Marine Biodiversity最新文献

Metridium senile (Linneaus, 1761) is simultaneously one of the most familiar sea anemones in temperate shallow water and a species embroiled in taxonomic and nomenclatural confusion. Their large body size, characteristic ruff of tentacles, and ability to thrive on artificial and natural substrates make these animals conspicuous and common on rocky ledges, pilings, wharfs, shipwrecks, and bivalve reefs. Their reported range encompasses all temperate habitats in the northern hemisphere plus a handful of locales in the temperate southern hemisphere that have typically been characterized as anthropogenic introductions. Understanding the range of M. senile has been confounded by confusion about its circumscription relative to its congeners and inconsistency in the names used. Here, we summarize the taxonomy of the genus and clarify the status of M. senile. Based on results of recent phylogenetic studies, we consider Metridium to have two valid species: M. farcimen (Brandt, 1835) and M. senile. We recognize M. senile as the valid, appropriate name for all populations of Metridium in the Atlantic and for some of the populations in the Pacific. We consider M. dianthus (Ellis, 1767), M. exile Hand 1955, M. huanghaiense Pei, 1998, and M. sinensis Pei, 1998 to be junior synonyms of M. senile. We clarify the differences between M. senile and M. farcimen, and comment on the status of M. canum Stuckey, 1914.

In order to counteract heavy foreland losses in the lower reaches of the Weser estuary, a system of sedimentation fields surrounded by brushwood groynes was constructed in 1958. Over the next forty years, the land accretion process was monitored by surveys of bottom-surface elevation, sedimentology, development of vegetation cover and changes in bottom-fauna composition. From the viewpoint of coastal protection, the sedimentation fields achieved a continuous growth of half a metre within forty years and successfully reduced the regression of the eroding shoreline. The ecological results represent a documentation comprising all succession stages from a bare tidal flat to a vegetated salt marsh. However, though the larger parts of the fields had already exceeded mean high-water level at the final survey of 1997, aquatic elements were still present in the vegetation as well as in the bottom fauna. The lack of a seaward inclination was most likely the reason, why saline water from spring tides and storm surges remained enriched in the soil. With growing elevation and condensing vegetation, each of the fields had developed a branched creek system and a varied geomorphological relief. Their habitat and species diversity proved to be equal to naturally grown mainland salt marshes.

Chondrichthyans are a very important taxon that plays a top predator role in the trophic level of the food web, and species are particularly vulnerable to exploitation in the marine ecosystem. The deep waters of the eastern Mediterranean Sea have been less studied than the continental shelf, especially for the chondrichthyans. Therefore, the present study was conducted to investigate the spatio-temporal distribution of chondrichthyans collected monthly in eight different (200–900 m) depth strata during different periods (2010–2011 and 2019–2021) using an otter bottom trawl. A total of 17 species were identified in upper bathyal, composed of 6 batoids, 10 sharks, and one chimaera. The constant species (dominance: DO% > 50) in the study area were Galeus melastomus, Scyliorhinus canicula, Etmopterus spinax, and Raja clavata. The most abundant species was E. spinax, followed by G. melastomus. Fourteen and 15 species were caught during the first and the second survey, respectively. Biodiversity characteristics (number of species, abundance, and diversity indices) varied only with bottom depth. Two different depthwise assemblages were estimated along the bottom depth gradient; ≤ 500 m and > 500 m. The discriminator species were R. clavata, S. canicula, G. melastomus, Dipturus oxyrinchus, and Squalus blainville found on the upper slope and E. spinax, G. melastomus, and Centrophorus cf. uyato found on the lower slope. With our results, total number of demersal chondrichthyan species found in the bottom (bathyal and continental shelf) of Antalya Bay was reached to 26 species.

The present study reports the occurrence of several specimens of the penaeid shrimp Penaeus notialis in the Gulf of Cadiz (Spain). The southern pink shrimp is a penaeid originating from east and west Atlantic tropical coastal waters. New observations of tropical species in temperate waters have increased in the last 20 years. This species may have been able to expand successfully northward to European waters, probably favored by global warming, although an accidental introduction by ballast waters cannot be completely discarded. The widespread presence of African biota such as P. notialis in the Gulf of Cadiz ecosystem underscores the necessity of establishing a long-term monitoring program that focuses on this and other currently established non-native species.

