Mitochondrial DNA variation in the caramote prawn Penaeus (Melicertus) kerathurus across a transition zone in the Mediterranean Sea

Abstract

In this study we analysed mitochondrial DNA variation in Penaeus kerathurus prawns collected from seven locations along a transect across the Siculo-Tunisian region in order to verify if any population structuring exists over a limited geographical scale and to delineate the putative transition zone with sufficient accuracy. Partial DNA sequences of COI and 16S genes were analysed. In contrast to the highly conservative 16S gene, the COI sequences exhibited sufficient diversity for population analysis. The COI gene revealed low levels of haplotype and nucleotide diversities. The size of the annual landings of this commercial species suggests large population sizes. Hence, the low genetic diversity detected in this study could indicate a possible reduction in effective population sizes in the past. We detected significant genetic differentiation between eastern and western populations likely due to restricted gene flow across the Siculo-Tunisian boundary. We discuss the different evolutionary forces that may have shaped the genetic variation and suggest that the genetic divide is probably maintained by present-day dispersal limitation.

Intra- and Inter-specific Variation of Four Acetes Species (Crustacea: Decapoda: Sergestidae) Sampled along the West Coast of Peninsular Malaysia

“…(Table 4). This pattern of base composition is similar to the COI gene region sequences in other groups of crustaceans, including Raymunida (Macpherson & Machordom 2001), Portunidae (Chu et al 1999;Lai et al 2010;Pfeiler et al 2005), Alpheidae Williams et al 2002, Gammaridae (Meyran et al 1997), as well as some penaeid shrimp species (Baldwin et al 1998;Maggioni et al 2001;Quan et al 2004;Tong et al 2000;Zitari-Chatti et al 2009). …”

Genetic variation and population structure of the carpet shell clam Ruditapes decussatus along the Tunisian coast inferred from mtDNA and ITS1 sequence analysis

“…For instance in the anchovy Engraulis encrasicolus (L., 1758) and in the Penaeus keraturus (Forsskål, 1775), genetic differentiation was found using both allozymes and mtDNA sequences (Borsa 2002;Nikula & Vainola 2003;Zitari et al 2008Zitari et al , 2009). This suggests that present day gene flow is still very low between two basins, possibly because of reduced population size resulting from overfishing.…”

Concordant patterns of mtDNA and nuclear phylogeographic structure reveal Pleistocene vicariant event in the green crab Carcinus aestuarii across the Siculo-Tunisian Strait

“…Numerous studies have analysed variable mitochondrial or/and nuclear markers in populations of several vertebrate and invertebrate species around the Siculo-Tunisian Strait and suggested the existence of a genetic boundary in this region, which is probably the signature of past isolation events (e.g. Quesada et al, 1995;Borsa et al, 1997;Bahri-Sfar et al, 2000;Nikula & Vainola, 2003;Zitari-Chatti et al, 2009;Marino et al, 2011;Ragionieri & Schubart, 2013;Deli et al, 2015). The existence of similar divergence patterns among populations of different species from the Eastern and Western Mediterranean basins reinforce the idea that these Mediterranean species were facing the same historical oceanographic events.…”