New data on Gaidropsarus granti (Regan, 1903) (Gadiformes: Lotidae) from the Mediterranean Sea, with emphasis on its parasites

Abstract

One adult male Azores rockling Gaidropsarus granti was captured by trammel nets at a depth of about 250 m near the coast of Arbatax (Sardinia, Italy) in early March 2007. This new report confirms a wide bathymetric range for this species. Macroscopic and microscopic analysis of the gonad showed a spent testis at a postspawning stage, with a weak residual spermatogenetic activity. Several body parts of Natantia (Crustacea: Decapoda) were detected in its stomach contents. Different developmental stages of 91 parasite specimens belonging to Arthropoda (Gnathiidae) and Nematoda (Anisakidae, Cystidicolidae and Philometridae) were found in its mouth and gills, and body cavity, respectively. Myxozoan spores were found in the gallbladder. Male and female nematodes of the genus Ichthyofilaria are reported for the first time from the Mediterranean Sea, and a very rare male of this genus is reported for the second time in the world. Parasitological results indicated that this Atlantic migrant probably entered the Mediterranean as an adult, suggesting for a non-indigenous species the possibilities of entering with natural parasites and/or acquiring native parasites in the introduced range.

Keywords

• gaidropsarus granti
• lotidae
• atlantic migrant
• mediterranean sea
• parasites
• non-indigenous species