Phylogeography of the Brittle Star Ophiura sarsii Lütken, 1855 (Echinodermata: Ophiuroidea) from the Barents Sea and East Atlantic

Abstract

Ophiura sarsii is a common brittle star species across the Arctic and Sub-Arctic regions of the Atlantic and the Pacific oceans. Ophiurasarsii is among the dominant echinoderms in the Barents Sea. We studied the genetic diversity of O.sarsii by sequencing the 548 bp fragment of the mitochondrial COI gene. Ophiurasarsii demonstrated high genetic diversity in the Barents Sea. Both major Atlantic mtDNA lineages were present in the Barents Sea and were evenly distributed between the northern waters around Svalbard archipelago and the southern part near Murmansk coast of Kola Peninsula. Both regions, and other parts of the O.sarsii range, were characterized by high haplotype diversity with a significant number of private haplotypes being mostly satellites to the two dominant haplotypes, each belonging to a different mtDNA clade. Demographic analyses indicated that the demographic and spatial expansion of O.sarsii in the Barents Sea most plausibly has started in the Bølling–Allerød interstadial during the deglaciation of the western margin of the Barents Sea.

Unveiling Ophiuroid Diversity Across North Atlantic Habitats: an integrative perspective

“…The splits within the O. aculeata, O. sarsii and O. abyssicola morphotypes might indicate cryptic lineages or ongoing speciation [46] However, it is known that GMYC tends to overestimate species diversity [33,47]. O. sarsii revealed a similar pattern as identi ed by [48] where two main mtDNA lineages across the Atlantic were identi ed.…”

DNA barcoding echinoderms from the East Coast of South Africa. The challenge to maintain DNA data connected with taxonomy

“…Also, due to the evolutionary history of some species, divergent mitochondrial lineages can coexist within a species. This was shown for Ophiura sarsii Lütken, 1855 from the Barent Sea where distances up to 3.11% have been reported among COI sequences [ 84 ]. Therefore, the putative species determined here based on COI need to be evaluated with integrative taxonomy, taking into account the life cycle, ecology, and if necessary, additional DNA data in order to infer the evolutionary history of the species [ 23 , 85 ].…”

DNA barcoding echinoderms from the East Coast of South Africa. The challenge to maintain DNA data connected with taxonomy

“…Also, due to the evolutionary history of some species, divergent mitochondrial lineages can coexist within a species. This was shown for Ophiura sarsii Lütken, 1855 from the Barent Sea where distances up to 3.11% have been reported among COI sequences (82). Therefore, the putative species determined here based on COI need to be evaluated with integrative taxonomy, taking into account the life cycle, ecology, and if necessary, additional DNA data in order to infer the evolutionary history of the species (23,83).…”