Stygiopontius senokuchiae is a hydrothermal-vent-specific copepod species (Dirivultidae, Siphonostomatoida) and abundantly distributes near vent orifices. This species is thought to have an early juvenile planktic stage, and previous studies using bulk tissue stable-isotope and radioisotope data suggest that adults ingest chemoautotrophic microbes growing on vent chimneys. However, ontogenetic changes in their diets have not been investigated. We analysed gut contents of copepodite I to adult stages of S. senokuchiae collected from a hydrothermal-vent chimney at the Izu-Ogasawara Arc to check for the presence of bacterial cells in oral tubes and guts. We compared these results with an unidentified co-occurring calanoid and a species of Ectinosoma (Harpacticoida) and to other Siphonostomatoid copepods, namely Hatschekia labracis (Hatschekiidae), which was attached to a scarbreast tuskfin (Choerodon azurio, Labridae), and Asterocheres sp. 1 (Asterocheridae), which was attached to a spirastrellid sponge. Carbon isotope ratios of S. senokuchiae at different stages and Ectinosoma were measured to complement the nutritional insights obtained from gut-content analysis. Our results clearly showed that most S. senokuchiae individuals possessed bacteria in the oral tube or gut regardless of growth stage, whereas the coexisting Ectinosoma and calanoid did not. The carbon isotopic compositions confirmed that S. senokuchiae gains its nutrition from chemoautotrophic bacteria that use the rTCA carbon-fixation pathway. Comparisons with other Siphonostomatoida copepods suggest that Dirivultidae are specifically adapted to feed on bacteria at hydrothermal-vent chimneys, allowing their high dominance and evolutionary success in these habitats.

In the present paper, we report the collection of a specimen of the West central Atlantic Stegastes variabilis in the shores of Israel, eastern shore of the Mediterranean. This record was preceded by a record of this species from Malta, in the central Mediterranean. The present record suggests that S. variabilis has established a small population in the Mediterranean.

We present the distribution of the parthenopid crab species Distolambrus maltzami from the North-east Atlantic with a first record from UK seas. The distribution of D. maltzami in the Celtic-Biscay area in the eastern Atlantic, is both described based on recent records from survey data and estimated from modelling its environmental niche. The predicted probability of occurrence is greatest in areas with fluctuating tidal currents and water masses that are rich in chlorophyll-a, cold (minimum bottom temperature lower than 10°C) and oxygen-rich. We include a simple key to distinguish the two parthenopid crab species previously encountered in the region and highlight the importance of a multidisciplinary approach to fisheries data collection.

We measured the concentrations of antifouling biocides in sediment, mangrove leaves and seagrasses from Merambong and Tinggi Island, Johor, Malaysia to evaluate their contamination levels. Although the concentrations of tributyltin (TBT) in mangrove leaves in Merambong in 2013 were significantly lower than those in 2012, the Sea-Nine 211 concentration in 2013 was significantly higher than that in 2012, suggesting that the use of antifouling biocides changed from TBT to Sea-Nine 211. The concentration of each BT (butyltin) and PT (phenyltin) in the mangrove area was significantly higher than the corresponding concentration in the seagrass area in Merambong, but the concentrations of Sea-Nine 211, diuron, chlorothalonil, Irgarol 1051 and M1 in seagrasses were significantly higher than those in mangrove leaves. There were differences in the accumulation profiles of OTs (organotins) and alternative biocides between the seagrass shoots and roots. The concentration of OTs in the seagrass roots was almost the same or higher than those in the shoots, whereas those of alternative biocides shows the opposite pattern to the OTs. Significant high relationships were observed between stable carbon isotope (δ13C) and OTs, Sea-Nine 211 and Irgarols in mangrove leaves. The concentrations of these compounds increased along with the δ13C values of the mangroves. These results suggest that mangroves take up the bicarbonate ions and nutrients in sediment and/or seawater through their roots, along with OTs, Sea-Nine 211 and Irgarols which were accumulated in sediment.

