Epibiotic ciliate communities on the crayfish Procambarus (Austrocambarus) sp. cultivated in a rustic aquaculture in southern Mexico.

Rustic aquaculture systems represent a sustainable production alternative in the world, providing appropriate conditions for the establishment of epibiotic ciliates on crayfish. However, the impact of epibiotic ciliates on the aquaculture production has been insufficiently studied hitherto. The objective of this work was to identify the epibiotic ciliates on the surface of the crayfish Procambarus (Austrocambarus) sp. and analyze whether there is any correlation between seasonality and environmental conditions in an artificial pond in Chiapas, Mexico. The crayfish were collected during dry and rainy seasons to investigate their ciliate epibionts. Some physical and chemical parameters of the sampled water were measured and correlation matrix analyses were applied to detect possible relationships between the presence of ciliates and environmental parameters. Thirteen species belonging to the subclasses Peritrichia and Suctoria were identified. Significant differences were found for some environmental parameters and species recorded in both seasons. The present data could help to better understand the relationship bewteen the epibiotic ciliate community on crayfish and some environmental parameters in aquaculture systems.

Morphology, molecular phylogeny, and taxonomy of trichodinids (Ciliophora, Mobilida) from Calanoid copepods.

Trichodinid ciliates were isolated from calanoid copepods and were characterized by morphological and molecular techniques. The trichodinids found in this study were morphologically similar to Trichodina acuta, but morphometric differences were observed between our specimens and T. acuta. The T. acuta specimens, isolated from fish in several geographical locations around the world, were slightly larger than specimens in our population. In fact, our morphological and morphometric data are more similar to Trichodina diaptomi populations, also found on copepods. Moreover, our phylogenetic analyses revealed that the 18S rRNA gene sequence from our samples emerged in a clade with two T. acuta sequences, infesting fish hosts in China. These three sequences showed 100% identity. Our data, along with a taxonomic review, suggest that the species T. diaptomi, described recently, is actually a synonym of T. acuta and that this species may be related to fish and copepod hosts. In conclusion, we highlight the urgent need to better investigate the polymorphism and host specificity within the Mobilida, as this data may represent important characters to better understand the evolution into this order.