Shellfish culture, based on ecological and market assessment, is considered a driving force for socio-economic change in ecologically complex coastal systems such as lagoons throughout the Mediterranean area. To diversify fish production, the Pacific oyster Crassostrea gigas was cultured at commercial farms in the Varano Lagoon (SE Italy). The aims of this study were to evaluate through four condition indices (CI, CICG, CIE and AFNOR index), the Polydora index (PI), lipid content, quality and market aspects of oysters reared at two different sites (FO and LA) of the Varano Lagoon, which are characterized by different hydrodynamic conditions. The results of this study highlighted the potential economic benefits associated with sustainable aquaculture development in the Varano Lagoon, proving that the area surrounding the LA site was more suitable for oyster culture, reaching commercial size (60 mm) in a shorter time (6–8 months). Higher growth performance of oysters was observed in the spring, when the nutrient availability positively affected the feeding response of suspension feeders. The opposite was found in winter and in summer, when the decrease in growth could be due to the reduction of nutrient and to the increase of salinity, TSM and ISM. The presence of the mud blister worm (Polydora sp.) during rearing could be a real problem, as it damages oyster market value and threatens serious financial loss to the local farmers.

The present study describes the morphological changes of the mouthparts and foregut of the freshwater prawn M. acanthurus that occur during the development of the larvae and first juvenile. The results indicate that the zoeae I have mouthparts with reduced setae and a structureless foregut that indicates obligatory lecithotrophic behaviour. There is an increase in the number of setae in these structures between the zoea II and the juvenile stage, indicating the adaptation of the organism for feeding. More complex structural alterations were observed in the first juvenile, which acquires benthonic habits, which ensure the capture and ingestion of a diversity of feeding resources found in the substrate.

Life history accounts for the chance of survival and reproductive success of a species, considering, for example, when, how often and how much a species reproduces. Consequently, it is directly related to the success or failure of bioinvasions. Here, we investigated some aspects of the life history of the cryptogenic calcareous sponge Sycettusa hastifera. A population from Arraial do Cabo, Brazil (south-western Atlantic) was investigated from September 2008 to December 2009 by monthly collections and histological analyses. We observed that S. hastifera reproduced continuously throughout the year without seasonality and presented high fecundity. The fecundity was not different depending on the sponge body part (top or base), but it was related to the wet weight of the sponge (although a minimum size was not required for reproduction). Reproduction could not be predicted by the seawater temperature. The reproductive characteristics of S. hastifera were similar to those of other previously studied calcareous sponges. Sycettusa hastifera shows traits of an invasive species, such as high fecundity, short life cycle, early sexual maturity and the ability to use pioneer habitats. Consequently, it possesses several characteristics that would allow it to invade new areas.

Ucides cordatus is a semi-terrestrial crab and key species endemic to mangrove areas of eastern Americas. In North-eastern Brazil this crab holds a major socio-economic function for artisanal fisheries, as in the São Francisco River Estuary (10°30′27″S 36°23′45″W). Nevertheless, decreases in this species’ stock have been reported since 2000, requiring assessments of the crab population for conservation and management purposes. This study aims at assessing the population status and the fishery potential of this species in the mangroves of this estuary and suggests strategies for its fishery and conservation, according to the guidelines of the National Management Plan for U. cordatus Sustainable Use. Six different sites established in 30 km2 of mangroves were sampled, with the density of U. cordatus burrows estimated to evaluate the population structure using the measure of burrow diameters. Results show that the crab mean burrow size was 56.82 (±12.2) mm and that the medium-size crabs (40–70 mm) are the most abundant. The total mean crab density was 1.2 crabs m−2, from which the density of crabs in commercial size (0.85 ± 0.55 crabs m−2) was significantly higher than those in non-commercial size (0.35 ± 0.21 burrow m−2). These mangroves showed a high potential for the crab fishery, with an immediate extractive potential (IEP) of 71.2% and future extractive potential (FEP) of 28.8%. Nevertheless, a lower crab density, probably due to high crab mortality, mangrove deforestation for shrimp farming and high fishery pressure, is a limiting factor for local fishery. We conclude that mangrove areas more appropriate for U. cordatus fishery (extractive areas) show higher mean crab size, IEP and density of commercial crabs, wherein a fixed exploitation rate or/and a fixed escapement rule should be considered. Exclusion areas, intended for the conservation, show lower values of these population parameters and higher FEP, wherein the fishery should be prohibited. These management strategies should also be considered in other Brazilian mangrove areas showing similar crab population structure, thus contributing to the National Management Plan for U. cordatus Sustainable Use.