Despite an increase in the number of new lumbrinerid descriptions globally and over recent decades, no new lumbrinerid species have been described from southern Africa over the last 40 years. This suggests that species richness in the region is currently underestimated, and that continued research would result in the discovery of more undescribed species. Here, a new species is described from grab samples collected off southern Namibia at >100 m depth. Ninoe namibiensis sp. nov. is characterized by simple multidentate hooded hooks with a long hood that only appears after chaetiger 18, branchiae from chaetiger 1–2 to 38 (with up to 7 filaments) and maxillary apparatus: MX III with one prominent tooth followed by a knob and MX IV unidentate with finely denticulate cutting edge (11 small teeth). A key to the Ninoe from southern Africa is provided.

The shallow-water hydrothermal system of Punta Mita in Banderas Bay is located on the fault called Fisura de las Coronas off Punta Pantoque beach. In this area, three sites with hydrothermal vents were studied at a depth of 9 m. This study aimed to characterize the structure of the benthic infauna communities that coexist in this hydrothermal system; therefore, physicochemical parameters were measured and the organisms found in the sediment samples were identified up to the class taxonomic level. The highest temperatures (89°C) were recorded within the hydrothermal influence area, which was reflected in an inverse relationship with pH, conductivity and salinity. Sediment temperature profiles increased at greater depth. A total of 371 individuals were found and these were grouped into eight classes: Malacostraca, Maxillopoda, Gastropoda, Bivalvia, Scaphopoda, Polychaeta, Leptocardii and Stenolaemata. The Malacostraca class was the most abundant with 240 individuals, while the Scaphopoda was the lowest with 3. The organic matter contents in the sediments were higher in the areas adjacent to the hydrothermal activity. The high temperature of the hydrothermal discharges structures the benthic community since it was the factor that differed most significantly in the study sites, causing lower abundances in the area of hydrothermal influence compared with the more distant areas. Despite the above, it is concluded that the benthic community of the area with hydrothermal activity is part of the community adjacent to this influence, only in lower numbers.

Two new species of Haliclona (Chalinidae, Haplosclerida) are described here from Brazilian oceanic islands and the coast of Ceará State. They derive from collections undertaken between 1999 and 2014, and materials are deposited in the Porifera collection of Museu Nacional in Rio de Janeiro (MNRJ). Haliclona (Halichoclona) insularis sp. nov. can be distinguished from other Haliclona spp. in the western Atlantic by the combination of surface with light to deep red colour intermixed with white to beige areas (occasionally completely beige), white to beige choanosome, small fistular outgrowths, fragile consistency and blunt oxeas (90–175 × 1–5 μm) with irregular tips. Haliclona (Soestella) moraesi sp. nov. is the only western Atlantic species of Haliclona with the combination of thickly encrusting to cushion-shaped habit, purple or light pink colour, and a dense (sub)isotropic skeleton with rounded meshes, and without microscleres. Several attempts to amplify COI mtDNA and 28S C2–D2 rRNA for both species were unsuccessful, in spite of the initial successful extraction of genomic DNA. The number of Haliclona spp. known from the Brazilian coast is now 17. The long gap between species collection and formal description supports the concept of the taxonomic impediment, which is particularly marked in speciose taxa with little morphological disparity, as observed in Haplosclerida.

The Galapagos Islands lie within the oceanic ecoregion of the Tropical Eastern Pacific, which has a unique fish assemblage composition due to the influence of several ocean currents and El Niño Southern Oscillation (ENSO) events. In the El Niño phase of these events, water temperature changes facilitate the movement of fish species between oceanic ecoregions, as well as across the Eastern Pacific Barrier. Here, we present five new fish records for the Galapagos Marine Reserve based on underwater imagery. These include two rays (Mobula thurstoni and Myliobatis longirostris) and three bony fishes (Lobotes pacifica, Lutjanus colorado and Sphyraena stellata). Of these, the first species is proposed as potentially resident to the Galapagos, and the latter four as vagrant species in the Galapagos until further sightings can conclusively determine their status. The effects of ENSO, the use of underwater video technology, and the importance of up-to-date and accurate species listings to understand the impact of the climate crisis are discussed.

