To assess the course and status of recovery of rocky intertidal zonation after massive subsidence caused by the 2011 Great East Japan Earthquake, from 2011 to 2013 we censused the vertical distribution of 10 dominant macrobenthic species (six sessile and four mobile species) in the mid-shore zone of 23 sites along the Sanriku coastline, 150–160 km north-northwest of the earthquake epicentre, and compared the vertical distributions of each species with their vertical distributions in the pre-earthquake period. The dynamics of rocky intertidal zonation varied substantially among species. Among sessile species, one barnacle dramatically increased in abundance and expanded its vertical range in 2011, but then decreased and completely disappeared from all plots by 2013. Zonations of other sessile species shifted downward following the subsidence in 2011. With some species, there was no clear change in abundance immediately after the earthquake, but they then began to increase and move upward after a few years; with other species, abundance continuously decreased. There was no clear change in the vertical distribution of any of the mobile species immediately after the earthquake. Abundance of two mobile species was unchanged, but abundance of the others decreased from 2012 and had not recovered as of 2013.

Redescriptions of three species of Apseudidae are given based on samples collected from the Kurile-Kamchatka Trench during the Kurambio deep-sea expedition: Fageapseudes bicornis, F. vitjazi and Leviapseudes zenkevitchi. The identification key for species of Fageapseudes is given. Tanaidacean fauna from the main world trenches is discussed.

Coral reef environments support a great diversity of benthic organisms, of which zoanthids form an integral part. Studies have been carried out regarding the degradation of coral reefs and changes in community structure under the present dynamics of climatic change. Zoanthids are dominant among the observed fauna in these degrading reef ecosystems. Zoanthids are observed at mid and lower intertidal zones beyond 20 m from highest high tide level. In the present study, distribution patterns of zoanthid species along three coastal villages of Saurashtra coast, Gujarat were studied. Line intercept transect method was performed to assess the zoanthid coverage. A total of seven species of zoanthids were recorded during the survey. Palythoa mutuki formed the abundant species in the area with 45.99% coverage, followed by Zoanthus sansibaricus with 33.67% and Zoanthus cf. sansibaricus with 12.26% coverage. Abiotic parameters (sea surface temperature, salinity, dissolved oxygen, pH) and nutrient data (ammonia, phosphate, total suspended solids and nitrate) were also recorded during sampling to determine their influence on zoanthid colonies. Higher levels of DO were found to favour the growth of Palythoa mutuki and Isaurus tuberculatus, whereas increased SST was tolerated by Palythoa tuberculosa only. Ammonia and phosphate were negatively impacting the growth of Palythoa mutuki and Zoanthus spp. The study provides new information on quantitative zoanthid distribution and the dynamic changes exhibited by zoanthids in relation to various environmental parameters. Zoanthids could be looked upon as an adaptive species which may support reef resurgence in degraded reefs under stress from climate change effects.

Of the three species of the genus Squalus that occur in the Mediterranean Sea, S. blainville and S. megalops are very difficult to distinguish. This study assesses the variability in morphological features that have been used to differentiate between these species. Squalus were collected from stations within the 25-nautical mile Fisheries Management Zone around the Maltese Islands; 349 specimens were dissected and categorized into male and female, mature and immature, and individuals were randomly selected from each category to make up a sample of 169 specimens. For each individual, total length and first dorsal fin parameters were measured, and morphology of denticles isolated from the laterodorsal area, of the upper and lower teeth and of the chondrocranium was analysed. The first dorsal spine was shorter that the fin base in 93% of the specimens, which is typical of S. megalops; this character was not related to either gender or maturity. Chondrocrania with one lateral process (typical of S. blainville) and two lateral processes (typical of S. megalops) were present. Teeth from the same individuals showed morphological features that overlap between S. blainville and S. megalops. Both unicuspid (typical of S. megalops) and tricuspid denticles (typical of S. blainville) were observed on the same individuals. Twelve specimens (six having one and six having two lateral chondrocranial processes) were analysed genetically by sequencing of the mtDNA marker Cytochrome Oxidase Subunit I (COI). All resulted to be S. blainville showing that intraspecific variability in supposedly diagnostic morphological features is large enough to render these unreliable to tell apart these two species, especially in the field.

