First record of parasites ofDosidicus gigas (d’ Orbigny, 1835) (Cephalopoda: Ommastrephidae) from the Humboldt Current system off Chile

The parasitic fauna of 124 jumbo squids (Dosidicus gigas) caught from oceanic and coastal waters off Central Chile (32ºS-40ºS) was described and quantified. The 97% of the squids harboured at least one parasitic taxon. Prevalence of infection and abundance were established for each parasite species. Each parasitic taxon was described based on light microscopy and scanning electron microscopy images. The parasitic fauna was composed of larval cestodes:Hepatoxylon trichiuri (Abundance: 2.6; Prevalence: 70.2%), Tentacularia coryphaenae (Abundance: 0.1; Prevalence: 5.6%), a Tetraphyllidean plerocercoid (Abundance: 9.1; Prevalence: 83.1%), Pelichnibothrium speciosum and the nematodes Anisakis Type I (Abundance: 0.06; Prevalence: 6.5%) and Anisakis Type II (Abundance: 0.52; Prevalence: 17.7%). Around nine taxa have been reported in D. gigas smaller than 40 cm mantle length, five of them were found in this study (Tetraphyllidean plerocercoid, Tentacularia coryphaenae, Pelichnibothrium speciosum, and Anisakis Type I and II), however, in bigger squids. The parasite H. trichiuri is a new record for D. gigas in these latitudes of the South Pacific, comprising the southern limit of its distribution range. The Tetraphyllidea plerocercoid could correspond toPhyllobothrium based on the shape and tissues of its apical organ, which is very similar to the accesory suckers. The nematodes Anisakis Type I and II can only be distinguished by the tail shape and presenceabsence of a mucron. It is suggested to carry out molecular analysis for diagnosis of larval stages when morphological characters are lacking.