This study reports on the life history of a rare alpheid shrimp, Salmoneus carvachoi, in the tropical western Atlantic. At an intertidal flat in Pontal Bay, Ilhéus, Bahia, north-eastern Brazil, S. carvachoi was collected from within burrows of the axianassid mud shrimp Axianassa australis and the caridean snapping shrimps Alpheus estuariensis and Alpheus chacei. These and earlier studies that reported S. carvachoi in dwellings constructed by other larger burrowing crustaceans suggest that S. carvachoi is a generalist species that establishes facultative symbiotic partnerships with larger burrowing decapods. We collected a total of 52 individuals during the sampling period (1 year); 19 (36.5%) of these shrimps carried embryos underneath the abdomen. The mean ± SD carapace length was 4.7 ± 0.7 and 5.5 ± 0.3 mm in non-brooding and brooding shrimps, respectively. All collected specimens, whether or not brooding embryos, bear appendices masculinae on the endopods of the second pleopods. Burrows harboured only one or two shrimps and never three or more shrimps. Pairs of shrimp that inhabited burrows consisted of two brooding shrimps (N = 3 pairs), two non-brooding shrimps (N = 3), or one brooding and one non-brooding shrimp (N = 1). The presence of appendices masculinae in all collected shrimps, whether or not brooding embryos, and the pairing of brooding shrimp within host burrows suggest that S. carvachoi is a simultaneously hermaphroditic species.

Species of dinophycean Amphidomataceae are producers of phycotoxins classified as azaspiracids. We provide the first records of two of their constituent species, Amphidoma languida and Azadinium dexteroporum, for the Irminger Sea off Iceland. Morphological examination and molecular characterization, including uncorrected mean pairwise distances between sequences of the Internal Transcribed Spacer (ITS), doubtlessly assigned the sub-Arctic strain 2A11 to the reference of Amphidoma languida. Strain 2A11 produced AZA-38 and AZA-39, corresponding to the toxin profile described for the type material. The sub-Arctic isolate 1D12 differed significantly in terms of ITS genetic distance (p = 0.04) from a Mediterranean Azadinium dexteroporum strain, but our morphological analysis did not reveal any major or stable diagnostic traits between the reference strain of Azadinium dexteroporum and the new strain described here. In contrast to the Mediterranean strain of Azadinium dexteroporum, the sub-Arctic strain 1D12 did not produce any known azaspiracids. The new records of Amphidoma languida and Azadinium dexteroporum from the Irminger Sea imply an important range extension of the species, formerly known from the northern and eastern Atlantic (Amphidoma languida) and from the Mediterranean area (Azadinium dexteroporum) only. Together with three new species of Azadinium recently described from the same expedition, the results clearly show that the biodiversity of the Amphidomataceae in the sub-Arctic is remarkably large.

Until recently, the only sponge-associated genera in the order Zoantharia were Parazoanthus (family Parazoanthidae), Epizoanthus and Thoracactis (family Epizoanthidae), both within the suborder Macrocnemina. The taxonomy of the genus Parazoanthus, as originally described, has been undergoing revision since 2010, with several species, genera and even families described. In 2015, multiple molecular markers were used in combination with morphological characteristics to erect the genus Umimayanthus inside the family Parazoanthidae. It included three species described from southern Japan, with other records for some of the species from the Great Barrier Reef, New Caledonia and the Red Sea. However, little is known of its distribution in the Pacific Islands. Here we report on the finding of Umimayanthus specimens in Palau, Micronesia, representing the first records for this region. A total of 32 specimens of Umimayanthus were collected from seven different locations; eight of the specimens were identified as Umimayanthus chanpuru, while the remaining 24 colonies were only identified to genus level.

Plocamopherus ocellatus, a conspicuous but very rare Erythraean nudibranch, was first collected in the Mediterranean Sea off the Israeli coast in 1977, but no additional observations from Israeli waters were recorded in the scientific literature. Biodiversity assessment surveys of the hard bottom biota off the Mediterranean coast of Israel and sightings by recreational divers/underwater photographers in the past dozen years seem to support the presence of a local self-sustaining population off the Israeli coast.

