The tip of the iceberg: extraordinarily high diversity while examining two infralittoral nematode communities on Okinawa-jima Island, Japan, using morphology and DNA barcoding.

Background: Nematodes are among the most diverse and abundant metazoans in aquatic habitats, contributing significantly to global biodiversity. Despite their abundance and importance, the presumed number of undescribed species is high and their diversity is often underestimated.

Methods: In this research, sediment samples were collected from three microhabitats (bare sand, seagrass, coral) in two sites around Okinawa-jima Island in subtropical southern Japan.

Biodiversity and biogeography of zooxanthellate soft corals across the Indo-Pacific.

Documentation of biodiversity and its geographical distribution is necessary to understand the processes and drivers of evolutionary diversification as well as to guide conservation and management initiatives. Among the most emblematic patterns of biodiversity in the world's oceans is the Coral Triangle (Indo-Australian Archipelago), widely recognized to be the center of species richness for a variety of marine life forms. The distribution of biodiversity remains incompletely documented, however, for a majority of reef-associated invertebrate taxa, including the zooxanthellate soft corals (Octocorallia) that dominate hard substrate on many Indo-Pacific reefs.

Marine litter on remote islands: Case study of beaches in Ishigaki and Taketomi Islands, Japan.

Marine litter pollution has become a global concern due to its adverse effects on biodiversity and general negative influence on marine ecosystem services. Marine litter pollution of remote islands is currently understudied due to accessibility challenges. This study evaluated marine litter abundance and distribution on 15 beaches around semi-remote islands of Ishigaki and Taketomi, Japan.

Parazoanthidae (Cnidaria, Zoantharia) associated with glass sponges on the Nishi-Shichito Ridge, northwestern Pacific Ocean, with the description of a new species.

Seamounts are biodiversity hotspots that face increasing threats from anthropogenic activities. Seamounts host diverse sessile suspension-feeding organisms such as sponges and anthozoans, which are crucial for seamount ecosystems as they construct three-dimensional habitats utilized by numerous other animals. Therefore, accurate identification of seamount fauna, in particular of sessile suspension-feeding organisms, is of paramount importance for robust conservation efforts.

Son of a beach: Coastal development and the loss of natural beaches over time (1919 to 2018) on Okinawa Island, southern Japan.

The coastline of Okinawa Island, Japan, has been affected by human-made alterations for decades, often from land reclamation and coastal defense construction. Here, we use an Imperial Japanese Army map made between 1919 and 1921 to describe the composition of the Okinawan coastline approximately 100 years ago, and by overlapping this old map with a modern-day map of Okinawa (2018), we identified 131 sites where coastlines showed clear human-made alterations. For these sites, we examined what kinds of ecosystems were lost and what has replaced them.

In situ observations confirm that the wrought-iron butterflyfish Chaetodon daedalma is a facultative corallivore.

Here, we provide the first in situ observations of foraging habitats of Chaetodon daedalma, which is endemic to the subtropical north-west Pacific. Overall, 62.4% of bites were from the substratum, 30.

The Trojan seahorse: citizen science pictures of a seahorse harbour insights into the distribution and behaviour of a long-overlooked polychaete worm.

Symbiotic marine invertebrates can be small, hidden or difficult to find, hampering the understanding of their distribution and ecological roles. is a polychaete inhabiting the gorgonian , where it lives in high densities within the host's coenenchyme and occupies burrows formed by host tissue near coral polyps. This study provides the first records of since its description in 1956, from colonies of Anthogorgiidae in southern Japan.

Assessment of marine litter interactions with urban coral reefs in Okinawa, Japan.

This study assessed different reef zones (lagoon, reef crest, reef slope) in three urban locations around Okinawa Island (Mizugama, Ginowan, Sunabe) and two marine protected areas around nearby Aka Island (Hizushi, Sakubaru) for marine litter pollution and litter interactions with reef organisms. A total reef area of 2250 m was surveyed by scuba diving, and 46 marine litter items were recorded. Litter density ranged from 0.

Trait networks: Assessing marine community resilience and extinction recovery.

