NO. 3570 PANDARIDAE — CRESSET 37 



185) located on midlateral edge of genital segment and consisting of a 

 group of 3 setae and 1 stout spine. All setae naked, spine finely- 

 barbed. Leg 6 (fig. 186) located near junction of abdomen and genital 

 segment and consisting of a single naked seta and a finely barbed 

 stout spine. 



Color in life cream white, no pigment. 



Remarks. — To date, 7 species of Perissopus have been described. 

 I have examined material of this genus from several hosts and noted 

 wide variation in body form. A closer examination of the append- 

 ages showed no differences between one form and another. Un- 

 fortunately, I had only a few specimens of each type available. Figure 

 187 shows an adult female from Carcharinus leucas, Sarasota, Fla. 

 Its measurements are 4.4 by 2.2 mm. Figure 188 is an adult female 

 from Carcharinus maculipinnis, Sarasota, Fla. (3.9 by 2.4 mm). 

 Figure 189 is an adult female from the Siboga Expedition to the Indo- 

 Pacific, host recorded only as a "shark." It measures 3.8 by 2.2 mm. 

 A cursory examination of these would indicate more than one species, 

 but I must, on the basis of the few specimens available, concur with 

 Capart (1953), who noticed this same variation and concluded that 

 they should be treated as 1 species. 



More material from these and other hosts may favor splitting the 

 genus into a number of species but, in the face of so small a sample, I 

 do not feel justified in doing this at the moment. One would expect 

 to find at least minor differences in the finer details if they are indeed 

 separate species. None seem to exist. I have thus placed all known 

 species in synonymy as Perissopus dentatus. Apparently Heegaard 

 (1962) did not know of the new species of Gnanamuthu or Kurian 

 when he described Perissopus serratus. 



Perissopus dentatus seems to be a parasite of inshore species of 

 sharks. The copepod is often found externally attached near the 

 nares and less often near the posterior border of the fins. It is the 

 only pandarid that attaches to its host by the use of cement. As 

 pointed out above, the maxilliped of the female bears a very large pad 

 that, upon removal of the copepod from the host, often shows denticles 

 or the impression of denticles adhering to the surface of this pad. 

 This adaption may be due to the rather hazardous area of attachment 

 on the host (nose). Undoubtedly the nose of the host is often bumped, 

 thus requiring an effective hold-fast structure if the parasite is to 

 remain on the host. 



The male is described here for the fh'st time. It was attached to a 

 female when found. 