The sicklefin devil ray (Mobula tarapacana) is a large, pelagic ray which is listed as Endangered by the International Union for Conservation of Nature (IUCN). Mobula tarapacana is thought to have a circumglobal, yet patchy distribution, and has not been verified extant off the eastern USA. Here, we report 180 sightings of M. tarapacana with a total of 361 individuals, collated across five datasets from aerial survey operations and incidental sightings in the waters off the US East Coast and Gulf of Mexico, between 1996 and 2022. This study extends the northern range of M. tarapacana in the Gulf of Mexico to 29°N, and in the Atlantic to 40°N. Seasonal trends were observed off the north-eastern coast of the USA, with M. tarapacana only present in the summer months. Measurements from high resolution digital aerial imagery found M. tarapacana off the New York coast to be adults and subadults with an average disc width of 268 cm (±25, range 232–316 cm). This study provides important spatial and temporal data for management, as well as informing areas for future research on M. tarapacana in the western Atlantic.

Salt marshes do not present favourable conditions for cryptic fish species to inhabit these areas, mainly due to dryness and high temperatures at low tides, and scarce places to hide. Despite the harsh environmental conditions, we report, for the first time, the occurrence of two specimens of the half-naked goby Gobiosoma hemigymnum at high marsh, between oysters and Spartina alteniflora stems. In this paper we report evidence of a possible positive effect of autogenic ecosystem engineer and invasive species, the Pacific oyster (Magallana gigas), over the gobid, Gobiosoma hemigymnum, found 600 km away from its southernmost normal range.

Of the 21 species recorded from the greater Azores region during the HMS ‘Challenger’ Expedition, 12 were newly introduced during the late 19th century. The respective types of these species are fixed, and eight species are redescribed based on scanning electron microscope analysis (Notoplites bilobus, Raxifabia minuta, Hemicyclopora canalifera, Smittoidea oratavensis comb. nov., Buskea ovalis comb. nov., Buskea fayalensis comb. nov., Celleporina ansata comb. nov. and Reteporella atlantica comb. nov.). Another four species are merely dealt with shortly either because the material is insufficiently preserved for a thorough revision (Columnella gracilis, Carbasea pedunculata), or because the species have recently been revised already (Notoplites clausus, Microporella hastigera). Moreover, two Azorean species that were introduced by later workers are synonymized with ‘Challenger’ species: S. oratavensis is considered a senior synonym of Smittia ensifera, and Lekythopora laciniosa is synonymized with C. ansata.

Beaks are one of the most important sclerochronological structures used to study the age and growth of cephalopods, in particular Octopus vulgaris Cuvier, 1797. The present study provides results of ageing of 128 O. vulgaris (56–239 mm dorsal mantle length, DML; 121–5974 g total weight, TW) collected in the southern Moroccan Mediterranean coasts between Fnideq and Jebha. The number of increments corresponding to the age (days since hatching) varied from 137–368 in females and from 129–382 in males. There was a significant correlation between beak and somatic growth. The correlation coefficients of the growth curves DML-Age and TW-Age were similar for both power and exponential models: DML = 0.185Age1.188 (R2 = 0.547), DML = 35.933e0.005Age (R2 = 0.546), TW = 0.00002Age3.260 (R2 = 0.532), TW = 29.56e0.014Age (R2 = 0.541). The average width of the increments was similar between females and males. It varied significantly with season and stage of sexual maturity. Comparison of the growth curve with those estimated by other authors showed that Moroccan Mediterranean O. vulgaris grew faster than that of Sardinia (Italy) and slower than that of the Mauritanian coast.

This study provides the first record of the beaded sea cucumber Euapta lappa at Madeira Island. A single individual was observed during a nocturnal scuba dive at 17 m depth, presumably feeding. After having its previous northern limit in the North-east Atlantic at the Selvagens Islands, this record expands the known distribution and northern limit of this tropical species by about 300 km. This new record of yet another tropical species expanding its range northwards can be seen as another indication of the ongoing tropicalization in the marine environment of Macaronesia in the North-east Atlantic.

We deployed jaws of the common thresher shark (Alopias vulpinus) on the seafloor at ~1000 m depth off Monterey California for 8 months. The jaws disintegrated, with all the hyaline cartilage disappearing, leaving some fragments of tessellated cartilage and the teeth. Two different Osedax species, O. packardorum and O. talkovici were found to have bored into the roots of some of the teeth, and were using the dentin pulp, which is rich in collagen, as a food source. The enameloid crowns of the shark teeth and the tessellated cartilage showed no signs of Osedax activity. This is the first demonstration of Osedax exploiting a source of food that is not bone. This raises questions as to the original food source of Osedax ‘bone worms'. Examination for the presence of Osedax in the skeletons and teeth of Mesozoic and possibly even Palaeozoic fossil sharks, bony fish and reptiles is warranted.