Extensive global habitat degradation and the climate crisis are tipping the biosphere toward a "sixth" mass extinction and marine communities will not be spared from this catastrophic loss of biodiversity. The resilience of marine communities following large-scale disturbances or extinction events is mediated by the life-history traits of species and their interplay within communities. The presence and abundance of traits in communities provide proxies of function, but whether the breakdown of their associations with species loss can delineate functional loss remains unclear.

Diversity, composition and potential roles of sedimentary microbial communities in different coastal substrates around subtropical Okinawa Island, Japan.

Background: Marine benthic prokaryotic communities play crucial roles in material recycling within coastal environments, including coral reefs. Coastal sedimentary microbiomes are particularly important as potential reservoirs of symbiotic, beneficial, and pathogenic bacteria in coral reef environments, and therefore presumably play a core role in local ecosystem functioning. However, there is a lack of studies comparing different environments with multiple sites on the island scale, particularly studies focusing on prokaryotic communities, as previous investigations have focused mainly on a single site or on specific environmental conditions.

Abundance and distribution of marine litter on the beaches of Okinawa Island, Japan.

This study evaluated the distribution and abundance of marine litter on 30 beaches around Okinawa Island, Japan. Beach quality indices and multivariate statistical analyses were used to assess the quality of the beaches and their pollution patterns. A total of 11,626 items weighing 513.

Genome sizes and repeatome evolution in zoantharians (Cnidaria: Hexacorallia: Zoantharia).

Across eukaryotes, large variations of genome sizes have been observed even between closely related species. Transposable elements as part of the repeated DNA have been proposed and confirmed as one of the most important contributors to genome size variation. However, the evolutionary implications of genome size variation and transposable element dynamics are not well understood.

Coral assemblages at higher latitudes favor short-term potential over long-term performance.

The persistent exposure of coral assemblages to more variable abiotic regimes is assumed to augment their resilience to future climatic variability. Yet, while the determinants of coral population resilience across species remain unknown, we are unable to predict the winners and losers across reef ecosystems exposed to increasingly variable conditions. Using annual surveys of 3171 coral individuals across Australia and Japan (2016-2019), we explore spatial variation across the short- and long-term dynamics of competitive, stress-tolerant, and weedy assemblages to evaluate how abiotic variability mediates the structural composition of coral assemblages.

Temperate functional niche availability not resident-invader competition shapes tropicalisation in reef fishes.

Temperate reefs are at the forefront of warming-induced community alterations resulting from poleward range shifts. This tropicalisation is exemplified and amplified by tropical species' invasions of temperate herbivory functions. However, whether other temperate ecosystem functions are similarly invaded by tropical species, and by what drivers, remains unclear.

Review of microplastics in museum specimens: An under-utilized tool to better understand the Plasticene.

This study summarises the status of microplastic research in marine and freshwater specimens in natural museum collections around the world. Abundances, distributions, and types of microplastics in the archived collections are discussed. Museum collections can fill knowledge gaps on evolution of microplastic pollution before and during the Plasticene era.

Morphological and phylogenetic study of Acanthosquilla Manning, 1963 (Stomatopoda: Nannosquillidae) mantis shrimps, with description of two new species from the Ryukyu Islands, Japan.

Three species of nannosquillid mantis shrimps, including two new species, Acanthosquilla ryukyuensis n. sp. and Acanthosquilla shoheii n.

The Complete Genome Sequences of 13 Species of Brachycnemina (Cnidaria, Hexacorallia, Anthozoa, Zoantharia).

We present the complete genome sequences of 13 species of the zoantharian suborder Brachycnemina (Haddon, and Shackleton, 1891; Poliseno et al., 2020). Genome sequencing was performed on genetic material from single wild-collected individuals.

A Draft Genome Sequence of (Antedonidae, Comatulida, Crinoidea, Echinodermata).

We present the complete genome sequence of . Genome sequencing was performed on genetic material from a single wild-collected individual. The sequence reads were assembled using a de novo method followed by a finishing step.

The Complete Genome Sequences of 7 Species of (Epizoanthidae, Zoantharia, Hexacorallia, Cnidaria).

We present the complete genome sequences of 7 species of the zoantharian genus . Illumina sequencing was performed on genetic material from single wild-collected individuals. The reads were assembled using a de novo method followed by a finishing step.