Three species of Australian endemic catsharks (grey spotted catshark Asymbolus analis, orange spotted catshark A. rubiginosus and Australian sawtail shark Figaro boardmani) were collected from the trawl grounds of a highly seasonal commercial fishery off southern Queensland, Australia. Specimens were collected on the mid to outer continental shelf at depths between 78 and 168 m. This study provides the first information on the reproductive biology of these three poorly-known species. Mature female and male A. analis were observed from 455 mm total length (TL), mature female A. rubiginosus from 410 mm TL, mature male A. rubiginosus from 405 mm TL, mature female F. boardmani from 402 mm TL and mature male F. boardmani from 398 mm TL (although a lack of immature specimens precluded more accurate assessments of size at maturity). The reproductive mode of all species was confirmed as single oviparous (carrying only one egg case in each uterus at a time). Ovarian fecundity (the number of vitellogenic follicles) ranged from 7–20 in A. analis, 5–23 in A. rubiginosus and 9–13 in F. boardmani. Several indicators suggest that Asymbolus catsharks off southern Queensland are reproductively active year-round. The proportion of female A. rubiginosus carrying egg cases was highest in spring (60%), intermediate in autumn (50%) and lowest in winter (44%).

Limaria hians functions as a keystone species in construction of a highly diverse biogenic habitat. An investigation to quantify the biodiversity of two L. hians beds was carried out during the winter and summer seasons at two sites on the west coast of Scotland. Cores were taken semi-randomly through 100% L. hians nest material, organisms removed, identified and enumerated. Univariate and multivariate analyses of the data were used to establish temporal and locational differences. A total of 7275 individuals were found representing 282 species from 16 phyla. Univariate analysis revealed significant differences between the species richness of the two populations, whilst multivariate analysis illustrated differences in the assemblage compositions between sites and times. This study showed that in terms of richness and diversity these beds are among the most important biogenic habitats in the UK.

The galatheid crab Shinkaia crosnieri, is the sole member of the subfamily Shinkaiinae. It is abundant and forms dense beds around active hydrothermal vents in the Okinawa Trough. Thousands of filamentous bacteria attached to the plumose setae on the ventral surface of this crab were observed using field-emission scanning electron microscopy and transmission electron microscopy. Nucleic acids were extracted from the filamentous bacteria, and the phylotypes of 16S rRNA genes were identified from 81 clones. These phylotypes were divided into three groups: Epsilonproteobacteria (74%); Gammaproteobacteria (20%); and Bacteroidetes (6%). Gamma- and major phylotypes of Epsilonproteobacteria were also detected using fluorescence in situ hybridization analysis. These Epsilon- and Gammaproteobacteria were closely related to cultured and uncultured bacteria from hydrothermal vent fields including episymbionts of vent-associated invertebrates such as Rimicaris exoculata, Alvinella pompejana, the scaly-foot snail, Kiwa hirsuta etc. The carbon isotopic compositions of the muscle of S. crosnieri and in filamentous bacteria were similar. The muscle of S. crosnieri contained monounsaturated C16 and C18 fatty acids, which are known to be characteristic of sulphur-oxidizing bacteria in H2S-rich marine habitats. Through the video images transmitted by a submersible and a remotely operated vehicle, S. crosnieri was observed to comb out its ventral setae using the third maxilliped and appeared to consume the contents. These evidences suggest the epibiotic association between S. crosnieri and the filamentous bacteria attached to the ventral setae of the crab, but the details of role and function are still unclear at the present study.

The construction of an artificial channel to a small embayment in the Chetumal Bay coastal lagoon complex, located on the Caribbean coast of Mexico, provided an opportunity to evaluate how large environmental changes influenced the structure of a low diversity benthic system. The objective of this study was to demonstrate that despite the absence of previous baseline information, the artificial channel has induced measurable changes in the biodiversity patterns of a hard substrata benthic community. The experimental design took into account the environmental setting influencing local benthic community structure and the sources of variability as a result of different substrate types and water depth. Four localities with ten replicates each were surveyed, and the presence/absence of macrobenthic biota species recorded during the rainy season. Our analysis using permutational multivariate analysis of variance indicated a significant increase in species richness in locations adjacent to the artificial channel. The highest species richness (66 species) was observed in the immediate area adjacent to the artificial channel and where exclusive species density was three to six times (18 exclusive species) than those present in other localities (6, 5 and 3 species) away from the channel. The presence of six species of hard corals indicated that the artificial channel offers a more suitable habitat for marine organisms colonizing the area than the natural channel. This study indicates the relative significance of confinement in structuring coastal lagoon benthic assemblages in tropical systems. Our results are similar to other findings underscoring the rate of colonization of marine organisms as a relevant process to explain benthic assemblage gradients and the importance of spatial–temporal interactions. The changes in species diversity caused by the artificial channel were clearly identified based on a sampling design that incorporated the main sources of environmental variability (distance to channels, substrate type and depth). Our study further demonstrates that changes in benthic community structure in the Chetumal Bay lagoon complex, as a result of human impacts, can be assessed even when community structure data before impact are absent.

