Ribbon worms in the genus Balionemertes from Vietnam, the Philippines, Australia, and Guam—as well as Cephalothrix suni from Vietnam—were examined. Our observations indicate that the worms crawl mostly with their ventral surface upwards (the ventral surface being where the mouth opens), a behaviour that has not been documented in previous literature. Like many other worm species with colour patterns, they have a darker-coloured and/or more intensely patterned behavioural dorsal surface (= anatomical ventral surface in Balionemertes and C. suni) than the other side. This type of behavioural dorsoventral body-axis inversion among vermiform benthos seems to be rare—not having hitherto been known at least in the phylum Nemertea—and may be related to their feeding strategy, which should be observed in future studies.

The western Antarctic Peninsula harbours a diverse benthic marine community where dense canopies of macroalgae can dominate the shallow subtidal zone (0–40 m or greater). In the lower portion of this range (below 25–35 m depending on topography), invertebrates such as sponges and echinoderms can be found in greater abundance due to reduced competition for space from the algal species. Dendrilla antarctica (previously Dendrilla membranosa) is a common demosponge that thrives in both communities and is known for producing diterpene secondary metabolites as a defence against sympatric sea star and amphipod predators. Omnivorous mesograzers such as amphipods inhabit both communities; however, they are in greatest abundance within the macroalgal canopy. Due to the differences between habitats, it was hypothesized that specific amphipod species not susceptible to the defensive metabolites of D. antarctica would take refuge from predators in the chemically defended sponge. Analysis of the metabolome and amphipod communities from sponges in both habitats found correlations of metabolic profile to both abundance and habitat. These studies serve to inform our understanding of the complex ecosystem of the Antarctic benthos that stands to be dramatically altered by the rapidly changing climate in the years to come.

Describing species has been a formal, intellectually rich and influential applied and basic area of study for many of the past 260 years. While formally described eukaryotic diversity still falls short of estimated eukaryotic species diversity by many hundreds of thousands of species, some recent accounts have suggested a growing number of taxonomists are within reach of describing all extant species. We present a case study that illustrates, to the contrary, a recent ‘taxonomic impediment’ in part attributable to derogation of taxonomy as a scientific discipline: contemporary practice has re-interpreted taxonomy largely as an endeavour in enumerating species. We argue that challenges lie in (1) a poor understanding of taxonomy's epistemology; (2) excessive displacement of interest toward ecological or molecular studies; (3) over-interpretation of the contributions of multiple authors describing a species; and (4) perspectives that are strongly influenced by well-known taxa. The historical and recent literature on scyphozoans reveal ghosts of taxonomy's past that persist in the present, but suggest also that a renaissance enabled by integrative taxonomy is possible in the (near) future.

Macroalgal communities of coastal ecosystems play a key role in maintaining overall coastal biodiversity. In this study, habitat preference (macroalgal host preference) and temporal changes (season) of epifaunal communities associated to five macroalgal species such as Padina, Sargassum, Ulva, Acanthophora and Gracilaria were observed at seasonal intervals (summer and winter) for 2 years from May 2012 to March 2014 on the Jeddah coastal waters of the Red Sea. Major epifaunal groups observed included polychaetes, amphipods, isopods, gastropods, mussels and crabs. Polychaetes were represented by 10 species followed by amphipods with five species. The abundance of gastropods, polychaetes and mussels showed significant variation between the macroalgae irrespective of morphology. Generally, the abundance of these taxa were high on Padina and low on Sargassum. Significant seasonal changes were observed on the abundance of polychaetes, amphipods and isopods. The abundance of some epifaunal groups showed a significant relationship with environmental parameters such as surface water temperature, salinity, pH and dissolved oxygen content.

Sea cucumbers (phylum Echinodermata) are common members of benthic communities in many marine ecosystems. They function as nutrient recyclers and bioturbators of soft bottoms, and are preyed upon by birds, fishes, mollusks, crustaceans and other taxa. In the Central Mexican Pacific, Islas Marietas harbours a complex and diverse community of corals and benthic invertebrates, with a particularly well-represented assemblage of echinoderms. However, little is known about the diversity of holothurians in the area. Between 2012 and 2014 a bimonthly census was conducted at Islas Marietas, and seven species were recorded for the first time at this location: Holothuria (Halodeima) inornata, Holothuria (Mertensiothuria) hilla, Holothuria (Platyperona) difficilis, Neocucumis veleronis, Lissothuria ornata, Afrocucumis ovulum and Pachythyone pseudolugubris. The absence of previous records of these species may be associated with their low densities and cryptic habits. This report acts to fill a critical knowledge gap in the distribution of holothurians in the eastern tropical Pacific and highlights the under-appreciated biodiversity of this Natural Protected Area.

Meroplankton community studies in the Antarctic have primarily focused on the coastal waters of both the Antarctic Peninsula and the Ross Sea. The New Zealand International Polar Year - Census of Antarctic Marine Life (IPY-CAML) voyage to the Ross Sea during the late summer (February–March) 2008 provided the first meroplankton samples from three regions in the deep, oceanic waters of the Ross Sea (shelf, slope and adjacent offshore Antarctic waters of Admiralty Seamount and Scott Island). We used a combined morphological and molecular approach to identify 36 larval operational taxonomic units based on sequences from three loci (16S, 18S, COI), and exclude early developmental stages of holoplankton. Overall, larval abundance was lower than previous Antarctic studies (5.19 specimens per 100 m3), with larvae most abundant in the first 200 m of the water column and most diverse in the shelf region. Multivariate analysis revealed significant differences in the meroplankton community between regions and depth ranges, but with low similarity within these groupings; differences between water masses were undetectable due to the confounding effect with both region and depth. The influence of nearby benthic populations (e.g. the acorn barnacle Bathylasma corolliforme) and/or locally abundant taxa (e.g. the nudibranch Tergipes antarcticus) was evident in the meroplankton community.

The heteronemertean Baseodiscus hemprichii is widely distributed in tropical to temperate Indo-Pacific waters, with the northern limit of its range formerly at Shirahama, Japan. A specimen collected intertidally at Tateyama, Japan, extends the northern boundary of the species' distribution by about 1°18′ in latitude. This northward range extension may be in response to warming ocean temperatures.

The identification of key resource users and patterns of depletion alongside ecological data are presented for a small-scale traditional invertebrate fishery in south-western Madagascar. Men, women and children undertake the fishery in the Anakao region at different phases of the tide and for different purposes. Invertebrate harvest data from June to September 2000 estimated that more than 34 taxa were caught and were dominated by holothurians destined for export and molluscs for local consumption. Crustacea formed a small component of the fishery despite a high diversity and abundance of many potentially edible species. Although there was slight spatial variation in number of species caught and their relative importance to the fishery, Chicoreus ramosus, Fasciolaria trapezium and Octopus vulgaris were generally most heavily targeted and were amongst the most abundant in the catch. There were several indications of over-exploitation of invertebrate stocks, including the absence of many large bodied species, low abundance of high yield species, greater catch effort needed for high yield taxa, and higher diversity of targeted species (including many low yield taxa) at sites of higher human habitation.

Detailed redescriptions of the poorly known isopods Cymodocella tubicauda Pfeffer 1887 and Exosphaeroma gigas (Leach 1818) are presented in order to allow easier identification of these two species. Similarities to and differences from other species of the genus are discussed.

Echinozone quadrispinosa (Beddard, 1886) is reduced to synonymy with E. spicata (Hodgson, 1910). A key is given to the four Antarctic species together with biogeographical information.