NOTES 



INTERSEX ANOMALIES IN SHRIMP OF THE 

 GENUS PliSAHOPSIS (CRUSTACEA: PENAEIDAE) 



While examining a relatively large collection of 

 Penaeopsis (40 lots containing 196 specimens) 

 taken by the U.S. steamer Albatross during the 

 Philippine Expedition. 1907-10, I found three 

 specimens having external characteristics of both 

 males and females. Each specimen had a fully 

 developed thelycum, a moderately well-developed 

 petasma (about two-thirds the length of the 

 petasma of males of corresponding sizei, small ap- 

 pendices masculinae. and genital apertures on the 

 coxae of the fifth pair of pereopods. The shrimps 

 were poorly preserved — the exoskeletons were 

 soft, rostrums and telsons broken, and internal 

 organs macerated; however, most of the features of 

 the carapace were clearly distinct and the external 

 genitalia intact. 



The discovery of these shrimp elicits several 

 questions: to which species do they belong? What 

 is their functional sex? Do they represent a transi- 

 tional stage in a protandrous hermaphroditic 

 species? If not, have their intersex-appearing 

 anomalies resulted from parasitism? Although 

 none of these questions is answered definitively, 

 all are discussed following a brief description of 

 the external genitalia of the shrimp. 



The specimens are deposited at the National 

 Museum of Natural History: USNM 170581. 23 

 mm cl (carapace length), Bohol Strait, between 

 Bohol and Cebu, 291 m, 25 March 1909, Albatross 

 stn 5418. USNM 170582. 24.5 mm cl, Bohol Strait, 

 320 m, 25 March 1909, Albatross stn 5419. USNM 

 170583, 19 mm cl. Gulf of Davao, SE Mindanao, 

 247 m, 18 May 1908, Albatross stn 5247. 



Description 



Petasma (Figure IB-C) with length about two- 

 thirds that of petasma of males off*, rectaciita of 

 comparable size, and twice as long as endopod of 

 first pair of pleopods in females of P. rectaciita 

 (Figure 1 A) and all other congeners. Dorsomedian 

 lobule with distinct distomedian projection and 

 well-formed proximal plate. Dorsolateral lobule 

 with supporting rib (in two of three specimens) 

 ending proximally in subelliptical process. Ven- 

 tral costa tapering distally, forming free, inwardly 



excavate, blunt projection directed dorsomesially 

 at broadly obtuse angle with shaft of petasma. 



FIGURE 1.— A, Penaeopsis rectacuta, USNM 170586, 9 23.5 mm 

 cl (carapace length), off Palompon. Leyte, Philippines, endopod 

 of left first pereopod, dorsal view. B, Penaeopsis sp. USNM 

 170582, 24.5 mm cl, Bohol Strait, Philippines, Albatross stn 

 5419, petasma, dorsal view of left half. C, Ventral view of same. 

 D. Left appendix masculina, dorsal view, same specimen. E, 

 Penaeopsis rectaciita, USNM 170587, 6 13 mm cl, off Mindanao, 

 Philippines, A /6a?ross stn 5518, petasma, dorsal view of left half 

 F, Ventral view of same. G, Right appendix masculina, dorsal 

 view, same specimen. 0.5 mm indicated. 



687 



