Genetic population structure of the endemic fourline wrasse (Larabicus quadrilineatus) suggests limited larval dispersal distances in the Red Sea

Abstract

The connectivity among marine populations is determined by the dispersal capabilities of adults as well as their eggs and larvae. Dispersal distances and directions have a profound effect on gene flow and genetic differentiation within species. Genetic homogeneity over large areas is a common feature of coral reef fishes and can reflect high dispersal capability resulting in high levels of gene flow. If fish larvae return to their parental reef, gene flow would be restricted and genetic differentiation could occur. Larabicus quadrilineatus (Labridae) is considered as an endemic fish species of the Red Sea and Gulf of Aden. The juveniles of this species are cleaner fish that feed on ectoparasites of other fishes. Here, we investigated the genetic population structure and gene flow in L. quadrilineatus among five locations in the Red Sea to infer connectivity among them. To estimate genetic diversity, we analysed 369 bp of 237 mitochondrial DNA control region sequences. Haplotype and nucleotide diversities were higher in the southern than in the northern Red Sea. Analysis of molecular variance (amova) detected the highest significant genetic variation between northern and central/southern populations (Phi(CT) = 0.01; P < 0.001). Migration analysis revealed a several fold higher northward than southward migration, which could be explained by oceanographic conditions and spawning season. Even though the Phi(ST) value of 0.01 is rather low and implies a long larval dispersal distance, estimates based on the isolation-by-distance model show a very low mean larval dispersal distance (0.44-5.1 km) compared to other studies. In order to enable a sustainable ornamental fishery on the fourline wrasse, the results of this study suggest that populations in the northern and southern Red Sea should be managed separately as two different stocks. The rather low larval dispersal distance of about 5 km needs to be considered in the design of marine protected areas to enable connectivity and self-seeding.

Zoogeography of Intertidal Communities in the West Indian Ocean as Determined by Ocean Circulation Systems: Patterns from the Tetraclita Barnacles

“…This promoted speciation and the Red Sea therefore serves as a glacial refugium with a level of endemism (e.g. T. achituvi in the present study [32], [51], [52]), especially in the northern Red Sea. Genetic analyses in the WIO either reveal a panmictic metapopulation [21], [53] or phylogeographic breaks that are consistent with the biogeographic boundary proposed above (e.g.…”

Genetic Connectivity among and Self-Replenishment within Island Populations of a Restricted Range Subtropical Reef Fish

“…In a similar way, the levels of evolutionary gene flow between three sympatric species pairs of three-spined stickleback ( Gasterosteus aculeatu ) have revealed natural hybridisation and break down of a species pair into a hybrid swarm [75]. In addition, evolutionary gene flow between locations has also been found in Red Sea reef fishes Larabicus quadrilineatus, Chromis viridis and Pseudanthias squamipinnis [76], [77]. Consequently, the lack of geographical structuring and observed spatial genetic homogeneity identified in this study of the endemic A. mccullochi , is likely due to high levels of evolutionary gene flow, which is sufficient for all locations to be connected on evolutionary time scales, thereby maintaining genetic homogeneity.…”

Geological history and oceanography of the Indo‐Malay Archipelago shape the genetic population structure in the false clown anemonefish (Amphiprion ocellaris)

“…2001; Fauvelot et al . 2003; Kochzius & Blohm 2005; Froukh & Kochzius 2007). In all three data sets, Fu's Fs test was significant, suggesting that either selection in form of genetic hitch‐hiking, or sudden demographic expansion must have occurred in recent history (Fu 1997).…”