Abstract

A new species of the genus Lunovula Rosenberg, 1990, Lunovula supingae sp. nov. feeding on deep-sea hydroid Solanderia sp. (Solanderiidae, commonly known as tree hydroid) is described and illustrated from the East China Sea and South China Sea. It is most similar to Lunovula venusta Tsuchida & Kurozumi, 1999 in general shell shape but can be distinguished from the latter by having a more elevated funiculum with two large raised teeth, higher number of labial teeth, less protruding posterior extremity, and most notably, by having an outer lip that entirely thickens to the outside. This represents the first record of a pediculariid species feeding on a hydroid other than a hydrocoral. Phylogenetic analyses based on the COI and 16S rRNA genes using Bayesian inference and maximum likelihood showed that Lunovula supingae sp. nov. falls into the family Pediculariidae, supporting the systematic placement of Lunovula in the family. Furthermore, the phylogenetic analyses recovered the Ovulidae as polyphyletic, suggesting that this family needs a further taxonomic revision.

During the expedition of the NSCMB FEB RAS aboard the R/V Akademik M.A. Lavrentyev to the Koryak slope of the Bering Sea, Northwest Pacific (NWP) in 2018, three species of the family Caprellidae were collected in a seep activity zone at a depth of 658–662 m using a remotely operated vehicle (ROV) Comanche-18. Two morphospecies of the genus Caprella Lamarck, 1801 were represented by a few juveniles or damaged specimens. The species of the genus Liropus Mayer, 1890 sampled at three stations appeared to be new to science. The genus Liropus is known from the shelf and bathyal zones of tropical and low-boreal waters of the Atlantic and Pacific Oceans. Thus, L. beringi sp. nov., described herein, is the northernmost record of the genus. The new species can be identified by the following combination of features: absence of eyes, three-segmented pereopod 5, presence of two proximal projections on the palmar margin of gnathopod 2 with two grasping spines on each projection. Data on the NWP bathyal fauna of Caprellidae is summarized and discussed. A key to the bathyal species of Caprellidae from the NWP is provided.

Changing temperature and ocean acidification are well-recognised consequences of climate change in marine systems. In contrast to global trends, the South African west coast is experiencing cooling due to increased frequency and intensity of upwelling. The implications of concurrent cooling and acidification for marine biota are poorly understood, particularly at the community level. This laboratory study assessed how cooling and acidification might affect fouling communities along the South African west coast. Communities were experimentally exposed to two temperatures, 13℃ (current) and 9℃ (cooling), and three pH treatments, 7.9 (current), 7.6 and 7.4, for 18 days. Cooling and acidification altered community structure. Species diversity declined in response to acidification but was not affected by cooling. This was driven by greatest loss of species at 7.4 pH. Notably, acidification reduced the abundance of both calcifying and soft-bodied taxa, highlighting the vulnerability of taxa like ascidians to acidification. Overall, these results highlight the dominant threat posed by acidification, even for alien taxa that are often perceived as resilient to climate change. Additionally, in regions experiencing cooling, acidification may pose a greater threat to fouling communities than thermal changes.

Pollution, sedimentation and physical destruction from net fishing are more imminent threats to temperate corals than thermal stress in the Sea of Marmara due to the unique conditions there. Our previous investigation into a massive die-off of benthic suspension-feeders in this inland sea revealed a knowledge gap concerning the bacterial microbiomes of affected corals. We therefore elucidated five unexplored/less-studied coral microbiomes, including those of Alcyonium acaule and Savalia savaglia, using 16S rDNA-amplicon sequencing-based profiling. Only the microbiome of Eunicella cavolini was found to be significantly different (p-value < 0.01) from those of Paramuricea clavata and Veretillum cynomorium. Host identity explained ~ 30% of the observed variation and was clearly less important than spatiotemporal factors in determining microbiome composition. All microbiomes included 12 to 19 highly persistent core members (e.g. from genera Pirellula, Synechococcus, Spirochaeta, Endozoicomonas, Halospirulina, Terasakiella, Pelagibius and Spiroplasma) plus another 16 to 42 resident bacteria (prevalence 50—75%). Endozoicomonas bacteria were however notably less abundant than previously reported in Mediterranean gorgonians; possibly due to anthropogenic stressors in the Sea of Marmara. Twelve core taxa were strongly associated with only one coral species (Spearman’s ρ > 0.6, p-value < 0.01), which indicate host preference. The functional roles of the core taxa are discussed.

We report the first documentation of in situ release of reproductive materials by female colonies of a soft coral, in this case Sclerophytum cf. heterospiculatum, from the subtropical island of Okinawa, Japan. Spawn release was observed on the nights of September 2 and 3, 2023 (two and three nights after the full moon). This observation widens our knowledge on the reproductive strategies of octocorals, providing insights into mechanisms of persistence of soft corals in marine ecosystems.