This paper evaluates if the bivalve Tawera gayi from southern South America represents an opportunity to test ecological variability and environmental changes during the last 6000 years in southern South America. For this purpose, we analyse both modern and fossil (mid-to-late Holocene) T. gayi shells from Tierra del Fuego using different techniques, including taphonomy, stable isotopes, cathodoluminiscence (CL) and linear morphometrics. Taphonomic analysis shows that differences between modern and fossil shells appear best related to local variations of physical factors such as current speed, wave action and freshwater input along the non-uniform Beagle Channel coast. However, slight changes of hydraulic energy regimes throughout the Holocene cannot be ruled out. The analysis of stable isotopes on T. gayi shells indicates a mixing of oceanic waters with freshwater from precipitation, river runoff and glacier meltwater during the mid-to-late Holocene. The high depletion of δ18O at ~4400 years before present would be associated with a period of warmer temperatures, the so-called Hypsithermal. Under CL modern and fossil T. gayi shells show a well defined pattern related to the growth dynamics of the shell, which can lead to a better understanding of its biology, adding details to further palaeoenvironmental analysis. Finally, conventional metrics shows that fossil T. gayi shells are smaller and shorter than modern shells. These differences could be related to Holocene environmental changes, but here are best explained on the basis of a predator–prey relationship. This study shows that T. gayi may be a good candidate for looking at evidences of environmental changes in southern South America, and multi-proxy data are necessary to better understand the driving mechanisms of ecological variability and changes over short geological time intervals of few thousands of years.

The bivalves Mytilus chilensis, Venus antiqua, Mulinia edulis and Tagelus dombeii inhabit different levels of the tidal flats in Yaldad Bay, southern Chile. Mytilus chilensis is an epifaunal bivalve, which, at this location, is also farmed in culture rafts; whereas the other species belong to the infauna. The objective of this study was to compare filtering capacity of these species; in order to do this, measurements of food consumption were taken by quantifying clearance rates, as well as taking morphological measurements of their feeding systems (gills and labial palps), and endoscopic observations to determine the velocity of particle transport within the gills. All of these parameters were related to the sediments present in environments occupied by these species. In Mytilus chilensis, both wild and farmed, gill area was significantly higher than in the three infaunal species. Mulinia edulis and Venus antiqua did not show any significant differences in gill area. As far as Tagelus dombeii is concerned, the species presented the lowest values among all species studied. Weight of labial palps was significantly higher in Mulinia edulis compared to the other species. There were no significant differences between labial palps of either wild or farmed Mytilus chilensis or in those of Venus antiqua and Tagelus dombeii. A positive, significant relationship was identified between labial palps size and mud sediment content. Both culture-rafts and intertidal Mytilus chilensis displayed a clearance rate that was significantly higher than the infaunal species, concurring with a significant relationship between clearance rate and gill area in the different species studied. Clearance rates displayed by Venus antiqua, Mulinia edulis and Tagelus dombeii did not show significantly different results among them. Mytilus chilensis from both culture-rafts and intertidal zone displayed higher values of particle transport velocity than the infaunal species. Particle transport was not observed in the dorsal canal of any of the species studied. The conclusion is that in these species filtering capacity is determined mostly by gill size and that labial palp size displays a strong relationship with sediment content in the mud of Yaldad tidal flats.