In this study photo-identification data were used to better understand movements, population structure and abundance of common bottlenose dolphin (Tursiops truncatus) in south-west England and surrounding waters, to inform conservation efforts. A catalogue of 485 photographic sightings of 113 individuals was compiled from ~150 common bottlenose dolphin encounters made on 87 dates between March 2007 and January 2014. From these and other data, three likely sub-populations were identified in the western English Channel, demarcated by bathymetry and distance to land: (1) south-west England – inshore Cornwall to Devon, (2) offshore English/French waters and (3) inshore France from Brittany to Normandy. Maximum abundance estimates for south-west England coastal waters, using two methods, ranged between 102 and 113 (range 87–142, 95% CL) over the period 2008–2013, likely qualifying the region as nationally important, whilst the yearly maximum was 58 in 2013. The population was centred on Cornwall, where 19 well-marked animals were considered ‘probable’ residents. There were no ‘probable’ resident well-marked individuals found to be restricted to either Devon or Dorset, with animals moving freely within coastal areas across the three counties. Movements were also detected within offshore English waters and French waters (from other studies) of the western English Channel, but no interchange has as yet been detected between the three regions, highlighting the possible separation of the populations, though sample sizes are insufficient to confirm this. Given the findings, south-west England waters should be considered as a separate management unit requiring targeted conservation efforts.

This study concerns the cephalopod species that are part of the diet of the small-spotted catshark Scyliorhinus canicula and the longnose spurdog Squalus blainville sampled by commercial trawlers in the Aegean Sea from 2005 to 2012. Based on the examined cephalopod beaks, 15 species were identified belonging in six families of Teuthida, one of Sepiida and two of Octopoda. The diversity of cephalopod prey species was higher for S. canicula (N = 15) than for S. blainville (N = 10). Nektonic cephalopods comprised the majority (>72%) of the preyed species by both sharks, among which about 55% inhabit the demersal zone and 45% the mesopelagic. In the diet of S. canicula, the demersal squid Illex coindetii and the pelagic sepiolid Heteroteuthis dispar were equally represented composing 20% of prey specimens, followed by the small-sized squid Abralia veranyi and the demersal sepiolid Rossia macrosoma. The latter species was substituted in the diet of S. blainville by the demersal medium-sized octopod Scaeurgus unicirrhus, which with the equally represented three other species, composed 50% of the cephalopod prey. Differences observed between S. canicula and S. blainville in the condition of beaks retained in their stomach contents and in the variation of prey species diversity by predator specimen size, may imply differences in their foraging tactics (hunting for prey vs scavenging on the bottom), habitats and stomach evacuation frequency.

The population parameters of mantis shrimp (Squilla mantis Linnaeus, 1758) were studied regarding age composition, sex ratio, growth, survival and mortality rates, and the exploitation rate in the Aegean coasts of Turkey in 2013. We collected 936 specimens by shrimp gillnets along the coasts of Izmir Province from April to October 2013. The mean condition factor was K = 1.02 for both sexes, while the sex ratio was 58.7% for female and 41.3% male. Mean lengths, mean weight and length–weight relationship were calculated as TL = 12.57 ± 0.07 cm, CL = 3.02 ± 0.02 cm, W = 22.14 ± 0.37 g, W = 0.0098 × L3.02. Age determination was based on indirect ageing through length–frequency data using the Bhattacharya method. The age of the population varied from 0+ to 3+. Von Bertalanffy growth parameters were estimated as TL∞ = 19.69 cm, CL∞ = 4.74, W∞ = 79.41 g, k = 0.50 year−1 and t0 = −0.37 year. Mortality and exploitation rates derived as Z = 1.90, M = 1.16, F = 0.74 and E = 0.39, respectively.

