Marine Biology Research Today is a free monthly online journal that collates and summarizes the latest research about Marine Biology, including details on oceans, coasts, marine wildlife, coral.

Range-wide population genetic structure of Symbiodinium associated with the Caribbean Sea fan coral, Gorgonia ventalina.

Andras JP, Kirk NL, Drew Harvell C

Department of Ecology & Evolutionary Biology, Dale R. Corson Hall, Cornell University, Ithaca, NY 14853, USA Department of Biological Sciences, Hochstetter Hall, State University of New York at Buffalo, Buffalo, NY 14260, USA.

Numerous marine invertebrates form endosymbiotic relationships with dinoflagellates of the genus Symbiodinium, yet few studies have examined the population structure of these symbionts. Here, we elucidate the population genetic structure of Symbiodinium harboured by the Caribbean octocoral Gorgonia ventalina throughout the entire range of the host. We used ten microsatellite loci to survey 35 localities spanning 3124 km across the Caribbean and Western Atlantic. Diversity of Symbiodinium haplotypes was low within colonies of G. ventalina but high among colonies. Despite high haplotypic diversity, significant evidence of clonal reproduction in Symbiodinium was detected, and most clones occurred within localities, not among them. Pairwise measures of F(ST) illustrated significant differentiation in 98% of comparisons between localities, suggesting low levels of gene flow. Clustering analyses identified six genetic groups whose distribution delimited four broad biogeographic regions. There was evidence of some connectivity among regions, corresponding with known geographic and oceanographic features. Fine-scale spatial surveys of G. ventalina colonies failed to detect differentiation among Symbiodinium at the metre scale. However, significant differentiation was observed among Symbiodinium hosted by sympatric G. ventalina colonies of different size/age classes. This cohort effect suggests that Symbiodinium may have an epidemic population structure, whereby G. ventalina recruits are infected by the locally predominant symbiont strain(s), which change over time.

Published 6 May 2011 in Mol Ecol.
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Articles on Marine Biology published 6 May 2011:

A bivalent Vibrio harveyi DNA vaccine induces strong protection in Japanese flounder (Paralichthys olivaceus).   Vaccine.

Vibrio harveyi is a severe aquaculture pathogen that can infect a large number of fish species. In previous studies, we have identified two protective immunogens, DegQ and Vhp1, from pathogenic V. harveyi strains. In this study, we examined the potentials of DegQ and Vhp1 as monovalent and bivalent DNA vaccines in a Japanese flounder (Paralichthys olivaceus) model. For this purpose, the DNA vaccine plasmids pDegQ, pVhp1, and pDV were constructed. pDegQ and pVhp1 express, respectively, degQ and ... [Abstract] [Full-text]

Articles on Marine Biology published 5 May 2011:

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A novel hydrothermal field has been discovered at the base of Lōihi Seamount, Hawaii, at 5000 mbsl. Geochemical analyses demonstrate that 'FeMO Deep', while only 0.2 °C above ambient seawater temperature, derives from a distal, ultra-diffuse hydrothermal source. FeMO Deep is expressed as regional seafloor seepage of gelatinous iron- and silica-rich deposits, pooling between and over basalt pillows, in places over a meter thick. The system is capped by mm to cm thick hydrothermally derived ... [Abstract] [Full-text]

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Articles on Marine Biology published 4 May 2011:

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