For studying community structure and biodiversity of macrofauna, seasonal samplings were carried out along three different depths (5, 15 and 30 m) in four transects (12 stations) at Noor coast during 2005. Four higher taxa were determined. Polychaeta was the dominant group comprising 96.61 of the total individuals, followed by Bivalvia 1.35%, Oligochaeta 1.15% and Amphipoda 0.87%. Of the six encountered species, the polychaete, Streblospio gynobranchiata accounted for 84.95 of the total population. Also, Tubificoides fraseri was observed in the Caspian Sea for the first time. During this study, density of macrofauna increased with depths, total organic matter and percentage of silt–clay. The highest density was obtained in winter and the lowest was observed in summer. Maximum diversity, richness, and evenness were obtained, 0.91, 1.05 and 0.88, respectively. Also, multivariate analysis separated differences of density between seasons and depths.

The genus Callinectes comprises seven species of blue crab found on the Brazilian coast, almost all are recorded in Cachoeira River estuary. The objective of this study is to analyse distribution of Callinectes species in the estuary of Cachoeira River (Ilhéus, Bahia). Monthly collections were conducted in the low tide of neap tide for a year and in five stations distributed according to the estuary salinity gradient. Six traps were assembled and submerged at each station for two hours. Sediment samples were collected for granulometric characterization and measuring of organic matter content. Temperature, salinity and pH were also measured in the bottom water, as well as water transparency at the start of each collection. Five species were collected: Callinectes danae, C. ornatus, C. exasperatus, C. larvatus and C. bocourti. The species presented different distribution patterns based on the salinity gradient and transversal profile of the estuary. Only C. danae was found in all collection points, and was the most abundant species throughout the study period. Callinectes ornatus was restricted to external estuarine areas, which presented higher salinity and transparency values. Callinectes larvatus predominantly occurred in the external station and estuary partitions, mainly in the margin. In spite of the occurrence of C. exasperatus throughout the entire estuary, this species was restricted to the margin. This study supports the assumption that species distribution patterns of this genus are the result of both variable influence, namely salinity, and complex intraspecific and interspecific relations between the congeneric species.

This study describes species of the genus Hymedesmia from three areas of cold-water coral reef: Mingulay Reef Complex (Scotland, UK) and Rockall and Porcupine Banks (off UK and Irish coasts). Five new species are described: Hymedesmia (Hymedesmia) gibbosa, H. stoneae, H. tendali, H. xavierae and H. valentinae. Records are provided of other poorly known Hymedesmia species: H. bocki, H. cohesibacilla, H. curvichela, H. ebria, H. gustafsoni, H. simillima, H. irregularis, H. proxima, H. hibernica and H. primitiva. Information on distribution of other Hymedesmia species occurring in Britain and Ireland is presented. The sites studied represent a variety of depth-ranges and the data collected suggest that some Hymedesmia species may be restricted to particular bathymetric zones.

A new species of Craniella from the Aleutian Islands is described. Craniella sputnika sp. nov. differ from all other species of Craniella in its habitus, absence of microscleres and size of spicules. The name refers to its resemblance to Earth's first artificial satellite, due to its spherical body with long spines. The new species was observed growing on another demosponge, Myxilla sp. We propose transferring two species currently in Craniella to Tetilla (Craniella ellipsoidea Hoshino, 1982 and Craniella laminaris (George & Wilson, 1919)) and two subspecies (Craniella globosa anamonaena Tanita, 1968 and Craniella laminaris symmetrica (Wilson, 1931)) from Craniella to Tetilla. As Craniella globosa anamonaena Tanita, 1968, is actually a species of Tetilla we suggest raising the subspecies to species rank as Tetilla anamonaena. Conversely we think that two species, Tetilla ovata (Thiele, 1898) and Tetilla hamatum Koltun, 1966 should be transferred to Craniella.

The reproductive biology of Psammobatis lentiginosa was studied in San Matías Gulf (Patagonia, south-west Atlantic). A total of 1033 skates was analysed, total length ranged from 17 to 52 cm for females and from 13 to 55 cm for males. Total length–total weights relationships differed between sexes, with TW = 0.005 × TL3.02 for females and TW = 0.005 × TL2.97 for males. The overall sex-ratio was 1:1. In females, the L50% was 41.06 cm, in males the L50% was 41.38 cm. The mean number of yolked oocytes per skate was 4.22 (±2.41). The mean number of yolked oocytes and the length of the female were linearly related. The diameter maximum of yolked oocytes was 24 mm. The species exhibited a continuous reproductive cycle throughout the year, with a peak of egg-case production during autumn that was synchronous with maximum values of the epididymis and uterus indices. This is the first record of a reproductive aggregation for P. lentiginosa in San Matías Gulf, North Patagonia. This finding together with its continuous presence around the year, suggest that this area is the main distribution area of P. lentiginosa in the south-west Atlantic.

