Unique COI haplotypes in Hediste diversicolor populations in lagoons adjoining the Ionian Sea

Abstract

The present study examines the genetic diversity (using cytochrome c oxidase subunit I [COI] haplotypes) of polychaete Hediste diversicolor populations in the Amvrakikos Gulf (western Greece) in order to test Cognetti's hypothesis on the formation of distinct isolated populations of species living in stressed transitional water habitats. To this purpose, the intraspecific diversity of H. diversicolor and the similarities among its populations in the brackish water habitats of the Eastern Mediterranean were investigated. Samples were collected from the lagoonal complex of Amvrakikos Gulf in 2010 and 2011. Analysis showed that populations in the Amvrakikos Gulf share unique haplotypes which are distinct from the haplotypes hitherto reported, suggesting that these populations are highly isolated. This evidence partially supports Cognetti's hypothesis. The results indicate that the genetic differentiation in the studied populations was probably caused by the complete isolation of the gulf and periodic hypoxic conditions during its formation history. The occurrence of unique haplotypes in the gulf underlines the importance of considering genetic diversity in the design of long-term biodiversity management and conservation plans.

Polychaetes of Greece: an updated and annotated checklist

“…Multiple genetic lineages exist in Europe (Nygren 2014, Lobo et al 2016) which could correspond to cryptic species. Vasileiadou et al (2016) found genetically highly isolated populations with unique haplotypes in Greek lagoons.…”

Revision of the species confused with “Nereis falsa” de Quatrefages, 1866 (Annelida, Nereididae)

“…Ehlers (1868: 554) added N. brevimanus Johnston, 1840, described from Ireland, to the list of synonyms. Black Sea population haplotypes differ from those present in nearby areas (Vasileiadou et al 2016); if this difference promotes regarding Black Sea specimens as belonging to a different species, N. falsa de Quatrefages, 1866 would be available for them.…”

Connectivity between coastal lagoons and sea: Asymmetrical effects on assemblages' and populations' structure

“…This would explain the high variability between lagoons and between years in the same lagoon, and the spatial heterogeneity in lagoon species composition. At the same time, the randomness of the colonization process, in which a rare allele can be amplified by a bottleneck effect, can explain the high proportion of exclusive or rare haplotypes and alleles in the lagoon populations despite the maintenance of relatively high gene fluxes whith open sea populations (Bellec et al, 2010;Vergara-Chen et al, 2010a, b;Mejri et al, 2011;Milana et al, 2012;Vasileiadou et al, 2016). This spatio-temporal variability, both genetic and in species composition (P erez-Ruzafa et al, 2007a(P erez-Ruzafa et al, , 2011a, could play an important role in conforming homeostatic mechanisms against eutrophication , human impacts and climate change, and could be a consequence of the restricted connectivity between the lagoon and the sea.…”