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Perkinsoide chabelardi n. gen., a protozoan parasite with an intermediate evolutionary position: possible cause of the decrease of sardine fisheries?
Author(s) -
Gestal Camino,
Novoa Beatriz,
Posada David,
Figueras Antonio,
Azevedo Carlos
Publication year - 2006
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2006.01008.x
Subject(s) - biology , dinoflagellate , parasite hosting , phylogenetic tree , sardine , evolutionary biology , zoology , phylogenetics , gene , ecology , genetics , fishery , fish <actinopterygii> , world wide web , computer science
Summary Phenotypic scrutiny on the life cycle of Icthyodinium chabelardi ( Perkinsoide chabelardi n. gen.) based on ultrastructural techniques, and molecular phylogenetic analysis of RNA gene sequences, were carried out in order to elucidate the taxonomic position of this parasite. The absence of plastid, presence of trichocysts, and chromosomes or chromatin condensed and low in number, suggested that this protozoan could be considered a dinoflagellate syndinial parasite. However, the life cycle, schizogonic divisions and structure of schizonts inside the host, the nuclei without the typical dinoflagellate appearance, presence of rhoptrias‐like structures, a possible pseudo‐conoid, and the biflagellated spore, resembled those of the genus Perkinsus. Phylogenetic analysis of genes transcribing for the RNA forming the small subunit and the large subunit suggests that this parasite has an ambiguous evolutionary position within the group formed by dinoflagellates, perkinsids and syndinials. Because of differences with dinoflagellates and similarities with perkinsids, we propose to change the generic name to P. chabelardi n. gen. High stationary infection prevalence on Sardina pilchardus eggs was observed. This protozoan parasite caused the death of all the infected sardine eggs, and therefore a high impact in the recruitment of this fishery in the Atlantic coast is expected.