Search

For the entire Brazilian coast, there are 22 published records of scyphozoans. On the other hand, only 35 species ofcubozoans were described worldwide, four of them reported for the Brazilian coast. However, little is known about thespecies of cubozoans and scyphozoans in the Northeastern states of Brazil. The aim of this study was to perform asurvey of the jellyfish (Cnidaria: Cubozoa and Scyphozoa) on the coast of Rio Grande do Norte state, Northeast ofBrazil. Specimens were collected using trawl net on beaches in the counties of Natal (in 2003) and Tibaú (in 2004). Forthe Rio Grande do Norte coast there were few records of large jellyfish, and new records of the following cubozoan andscyphozoan species were verified: Chiropsalmus quadrumanus; Chrysaora lactea; Lychnorhiza lucerna andStomolophus meleagris. The studied species had their distributions expanded in the coast to the State of Rio Grande doNorte.

Encapsulation of embryos in marine gastropods affords protection for the developing young, whether or not parental care takes place. The capsule wall is laminated and its dimensions change during development. Dissolution of the capsule wall releases dissolved organic matter (DOM) into the intracapsular fluid, providing a nutritional source for the embryo. The capsule wall of Acanthina monodon is composed of three layers, a thin outer layer with projections to the exterior, a thicker intermediate layer containing vacuoles and a thin inner layer that gives rise to the hatching plug. During embryonic development the capsule wall lost 27.2% of its initial mass owing to a pronounced thinning of the outer layer, especially of the projections. The organic fraction in the capsule wall (>85% of total mass) decreased by 23.3%, mostly due to the loss of 52.8% of the protein originally present. The internal layer of the capsule wall became 35.2% thinner during embryonic development, and in capsules containing embryos in the prehatching stage the surface area of a section through the plug was reduced to 2% of its original value. Total protein concentration in the intracapsular fluid decreased by 54% during embryonic development. The dry weight of the encapsulated juveniles immediately before hatching was 96% greater than that of the eggs from which they developed. Total protein concentration increased by 148% between the egg and the advanced veliger stages, then decreased in the prehatching juvenile, presumably as a result of the energy cost of metamorphosis, which occurs within the capsule before the juveniles are released. During development, material was lost from the exterior surface of the outer layer of the capsule wall. In contrast, the inner layer partially dissolved and disintegrated into the intracapsular fluid, providing the developing embryos with a secondary source of nutrition, mainly protein, during the later stages of encapsulation, when the material from the nurse eggs was exhausted. [ABSTRACT FROM AUTHOR]

Melanoides tuberculatus is an Afro-Asiatic thiarid, common in freshwater environments, now present in a wide portion of the tropical and subtropical regions of the New World. The present study had as its objective to register the occurrence of M. tuberculatus in the area of mangrove of the estuary of the Ceará River, verifying its density and the salinity which the specimens were submitted to verify its euryhalinity. Specimens of M. tuberculatus were collected in mangrove areas of the estuary of the Ceará River, located on the boundary of Caucaia and Fortaleza. Some specimens collected by hand in February 2006 were kept in an aquarium for a month. The abundance of M. tuberculatus in the studied areas varied from 0.76–10.22 individual/cm2. The salinity of the areas varied from 0–30 in the studied months. The presence of M. tuberculatus in these mangrove areas, whose salinity reached a peak of 30, and their survival in the laboratory, under a salinity of up to 35, prove the adaptation of this limnetic gastropod to euryhalinity. [ABSTRACT FROM PUBLISHER]

Gastropods of the superfamily Conoidea are present in high diversity in the oceans and are characterized by having modified foregut anatomy and radular morphology. This study provides details on variations in the radula teeth of the species Hastula cinerea, which have hypodermic radula teeth of the toxoglossan type and are part of the Terebridae family - inserted in the Conoidea superfamily. Hastula cinerea specimens were collected at Flecheiras beach, Trairi, Ceará, Brazil. Scanning Electron Microscopy (SEM) was performed to analyse the radula specificities. Thirty specimens were used between females and males, with different sizes. The total length of the shell and the length of the teeth of all analysed specimens were measured. With the SEM result, more than one radula tooth morphotype was found for the species H. cinerea. The pattern of the teeth found is similar to the hypodermic teeth of the group, however, with structural and length differences between smaller and larger individuals. It was possible to observe three radula variations (morphotype-1, morphotype-2 and morphotype-3), 26 related to different sizes of individuals, regardless of sex, configuring a variation in the radula teeth. Therefore, this result brings a contribution that stimulates future research with the functional morphology of H. cinerea and others auger snails., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier GmbH. All rights reserved.)

