Paramecium - Deutsche Gesellschaft für Protozoologie / German ...

New choanoflagellate species from Deep Sea and from
brakish waters
Frank Nitsche 1 , Hartmut Arndt 1 , Markus Weitere 1 , Frank Scheckenbach
1 ,Klaus Hausmann 2 , Claudia Wylezich 1
1 Universität zu Köln, Allg. Ökologie
2 Freie Universität Berlin, Institut für Biologie/Zoologie
Despite their high abundance and their high importance for the oceanic
matter flux, heterotrophic nanoflagellates are only poorly studied
in the deep-sea regions. Studies on the choanoflagellate distribution
during two deep-sea expeditions, to the South Atlantic (5038 m) and
Antarctica (Weddell Sea, 2551 m), revealed the deepest records of
choanoflagellates so far. A new species, (Lagenoeca antarctica) with
a conspicuous spike structure on the theca is described from deep
Antarctic waters. A second species, Salpingoeca abyssalis sp. n., was
isolated from the abyssal plain of the South Atlantic (5038 m depth).
Floating and attached forms were observed. Phylogenetic analyses
based on a fragment of SSU rDNA revealed Salpingoeca abyssalis to
cluster together with a marine isolate of Salpingoeca infusionum
while Lagenoeca antarctica clusters separately from the other codonosigid
and salpingoecid taxa. Salpingoeca abyssalis and an undetermined
Monosiga species seems to be the first choanoflagellate species
recorded from the abyssal plain.
Additionally, a new species of acanthoecid choanoflagellate isolated
from brackish waters of the Danshui estuary in North Taiwan is described.
Due to the similar morphology shered with Diplotheca
costata the new species has been placed in the same genus and named
Diplotheca elongata. A phylogenetic analysis of partial SSU rDNA
sequences from Diplotheca costata and D. elongata supports this
taxonomic affiliation. This is a large and distinctive choanoflagellate
which has not been reported in any previous study, suggesting that it
may be an endemic species of restricted distribution.
nitsche_frank@hotmail.com
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