The polychaete Gallardoneris iberica was described in soft-bottom benthic habitats from the Atlantic Iberian Peninsula coasts in 2012. Since then, successive studies have found this species in Spain, Italy and Croatia. The present study is the first to report G. iberica for Greece and Cyprus (42 new records) confirming its wide geographic distribution on southern European coasts. Taxonomic accounts and ecological preferences based on a large survey and review of available literature are being presented. The species was frequently found in habitats characterized by infralittoral muddy sands with variable organic matter and ‘Moderate’ ecological quality status; nevertheless it was also recorded in coarser and finer sediments, circalittoral mixed sediments, phytal substrates and undisturbed sites. Its relative abundance per sample was always lower than 2%. A review of the available ecological and geographic data of the other Gallardoneris species and a worldwide taxonomic key to Gallardoneris species are provided.

The polychaete assemblages inhabiting the coastal waters of the Oualidia lagoon were studied during winter 2013 and summer 2013. Taxonomic composition and diversity were determined at 43 sample sites. Among the 13 species of polychaetes recorded, 10 were newly reported for Oualidia lagoon. Hediste diversicolor and Capitella sp. were the most abundant taxa in both seasons. Temperature and salinity were higher, and chl-a and OM were lower, in summer than in winter. The structure of the polychaete assemblages was characterized by forming three main clusters, either based on sampling stations or on polychaete species. These clusters were organized according to a downstream gradient, with the stations having fine sediments and a H. diversicolor assemblage in the inner lagoon being replaced by stations with medium grain-sized sediment and a Capitella sp. assemblage in the mid-lagoon, which were in turn replaced by stations having sandy sediments and assemblages dominated by Glycera alba (winter) and P. africana (summer) in the areas closer to the lagoon inlets. The shift was, in fact, from a classical, brackish, lacunar assemblage to two different, temporal aspects of a marine assemblage (close to the inlets), with a transition assemblage in between. This corresponded with a typically paralic spatial structure whose main descriptors responded to a confinement gradient. Despite the absence of a river, the organization of the polychaete assemblages closely resembled that of an estuarine system, with the tidal regime playing a major driving role.

Reproductive aspects of the sea cucumber Athyonidium chilensis were studied over a year in Valdivia, Chile, through gonad index (GI) analysis, macro- and microscopic analysis of the gonads, fecundity and size at first sexual maturity estimations. We also explored the reliability of live size estimators for their use in fisheries. Athyonidium chilensis showed continuous gametogenesis and spawning individuals could be found throughout the year. However, spring was the main reproductive time, where an important GI decrease coincided with enhanced spawning activity evidenced through histology. GIs recovered in summer, and new signs of enhanced spawning activity were observed towards autumn (April 2008). GI peaks were observed in August 2007 and March 2008 for females (22.8 and 24.4% respectively) and September 2007 and March 2008 for males (31.9 and 25.9% respectively). Low mean GIs occurred in May and December 2007 for females (15.2 and 11.6% respectively) and May and October 2007 for males (12.7 and 14.1% respectively). Males reached sexual maturity at a smaller size than females (males: 21.2 g, females: 43.7 g eviscerated weight), and mature females showed a high mean absolute fecundity for a species with lecithotrophic larval development (6.31 × 105 ± 1.97 × 105 SD). For fisheries, we recommend a minimum catch size over 237.89 g drained weight to ensure that caught individuals are sexually mature. This study provides relevant information for the conservation and fishery management of A. chilensis. Continuous gametogenesis and high fecundity make this species particularly suitable for aquaculture in southern Chile.

