Population genetic structure of the messmate pipefish Corythoichthys haematopterus in the northwest pacific: evidence for a cryptic species

Abstract

The population genetic structure of the messmate pipefish, Corythoichthys haematopterus, in the northwest Pacific was investigated based on the partial mitochondrial DNA cytochrome b (589 bp) and 16S rRNA (528 bp) region sequences of 108 individuals collected from six sites along the coast of the Japanese archipelago and one site on Mactan Island, the Philippines. A total of 60 and 28 haplotypes were obtained from the cytochrome b and 16S rRNA regions, respectively. Two genetically distinct lineages were detected: lineage A and B, which are separated by mean pairwise genetic distances of 23.3 and 14.1% in the partial cytochrome b and 16S rRNA genes, respectively. Such a huge genetic divergence between lineages, which is comparable to or even higher than the interspecific level, and the difference in their geographical distributions and habitat preferences suggests that they are distinct species, although there is no marked difference in their morphology. Haplotype network and gene and nucleotide diversity statistics indicate that the two lineages have different biogeographic histories: lineage A experienced rapid population expansion after a population bottleneck whereas lineage B has a long evolutionary history in a large stable population. In contrast, the levels of genetic variation among populations are relatively low in both lineages, probably because of frequent gene flow among populations resulting from the dispersal of pelagic larvae by the Kuroshio Current. These results indicate that past climatic events and contemporary oceanographic features have played a major role in establishing the population genetic structure of C. haematopterus.Electronic supplementary materialThe online version of this article (doi:10.1186/2193-1801-2-408) contains supplementary material, which is available to authorized users.

A multidisciplinary approach to identify priority areas for the monitoring of a vulnerable family of fishes in Spanish Marine National Parks

“…The Cytb haplotypes in this study confirmed a strong differentiation between the Italian S. abaster lineage, represented by reference samples reported by Mwale et al [ 58 ] and the S. abaster haplotypes from PNAC, in Balearic Islands, which has been proposed to be part of the westernmost group along with adjacent sectors in Sardinian Sea [ 81 ]. Genetically divergent populations in species associated with long term isolation and restricted potential for dispersal has been pointed in different species inhabiting marine coastal habitats, including syngnathids, such as reported for the north-western Pacific messmate pipefish [ 81 , 86 ].…”

“…Genetic data are useful to solve taxonomic issues and complement morphological information, as a basic step towards the characterization and conservation of species and associated habitats [ 102 ]. Different mitochondrial markers have shown strong molecular support for species identification of seahorse and pipefish to clarify population and conservation studies (e.g., [ 51 , 86 , 100 , 102 ].…”

DNA barcodes for the pipefish genus Corythoichthys (Actinopterygii: Syngnathiformes) from the Indian Ocean provide insights into cryptic diversity

“…Considering the possibility of ‘species complexes’ within this genus, Kuiter estimated the diversity to be as high as 23 species. The possible reasons for ‘species‐complexes’ in syngnathids may result from colonization by few founder events (Sanna et al ., 2013; Teske et al ., 2005) and/or hybridization (Moser & Wilson, 2020; Wilson, 2006), and cryptic speciation due to past climatic events, contemporary oceanographic features (Sogabe & Takagi, 2013) and/or genetic barriers (Riquet et al ., 2019).…”

“…Genus Corythoichthys is a taxonomically complex group of syngnathids known for their interspecific variations and absence of strong 'species-specific' diagnostic characters (Dawson, 1977). Due to overlapping morphological characters in geographically separated species, Kuiter (2009) proposed 'species-complexes' and Sogabe and Takagi (2013) suggested the presence of cryptic species in the genus. Species complexes are common, especially among widely distributed syngnathids, and molecular data is essential in resolving these challenges (Garcia et al, 2019;Lourie et al, 1999Lourie et al, , 2016Sanna et al, 2013;Silveira et al, 2014).…”