Cardicola aurata sp. n. (Digenea: Sanguinicolidae) from Mediterranean Sparus aurata L. (Teleostei: Sparidae) and its unexpected phylogenetic relationship with Paradeontacylix McIntosh, 1934.

A new sanguinicolid trematode, Cardicola aurata sp. n., is described from gilthead seabream Sparus aurata L., from off the Spanish Mediterranean coast. The morphology of C. aurata sp. n. generally agrees with the diagnosis of the genus, however, in contrast to all other reported Cardicola spp. the male pore is located sub-medially at the posterior end of the body instead of sinistrally before the posterior end of the body. Based on a comparison of the morphology as well as partial 28S and ITS2 rDNA sequence data from the present species with that from closely related species, it was decided to emend the diagnosis of Cardicola rather than create a new genus, as the aberrant position of the male pore is likely to be an autapomorphy. The phylogenetic analyses revealed a close relationship between Cardicola and Paradeontacylix, two genera with considerable morphological differences; C. aurata sp. n. occupies a position intermediate to these genera. Thus, a morphological comparison of Cardicola, Paradeontacylix and Braya, a genus which is morphologically similar to Cardicola but clusters basal to the Cardicola/Paradeontacylix clade, was conducted. The results of this comparison showed that despite large differences with regard to body shape, the organisation of the internal organs is very similar in species of Cardicola and Paradeontacylix. The synopsis of morphological data and molecular phylogeny allows for interpretations regarding the importance of different morphological features for the phylogenetic inference of the Sanguinicolidae.

Changes in epizoic crustacean infestations during cetacean die-offs: the mass mortality of Mediterranean striped dolphins Stenella coeruleoalba revisited.

In the summer and autumn of 1990, a cetacean morbillivirus caused a massive epizootic mortality of striped dolphins Stenella coeruleoalba in the western Mediterranean. Previous circumstantial evidence suggested that the disease could also have increased host susceptibility to infestations with epizoic crustaceans. In this study we provide strong evidence supporting this hypothesis. We examined striped dolphins stranded along the Mediterranean central coast of Spain from 1981 to 2004 (n = 136), and recorded data on prevalence, intensity of infestation, size and reproductive status of 2 sessile crustacean species specific to cetaceans, the phoront cirriped Xenobalanus globicipitis and the mesoparasitic copepod Pennella balaenopterae. Compared with the pre-epizootic (n = 12) and post-epizootic (n = 62) dolphin samples, the following changes were noted in the dolphins stranded during the epizootic (n = 62): (1) the prevalence of both X. globicipitis and P. balaenopterae increased; (2) the intensity of X. globicipitis and P. balaenopterae infestations did not increase; indeed, it was even slightly lower than in the other periods, as was their degree of aggregation; (3) individuals of both species were smaller, and a higher proportion were non-gravid; (4) the 2 species tended to co-occur in the same dolphins, but their numbers did not co-vary. These patterns strongly suggest that, during the epizootic, there was a short-term increase in the probability of infestation of these 2 species because of the sudden rise in the population of susceptible hosts; the growth of the new recruits was limited by the early death of dolphins. The high susceptibility was likely related to the immunosuppressive effects of viral infection and the abnormally heavy loads of polychlorinated biphenyls found in sick dolphins; the level of inbreeding was also higher in dolphins from the 'epizootic' sample. Epizoic crustaceans could be suitable indicators of health in cetacean populations.