The study focuses on the question, how a seamount in the oligotrophic eastern Mediterranean affects the zooplankton community, as compared to the open water. Zooplankton samples were taken with 333 µm nets at two sites, the Rhodes Basin and the Anaximenes Mountain, in December 2006. The samples were sieved into size fractions, and the composition, biomass, abundance and stable isotope signatures were analysed. In general, biomass and abundance of zooplankton were low, reflecting the oligotrophic character of the eastern Mediterranean, but zooplankton standing stocks were higher at the Rhodes Basin than at the Anaximenes Mountain. Stable isotope signatures showed, at a generally low level, enrichment in zooplankton taxa along the food chain within the different pelagic zones and from the surface to the deep-sea, but no significant differences between Rhodes Basin and the seamount were evident in the food web structure. The zooplankton community in the Anaximenes Mountain region in the northern Levantine Basin seems not to be influenced by a local seamount effect, despite the difference in standing stocks between the seamount and the Rhodes Basin. This seems to be driven by larger-scale upwelling and downwelling structures of cyclones and anticyclones, dominating the circulation in the area.

A new species, T. strongylata sp. nov. is described on the basis of material collected from the Pacific Ocean. The new species is characterized by the presence of sinuous strongyles. Moreover the incomplete description of T. simplex (Sarà, 1959) is implemented on the basis of new abundant material allowing, for the first time, the complete description of the skeleton of a Triptolemma species and the detecting of the presence of monaxonic spicules in the spicular complement of the genus. The skeleton is composed of a thick crust of disorderly arranged mesotriaenes and scattered microscleres, supported by diverging spicule tracts formed by oxeas towards the surface. Both species were recorded associated to boring sponges (Spiroxya and Cliona) in excavations of the calcareous scleraxis of precious corals or in organogenic concretions. In the cavities where the tissue of Triptolemma was recorded the wall of the excavation partially lost its typical pattern characterized by ovoid scars and became irregularly eroded. Our hypothesis is that Triptolemma insinuates inside the erosions produced by other sponges and it is able to enlarge them by an etching mechanism based on chemical dissolution only.

The north-eastern Aegean Sea (NEA) is a marine system of high hydrological complexity, principally induced by the inflow and subsequent advection of the low salinity (<30) Black Sea water (BSW). This water mass occupies the upper layer (~0–20 m) of the NEA and plays a key role in the determination of circulation patterns and the generation of various frontal and eddy structures. Here we are concerned with the examination of mesozooplankton assemblages in the NEA during the thermal stratification period (July 2004) in two discrete sampling layers: (a) Layer 1 (from the base of halocline to the surface: ~0–20 m) which is directly influenced by BSW; and (b) the deeper ~20–50 m layer (Layer 2). Our main objective was to assess the response of mesozooplankton to the BSW and the associated hydrological structures. In July 2004, the BSW was mainly restricted in the eastern part of the NEA where it was entrapped in a ~50-km wide anticyclonic gyre (Samothraki gyre). A marked spatial differentiation in mesozooplankton assemblage structure, significantly related to this hydrodynamic partitioning, was detected in Layer 1. Sampling sites under the direct influence of low salinity–high temperature gyre waters were characterized by a considerably higher mesozooplankton stock than the remaining area, mainly due to the outstanding numerical dominance of the cladoceran species Penilia avirostris. Copepods displayed notably low densities within the gyre and low species diversity, the calanoid Temora stylifera was the only abundant species. The mesozooplankton community outside the gyre zone shifted towards lower levels of total abundance, with a lesser contribution of cladocerans and an increase in the importance of small-sized copepods (e.g. Acartia clausi, Paracalanus parvus, copepodites of Oithona spp. and Clausocalanus spp.). In the subsurface layer (Layer 2), the mesozooplankton community also exhibited spatial heterogeneity which could be hardly explained by variability in environmental parameters. The periphery of the anticyclone below the halocline was distinguished from the remaining neritic area, presenting markedly high mesozooplankton productivity and distinct group composition. An inverse pattern in the mesozooplankton stock vertical distribution was observed at the periphery of the gyre (Layer 2> Layer 1) comparative to the remaining sites (Layer 1 > Layer 2), which was mainly due to unusually high concentrations of surface-living zooplankters below the halocline. The latter could be explained in terms of expected water flow patterns in an anticyclonic eddy.

