184 



Fishery Bulletin 101(1 



55 



50 



45 - 



^ (iidl or M. I^%«reiH-e 



• luhut Stniil 



"^ Latirt'iititin ( luutm-l (\tai)iuf ri 



I l.aun'ntiaii <. luinm-t ( \s iitftrl 



A Hiniivh Clip 



Souttm cslern Lnbrador Sea 



Quebec 



Figure 1 



Map of redfish [Sehastes mentella) collection sites (various symbols) in the northwestern Atlantic 

 Ocean in 1996 and 1997. The eight areas currently used for redfish management are delineated: 1) 

 subarea 2 and division 3K (southwestern Labrador Sea). 2) divisions 3LN (northern and western 

 Grand Banks I: 3) division 3M (Flemish Cap); 4) division 30 (southwestern Grand Banks); 5) unit 

 1 (Gulf of St. Lawrence); 6) unit 2 (Laurentian Channel); 7) unit 3 (Scotian Shelf); and 8) the Gulf 

 of Maine. The hatched area (Cabot Strait) is part of unit 1 from January to May and unit 2 from 

 June to December. Numbers near collection sites represent set numbers. Jagged line indicates the 

 200-m depth contour. 



separated, and then examined individually. The stomach, 

 pyloric ceaca, and intestine were separated, opened lon- 

 gitudinally, and their contents rinsed into beakers where 

 they were mixed with sodium bicarbonate and allowed to 

 settle to remove endoparasitic helminths. The wall of the 

 stomach, pyloric ceaca, and intestine, and the liver, spleen, 

 kidney, and heart were compressed between glass plates 

 and examined for parasites. The body musculature was 

 removed from the vertebral column, the skin was removed 

 from the fillets, and flaps were thinly sliced and all were 

 inspected for helminths and dead neck stalks or sores 

 caused by old infestations by Sphynon lumpi. 



All parasites were sorted into major laxonomic groups, 

 cleaned, and counted for each organ. Nematoda and Co- 

 pepoda were identified fresh to the lowest taxon and then 

 fixed in lQ'/< ethanol with lO'J glycerin. Old ce[)haloth()- 

 races and .sores caused by Spliynon lumpi were identified 

 and counted. Digenea and Cestoda were fixed in alcohol- 

 formalin-acetic acid ( AFA) and stained in acetocnrmine for 

 later identification. 



Statistical analyses 



Results of analyses may be influenced by variations in 

 factors such as size and sex. In our study, there were no 

 significant differences in mean size of fish sampled from 

 the various regions (Table 1). Males were smaller than 

 females from all regions, except those from the Labrador 

 Sea, where the size difference was reversed. However, 

 none of the parasites retained for multiple parametric 

 analyses differed between the sexes (ANOVA, P>0.05). 



Because parasite counts for all areas were not normally 

 distributed and normality could not be reached by using 

 various transformations, multiple nonparametric analy- 

 ses (SAS version 8.0. SAS Institute, Inc., 1999) were used 

 to investigate the usefulness of parasites in discriminat- 

 ing host collections. All parasites used in this analysis 

 were relatively long lived and thus accumulated with host 

 age (length). However, the relationship between size and 

 intensity of certain parasites (Ariisakis simplex) was not 

 linear, thus rendering covariant analyses inappropriate. 



