Systematics of Nautiliniellidae Miura and Laubier, 1990 (Annelida);
symbionts of seep and vent bivalves
Nautiliniellids are a small group of polychaetes appearing to live symbiotically in the
mantle cavity of bivalves, mainly from cold seeps and hydrothermal vents. During the
last few years, several new species have been discovered and described, however the
taxonomic status and ecology of this family are not fully understood and the evolutionary
relationships within polychaetes are still very elusive.
Recently, Dr. Greg Rouse at the Scripps Institution of Oceanography (SIO) collected
numerous specimens of 3 or 4 new species of nautiliniellids from three groups of bivalves
(Acharax sp. Calyptogena sp. and Bathymodiolus spp.) in the deep seeps of the Costa
Rican Margin. Additionally, in the collections of SIO there is another undescribed species
of nautiliniellid from the North Fiji Basin hydrothermal vents. More over, more carbonate
seep fauna is expected to be collected during a future cruise to the Hydrate Ridge in
2010. Additionally, all the Nautiliniellidae and Antonbrunidae (a closely related family of
polychaetes, also symbiont of molluscs) collected during another future cruise to the
Chilean methane seeps will be available for us to study.
Thanks to the TAWNI award, I am going to stay at the SIO for two months studying the
Nautiliniellidae collections and describing 4-5 possible new species from the Pacific
Ocean. I will also participate in the future cruise to the Hydrate Ridge where more
material will surely be found. Part of the material will be used to get DNA sequences
(mitochondrial and nuclear genes). Then, I will be able to perform a revision of the
family based on a cladistic analysis in which morphological information together with
molecular data will be combined. Our results will let us investigate the phylogenetic
relationships of Nautiliniellidae within polychaetes. This will also assess their
biogeography and co-evolution with their bivalve hosts.