The under-rock guild of nemerteans from Lough Hyne, south-west Ireland was recorded during a long-term benthic survey of the marine reserve. From 2004 to 2014, common nemerteans were recorded annually in late summer for ten historical monitoring sites (each 10 m of shoreline); more comprehensive surveys were completed in 2012 (4126 low-intertidal to shallow-subtidal rocks were turned) and 2014 (1289 rocks turned) with supplementary information in 2015. The bootlace worm, Lineus longissimus, was the most abundant nemertean species. It was significantly more abundant at the extremely shallow East Castle site than the other nine sites; peak populations (across all ten sites) occurred in 2012. The Lusitanian nemertean Paradrepanophorus crassus was abundant after 2007. To date, 13 nemertean species were recorded with numerous new records for the lough, including Tubulanus annulatus, Micrura purpurea, Ramphogordius sanguineus, Micrella rufa and Emplectonema gracile. Three additional nemertean species were previously recorded, indicating that at least 16 species occur in the lough. Given the low densities and paucity of comprehensive earlier records, we are not able to ascertain definitely whether these species are new incursions or if sparsely distributed residents have increased.

The behavioural responses of scavenging animals to mackerel (Scomber scombrus) baits were studied by short-term video photography in shallow water (16–18 m depth) at Lough Hyne, Ireland. Earliest arrivals (after seconds/minutes) at baits were small fish or swimming crabs (Liocarcinus depurator), followed by crawling portunid crabs. After tens of minutes, juvenile whelks 2–4 mm shell length (Nassarius reticulatus and/or Nassarius incrassatus) sometimes arrived to feed. They moved at a mean speed of 1.24 (SD 0.392) mm s−1. After tens of minutes or hours, single large scavengers arrived, consuming most of the bait; the most common of these were Cancer pagurus that fed in a wasteful fashion, generating large quantities of mackerel scraps. Cancer pagurus moved into view at a mean speed of 48.7 (SD 16.9) mm s−1(39 times the whelk speed). A single individual of C. pagurus (197 mm carapace width) arrived at a bait carrying 24 juvenile whelks on the dorsal surface of its carapace. No whelks were present on walking legs or chelipeds. The crab fed for 6.8 min and 3 whelks fell off before it departed. The nature of this crab/whelk association is discussed; on balance it appears that it is a previously unreported example of phoresy/phoresis. No whelks were observed being carried by other edible crabs or upon large numbers of scavenging portunid crabs.

Rare and cryptic species can be easily missed during ecological surveys of coral communities. This study reveals a disparity in the reported geographic range of a rare species, Echinomorpha nishihirai, between three different sources; none of which are wholly consistent with the available published occurrence records. Discrepancies in the species ranges reported in two comprehensive online databases are greater for rare, compared with common, coral species, suggesting a need for a more cautious treatment of rare species in biogeographic studies.

Three adult specimens of the fish species Acentrogobius dayi were collected from Sawa Lake, south-west of Baghdad, Iraq. The current report represents the first record of A. dayi from Sawa Lake and from other inland water bodies of Iraq.

Ascension and Saint Helena Islands are isolated volcanic islands in the South Atlantic Ocean. Records of annelids from the family Amphinomidae, commonly known as fireworms, are rare. Fireworm species recorded in both localities include Eurythoe complanata and Hermodice carunculata, which are broadly distributed throughout the Atlantic Ocean. Here we present the characterization of both species from a recent expedition to Ascension and Saint Helena. Morphologically, specimens from H. carunculata correspond to the West Atlantic population, while E. complanata specimens were clearly identified based on chaetal type. A genetic analysis, including material from Ascension and Saint Helena Islands, will be necessary to elucidate the genetic connectivity across the Atlantic Ocean.

Even though very few biological data on dinoflagellates from Iraqi aquatic ecosystems are available to date, there are none on the genus Scrippsiella. For this reason, the survey was conducted along four sites in the Shatt Al-Arab River between November 2009 and July 2010. A dense population of Scrippsiella-like dinoflagellate was observed in the studied samples during November and December 2009. Less dense population of the same taxon was encountered in the downstream sites in July 2010. Based on observations of thecal plate pattern in epifluorescence microscopy, the species was attributed to Scrippsiella trochoidea. The occurrence of S. trochoidea is reported for the first time in Iraqi waters from a wide range of temperature (17.9°C–35.2°C) and salinity (2.3–16.7).

