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An unexpected new Metapenaeus shrimp species has arrived to the coastal water of Alexandria City, Egypt. Morphological and molecular studies were conducted for its identification. The results revealed that it is the Indo-West Pacific species, Metapenaeus affinis (H. Milne Edwards, 1837), which is considered as a new addition to the already present local penaeidae species; Metapenaeus monoceros (Fabricius, 1798) and Metapenaeus stebbingi (Nobili, 1904). Large numbers of Metapenaeus affinis were observed and collected by the Egyptian fishermen from the coastal waters of Alexandria City, Egypt, during the study period (2020–2021), which indicates its establishment in the area. A recommendation was presented for further studies regarding the suggested ways of introduction and the prediction for future new species appearance. Such phenomenon requires international efforts to deal with the non-indigenous species’ entries that are recently intensified on the global and regional level.

Africa is a continent that incubates huge inland freshwater reservoirs, representing 27% of total world liquid freshwater, and bounded by marine blue belt. This topography makes Africa harboring diverse freshwater and marine fishery resources. However, fisheries in Africa are still facing big challenges that can be resolved by molecular genetic tools. The present review demonstrated how DNA barcoding approaches expand in African fisheries to solve the problems of fish species identifications, evolutions, population differentiations and biogeographic distributions. Additionally, the limited DNA metabarcoding applications in screening African fish gut microbiome and fish diseases were discussed. Also, we highlighted future perspectives in molecular barcoding applications in African fisheries and a concept for establishing of Africa fish gene bank.

Recurring outbreaks of crown-of-thorns starfish (COTS) severely damage healthy corals, especially in the Western Pacific Ocean. To obtain a better understanding of population genetics of COTS and historical colonization across the Pacific Ocean, complete mitochondrial genomes were sequenced from 243 individuals collected in 11 reef regions. Our results indicate that Pacific COTS (Acanthaster cf. solaris) comprise two major clades, an East-Central Pacific (ECP) clade and a Pan-Pacific (PP) clade, separation of which was supported by high bootstrap value. The ECP clade consists of COTS from French Polynesia, Fiji, Vanuatu and the Great Barrier Reef (GBR). The Hawaii population is unique within this clade, while California COTS are included in EPC clade. On the other hand, the PP clade comprises multiple lineages that contain COTS from Vietnam, the Philippines, Japan, Papua New Guinea, Micronesia, the Marshall Islands, GBR, Vanuatu, Fiji and French Polynesia. For example, a lineage of the PP clade, which has the largest geographic distribution, includes COTS from all of these locations. These results suggest two alternative histories of current geographic distributions of COTS in the Pacific Ocean, an ECP clade ancestry or Western Pacific clade ancestry. Although further questions remain to be explored, this discovery provides an evolutionary context for the interpretation of COTS population structure which will aid future coral reef research in the Pacific Ocean, and ultimately improve reef management of COTS.

Despite being one of the world’s leading countries in coral reef conservation and management, very little data exist for coral reef-associated species in the island nation of Palau, hampering managers’ ability to more effectively protect coral reef ecosystems. Here we examine populations of the vermetid Ceraesignum maximum, a common species on coral reefs, with short or absent pelagic larval stage, in order to elucidate patterns of gene flow within Palauan reefs. We collected specimens (n = 582) from 20 sites across Palau. Cytochrome oxidase subunit I analyses show private haplotypes at all sites examined, with a clear separation between outer and inner reef locations, and a unique population within isolated Nikko Bay. Oceanographic isolation between the waters of Nikko Bay, inner and outer reefs may contribute to our observed genetic differentiation. Our results indicate past demographic expansion of C. maximum across the region and also indicate that multiple sites of both inner and outer reef locations would need to be protected to conserve this species’ genetic diversity, including unique Nikko Bay. These results demonstrate the utility of C. maximum as a good species to investigate gene flow across small scales (

Our knowledge of the ecology and habitat of juveniles of many sea cucumber species is limited, due to their cryptic habitats and differing color and shape from adults. In the present study, a juvenile specimen of the sea cucumber Thelenota anax H. L. Clark, 1921, collected from 30 m at Rukan Reef, Okinawa, Japan, is described. We confirmed specific identity using cytochrome oxidase subunit I (COI) sequences. We show that the pseudotable ossicles in Thelenota are table ossicles, and document synallactid-like ossicles not previously recorded in the Stichopodidae.

