Grouping behaviour impacts on the parasitic pressure and squamation of sharks.

The evolution of grouping behaviour involves a complex trade-off of benefits and costs. Among the latter, an increase in the risk of parasitic transmission is a well-documented phenomenon that has likely promoted the evolution of defensive mechanisms in aquatic vertebrates. Here, we explore the relationship between grouping behaviour, parasitic richness (∼parasitic pressure), and the evolution of potential defensive traits in the squamation of sharks through phylogenetic, standard and zero-inflation regression models.

A severe microsporidian disease in cultured Atlantic Bluefin Tuna (Thunnus thynnus).

One of the most promising aquaculture species is the Atlantic bluefin tuna (Thunnus thynnus) with high market value; disease control is crucial to prevent and reduce mortality and monetary losses. Microsporidia (Fungi) are a potential source of damage to bluefin tuna aquaculture. A new microsporidian species is described from farmed bluefin tunas from the Spanish Mediterranean.

Cardicola mediterraneus n. sp. (Trematoda, Aporocotylidae): a new species infecting the gilthead seabream, Sparus aurata L., from the Western Mediterranean Sea.

The genus Cardicola Short, 1953 has the highest number of species within the family Aporocotylidae (Trematoda: Digenea). Five Cardicola species have been reported to date in the Mediterranean Sea, one of them in the gilthead seabream Sparus aurata L. Analyses of infected S.

Skoulekia erythrini n. sp. (Digenea: Aporocotylidae): a parasite of Pagellus erythrinus (L.) (Perciformes: Sparidae) from the western Mediterranean with an amendment of the generic diagnosis.

A new aporocotylid, Skoulekia erythrini n. sp., is described from the heart, cephalic kidney and gill blood vessels of the common pandora Pagellus erythrinus (L.

Accacoelium contortum (Trematoda: Accacoeliidae) a trematode living as a monogenean: morphological and pathological implications.

Background: Accacoelium contortum (Rudolphi, 1819) Monticelli, 1893 is a frequent but poorly known trematode found on gills, pharynx and digestive tract of the ocean sunfish Mola mola (L.). Although the morphology of A.

Morphological characterisation and identification of four species of Cardicola Short, 1953 (Trematoda: Aporocotylidae) infecting the Atlantic bluefin tuna Thunnus thynnus (L.) in the Mediterranean Sea.

Blood flukes of the genus Cardicola Short, 1953 are considered the most potentially pathogenic parasites in bluefin tuna cultures. Morphological study and genetic analyses of the ribosomal internal transcribed spacer ITS-2 and the mitochondrial cytochrome c oxidase 1 (cox1) gene fragments revealed the occurrence of four aporocotylid species (C. forsteri Cribb, Daintith & Munday, 2000, C.