Large gaps in reef distribution may hinder the dispersal of marine organisms, interrupting processes vital to the maintenance of biodiversity. Here we show the presence and location of extensive reef habitats on the continental shelf between the Amazon Reef System (ARS) and the Eastern Brazilian Reef System (ERS), two reef complexes off eastern South America. Formations located 20-50 m deep include both biogenic and geogenic structures. The presence of diverse reef assemblages suggests the widespread occurrence of rocky substrates below 50 m. These habitats represent an expansion of both the ARS and ERS and the closure of the only remaining large-scale gap (~ 1000 km) among West Atlantic reef environments. This indicates that the SW Atlantic harbors a single, yet heterogeneous, reef system that stretches for about 4000 km, and thus, represents one of the largest semi-continuous tropical marine ecosystems in the world., (© 2022. The Author(s).)

Early naturalists suggested that predation intensity increases toward the tropics, affecting fundamental ecological and evolutionary processes by latitude, but empirical support is still limited. Several studies have measured consumption rates across latitude at large scales, with variable results. Moreover, how predation affects prey community composition at such geographic scales remains unknown. Using standardized experiments that spanned 115° of latitude, at 36 nearshore sites along both coasts of the Americas, we found that marine predators have both higher consumption rates and consistently stronger impacts on biomass and species composition of marine invertebrate communities in warmer tropical waters, likely owing to fish predators. Our results provide robust support for a temperature-dependent gradient in interaction strength and have potential implications for how marine ecosystems will respond to ocean warming.

In this study, we provide a baseline assessment of introduced marine species along the extensive (~600 km) Brazilian semiarid coast. We reported 27 introduced and 26 cryptogenic species. Moreover, the main vectors of introduction were ballast water, shipping lines, oil and gas activities, biofouling, and rafting on plastic debris. The taxa were Ascidiacea (17 species) and Bryozoa (17), followed by Crustacea (6), Mollusca (6), Cnidaria (3), Echinodermata (3), and Porifera (1). Among these invertebrates, some species are recognized as drivers of impacts such as the invasive corals (Tubastraea tagusensis and Tubastraea coccinea), the bivalves Isognomom bicolor and Perna viridis, the crab Charybdis hellerii, the brittle star Ophiothela mirabilis, and, finally, the bryozoan Membraniporopsis tubigera. These species threaten the biodiversity of unique ecosystems such as intertidal sandstone reefs, shallow-water coral reefs, and mesophotic ecosystems. Moreover, the up-to-date results highlight that this region is a hotspot of bioinvasion in the tropical South Atlantic., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Rhodolith growth and CaCO 3 production remain poorly quantified along the SW Atlantic Ocean, and it is difficult to relate the available measurements with biomass estimates. Suboptimal conditions may clarify how harsh environments influence nodule growth and abundance, elucidating their relationship. Off the energetic South American equatorial coast a rhodolith bed (~65 km 2 ), formed mainly by Mesophyllum sp. and Lithophyllum sp., alters the regional sedimentary pattern and sustains a diverse biota. Its nodules present fast growth rates (2.8 mm year -1 ), but small biomasses (18 nodules∙m -2 covering 26 ± 3% of the substrate), resulting in a CaCO 3 production of 163.33 g m -2 ∙year -1 . Despite the small biomass, the bed seems stable, with living and dead nodules both on and inside the substrate. And the suboptimal environment apparently affects growth and abundance independently. Therefore, fast growth rates and relevant structural roles are not necessarily associated with dense rhodolith assemblages, and ecological assessments of rhodolith beds should consider the dynamics of both individual nodules and the whole population., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