One species of Microtabella, Microtabella interrupta, is widespread and has been known since the 19th Century but it has a convoluted taxonomic history leaving it presently the only species in the genus. The name interrupta derives from the chain-forming habit and the plastids being confined to a portion of the cell by a set of distinctively distended septa. This character makes it very easy to identify and very easy to overlook similar species, especially because the tabulate frustules are most often seen in girdle view. I found specimens of a new taxon that had these characters and was distinguished with difficulty in girdle view by the coarser striae on the copulae and the recurved edges of the septa. However, in valve view Microtabella rhombica n. sp. has a much broader, rhombic outline. Ultrastructural differences include a more elongated apical pore field with a prominent spine, biseriate striae on the copulae and a different form of the ligule (a raised bar on the last copula). Like Microtabella interrupta, the mature epitheca of Microtabella rhombica comprises numerous copulae with nearly flat septa, two copulae with distended septa and four hyaline pleurae that lack septa. This species could well be widespread but, as with other monospecific genera in which there is a strong distinguishing character, care must be taken to look beyond the outstanding feature.

The amphinomid polychaete Linopherus cf. canariensis was recorded for the first time in the coast of Rio de Janeiro (South-east Brazil). In 2011, a total of 15 specimens were collected in the intertidal zone of Itaipu Beach (Niterói) in dead Encope emarginata test fragments. In this study, the specimens are described, and a brief discussion about their morphological variation and invading potential is provided.

Three individuals of small, young giant squid Architeuthis dux were caught in or near Japanese coastal waters during April–June 2013. The first occurrence of a young individual of 140.8 mm dorsal mantle length with a total weight of 44.81 g was recorded on the coast off Uchinoura, Kagoshima, Kyushu Island, southern Japan. The remaining two young individuals, both measuring 332.0 mm in dorsal mantle length with total weights of 390.63 and 356.95 g respectively, were caught on the coast off Hamada, Shimane, south-western Sea of Japan. Most morphological traits of all the specimens were consistent with those of A. dux, which was supported by further genetic analysis. Here we present some morphological traits of young giant squids with morphometric data and photographs.

The present report provides the first account of the shallow water hydroids of St. Helena, which comprises 17 species, and adds nine new records to the hydrozoan fauna of the Tristan da Cunha group of islands, raising their number to 34. A total of 34 species, belonging to five families of Anthoathecata and eight families of Thecata, are discussed herein. Although distributional data are given for each species, brief diagnoses are provided for the lesser known or unidentifiable species, and the common taxa are occasionally accompanied by succinct remarks. Illustrations are provided for nearly all species in order to justify their identification and to facilitate identification by others. Fiordlandia protecta and Filellum bouvetensis, both from Gough Island, represent the second world records and extend their known area of distribution.

The surrounding area of the St. Peter and St. Paul Archipelago (SPSPA) (0°55′10″N 29°20′33″W) was investigated in order to verify the physical and chemical influences in species composition and abundance, and the patterns of distribution of phytoplankton in the water column, especially in the thermocline depths. The expedition was held on board the Cruzeiro do Sul Hydro-oceanographic ship, from 21 to 23 July 2010 in two perpendicular and opposite transects. A cylinder-conical net and Niskin bottles were used. Two water masses were identified (Tropical Water and South Atlantic Central Water), and the thermocline depths varied from 40 to 110 m. A total of 128 species of phytoplanktonic organisms were identified, belonging to four phyla. The most conspicuous species was the cyanobacteria Trichodesmium thiebautii; nevertheless, 22 species were considered new registers for the region. The total phytoplanktonic density (1 × 103 to 183 × 103 cells l−1) was low and typical of oligotrophic regions, decreasing slightly with depth. Among the 35 species identified in the vertical distribution, 22 were present in the thermocline depth. The total density of Trichodesmium thiebautii, Oxytoxum longiceps and Protoperidinium minimum had significant correlations with the physical and chemical parameters. These data indicate that SPSPA can be associated to an island mass effect in the local oceanic circulation that mainly affects the physical and chemical characteristics of the surrounding waters. Consequently, these interactions influence the phytoplanktonic community, mainly those located at the end of the photic zone and those that are under the influence of thermocline oscillation.

This report presents the first record of the crowned jellyfish Netrostoma coerulescens from Pakistani waters and establishes its first confirmed record from the Arabian Sea. The jellyfish is briefly described and compared with its congeners. In the region, this is the second record of the genus; the first was Netrostoma setouchianum.

We report a first record of the alien fish Cryptocentrus caeruleopunctatus in the Mediterranean Sea. The fish was found along the northern coast of Israel. This finding increases the number of Red Sea gobies in the Mediterranean to six, and the number of shrimp-gobies to two. A dense colony of this species was observed at depths of 20–30 m in the Rosh Ha'nikra-Achziv Nature Reserve.