Invasive algae can have substantial negative impacts in their invaded ranges. One widely cited mechanism that attempts to explain how invasive plants and algae are often able to spread quickly, and even become dominant in their invaded ranges, is the Enemy Release Hypothesis. This study assessed the feeding behaviours of two species of gastropod herbivore from populations exposed to the invasive alga Sargassum muticum for different lengths of time. Feeding trials, consisting of both choice and no-choice, showed that the herbivores from older stands (35–40 years established) of S. muticum were more likely to feed upon it than those taken from younger (10–19 years established) stands. These findings provide evidence in support of the ERH, by showing that herbivores consumed less S. muticum if they were not experienced with it. These findings are in accordance with the results of other feeding-trials with S. muticum, but in contrast to research that utilizes observations of herbivore abundance and diversity to assess top-down pressure. The former tend to validate the ERH, and the latter typically reject it. The potential causes of this disparity are discussed, as are the importance of palatability, herbivore species and time-since-invasion when considering research into the ERH. This study takes an important, yet neglected, approach to the study of invasive ecology.

Herbivorous amphipods of the family Ampithoidae have an important role in marine ecosystems. Ampithoe qeshmensis sp. nov. is a new member of Ampithoidae from the Qeshm Island, Persian Gulf. The new species resembles A. kava, A. katae and A. cookana based on the second male gnathopod. Ampithoe qeshmensis sp. nov. is characterized by round and reduced distoventral spur on uropod 1 in male, mandibular palp article 3 longer than second one, robust seta on palm of second male gnathopod, and longer flagellum than peduncular article 5 on the second antenna.

This study intends to reliably estimate the general status of the benthic and the epiphytic foraminifera community related to each studied seagrass ecosystem (Posidonia oceanica, Cymodocea nodosa and Halophila stipulacea) distributed in different shallow sites in the coastal archipelago of Kerkennah (Gulf of Gabes, Tunisia) during winter. We were able to first sort and subsequently identify some characteristics conditioning their behaviour. Twenty-four species of foraminifera were encountered. Among them, three epiphytic species identified on these seagrass leaves had a much lower abundance than those in the sediment. We were interested in highlighting the foraminiferal community related to Halophila stipulacea, since this seagrass species is newly introduced into the Mediterranean sea. Thanks to the statistical study, we were able to identify the favourable habitat for epiphytic and benthic foraminifera among the three seagrass ecosystems. A correlation between the identified foraminifera species and some environmental parameters was addressed using a variety of software.

A new species of Laeonereis from a shrimp farm associated with a subtropical coastal lagoon on the Mexican Pacific coast is described. The new species is characterized by a deep anterior groove on the prostomium, which is shared only with L. culveri. However, longer tentacular cirri extending back to the anterior margin of chaetiger two, the number of papillae of each group on the maxillary ring of the pharynx, and the relative size of the homogomph falcigers in the new species, allow us to separate the two species. Although the species has not been previously detected in the coastal lagoon surrounding the shrimp farm, we postulate that L. watsoni n. sp. is likely to be part of the invertebrate communities of the upper parts of similar coastal lagoons that are common along the tropical coasts of Mexico.

