A Key to the Tadpoles of North Carolina 

 Joseph Travis 1 



Department of Zoology, 

 Duke University, Durham, North Carolina 27706 



ABSTRACT.— A dichotomous key for identifying the tadpoles of 

 North Carolina and a guide for their field identification with a hand 

 lens are offered. Problems in identifying tadpoles are discussed. The 

 key should be useful throughout the southeastern United States, 

 because it treats most of the species present in this area. 



INTRODUCTION 



Although anuran larvae are excellent subjects for various types of 

 field and laboratory research, the difficulty of correctly identifying tad- 

 poles is well known. Early keys were either difficult to use (e.g., Wright 

 and Wright 1949) or restricted in taxonomic (e.g., Orton 1952) or geo- 

 graphic (e.g., Smith 1934) coverage. Altig (1970) provided a key to all of 

 the tadpoles found in the continental United States and Canada, and 

 proposed a standard terminology for use in identifying tadpoles. Later 

 references to Altig will be to this 1970 paper. A complete key to variable 

 animals such as anuran larvae can prove difficult to use. Geographic 

 variation can produce ambiguities in identification, and characters that 

 may be diagnostical at a local level may prove impossible to integrate 

 into a more thorough treatment. 



North Carolina, with 30 species of anurans (Martof et al. 1980), 

 provides an excellent situation for the development of a more restricted 

 key. The extensive phenotypic variability seen in some species, such as 

 Hyla crucifer and Rana clamitans, often precludes the effective use of 

 Altig's key in the state. A North Carolina key should also be useful in 

 the southeastern United States, because it includes most of the species 

 found in this area. 



My local key was constructed from Altig's and others in the litera- 

 ture, specimens collected by me and others during my four years in 

 North Carolina, and laboratory rearings of unidentified tadpoles. Some 

 key characters used by other workers subsequently proved unreliable 

 and have been deleted. I examined many specimens of 27 of the 30 

 North Carolina species, including living individuals. Pseudacris brim- 

 leyi, P. brachyphona, and Rana heckscheri were not personally exam- 

 ined. Hyla versicolor was obtained from Giles County, Virginia, and 

 specific identity was verified by karyotype analysis. The occurrence of 

 H. versicolor in North Carolina remains problematic (Martof et al. 

 1980). 



Present address: Department of Biological Science, Florida State University, 

 Tallahassee, Florida 32306 



Brimleyana No. 6: 1 19-127. December 1981. 119 