The anatomy of Crenella decussata (Mytiloidea) is described. Individuals of this circumboreal species occupy granular crypts composed of sand grains held in place by mucus. The swollen basal region of the tubule is occupied by an individual, which connects to the sediment surface by two posterior tubes accommodating the inhalant and exhalant streams. There is reduction in musculature and, most importantly, anterior foreshortening of the outer ctenidial demibranchs and loss of the labial palps. This creates an anterior space in the mantle for the initial brooding of fertilized ova by females to the prodissoconch stage. Subsequently, these larvae are transferred to the exhalant tube of the crypt wherein they attach by a single fine byssal thread and are further brooded until the crawl-away juvenile stage is attained. Experimental studies of larval behaviour suggest that parental pheromones sustain the female/offspring bond. Newly hatched individuals responded to parental exhalant water by actively attaching themselves using a byssal thread. This response persisted for 28 days, but not after 55 days when, we suggest, the pheromonal response ceases and offspring are developed sufficiently to take up life in their own nests. Offspring retrieved from parental crypts and fed continuously reached an average shell length of 500 μm after 7.5 months. Brooded offspring thus appear to rely on embryonal energy resources until post-metamorphosis, after which suspension feeding becomes essential for further growth and development before the parental crypt is vacated.

A mangrove forest can harbour several macroalgal assemblages growing on pneumatophores, roots, stems and other hard substrates. These algae belong to various genera, most typically Bostrychia, and form a community called the Bostrychietum. This study describes the fauna associated with the Bostrychietum and the effect of emersion time on the community. Seasonal samples were collected from pneumatophores on an island in Araçá Bay in 2012, in two areas, one on the border of the island and one inland. Each pneumatophore was considered a sample. The border samples, with a shorter emersion time, contained a richer algal flora associated with pneumatophores, and fauna with species of varied dietary habits. The inland samples, with a longer emersion time, contained only two algal genera and fauna species comprised mostly of omnivorous amphipods and desiccation-resistant detritivorous species. Macrofauna diversity and richness varied over time and were lower in spring. Therefore, the emersion time of the Bostrychietum and the period of the year affect the community structure, for both the macroalgae and the associated fauna.

A new species of polychaete, Armandia sampadae was collected from shallow sandy sediments off Rutland Island (57 m depth) and off North Andaman (52 m depth) during a benthic survey along the continental shelf of Andaman and Nicobar Islands. The major character which distinguishes this species from other members of the genus Armandia is the presence of a pair of large, flattened, rounded, stalked, pigmented, leaf-shaped ventral papillae at the ventral base of the ringed anal funnel and the occurrence of a pair of sub-triangular black pigmented spots in the basal portion of the ventral papillae.

A new species, Myrianida paredesi, and new records of Myrianida pentadentata (Imajima, 1966), and Procerarea micropedata (Hartmann-Schöder, 1962), are described from the central coast of Peru. Myrianida paredesi is characterized by the presence of an additional mid-dorsal, digitiform structure, quite similar to a dorsal cirrus (unique among all syllids), a subtriangular prostomium with a posterior region extended to middle peristomium, pharynx with a single elongated sinuation and a trepan with 14–15 equal teeth in a single ring. Descriptions of male and female stolons are also provided. The phylogenetic position of the new species within Myrianida is determined using molecular data, suggesting it is closely related to the species that share the presence of one ciliary troch per segment (except M. pachycera; unknown in M. australiensis), moderate number of equal teeth on trepan (except M. pachycera), and the mode of reproduction.

Descriptions of the collected specimens of Myrianida pentadentata (Imajima, 1966), and Proceraea micropedata (Hartmann-Schröder, 1962), both new reports to Peru, are also included.

The amphipod genus Aoroides is reported for the first time in European marine waters. Specimens of Aoroides semicurvatus and Aoroides curvipes were collected in oyster reefs in Arcachon Bay between 2009 and 2014 and in Hossegor Lake in 2014 (SW France). Specimens of Aoroides longimerus were collected in 2013 and 2014 in subtidal slipper limpet beds and Zostera marina meadows in Arcachon Bay and in 2014 on floating pontoons in the Bay of Brest (W France). These species, native to Asia, may have been accidentally introduced in Arcachon Bay and Hossegor Lake with oyster transfers and in the Bay of Brest through both oyster transfers and shipping.

Two new species are described from the Patagonia coast of Argentina, South Atlantic, and written keys to both genera are given. Chaetonema patagonica sp. nov. can most easily be differentiated from the other four species of the genus by the amphid shape and by the absence of a precloacal organ. Admirandus sanjuliensis sp. nov. is characterized by position of the Demanian pores, one preanal and two postanal, the configuration of pre- and postcloacal papillae and setae and by having the shortest stoma in the genus.