Japan is known for its marine biodiversity and diverse ecosystem due to its unique geological composition and water currents creating suitable habitats for a wider range of marine species. A rich deep-sea shark community with high endemism occurs on the continental shelf. Yet, the deep-sea shark taxonomy is still under development and poorly documented. Here, a DNA barcoding technique was adopted using the mitochondrial cytochrome oxidase I (COI) and NADH2 genes of samples collected from Japan with additional samples from genetic databases to draft out a phylogenetic tree of the deep-sea shark genus Squalus (dogfishes). The morphological divergence of congeners was further examined. Bayesian and maximum-likelihood-based species-level phylogenetic analyses of mitochondrial COI, ND2 and combined sequences provided strong support for distinct clades corresponding to the parental species with substantial sequence divergence between parental species. The combined dataset of the COI and ND2 gene was most suitable for barcoding of Squalus dogfishes. A multivariate analysis of morphological traits was largely consistent with the genetic data showing small but discrete differences in phenotypic characteristics allowing to separate Squalus species. Genetic samples of the taxonomically problematic Shortspine spurdog ‘Squalus mitsukurii’ from the Atlantic Ocean and Taiwan did not match with the type material of S. mitsukurii Jordan & Snyder, 1903 from mainland Japan. Squalus mitsukurii once considered a globally distributed species is a single, unique spurdog restricted to temperate Japan and Korea and may present an endemic in the Northwestern Pacific. This study further resolved two genetically and phenotypically distinct species of Squalus dogfishes in Japan, one in sympatry with S. mitsukurii in mainland Japan and one in sympatry with subtropical waters associated congeners in the Ryukyu Archipelago. The occurrence of populations of the ‘high-fin’ Taiwan spurdog, Squalus formosus, in subtropical Japan is herein confirmed.

In this study we investigated the phylogenetics of two sea urchin species, Arbacia lixula and Paracentrotus lividus from the Mediterranean Sea. Specimens were collected from the east coast of Alexandria City, Egypt. Pigmentation examination showed four sympatric color morphotypes (black, purple, reddish brown, and olive green). Mitochondrial DNA was extracted from specimens and mitochondrial cytochrome oxidase subunit I (COI) and 16S ribosomal RNA (16S) were sequenced. The results showed that all black specimens constituted the species A . lixula . All other colors belonged to P . lividus , with no apparent differentiation between color morphotypes. Moreover, P . lividus showed high haplotype diversity (COI; H = 0.9500 and 16S; H = 0.8580) and low values of nucleotide diversity (COI; π = 0.0075 and 16S; π = 0.0049), indicating a high degree of polymorphism within this species. This study represents the first attempt at DNA barcoding of echinoid species in the southeast Mediterranean off the Egyptian coast, and will provide a base for future phylogenetic analyses.

Phylogenetic comparison for lessepsian puffer fish Lagocephalus sceleratus (Gmelin, 1789) from the Egyptian waters (Mediterranean and Red Seas) was performed using morphological and genetic characteristics to confirm its identification and to recognize any variations due to differences in both habitats. A similar identity in body description from both habitats was observed. Slight phenotyping variations in some morphological measurements were observed with no significant difference. The correlation between the reference length and most of morphological indices was similar (0.99) for both habitats. Molecular phylogeny, using two primers (16S rRNA and Cytochrome b) showed similar size bands at 600 bp and 400 bp ladders for both primers respectively in both habitats. The obtained sequences were aligned showing an identity (more than 99%) to the published sequences of L. sceleratus indicating high genetic resemblance. So, the present populations from both habitats don’t appear to be separated species, indicating no obvious genetic variations after its migration into new habitat, expecting that, genetic differentiation may occur very slowly. This supported the idea that both morphological and genetic characteristics are recommended to be used together in identification and phylogenetic relations of the population from two habitats. The specific primers 16S rRNA and Cyt b showed confirmable tools to support the same target where the environmental variations may alter phenotypic variations.

The Japanese sea cucumber Apostichopus japonicus has a pelagic-lecithotrophic larva. Here, we clarify larval dispersal among Japanese sea cucumber populations by describing the levels of distinctiveness and gene flow among red and green variant populations of A. japonicus across Toyama Bay using 11 polymorphic microsatellite markers. Samples of Japanese sea cucumber populations were collected from three localities (Noto, Shinminato, and Uozu) around Toyama Bay. Geographically separated populations of red and green variants were determined to be genetically distinct, supported by phylogenetic analysis and the distinctiveness range values of pairwise multilocus estimates of F ST. Contemporary migration analyses indicated that the majority of estimated migration events occurred within A. japonicus populations comprised of only either red or green variants. In a historical gene flow analysis, two best-fit models (n-island and stepping stone models) showed circulation for the gene migration in Toyama Bay among red variant populations. Our results provide useful information on the genetic structure of Japanese sea cucumber populations and will be helpful for genetic conservation and fisheries management of sea cucumber populations in Toyama Bay.

We report the spontaneous spawning, larval development, survival rate and larval growth rate patterns observed in the green and red variants of the Japanese sea cucumber Apostichopus japonicus. The green variant adapted well to the captive conditions in the Sasebo City Fisheries Center and spontaneously spawned without any induction or stimulation. One hundred individual green variants spawned nine times and produced approximately 155 million eggs. In contrast, 50 individual red variants showed poor adaptation to captivity and spawned spontaneously only three times, producing about 12 million eggs. Larval development and growth rate pattern was almost identical between the two variants of A. japonicus. In contrast, the larval survival rate for the green variant was over 90% up to the auricularia stage (10 days), but much low (less than 30%) for the red variant. We demonstrated that the green variant of A. japonicus was easier to rear in captivity. This provides a useful method for maintaining sustainable harvests and eventually contributing to restocking and sea ranching of the existing population. Further studies about optimal ecological conditions and behaviour are needed to improve egg production and survival rate of the red variant of A. japonicus.