Fishes of the JVestern North Atlantic 



479 



Color. Specimens preserved in alcohol are brown above, brownish white below, 

 darker towards the tips of the pectorals. 



Size and Development. The state of development of specimens 435-488 mm wide 

 in our Study Material (p. 477) suggests a breadth of about 450-500 mm at birth, which 

 is approximately the same as for R. bonasus. The largest specimens reported have been 

 890 (one)55 and about 910 mm (one) wide.^* But no information is available as to the 

 size at sexual maturity or as to the maximum to which R. brasiliensis may grow. 



Figure 109. Rhinoptera brasiliensis, upper teeth (above) 

 with front row uppermost, and lower teeth (below) with 

 front row lowermost, from head of a specimen about 910 

 mm wide (estimated), from Rio da Janeiro, Brazil (Harv. 

 Mus. Comp. Zool., No. 534), about 0.4 x. 



Habits. Nothing whatever is known of the habits of this Ray. 



Range. In the western Atlantic, all reported captures of Cow-nosed Rays with nine 

 or more series of teeth in one jaw or in both, hence referable to R. brasiliensis^ have been 

 from Santos, Rio Grande do Sul, and Rio de Janeiro, Brazil, except for a single specimen 

 from Beaufort, North Carolina, which had nine series above and eight below. With no 

 more than this to go on, it seems likely that this last specimen was actually an aberrant 

 R. bonasus and that the range of the multidentate species R. brasiliensis is normally 

 restricted to the South American Coast in the southern hemisphere. 



Synonyms and References: 



Rhinoptera brasiliensis Miiller, Vergl. Anat. Myxinoiden, 1835: 276, pi. 9, fig. 12 (ill. skel. of head); Miiller 



and Henle, Plagiost., 1841 : 182 (descr., meas., Brazil); Dumeril, Hist. Nat. Poiss., J, 1865: 646 (descr., 



size, Brazil). 

 Rhinoptera jussieui Giinther, Cat. Fish. Brit. Mus., 8, 1870: 493 (descr., Brazil specimen); Woodward, Ann. 



55. Dumeril, Hist. Nat. Poiss., j, 1865: 646. 



56. Breadth as calculated from breadth between spiracles of detached head; see Study Material, p. 477. 



