Genetic barcoding and preliminary phylogenetic analysis of Serranidae species from Maltese coastal waters, with a perspective on their Mediterranean phylogeography

Volume 1, No. 3, 66-77, 2016 - RESEARCH ARTICLE Genetic barcoding and preliminary phylogenetic analysis of Serranidae species from Maltese coastal waters, with a perspective on their Mediterranean phylogeography Adriana Vella*1, Noel Vella Conservation Biology Research Group, Department of Biology, University of Malta, Msida MSD2080, Malta Abstract Ten species of the Serranidae Family sampled from the Mediterranean, including two nonnative species, were identified using molecular genetic tools. Two mitochondrial genes, cytochrome c oxidase subunit I (COI) and Cytochrome b (Cyt b) genes were studied covering a total of 980 bp of which 360 bp exhibited genetic differences. Within species the members of the genus Serranus exhibited the highest haplotypic diversity, while the genera of larger grouper taxa have shown low haplotypic and nucleotide diversity indices with these genetic markers. Each sequence was also checked against BOLD and GenBank databases to compare species categorization. COI data on S. cabrilla and S. scriba were used in a preliminary phylogeographic analyses for these two species. Results show significant differences between certain sampling locations, indicating localized populations within the Mediterranean. Keywords: Serranidae; DNA barcoding; phylogenetics; phylogeography; COI; Cyt b Article history: Received 16 December 2016, Accepted 19 December 2016, Available online 21 December 2016 Introduction In the Mediterranean, the Family Serranidae is represented by eleven native species from the subfamilies Anthiinae, Epinephelinae and Serraninae (Heemstra & Randall 1993; Abdul Malak *Corresponding Author: Adriana Vella, email: Natural and Engineering Sciences 67 et al., 2011; Froese & Pauly 2016). In addition to these, there have been increasing records of non-native serranids from the subfamily Epinephelinae (Heemstra & Randall 1993; Ben-Tuvia & Lourie 1969; Heemstra & Golani 1993; Lelong 2005; Bariche & Heemstra 2012; Dulčić & Dragičević, 2013; Golani et al., 2015; Rothman et al., 2016; Vella et al., 2016), with Epinephelus coioides (Ben-Tuvia & Lourie, 1969; Parenti & Bressi, 2001; Gokoglu & Ozvaol, 2015) and C. taeniops (Ben Abdallah et al., 2007; Guidetti et al., 2010; Vella et al., 2016) showing up multiple of times in landing records possibly indicating multiple introductions or population establishment in the region. The Family Serranidae encompasses a number of economically important species, that are commonly caught by commercial, artisanal and recreational fishermen. Therefore, the correct species identification is an important basic requirement in monitoring for sustainable fisheries management and identifying the species specific conservation needs of this Family’s biodiversity throughout the Mediterranean region (Vella, 2009). FAO data for the GFCM area indicates that in 2014 at least 5.7% of the marine fish landings were classified as unidentified, while several others, including some species of groupers, are classified down to high taxonomic levels such as Ephinephelus spp. (FAO, 2016). Moreover, there are several instances where due to untrained personnel or due to unpronounced and overlapping morphological characters, species are misidentified and placed in the wrong species category (Vella, 2009; personal observations by authors). Illegal, unreported and unregulated (IUU) fisheries activities which impact on species of this Family are difficult to quantify, especially where sport spearfishing is also practiced, with the fish being sold privately or used for personal consumption and not recorded through the national fish-market. Most of these species are coastal and exposed to unrecorded catches by recreational fishermen (personal observation by authors). These factors affect the actual landings, exploitation and their accurate records for species of the Family Serranidae. Direct exploitation has been the main cause leading to the inclusion of Ephinephelus marginatus as an Endangered species within the IUCN Red List of Threatened Species both at global (Cornish & Hermelin-Vivien, 2004) and at Mediterranean level (Cornish & HermelinVivien, 2011) due to serious declines in its population. However environmental changes in the marine habitats due to climate change, anthropogenic activities and increasing presence of alien species (Coll et al., 2010; Occhipinti-Ambrogi & Galil, 2010; Vella et al., 2015 a & b; Vella et al., 2016 a & b) are posing additional threats to the Serranidae species in the central Mediterranean Sea. Therefore, to ensure effective conservation measures, the genetic identity and phylogenetics of the species around the Maltese Islands are useful to comparing these with similar species found elsewhere within and outside the Mediterranean region. Accurate genetic identification through the analyses of multiple genes can be used as molecular tools to assess the genetic identity and phylogenetic relationships between species, while subtle genetic differences found within each species can provide preliminary understanding on its phylogeographic distribution, thus identifying any distinct stocks or limited gene flow. Materials and Methods In this study, 43 specimens representing 10 species of the Family Serranidae (including Anthias anthias; Cephalopolis taeniops; C. nigri; Epinephelus costae; E. marginatus; Hyporthodus haifensis; Serranus atricauda; S. cabrilla; S. hepatus; and S. scriba) were collected from fisheries landings and from recreational fishermen catches. Specimens were identified down to the species level using morphological identification keys (Heemstra & Randall, 1993; Froese Natural and Engineering Sciences 68 & Pauly, 2016). DNA was extracted from 5 mg caudal fin clips using GF-1 Tissue DNA Extraction Kit (Vivantis Technologies) following the manufacturer’s protocol. The two sequences analysed in this study were the partial cytochrome c oxidase subunit I (COI) gene which is homologous to the conventional gene used in DNA barcoding and the 5’ end of cytochrome b (Cyt b) gene. The COI gene was amplified using the FISH-F1 and FISH-R1 primers as described in Ward et al., (2005), while Cyt b gene using primers A and C for all specimens except for Anthias anthias which was amplified through the use of A and D primers as described in Martin and Palumbi (1993). PCR products were sequenced in both directions using ABI3730XL and the forward and reverse sequence of each PCR product were assembled using Geneious R10 (http://www.geneious.com, Kearse et al., 2012). The resulting sequences of the native Serranidae species were deposited in GenBank under accession number KX925317-98. The sequences were aligned using ClustalW within Geneious R10. Phylogenetic analyses were conducted via MEGA v7 (Kumar et al., 2016) using Kimura-2-parameter distance model (Kimura, 1980), with Maximum Likelihood and 1500 bootstraps were carried out for the COI, Cyt b and for the combined data. Molecular diversity indices (haplotype (...truncated)