Sampling in subtidal waters of the Persian Gulf revealed a new species of ghost shrimp from the family Gourretiidae. Gourretia qeshmensis sp. nov. resembles G. sinica from the South China Sea and G. manihinae from Tanzania. Gourretia qeshmensis sp. nov. differs from these two species by characters of the ischium of the large cheliped, pereopod 3, exopod of the uropod and maxilliped 3.

Popularly known as blue land crab, Cardisoma guanhumi is heavily exploited as food and considered as an important economic resource in Brazil. In recent decades, the species has experienced a sharp population decline by the loss and/or degradation of its natural habitat and overfishing. The present study aimed to investigate the genetic variation and connectivity among 154 specimens of C. guanhumi sampled along the coast of Pernambuco in five different levels of tropical mangroves conservation. Nine ISSR primers were used for assessing the genetic variation of the species. The genetic diversity observed in C. guanhumi was high reinforcing the condition of a resilient species, indicating a good conservation status of this resource in Pernambuco. The hypothesis of panmixia was rejected in favour of a heterogeneous distribution of the genotypes of C. guanhumi (ФST = 0.19) despite the high gene flow observed in the study region. Such difference could be attributed to the candidate loci being under positive selection and differentially distributed between the geographic regions assessed. The genetic structure showed a pattern of fine-scale genetic structuring better fitted to a model of selection-mediated geographic cline. Cluster analysis and candidate loci under positive selection suggested that the populations of C. guanhumi in the North-central and South coasts of Pernambuco might be different management units and must be managed independently. In conclusion, exhaustion of natural stocks upon which fishing is totally dependent will lead to serious ecological and sociocultural impacts.

Existing population studies of deep-sea amphipods have focused on species that inhabit deep-sea vent or trench environments but few cosmopolitan species have been studied. Here we provide new insight into the life history and population ecology of the pan-oceanic scavenging amphipod Paralicella caperesca and discuss the influence of nutrient-rich submarine canyon environments on the growth and reproduction of this species. Data were collected through the dissection and measurement of 2997 P. caperesca from 14 samples taken from abyssal plains, continental slopes and submarine canyons in the North-East Atlantic. Sexual dimorphism was less pronounced than observed for other scavenging amphipod species but females were significantly larger and had shorter antennae than males. The size of oostegites in female P. caperesca varied considerably within size classes, ovaries contained a relatively large number of oocytes, and no empty ovaries were observed. These factors, in combination with absence of mature females, suggest that P. caperesca practices semelparity, a reproductive strategy that complements the feeding strategy of this obligate necrophage. Five male and seven female size-grouped cohorts were identified for P. caperesca. Cohorts from deep-sea submarine canyon populations showed consistently larger mean total body lengths than non-canyon cohorts. Individuals from canyon samples also expressed sexual characteristics at smaller sizes than non-canyon individuals. We hypothesize that these trends are indicative of nutrient-mediated growth, maturation, and reproduction in P. caperesca. The species is able to grow and reproduce relatively quickly in response to increased nutrient input in canyon environments and therefore dominates scavenging amphipod assemblages.

When and where marine eels spawn is poorly known even though species such as those of the family Congridae, Muraenidae and Ophichthidae can be caught in continental shelf habitats. The congrid genus Ariosoma includes small continental shelf eel species whose life histories are not yet known. Mature male and female eels of Ariosoma meeki were observed and captured on 17 August 2009 at the surface at night in the western side of the Kuroshio Current in the East China Sea close to new moon, while they were swimming slowly at the surface and exhibiting apparent reproduction-related behaviour. One male and one sex-unidentified eel (seemingly a male based on body shape) were observed to be chasing one larger female with their heads located near her urogenital pore area. The gonads of the female (540 mm) and the male (410 mm) that were caught by a long-handled dip net were in reproductive condition, because some eggs or seminal fluid were released during handling of the two specimens and high gonad-somatic index (GSI) values of 53 in the female and 20 in the male were recorded. This is one of the few cases in which fully ripe reproductive-condition marine eels have been observed or collected and it provides rare information about the spawning location and timing of this eel species.

We present some additional information to Acritagasyllis longichaetosus Lucas, San Martín & Sikorski 2010, the only representative of an enigmatic genus of Syllidae from subpolar areas off Norway, based on two newly found specimens and one male and another female stolons. The armature of the pharynx was incorrectly interpreted in the original description, having in fact a trepan instead of a single pharyngeal tooth as originally described. The reproductive stolons are herein described for the first time. With this new information we performed a maximum parsimony phylogenetic analysis that placed this genus within the subfamily Autolytinae, despite its peculiar morphological characteristics. For this reason, we propose a new diagnosis to the genus Acritagasyllis as well as a modified diagnosis of the subfamily Autolytinae.