The structure of hitherto-unknown exocrine glands in the caudal rami of the pelagic copepods of the genus Calanus was investigated, together with the vertical, diel and seasonal variations in the occurrence of granules secreted from the glands. Zooplankton samples were collected in Sagami Bay by vertical tows of a net from 4 discrete layers at 250-m intervals in the upper 1000 m both day and night, with an additional seasonal sampling in the upper 200 m. The samples contained copepodids of Calanus sinicus (stages IV–VI), C. jashnovi (stages IV–V), and unidentified Calanus (stages I–III), which possessed the glands regardless of the developmental stage and sex. Each caudal ramus has an inner- and an outer gland each of which opens in a pore at the ventral base of a caudal seta. According to light microscopy the cavities of only the inner glands contained many transparent granules, some of which appeared to have been discharged to the environment. The granules were present regardless of day/night, depth, and season, with the maximum number of 52/copepod. The cells surrounding the inner cavity contained well-developed rough endoplasmic reticulum, mitochondria, Golgi-bodies, and secretory granules; the outer cavity contained granules of much lower density than those in the inner cavity. These observations rule out the possible functions of the glands for egg and sex pheromone production, and suggest most likely function is predator avoidance. However, neither has mechanical disturbance excited luminescence, nor has ultraviolet emission excited fluorescence, suggesting the secretion is non-luminescent. Alternative possible functions include secretion of defensive substances or substances that might enhance swarm formation. A survey of preserved copepod collections indicated presence of similar glands in Calanus helgolandicus, C. pacificus, Cosmocalanus darwinii, Mesocalanus tenuicornis, and Nannocalanus minor, suggesting evolution of the glands in the common ancestor of these species that comprise a monophyletic group within the Calanidae.

We studied the distribution of phytoplankton and ciliate communities in relation to environmental factors at 6 stations sampled between 28 and 31 July 2006 during the summer water stratification in the Gulf of Hammamet (Tunisia, eastern Mediterranean Sea). A strong thermocline was established at 30 m, and, on average, the N/P ratio was lower than the Redfield ratio (16), suggesting a potential N limitation. The inshore location was numerically dominated by dinoflagellates (55%) represented essentially by members of the genera Protoperidinium, Gymnodinium, and cryptic Scrippsiella trochoidea and on the offshore by diatoms (68%). The phytoplankton assemblage was largely dominated by the diatoms Thalassionema nitzshioides and Rhizosolenia styliformis, while the ciliate community was numerically dominated by small taxa such as Lohmanniella oviformis (6 × 102 cells l−1) and Uronema marinum (5.50 × 102 cells l−1). The total phytoplankton abundance increased from the coastal area (5.26 × 102 ± 4.48 × 102) to the open sea (10.33 ×102 ± 28.06 × 102) and decreased from the surface to the bottom, inversely to the ciliate abundance. Total phytoplankton and abundances showed similar patterns. Total ciliate biomass decreased from the inshore (0.25 ± 0.58) to the offshore (0.06 ± 0.10) areas but increased from the surface to the bottom. The diversity index of both phytoplankton and ciliate communities showed a decrease with a coastal–open sea gradient. The relationships between phytoplankton and ciliates suggest planktonic micro-heterotrophs were implicated in the channelling of matter and energy through the microbial loop in the Gulf of Hammamet.

The feeding habits of the Rio skate, Rioraja agassizi, from off Uruguay and north Argentina were evaluated using a multiple-hypothesis modelling approach. Relationships between number of preys and sex, maturity stage, body size, season and region were assessed by building generalized linear models. Rioraja agassizi fed mainly upon crustaceans (shrimps, crabs and amphipods) and teleosts, but also upon isopods, cumaceans, lancelets and polychaetes. Ontogenetic diet shifts were found: small R. agassizi consumed amphipods, cumaceans and isopods and large individuals on shrimps, crabs and teleosts. The consumption of crustaceans (amphipods, shrimps, crabs, isopods and cumaceans) was higher in the northern (34°–38°S) than in the southern area (38°–41°S). Rioraja agassizi consumed more teleosts in the cold season and preyed more on lancelets in the warm season. Prey size increased with increasing body size of R. agassizi, but large individuals also consumed small prey. Ontogenetic shifts may be related to body size rather than other life-history traits. Rioraja agassizi adapts its feeding habits in response to regional and seasonal changes.

