Effective conservation of marine biodiversity requires a strong understanding of how marine systems change over time. Connections between coastal benthic and pelagic systems mean that additional insight may be gained from surveying both habitats alongside each other to investigate if interannual trends are similar. We utilised a multiyear dataset of both seabed and midwater baited remote underwater video systems (BRUVS) deployments from the Shark Bay World Heritage Area to investigate interannual changes in broad metrics of abundance, richness, biomass, and length, as well as composition for neighbouring pelagic and demersal communities. In total, 297 taxa were recorded, 272 from seabed surveys and 47 from midwater surveys. Between four surveys across a 5-year period, patterns in benthic and pelagic habitats differed, but both showed significant shifts in community composition between each survey. Benthic communities were broadly stable in biomass, fork length, and abundance. Pelagic communities increasingly favoured larger abundances of smaller fishes which may be indicative of excessive fishing pressure. Several vulnerable species were recorded including multiple young of the month shortfin mako sharks (Isurus oxyrinchus). The Shark Bay World Heritage Area was found to be an area of high biodiversity undergoing significant interannual change in both its pelagic and demersal communities, which should inform current and future conservation approaches.
A new species of echinoderid kinorhynchs, Echinoderes dimorphus sp. nov. collected from oxidized brown mud in the northwestern part of the Sea of Japan, Northwestern Pacific, is described and illustrated using light (LM) and scanning electron (SEM) microscopy, and DNA sequences from the mitochondrial cytochrome c oxidase subunit 1 (COI) gene. This new representative of the most diverse kinorhynch genus is characterized by its unique arrangement and morphology of spines, tubes, glandular cell outlets and cuticular plate composition, thus being distinguished from other congeners. Glandular cell outlets type 2 are present in subdorsal, laterodorsal, sublateral and ventrolateral positions on trunk segment 2, in subdorsal position on trunk segment 4, in midlateral position on trunk segment 5, and in sublateral position on trunk segment 8. Trunk segment 2 has a midventral fissure; trunk segment 11 with middorsal protuberance and at least partially subdivided tergal plate; tergal extension with long subterminal seta. This species is well recognized by the presence of sexual dimorphism remarkably expressed in the length and shape of lateral terminal spines. Females have very short and stout lateral terminal spines, while males possess very long lateral terminal spines with a thin and flexible distal portion about three times longer than those in females.
Sea pen fields function as critical biogenic structures that add three-dimensional complexity to soft-sediment habitats, making them priority targets for marine conservation and subsequent monitoring. However, the capacity of certain species to completely retract beneath the sediment introduces a significant detection bias into non-invasive visual surveys. To quantify these autogenic retraction dynamics, two high-resolution camera-equipped benthic landers were deployed 600 m apart within the Gully MPA (northwest Atlantic) from October 2022 to July 2023, capturing seafloor images at 30-min intervals. Image time-series from the primary site, dominated by the sea pen Pennatula aculeata, were analyzed using a combination of manual annotations (Lightroom, BIIGLE) and supervised machine learning pixel-segmentation (RootPainter). While individual P. aculeata colonies remained visible across 70–90
The opening of the Suez Canal in 1869 initiated a decades-long migration of hundreds of Indo-Pacific and Red Sea species into the Mediterranean Sea. One such species, the nakedband gaper (Champsodon nudivittis), was first recorded in the Levantine Sea in 2008. It subsequently spread westward to the Southeastern Aegean Sea in the early 2010s and widely throughout the North Aegean Sea during the early 2020s. However, the strong morphological similarities within the Champsodontidae family often complicate accurate species identification. To address this, the present study analyzed Champsodon specimens collected from the North Aegean Sea using a combined approach of morpho-anatomical and genetic techniques. Standard diagnostic features, including anatomical, morphometric, and meristic traits, were complemented by landmark-based geometric morphometric analysis of body form that was carried out using digital images of the body and head. DNA barcoding, specifically sequencing the cytochrome c oxidase subunit I gene, was used to confirm species identification. The results demonstrated overall consistent morpho-anatomical patterns among specimens, with only minor variations in meristic and scale traits. These findings support the conclusion that C. nudivittis is likely the sole Champsodon species introduced into the Mediterranean.
Allotanais Shiino, 1978 is a poorly known tanaidacean genus represented by a single species, A. hirsutus (Beddard, 1886), originally described from Prince Edward Island (southern Indian Ocean, Subantarctic) and later redescribed from Subantarctic localities. Examination of material collected from intertidal and shallow subtidal habitats in the Strait of Magellan revealed specimens that consistently differ from A. hirsutus in several diagnostic characters. These specimens are herein described as a new species, and a rediagnosis of the genus Allotanais is provided. The genus is characterised by a pleon with five free pleonites, antennula articles 1–2 with a distal ring of long plumose setae, a distinctly ensiform maxillule, and elongate uropods with 11–13 articles. Allotanais kawesqari Revanales Esquete, sp. nov. differs from A. hirsutus in having ventral spiniform projections on pereonites 2–6, a cheliped carpus 1.5 times as long as broad in the female and as long as broad in the male, without a ventral triangular process, a ventromedial spiniform apophysis on the dactylus of pereopods 4–6, and a distal crown of long setae on the propodus of pereopod 6. Our findings indicate that the diversity of Allotanais is underestimated and suggest that the broad distribution previously attributed to A. hirsutus may partly reflect unresolved taxonomic diversity.
