The hidden companion of non‐native fishes in north‐east Atlantic waters

Abstract

A tropicalization phenomenon of ichthyofauna has been described in the last decades in Galicia (north‐eastern Atlantic), with increasing reports of tropical and subtropical fishes appearing northward this distribution range. A search for parasites was carried out in the digestive tract of two specimens first captured in Galician waters: the prickly puffer Ephippion guttifer (Tetraodontidae) and the African stripped grunt Parapristipoma octolineatum (Haemulidae). Examination of E. guttifer showed high intensity of nematodes, from three different genera: Cucullanus (Cucullanidae), Hysterothylacium (Raphidascaridae) and Anisakis (Anisakidae), with demonstrated pathogenicity to humans. Molecular identification allowed the identification of Anisakis pegreffii, already described in the area, and first reports for European waters of Cucullanus dodsworthi, Hysterothylacium reliquens and a new Hysterothylacium sp. P. octolineatum showed a far lower level of parasitization, with two Hysterothylacium larvae, genetically identified as Hysterothylacium deardorffoverstreetorum, also its first report in the eastern Atlantic. Thus, possible ecological impact of the occurrence of two non‐native individual fishes in a new area could be remarkably higher if we see this issue through the lens of the parasitological perspective, as far as only two individual fish can harbour more of one hundred nematode parasites belonging to different species, most of them also new species for that area.

Parasites of pufferfish, Lagocephalus spp. and Torquigener flavimaculosus of the Israeli Mediterranean: A new case of Lessepsian endoparasites

“…H. reliquens is reported globally ( Deardorff and Overstreet, 1981 ; Zhao et al, 2016 ), including the Mediterranean Sea ( El-Sayed et al, 2004 ; Simsek et al, 2018 ). Reported hosts include pufferfish in the Atlantic Ocean ( Rodríguez et al, 2019 ). Sequence analyses revealed high similarity (Query Cover 94–100% and identity 99.8–100%) with various vouchers from the Atlantic Ocean, Arabian Gulf and the Mediterranean Sea, confirming this nematode as globally distributed and not as a Lessepsian migrant species.…”