A taxonomic revision of the Nystiellidae from Brazil, including samples from the Rio Grande Rise, South Atlantic, was performed based on shell morphology. Five genera and 17 species were recognized. For the richest genus, Eccliseogyra, the three species previously recorded from Brazil were revised: E. brasiliensis and E. maracatu, previously known only from their respective type series, were re-examined. Newly available material of E. maracatu expanded the known geographic range of this species to off south-east Brazil. Eccliseogyra nitida is now recorded from north-eastern to south-eastern Brazil, as well as from the Rio Grande Rise. Three species of Eccliseogyra are newly recorded from the South Atlantic: E. monnioti, previously known from the north-eastern Atlantic, occurs off eastern Brazil and on the Rio Grande Rise; its protoconch is described for the first time, confirming its family allocation. Eccliseogyra pyrrhias occurs off eastern Brazil and on the Rio Grande Rise, and E. folini off eastern Brazil. The genus Iphitus is newly recorded from the South Atlantic. Iphitus robertsi was found off northern Brazil, although the shells show some differences from the type material, with less-pronounced spiral keels. Additional new finds showed that Iphitus cancellatus ranges from eastern Brazil to the Rio Grande Rise, and Iphitus notios sp. nov. is restricted to the Rio Grande Rise. Narrimania, previously recorded from Brazil based on dubious records, is confirmed, including the only two living species described for the genus: N. azelotes, previously only known from the type locality in Florida, and N. concinna, previously known from the Mediterranean. A third species, Narrimania raquelae sp. nov. is described from eastern Brazil, diagnosed by its numerous and thinner cancellate sculpture. To the three species of Opaliopsis previously known from Brazil, a fourth species, O. arnaldoi sp. nov., is added from eastern Brazil, and diagnosed by its very thin spiral sculpture, absence of a varix, and thinner microscopic parallel axial striae. Papuliscala nordestina, originally described from north-east Brazil, is recorded off eastern Brazil and synonymized with P. elongata, a species previously known only from the North Atlantic.

The degree of isolation of oceanic islands makes these environments an excellent model for evolutionary studies. Proper knowledge of the species composition of oceanic islands, however, is required to better understand evolutionary processes (e.g. speciation events). A 3-year survey in the shallow waters (up to 30 m) of the Trindade and Martin Vaz oceanic insular complex, and a literature review on the data published for these islands and for Fernando de Noronha and São Pedro and São Paulo oceanic archipelagos have been conducted to document the biodiversity of echinoids and holothuroids from these isolated Brazilian oceanic islands. Sixteen species were collected and characterized morphologically, including two first records for the South Atlantic and one for Brazil. Comparison with conspecific specimens from the Brazilian coast and congeners was also done. Species richness increased from six to 18; the richness in Trindade Island being the highest among the South Atlantic oceanic islands. However, these islands remain undersampled beyond 30-m depth. Endemism was very low, suggesting the potential role of oceanic currents and seamounts as stepping-stones in transoceanic dispersal of species to remote islands. The Brazilian oceanic islands are impoverished oceanic outposts of the Brazilian Province; nevertheless, endemic species and intraspecific morphological variations compared with the mainland suggest they may also be regions of speciation. Documenting their biodiversity is critical for effective management and conservation of their marine ecosystems.

Increasingly, baseline knowledge of habitat preferences and movement patterns of marine species is required to inform anthropogenic developments. The aim of this study was to determine baseline spatio-temporal distribution and habitat preference of cetaceans in the coastal waters of Algoa Bay. Areas of potential conflict with anthropogenic activities were also assessed. Monthly sea-based surveys were conducted between June 2008 and May 2011. A total of 500 cetacean sightings comprising six species were recorded in 106 surveys. Tursiops aduncus (Indo-Pacific bottlenose dolphin), Sousa plumbea (Indian Ocean humpback dolphin), Delphinus capensis (long-beaked common dolphin) and Balaenoptera brydei (Bryde's whale) were observed year-round, while Eubalaena australis (southern right whale) and Megaptera novaeangliae (humpback whale) were recorded from May to December. A large portion of sightings were associated with a Marine Protected Area and shipping zones. Eubalaena australis, T. aduncus and S. plumbea were found inshore (water depths < 12 m), while the other species were associated with deeper waters. Tursiops aduncus were most commonly seen (233 sightings). Megaptera novaeangliae were sighted often in austral winter, with 113 sightings. Only nine D. capensis sightings were recorded. Spatial distributions of species were corrected for search effort to identify habitat preferences. A number of key observations were made, including opportunistic foraging in M. novaeangliae, and the expansion of nursery grounds for E. australis, to include Algoa Bay. Four preferred habitat areas are proposed, providing important information for conservation and management of cetaceans in Algoa Bay. The spatial approach can be used to inform future relevant management decisions elsewhere.

