GRUBER and COMPAC.NO: TAXONOMIC STATUS AND BIOLOC.Y OK BICKYE THRESHER 



Figure 4. — Dorsal view of the head of a 356 cm TL male Alopias superciliosus (SHG-A7 ) showing the head grooves and upward looking 



eyes. (The lens of the right eye has been removed.) Photo: S. Spielman. 



STATUS OF ALOPIAS PROFUNDUS 



Nakamura (1935) described two new species of 

 thresher sharks, A. profundus and A. pelagicus, 

 from Taiwan. The thresher sharks were collected 

 at a fish market and capture data were unavail- 

 able. Nakamura thought that one of these species 

 lived near the sea bottom and so named it 

 A. profundus. He was evidently unaware of Lowe's 

 account of A . superciliosus, and only compared his 

 new species with each other. Nakamura concluded 

 that there was insufficient evidence in the litera- 

 ture to determine if either of his two species was 

 equivalent to the wide-ranging 'Alopias vulpes" 

 (= A. vulpinus), and gave this reason as justifi- 

 cation in naming A. profundus and A . pelagicus . 



Fowler (1941) listed both Nakamura's species 

 as questionable synonyms of A. vulpinus but 

 Bigelow and Schroeder (1948) recognized them as 

 distinct. They noted that Alopias can be divided 

 into two groups, one including A. profundus and 

 A. superciliosus , both with the free rear tip of the 



first dorsal fin extending to over the pelvic origins 

 and with huge eyes; and the other including 

 A. vulpinus, A. pelagicus, and the dubious 

 A. caudatus, having the first dorsal rear tip well 

 anterior to the pelvic origins and with smaller 

 eyes. Using Nakamura's (1935) account as a 

 source for A. profundus, Bigelow and Schroeder 

 (1948) distinguished the two species in the "big- 

 eye" group as follows: 



1) "Rear tip of 2nd dorsal terminates consider- 

 ably anterior to origin of anal; pelvics a little 

 higher vertically than 1st dorsal and a little 

 larger in area; anterior margin of 1st dorsal 

 strongly convex; no lower precaudal pit." Alopias 

 superciliosus. 



2) "Rear tip of 2nd dorsal terminating over base 

 of anal; pelvics less than 1/2 as high vertically as 

 1st dorsal and much smaller in area; anterior 

 margin of 1st dorsal only very weakly convex; a 

 precaudal pit below as well as above." Alopias 

 profundus. 



Several writers, following Bigelow and Schroed- 



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