In the absence of chemical or physical gradients, random displacement of organisms can result in unpredictable distribution patterns. In spite of a limited locomotive capability, marine nematodes may choose where to settle after re-suspension and may maintain their position in the sediment under calm conditions, leading to small-scale (<1 m) spatial variability. However, in more energetic environments, nematodes become re-suspended with sediments and re-distributed at distances dependent on prevalent hydrodynamic regimes, from metre- to decametre-scale or more. In this study, we tested the hypothesis that micro-habitats (i.e. runnels and sandbars) in a macrotidal sandy beach influence the distribution patterns of free-living marine nematodes by exhibiting contrasting hydrodynamic regimes. Specifically, we predicted patchier distributions in the calmer environment (runnel). We sampled nematodes in each habitat from <1 m to decametre scales. Our results show more heterogeneous spatial distributions in the runnel, presumably owing to a predominance of active displacement under calmer conditions and sediment cohesion by algal films. Biological similarity among runnel replicates was low, whereas replicates from the sandbar exhibited higher similarity, presumably because of homogenization of the sediment and inhabiting fauna by tidal currents. A significant negative correlation between biological similarity and sampling distance was found in the runnel, but not in the sandbar. The most similar samples were the closest in the runnel and the most distant in the sandbar. More patchily distributed taxa were found in the runnel and a larger fraction of homogeneously or randomly distributed taxa in the sandbar. We conclude that different hydrodynamic regimes in contrasting intertidal micro-habitats significantly influenced the nematofaunal distribution, resulting in different spatial patterns next to one another in the same beach. This has significant implications for sampling and monitoring designs and begs the need for detailed studies about the physical and biological processes governing meiobenthic communities.

Three new species of coral reef boring sponges were found in remote coral reefs from Revillagigedo Island, an archipelago that is 386 km from the continent. Cliona medinae sp. nov. is a sponge with orange-yellow papillae characterized by short almost straight spirasters. Cliona tropicalis sp. nov., is a yellow papillate sponge with a spicule complement similar to the species included in the Cliona viridis complex. However, the new species differs from the rest of the species mainly in its external morphology and by differences in the size and shape of spicules. Thoosa purpurea sp. nov. is characterized by its purple colour, and the spicular complement formed by tylostyles, two amphiaster categories, bi- tri- and tetra-radiate oxyasters and smooth or microspined centrotylote oxeas. In addition, Cliothosa tylostrongylata sp. nov. is also described from coral reefs from the southern Mexican Pacific Ocean. This is a light red species, with tylostyles and tylostrongyles as megascleres and ramose and nodulose amphiasters as microscleres. The four species were found exclusively excavating skeletons of live or dead corals of the genus Pocillopora. This study increases the number of boring sponges known from the Mexican Pacific Ocean to 22 species and it is the first study on marine sponge fauna from the Revillagigedo archipelago.

Mussismilia braziliensis is endemic to the south-western Atlantic, where it plays an important role as a major reef builder. It occurs in a wide range of sediment conditions between coastal and offshore environments. Here, we investigated its reproductive effort along an inshore–offshore gradient. Three sites were sampled with varying distances (15 to 60 km) from the mainland in the Abrolhos Reef Complex (18° S). Reproductive effort was estimated as fecundity (number of eggs per: polyp, cm2, mm3, and mesenteries). Mean fecundity per polyp was 338.7 (±73.5 SD) and the highest number of eggs per polyp was 987. Percentages of fertile mesenteries per polyp were similar among sites. However, the fecundity per mesentery varied among colonies and among sites. Fecundity per polyp increased as its area, volume, height and number of fertile mesenteries increases. The area closest to the coast (‘Pedra de Leste’) presented the highest mean fecundity per polyp (410 eggs ± 159.2 SD), cm2 (233.47 eggs ± 219.44 SD), mm3 (4.95 eggs ± 2.34 SD) and mesentery (10.6 eggs ± 4.3 SD). Corals closest to the coast had 55% higher fecundity per polyp and 64% higher fecundity per cm2 than corals offshore. This area presented the highest contribution of non-carbonate sediments deposited on the reefs. Therefore, we suggest that colonies of M. braziliensis may present higher uptake rates of particulate matter at inshore reefs, which allow for higher rates of tissue growth (less nutrient limitation) and energy allocation to reproduction.