Bathymetric and geographic population structure in the pan-Atlantic deep-sea bivalve Deminucula atacellana (Schenck, 1939)

• Published in: Molecular ecology 2006-03, Vol.15 (3), p.639-651
• Main Authors: ZARDUS, JOHN D., ETTER, RON J., CHASE, MICHAEL R., REX, MICHAEL A., BOYLE, ELIZABETH E.
• Format: Article
• Language: English
• Subjects: Animal populations; Animals; Atlantic Ocean; bathymetric patterns; Biodiversity; Bivalvia - genetics; deep sea; Deminucula atacellana; dispersal barrier; DNA, Mitochondrial - genetics; DNA, Ribosomal - genetics; Genetic diversity; Genetic Variation; Geography; Haplotypes; isolation by depth; Marine; mid-Atlantic Ridge; Mitochondrial DNA; Mollusks; Phylogeny; population genetic structure; Sediments; Sequence Analysis, DNA
• ISSN: 0962-1083; 1365-294X
• DOI: 10.1111/j.1365-294X.2005.02832.x

The deep‐sea soft‐sediment environment hosts a diverse and highly endemic fauna of uncertain origin. We know little about how this fauna evolved because geographic patterns of genetic variation, the essential information for inferring patterns of population differentiation and speciation are poorly understood. Using formalin‐fixed specimens from archival collections, we quantify patterns of genetic variation in the protobranch bivalve Deminucula atacellana, a species widespread throughout the Atlantic Ocean at bathyal and abyssal depths. Samples were taken from 18 localities in the North American, West European and Argentine basins. A hypervariable region of mitochondrial 16S rDNA was amplified by polymerase chain reaction (PCR) and sequenced from 130 individuals revealing 21 haplotypes. Except for several important exceptions, haplotypes are unique to each basin. Overall gene diversity is high (h = 0.73) with pronounced population structure (ΦST = 0.877) and highly significant geographic associations (P