Gut content metabarcoding of specialized feeders is not a replacement for environmental DNA assays of seawater in reef environments.

In tropical marine ecosystems, the coral-based diet of benthic-feeding reef fishes provides a window into the composition and health of coral reefs. In this study, for the first time, we compare multi-assay metabarcoding sequences of environmental DNA (eDNA) isolated from seawater and partially digested gut items from an obligate corallivore butterflyfish () resident to coral reef sites in the South China Sea. We specifically tested the proportional and statistical overlap of the different approaches (seawater gut content metabarcoding) in characterizing eukaryotic community composition on coral reefs.

Safeguarding Imperiled Biodiversity and Evolutionary Processes in the Wallacea Center of Endemism.

Wallacea-the meeting point between the Asian and Australian fauna-is one of the world's largest centers of endemism. Twenty-three million years of complex geological history have given rise to a living laboratory for the study of evolution and biodiversity, highly vulnerable to anthropogenic pressures. In the present article, we review the historic and contemporary processes shaping Wallacea's biodiversity and explore ways to conserve its unique ecosystems.

, a new species of pygmy seahorse from South Africa, and the first record of a pygmy seahorse from the Indian Ocean (Teleostei, Syngnathidae).

A new species and the first confirmed record of a true pygmy seahorse from Africa, , is herein described on the basis of two specimens, 18.9-22 mm SL, collected from flat sandy coral reef at 14-17 meters depth from Sodwana Bay, South Africa. The new taxon shares morphological synapomorphies with the previously described central Indo-Pacific pygmy seahorses, , , , and , and , including diminutive size, twelve trunk rings, prominent cleithral ring and supracleithrum, spines on the fifth and twelfth superior and lateral trunk ridges, respectively, and prominent wing-like protrusions present on the first and/or second superior trunk rings posterior to the head.

Environmental DNA can act as a biodiversity barometer of anthropogenic pressures in coastal ecosystems.

Loss of biodiversity from lower to upper trophic levels reduces overall productivity and stability of coastal ecosystems in our oceans, but rarely are these changes documented across both time and space. The characterisation of environmental DNA (eDNA) from sediment and seawater using metabarcoding offers a powerful molecular lens to observe marine biota and provides a series of 'snapshots' across a broad spectrum of eukaryotic organisms. Using these next-generation tools and downstream analytical innovations including machine learning sequence assignment algorithms and co-occurrence network analyses, we examined how anthropogenic pressures may have impacted marine biodiversity on subtropical coral reefs in Okinawa, Japan.

Digging for DNA at depth: rapid universal metabarcoding surveys (RUMS) as a tool to detect coral reef biodiversity across a depth gradient.

Background: Effective biodiversity monitoring is fundamental in tracking changes in ecosystems as it relates to commercial, recreational, and conservation interests. Current approaches to survey coral reef ecosystems center on the use of indicator species and repeat surveying at specific sites. However, such approaches are often limited by the narrow snapshot of total marine biodiversity that they describe and are thus hindered in their ability to contribute to holistic ecosystem-based monitoring.

Behavioural and pathomorphological impacts of flash photography on benthic fishes.

Millions of people take animal pictures during wildlife interactions, yet the impacts of photographer behaviour and photographic flashes on animals are poorly understood. We investigated the pathomorphological and behavioural impacts of photographer behaviour and photographic flashes on 14 benthic fish species that are important for scuba diving tourism and aquarium displays. We ran a field study to test effects of photography on fish behaviour, and two laboratory studies that tested effects of photographic flashes on seahorse behaviour, and ocular and retinal anatomy.

Time to stop mucking around? Impacts of underwater photography on cryptobenthic fauna found in soft sediment habitats.

Scuba diving tourism is a sustainable source of income for many coastal communities, but can have negative environmental impacts if not managed effectively. Diving on soft sediment habitats, typically referred to as 'muck diving', is a growing multi-million dollar industry with a strong focus on photographing cryptobenthic fauna. We assessed how the environmental impacts of scuba divers are affected by the activity they are engaged in while diving and the habitat they dive in.

Biofluorescence as a survey tool for cryptic marine species.

As ecosystems come under increasing anthropogenic pressure, rare species face the highest risk of extinction. Paradoxically, data necessary to evaluate the conservation status of rare species are often lacking because of the challenges of detecting species with low abundance. One group of fishes subject to this undersampling bias are those with cryptic body patterns.

Cohabitation promotes high diversity of clownfishes in the Coral Triangle.

Global marine biodiversity peaks within the Coral Triangle, and understanding how such high diversity is maintained is a central question in marine ecology. We investigated broad-scale patterns in the diversity of clownfishes and their host sea anemones by conducting 981 belt-transects at 20 locations throughout the Indo-Pacific. Of the 1508 clownfishes encountered, 377 fish occurred in interspecific cohabiting groups and cohabitation was almost entirely restricted to the Coral Triangle.