Proceedings of 
the United States 
National Museum 
SMITHSONIAN INSTITUTION +« WASHINGTON, D.C. 
Volume 125 1968 Number 3653 
Caligoid Copepods Parasitic on Isurus oxyrinchus 
With an Example of Habitat Shift 
By Roger F. Cressey 
Associate Curator, Division of Crustacea 
Several recent collections of parasitic copepods from 17 specimens 
of the mako shark, Jsurus oryrinchus, have made possible redescrip- 
tions of certain species of these parasites commonly found on this 
shark. These, plus 15 collections from the Indian and Atlantic Oceans 
previously reported (Cressey, 1967a and 1967b), form the basis of this 
paper. 
Ten species of caligoid copepods are reported herein. Both sexes of 
Nemesis lamna Risso and the males of Dinemoura producta (Miiller) 
and D. latifolia (Steenstrup and Liitken) are redescribed. The last 
copepodid instar and three chalimus stages of Phyllothereus cornutus 
(Milne-Edwards) males are described for the first time. The remaining 
species have been redescribed recently by various workers (Shiino, 
1955; Lewis, 1966; and Cressey, 1967a), and no further redescription of 
these species is considered necessary. 
All drawings have been made with the aid of a camera lucida. All 
specimens are preserved in 70 percent alcohol and deposited in the 
U.S. National Museum. 
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