The cloning of cDNAs encoding facilitated urea transporters (UTs) from the kidneys of the elasmobranchs indicates that in these fish renal urea reabsorption occurs, at least in part, by passive processes. The previously described elasmobranch urea transporter clones from shark (shUT) and stingray (strUT-1) differ from each other primarily due to the c-terminus of the predicted strUT-1 translation product being extended by 51 amino acid residues compared to shUT. Previously, we noted multiple UT transcripts were present in stingray kidney. We hypothesized that a c-terminally abbreviated UT isoform, homologous to shUT, would also be present in stingray kidney. Therefore, we utilized 5'/3' RACE to identify a 3'UTR-variant (strUT-1a) of the cDNA that encodes (strUT-1) as well as three, 3'UTR-variant cDNAs (strUT-2a,b,c) that encode a second phloretin-sensitive, urea transporter (strUT-2). The 5'UTR and the first 1132 nucleotides of the predicted coding region of the strUT-2 cDNAs are identical to the strUT-1 cDNAs. The remainder of the coding region contains only 5 novel nucleotides. The strUT-2 cDNAs putatively encode a 379 amino acid protein, the first 377 amino acids identical to strUT-1 plus 2 additional amino acids. We conclude that 1) a second UT isoform is expressed in the Atlantic stingray and that this isoform is similar in size to the UT previously cloned from the kidney of the dogfish shark, and 2) at least 5 transcripts encoding the 2 stingray UTs are derived from a single gene product through alternative splicing and polyadenylation.