The Infection Parameters of Two Onchoproteocephalidean Species in Two Shark Species from the Persian Gulf

Parasite assemblages are highly complex and dynamic systems, some of which are very host specific. Of those, the cestode order Onchoproteocephalidea has a subset of elasmobranch-hosted hook-bearing genera, one of which is the genus Phoreiobothrium Linton, ۱۸۸۹ and its members infect the two families in the shark order Carcharhiniformes. Recently, some studies have focused on the faunistic situation of this genus in the Persian Gulf and the present study, in the same direction, evaluates the infection of two shark species with the species of Phoreiobothrium .As a part of a stock assessment project conducted by the Iranian Fisheries Science Research Institute during November–December ۲۰۰۷, ۳۵ specimens of Carcharhinus dussumieri and ۲۲ specimens of Rhizoprionodon oligolinx were collected on board the research vessel Ferdous I from the coast of Hormozgan province. Each of the spiral intestines was removed, fixed in ۱۰% buffered formalin and then all worms were transferred to ۷۰% ethanol for storage .The specimens were stained according to the acetic carmine method .From each host species, one undescribed species of Phoreiobothrium was isolated namely Phoreiobothrium sp.۱ from C. dussumieri and Phoreiobothrium sp.۲ from R. oligolinx .The prevalence, intensity, mean abundance, and mean intensity of Phoreiobothrium sp.۱ were respectively ۸.۶%, ۱-۴, ۰.۲±۰.۸ and ۲.۳±۱.۵ in C. dussumieri and likewise these indices were respectively ۴.۵%, ۶۸, ۳.۱±۱۴.۵ and ۶۸ for Phoreiobothrium sp.۲ in R. oligolinx. The differences in infection parameters between the two shark species likely reflect the variations in foraging strategies and availability of intermediate hosts.

کلیدواژه ها:

parasite ، host ، Phoreiobothrium ، Carcharhinus dussumieri ، Rhizoprionodon oligolinx