ISSN:
1550-7408
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
This study represents the first extended report on the heterotrichid ciliate Chattonidium setense since the original description by Villeneuve in 1937. This rare marine ciliate is in fact the only representative of the family Chattonidiidae, which is the eighth, often neglected, family of order Heterotrichida. As in our previous works, here we redescribe the species combining morphological observations (live, stained, scanning, and transmission electron microscope) with behavioral and molecular data as we are convinced that both taxonomic determination and molecular characterization are necessary for the clarification of phylogenetic relationships between a species and related genera. Live observation, Feulgen procedure and SEM analysis showed, besides a number of other interesting features, the presence of a characteristic aboral ciliated cavity of undetermined function, whose presence makes ciliate's identification unambiguous. TEM observation evidenced the following main features: well-divided ecto-and endoplasm; deep insertions of the rows of somatic dikinetids in cortex invaginations; paraglycogen granules as polysaccharide reserve; large bundles of microtubules and fibers delimiting the body region surrounding the aboral cavity; two kinds of subcortical extrusomes. Since the revision of heterotrichs ciliates by Villeneuve-Brachon (1940) many genera and families have been transferred to other classes on the basis of both new molecular data and reconsidered morphological characters. Our results support previous statements that Chattonidium has the general morphology typical of Heterotrichida and that the main similarities are with genus Condylostoma. 18S rRNA molecular data firmly confirm that Chattonidium belongs to class Hetrotrichea, order Hetrotrichida (Lynn, D. H. 2003. The Ciliate Resource Archive. ) as an independent lineage. Preliminary molecular data also suggest an association between genera Chattonidium and Condylostoma. Finally, some behavioral and ecological notes on the ciliate are added.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1550-7408.2005.05202003_6_10.x
