Clarke et al Prevalence of the nematode Philometra saltatrix in the ovaries of Pomatomus saltan i 



119 



Long Island, NY 



41N 



'05 -^t, iO -"6 ts' -"5 50 "5" 25" 



Outer Banks, NC 



'^^'T^^/ Cape 



Hatteras 



-Tros -Tew -Te' 15' -75' sc -sas' 



Figure 1 



Map of the sampling area, Long Island, New York, and Outer Banks, North Carolina, where adult 

 bluefish iPomatomus xaltatrix) were collected from commercial gill-netters, trawlers, and seafood 

 markets in 2002-03 for examination of infestation bv the nematode Philometra saltatrix. 



potential and early life history success of bluefish is 

 unknown. No information other than location of oc- 

 currence (Ramachandran, 1973) and a brief abstract 

 describing the presence of philometrids in the heart 

 of juvenile bluefish is available (Cheung et al.M. The 

 purpose of this study is to investigate the prevalence, 

 intensity, and effect of Philometra saltatrix in the ova- 

 ries of bluefish. 



Materials and methods 



Adult bluefish were collected from commercial gill-net- 

 ters, trawlers, and seafood markets on Long Island, 

 NY, and the Outer Banks, NC (Fig. 1). In NY, fish were 

 caught off the southern coast of Long Island from Shin- 

 necock Inlet to Montauk Point, approximately 1-15 km 

 offshore. In NC, fish were caught approximately 1-40 

 km off the coast, and the majority of fish were caught 

 30-40 km east of Oregon Inlet. 



Cheung, P. J., R. F. Nigrelli, and G. D. Ruggieri. 1984. Philo- 

 metra saltatrix infecting the heart of the 0-class bluefish. 

 Pomatomus saltatrix (L.), from the New York coast. In S. F. 

 Snieszko commemoration fish disease workshop, p. 27. Joint 

 Workshop of Fish Health Section, AFS, and Midwest Disease 

 Group, Little Rock, AR. 



Sampling dates were determined by the availability 

 of fish through the local fishermen. In 2002, bluefish 

 were sampled from mid-July through early October 

 off the southern coast of Long Island, NY (80 females, 

 108 males). In 2003, fish were collected in NC in April 

 (43 females, 21 males) and in NY from the end of June 

 through September (123 females, 42 males). 



Fork length (FL), fish weight, gonad weight, preva- 

 lence of both live and dead worms, total worm weight, 

 and gonadosomatic indices (GSI) were recorded for each 

 fish. Worms were often intertwined making it difficult 

 to count the number of worms in each ovary; therefore, 

 total worm weight per ovary was used as a proxy for in- 

 tensity. Representative samples were fixed in a solution 

 of 95% glacial acid and 5% formalin for identification. 

 Initially, examinations of both male and female fish 

 were conducted, but after preliminary evidence showed 

 that nematodes were not present in the gonads of male 

 fish, future examinations were restricted to female fish. 



Haphazardly selected ovaries were preserved in 10% 

 formalin and processed according to standard histo- 

 logical methods (Luna, 1968) to investigate pathologies 

 associated with the parasite. Transverse sections were 

 cut from the same region in the center of each ovary. 

 These were examined under a light microscope and 

 images were captured with a Spot Insight digital CCD 

 and processed with ImagePro Plus software (Media 

 Cybernetics, Silver Spring, MD). 



