Search Results (3)

At a depth of approximately 9 m off the coast of Banderas Bay, hydrothermal activity occurs through various seabed vents, discharging liquids and gases that reach temperatures of up to 89 °C and pH values lower than the surrounding seawater. This study examines the composition of the benthic infauna inhabiting the sediments of this hydrothermal system in two time periods: November 2017 (previously reported) and September 2023 (recorded for this study). In total, for both samplings, we identified 17 benthic infaunal groups—amphipods, isopods, cumaceans, tanaidaceans, crabs, shrimps, copepods, snails, limpets, caecids, chitons, bivalves, scaphopods, polychaetes, amphioxus, ophiuroids, and bryozoans—belonging to these ten taxonomic classes: Malacostraca, Maxillopoda, Gastropoda, Polyplacophora, Bivalvia, Scaphopoda, Polychaeta, Leptocardii, Ophiuroidea, and Stenolaemata. Additionally, we identified galleries of polychaetes, vermetids, and peracarids. Despite the stressful hydrothermal conditions, statistical analyses of both sampling campaigns revealed no significant differences in abundance, highlighting the potential persistence and adaptability of benthic communities in hydrothermally influenced habitats. Full article

Seamounts can have a strong influence on the distribution and diversity of species, creating an oasis effect that may favour diversification. In order to assess how and to what extent supra- and epibenthic crustaceans can colonise these environments, the eucarid and peracarid fauna collected from the summit of the Valencia Seamount (VS), a small deep seamount (summit depth: 1056 m), rising from a depth of ca. 1850 m, in the oligotrophic Balearic Basin, was analysed. Based on a first sampling (beam trawls, plankton nets and stomach contents), and a faunal reconstruction from a sediment core (MC2, at 1151 m), the supra(epi)benthic crustaceans at the VS summit (to 1300 m) were composed of nine Eucarida and 25 Peracarida. Polycheles typhlops, Munida tenuimana, and Aristeus antennatus were the dominant species among eucarids. Among Peracarida the most abundant species were the Mysida Boreomysis arctica, the Amphipoda Rhachtropis caeca, and the Isopoda Munnopsurus atlanticus. Among Decapoda, a species with a wide amplitude in their depth distribution and small eggs (i.e., with planktotrophic larvae), showed a higher colonisation capacity. In the absence of larvae, the colonisation of peracarids depends on the amplitude of their depth distribution and only those species that reach the highest depths in the entire Balearic Basin, at least 1600–1800 m, were able to colonise the summit of VS. The natatory capacity of the species also has some influence and whole groups with low natatory capacity, such as the Desmosomatidae, were completely absent on the VS summit; however, they are distributed throughout the Balearic Basin to depths (up to about 1500 m) exceeding the depth of the seamount summit. Therefore, colonisation by peracarids must not have occurred by swimming through the entire water column, but by swimming along or just above the bottom. Remains of some suprabenthic species (mainly the isopod M. atlanticus) in MC2 and another core collected in NW Mallorca (MC3, 1114 m), i.e., out of the VS, showed how isopod diversity and size distribution changed historically. Also, after the 1960s, a decrease in primary production due to a decrease in rainfall and river runoff associated with river damming could have reduced the abundance of M. atlanticus. These types of historical studies can be useful in interpreting long-term changes in deep-sea communities and optimising the management of these vulnerable areas. Full article

We present 52 new geographic location records for the peracarid crustacean Antromysis cenotensis Creaser, 1936, endemic in cenotes of the Yucatan Peninsula, Mexico. This species is currently considered threatened and, therefore, is protected by Mexican law. These results arise from several expeditions carried out between 2017 and 2020 in 75 locations within the cenote-ring, the interior, and coastal plains of the peninsula. A comprehensive literature review provided 84 geographic location records since the species was described in 1936. A map with 136 geographic location records that better describe the current species distribution is also included. With this information, plus some notes on the ecology of the species, a comprehensive literature and data review, and a brief analysis regarding the possible factors associated with the confirmed absence of the species in some locations in the state of Yucatan, we provide a brief and condensed summary of the actual knowledge on this particular species. The data in Darwin Core format can be retrieved in Zenodo. Full article