The diet and feeding of juvenile common two-banded sea bream, Diplodus vulgaris, in the eastern central Adriatic Sea was studied to better understand local ecosystem dynamics in this region. Stomach contents of 140 individuals with total length (TL) between 22 and 106 mm, collected by small beach seines from February to November, were analysed. Food items identified in stomachs belonged to 16 prey groups: Copepoda, Gastropoda, Teleost eggs, Ostracoda, Polychaeta, Bivalvia, unidentified Crustacea, Amphipoda, Decapoda, Cumacea, Echinoidea, Anisopoda, Euphausiacea, Mysidacea, Branchiopoda and Isopoda. Overall, planktonic copepod crustaceans were the most important prey group (percentage index of relative importance, %IRI = 78.9), followed by gastropods (%IRI = 14.9). All other prey groups had much lower %IRI values and thus were of less importance. Fish size was an important factor influencing food composition. Planktonic copepods were the most important prey in juveniles of smaller sizes (up to 76 mm TL), whereas large-sized juvenile individuals (>76 mm TL) mainly consumed benthic prey, such as gastropods, polychaetes and bivalves. Feeding intensity was very high as indicated by the low vacuity index.

Investigations on the diversity of cryptobenthic reef fishes resulted in observation of seven new geographic records for Lakshadweep waters, India: halfbarred goby Amblygobius semicinctus, target shrimpgoby Cryptocentrus strigilliceps, thread shrimpgoby Ctenogobiops mitodes, eye-bar goby Gnatholepis anjerensis, Miki's dwarfgoby Eviota mikiae, Erythrops goby Bryaninops erythrops, and Enneapterygius sp. Ctenogobiops mitodes is a new record to Indian waters. The genera Cryptocentrus and Bryaninops are reported from Lakshadweep for the first time. The observations were conducted in the lagoon and reef slope of Kavaratti Island, one of the 12 atolls of the Lakshadweep archipelago, from January–March 2021. The cryptobenthic reef fishes were observed and recorded through underwater photography and videography.

Bunodeopsis pelagica is one of the few species of sea anemones known to be found in the floating algae of Sargassum spp. It has been reported in the North Atlantic, particularly in the Canary Islands and the coast of Jamaica. The present study is the first to report the occurrence of B. pelagica in the Mexican Atlantic, found as epiphyte on Sargassum natans off Alacranes reef (southern Gulf of Mexico) and in Puerto Morelos reef (Mexican Caribbean), revealing that this species is much more widespread than has been reported. Bunodeopsis pelagica is mainly distinguished from other species of Bunodeopsis by having simple minute protuberances on its column, while its congeners have larger and much more developed vesicular projections. With the record of B. pelagica, the number of known species of actiniarian sea anemones from the Mexican Atlantic increases to 23.

The eastern rock lobster (Sagmariasus verreauxi) inhabits the east coast of Australia from southern Queensland to the South Australian border including Tasmania, with the highest abundances found in New South Wales. Changes in strength, duration, and intensity of the eastern Australian current have expanded the species range southward but until recently, records of the species in western regions of south-eastern Australia were rare. Here, we report the first ever verified records of S. verreauxi in the northern zone rock lobster fishery of South Australia, which are the most westerly records ever documented in terms of overall distribution for this species. We hypothesise that two westward flowing systems, the offshore Flinders current and the inshore coastal current may be possible mechanisms for larval transport.

The smallest fish of the Mediterranean Sea, pygmaean goby, Pomatoschistus nanus, and Massuti's goby, Buenia massutii, were obtained from new locations. While P. nanus specimens were collected from both the north-eastern and south-eastern Aegean Sea, B. massutii specimens were collected from two different sub-basins, Sea of Marmara and the Aegean Sea, representing the first report of this species in the eastern Mediterranean Sea. The species were identified by both morphological and molecular techniques. The present paper contributes to filling gaps in the knowledge of the limited distribution of these species in the eastern Mediterranean Sea.