Three new species of temporary fish parasite, Gnathiid Isopods (Crustacea: Isopoda: Cymothoida) from Kuwait.

Gnathiid isopods (Crustacea) were collected between 2014 and 2022 from various sites in shallow waters of the Kuwait coasts. Three new species of gnathiids are described: Caecognathia alsalmiyah sp. nov. is characterised by the well-extended, distally pointed with three cusps supraocular lobe and the presence of pylopod with four articles; Elaphognathia alshumaimah sp. nov. is distinguished from its congeners by having an elongated, distally curved mandible, with a single pronounced conical internal lobe; Gnathia kuwaitensis sp. nov. is easily distinguished from the other species of the genus Gnathia by the conical mediofrontal process, which is slightly sunken and having pronounced superior frontolateral process, with median notch distally.

Diversity and distribution of the Isopoda (Crustacea, Peracarida) of Kuwait, with an updated checklist.

Thirty-eight species of Isopoda, belonging to 13 families and 29 genera, are listed from Kuwait based on previous literature records (of 17 species) and collections carried out along Kuwait's coastal and subtidal zones during the present study. The majority of species belongs to the suborder Cymothoida (23), followed by Sphaeromatidea (9), Oniscidea (3), Valvifera (2), and Asellota (1). In total, 25 species were collected and identified from 12 families and 22 genera from Kuwaiti coastal and subtidal areas. These include eight families, 15 genera, and 21 species recorded for the first time from Kuwait. Isopod diversity was highest in the sandy rock areas, including southern Kuwait, particularly in Al-Khiran and Al-Nuwaiseeb, and in mixed habitat (muddy, rocky, and sandy) intertidal transects such as in Failaka Island. The species number increased from the subtidal and lowest zones into the high tidal zone. Isopods were found in sandy substrata, among shells, cobbles, rocks, dead corals, and algae.