Understanding the diet of marine predators is essential to defining their trophic role in an ecosystem. Elasmobranchs (sharks and batoids) are considered pivotal components of marine food webs, and are often included in the top predator or mesopredator groups. However, in comparison with other Mediterranean areas, research focusing on marine predators inhabiting the Levantine Sea (eastern Mediterranean Sea) is very limited. Here, we examined the feeding habits (diet, trophic width and trophic position) of three endangered batoids (Gymnura altavela (Linnaeus, 1758), Raja asterias Delaroche, 1809 and Raja clavata, Linnaeus, 1758) coexisting in Iskenderun Bay (north-eastern Levantine Sea, Mediterranean Basin) by combining stomach content and stable isotope analyses. The results revealed clear differences in the trophic habits between them. Stomach contents showed differences in the diet between species, showing a clear feeding preference for teleosts in the case of G. altavela and a diet composed of fish and crustaceans in the case of R. asterias and R. clavata. In line with stomach content results, interspecific differences in the isotopic values and trophic levels were found. In particular, G. altavela was isotopically segregated from R. asterias and R. clavata, showing lower isotopic trophic width and higher trophic level. The results of this study provide new insights into the ecological role of these three endangered batoid species in the Levantine Sea and are of crucial importance for management and conservation of these species.

The present study investigated the population dynamics of Exhippolysmata oplophoroides in an area influenced by upwelling, focusing on reproductive period, sex ratio, growth rate, longevity, mortality, relative growth and size of sex change. We also tested the hypothesis that the appendices internae increased in size with sex change from the male to the simultaneous hermaphrodite phase as possible replacements for the male appendices masculinae, which are reduced or lost at sex change. Population structure was assessed by the distribution of size frequency in three demographic groups: male phase, hermaphrodite phase with, and without embryos. For relative growth analysis, the length of the following structures was measured: carapace, second pleuron, first pereopod, second pereopod, appendices internae of the second to fifth pleopods, and appendix masculina. Smaller size classes were composed only by male-phase individuals. The sex ratio was significantly biased towards the simultaneous hermaphrodite phase. Reproduction was continuous in the population throughout the year. Slower growth rates but higher maximum body sizes than those estimated at other locations in south-eastern Brazil were observed in the population studied. Cooler temperatures and higher nutrient levels associated with upwelling may have produced this pattern of reproduction and growth, similar to that found in more southerly austral latitudes. We also found that sex change influences the relative growth of body structures such as the second pereopods, appendices internae, and appendix masculina, and hypotheses on the adaptive value of such allometric growth are proposed.

Echinoderms are exclusively marine, osmoconformer invertebrates. Their distribution patterns are strongly influenced by salinity. Nevertheless, several species of the phylum inhabit the challenging intertidal zone, characterized by steep and fast salinity fluctuations. This study evaluated the response of coelomic fluid ionic concentrations (sodium, chloride, magnesium and potassium) of the intertidal sea cucumber Holothuria grisea to hypo- and hypersaline challenges. A stepwise protocol was performed for the whole animal exposure to both anisosmotic conditions: from 35 to 15 psu along 8 h, and from 35 to 45 psu along 6 h, to simulate intertidal conditions. Tissue water regulation by the longitudinal muscle, oesophagus and posterior intestine was also evaluated, upon hypo- and hyper-osmotic shocks of 20 and 50% of intensity with respect to the isosmotic control. Ionic gradients were observed between coelomic fluid and external water, mainly for potassium and magnesium, but also sodium, and in a greater extent under hyposaline conditions than under hypersaline exposure. Consistently, H. grisea shows retracted tube feet in 15 psu, but a more relaxed appearance and exposed tube feet in 45 psu. In addition, H. grisea showed greater capacity for tissue water maintenance during hyper- than in hyposmotic conditions. Holothuria grisea shows an avoidance behaviour in low salinity (thus sustaining ionic gradients), preventing its tissues from intense swelling. This strategy allows it to dwell in the intertidal region.