Infestation of luderick (Girella tricuspidata) populations with parasitic isopods

Abstract

Observations were made on the infestation of luderick (G. tuicuspidata) populations with the parasitic isopods Codonophilus and Irona. Luderick samples obtained from different estuarine localities showed infestation rates varying from 0 to about 50%. The parasites live in the opercular and buccal cavities of the fish, causing only minor damage to the gills and no obvious damage to the buccal region. However, biometrical evidence indicates that the condition of the fish carrying two parasites is worse than that of those infested with only one parasite. The condition of the fish in the latter category is only marginally different from that of the non-infested luderick.