Helminth infection in the short-finned squid Illex coindetii (Cephalopoda, Ommastrephidae) off NW Spain

Abstract

A survey of parasites in 600 short-finned squid Illex coindetii (Verany. 1839) taken from 2 locations (north and south Galicia) off the northwestern Iberian Peninsula revealed the presence of numerous somatoxenous helminths. Three genera of Tetraphyllidean plerocercoids were represented (prevalences: Phyllobothrium sp., 45.7%; Dinobothrium sp., 0.8%; and Pelichnibothrium speciosum, 0.001 %); 1 Trypanorhynchidean metacestode was also present (Nybelinia yamagutii. 0.4 %). In addition, larval nematodes of Anisakis simplex (L3) were recorded (10.6%). Abundance of infection was examined in relation to squid sex, standard length, maturity and locality. This analysis indicated that parasite infection was lower in the southern squids than in the northern squid group. Over the entire survey area, parasite infection showed a close positive correlation with host life-cycle, often with the greatest number of parasites among the largest and highest maturity individuals (>l8 to 20 cm; maturity stage V)