slightly by Duellman and Trueb (1989). Wild (1992), following the conventional grouping, provided detailed larval characters for this group. The small hylid frogs of the Hyla parviceps group occur mainly in the Amazon Basin and northern South America (Duellman and Crump, 1974). The only exceptions are Hyla microps Peters, 1872 and H. giesleri Mertens, 1950, which occur in southeastern and southern Brazil. These species were originally described from Rio de Janeiro State. Weygoldt and Peixoto (1987) described H. ruschii from Espirito Santo State, suggesting that it could also be a member of the Hyla parviceps group. Hyla microps and H. giesleri were long considered as synonymous due to the great morphological similarity of their adults (Cochran, 1955; Bokermann, 1966; Lutz, 1973; Duellman and Crump, 1974). Heyer (1980) revalidated H. giesleri based on differences found in the mating call and color pattern of subocular region. Bokermann (1963) briefly described the tadpole of H. microps from material collected in Sao Paulo State. Heyer et al. (1990) also described the tadpole of H. microps from Sao Paulo State. Herein, we describe and compare the tadpoles of H. giesleri and H. microps. The description of the former species was based on two distinct populations. MATERIAL AND METHODS All specimens examined in this study belong to the Collection of Departamento de Zoologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro (ZUFRJ). We collected adults and tadpoles of H. giesleri (ZUFRJ 2324, 928) from two populations (Fig. 1), one in Rio de Janeiro State (Municipio de Mage, 22?39'S; 43002'W) and the other in Espirito Santo State (Municipio de Linhares, 19?23'S; 40?04'W). The tadpoles from Rio de Janeiro were obtained from eggs collected in March 1984 and raised in captivity. Those tadpoles from Espirito Santo State were collected in January 1980. The tadpoles of H. microps (ZUFRJ 4145, 4390, 4391) were collected from a single population in Rio de Janeiro State (Municipio de Teresopolis, 22?24'S; 42?57'W) (Fig. 1). The tadpoles ZUFRJ 4145 were obtained from eggs (ZUFRJ 4011) collected in September 1989, the others were collected in February and March 1991. Tadpoles were anesthetized in 0.1% chloretone and stored in 5% formalin. Adults were anesthetized in 0.25% chloretone, preserved in 10% formalin, and stored in 70% alcohol. Some couples collected in amplexus were kept alive to obtain eggs. Tadpoles that emerged from these eggs were reared until the stages desired for study. Tadpoles collected in the field were identified by means of comparisons with those obtained from eggs or reared until metamorphosis and then compared with determined adults. Tadpoles were reared in captivity in aquariums (measurements: 60 x 30 x 30 cm) with slightly acid water and a dense layer of leaves on the bottom. About 20 tadpoles were maintained per aquarium. Fish food was provided regularly. The water temperature was not controlled. Tadpoles in stage 33 (Gosner, 1960) were used in the descriptions and measurements. Measurements were taken according to the methods of Altig (1970) and Duellman (1970), except for interorbital distance, which was taken between This content downloaded from 157.55.39.149 on Sat, 09 Jul 2016 04:57:02 UTC All use subject to http://about.jstor.org/terms