Redescription of Naobranchia variabilis Brian, 1924 (Siphonostomatoida: Lernaeopodidae), parasitic on the grey triggerfish Balistes capriscus Gmelin in Algerian coastal waters.

Adults of both sexes of Naobranchia variabilis Brian, 1924 (Lernaeopodidae) are described based on material collected from the gill filaments of Balistes capriscus Gmelin, caught off the coast of Algeria. This is the second species of Naobranchia Hesse, 1863 to be found in the Mediterranean and the host record is new. Morphological comparisons are made with existing descriptions of N. variabilis and it is inferred, from small variations between material from different hosts and different localities, that N. variabilis may represent a species complex. The corrugated lobes on the head of Naobranchia females are interpreted as novel structures involved with temporary attachment during feeding.

A new species of Prohatschekia Nunes-Ruivo, 1954 (Copepoda: Hatschekiidae) parasitic on Scorpaena elongata (Cadenat) off Algeria.

A new species of parasitic copepod, Prohatschekia mediterranea n. sp. (Siphonostomatoida: Hatschekiidae), is described from a scorpaenid fish, Scorpaena elongata, collected off Algeria. This is the seventh species of Prohatschekia Nunes-Ruivo, 1954 to be described and the first record of the genus from the Mediterranean Sea. The new species is most closely related to P. cremouxi Nunes-Ruivo, 1954, known from a congeneric host collected in Senegal. A key is provided to distinguish the new species from other members of the genus.