A reliable taxonomy, together with more accurate knowledge of the geographical distribution of species, is a fundamental element for the study of biodiversity. Multiple studies on the gastropod family Neritidae record three species of the genus Neritina in the Brazilian Province: Neritina zebra (Bruguière, 1792), Neritina virginea (Linnaeus, 1758), and Neritina meleagris Lamarck, 1822. While N. zebra has a well-established taxonomic status and geographical distribution, the same cannot be said regarding its congeners. A widely cited reference for the group in Brazil considers N. meleagris a junior synonym of N. virginea . Using a molecular approach (phylogenetic, species delimitation, and statistical parsimony network analyses), based on two mitochondrial markers (COI and 16S), this study investigated if N. virginea and N. meleagris are distinct species. The molecular results confirmed the existence of two strongly supported distinct taxonomic entities in the Brazilian Province, which is consistent with the morphological descriptions previously proposed for N. virginea and N. meleagris . These species occur in sympatry in the intertidal sandstone formations of Northeastern Brazil. Despite the great variation in the colour patterns of the shells, the present study reinforced previous observations that allowed the differentiation of these two species based on these patterns. It also emphasized the importance of the separation of these two clades in future studies, especially those conducted in the Brazilian Province, since these species may cohabit., (Cristiane Xerez Barroso, João Eduardo Pereira de Freitas, Helena Matthews-Cascon, Luis Ernesto Arruda Bezerra, Tito Monteiro da Cruz Lotufo.)

Prior to Brazil's worst environmental disaster, caused by a mining dam collapse, we had carried out a study of the marine benthic macrofauna (11-51 m depth) under the influence of the Doce River. Our results showed significant diversity, in which mollusks, polychaetes, and crustaceans had the highest frequency, density, and abundance, represented by 162 families in summer and 173 in winter. Our results suggested that richness, abundance, and diversity increase with distance from the coast. Furthermore, with increasing distance from the coast and river mouth, in addition to increasing depth, there was a differentiation in composition and abundance. Multivariate analyses showed depth, carbonate, and organic matter as important factors that explain variations in composition and diversity across the continental shelf. The results could provide an invaluable baseline for measuring the effects on shallow and mesophotic communities of one of the largest tailings dam failures worldwide., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

A new Late Cretaceous species of Petalobrissus, Petalobrissus lehugueurae sp. nov., is described from the Jandaíra Formation, Potiguar Basin, state of Rio Grande do Norte. To date, this genus comprises a total of 20 species, only two of which, Petalobrissus setifensis and Petalobrissus cubensis have so far been recorded from the Jandaíra Formation. Petalobrissus lehugeurae sp. nov. is distinguished from its congeners in that gonopores occupy only a small portion of the genital plates, in having a slit-like periproct and a unique abrupt depression of the test that forms a pronounced keel below the periproct. In addition, an identification key to species of Petalobrissus is presented.

The chemical study of the Brazilian brittle star Ophionereis reticulata led to the isolation of three chamigrene sesquiterpenes, including the partially characterized isoobtusadiene (1), its unreported acetyl derivative (2), and the known (+)-elatol (3). The complete elucidation of the structures 1 and 2 was accomplished by 1D and 2D NMR spectroscopy. The first assignment of the absolute configuration of the isoobtusadiene skeleton is suggested as 6S,9R,10S on the basis of the NMR analysis of the Mosher's ester derivatives of 1 and the ECD study of the acetyl derivative 2. Chamigrenes are typical constituents of Laurencia red algae. O. reticulata is a predator with a preference for algae. Thus, the origin of these metabolites can be likely ascribed to diet.

A new lectin from Aplysia dactylomela eggs (ADEL) was isolated by affinity chromatography on HCl-activated Sepharose™ media. Hemagglutination caused by ADEL was inhibited by several galactosides, mainly galacturonic acid (Ka = 6.05 × 10 6  M -1 ). The primary structure of ADEL consists of 217 residues, including 11 half-cystines involved in five intrachain and one interchain disulfide bond, resulting in a molecular mass of 57,228 ± 2 Da, as determined by matrix-assisted laser desorption/ionization time of flight mass spectrometry. ADEL showed high similarity with lectins isolated from Aplysia eggs, but not with other known lectins, indicating that these lectins could be grouped into a new family of animal lectins. Three glycosylation sites were found in its polypeptide backbone. Data from peptide-N-glycosidase F digestion and MS suggest that all oligosaccharides attached to ADEL are high in mannose. The secondary structure of ADEL is predominantly β-sheet, and its tertiary structure is sensitive to the presence of ligands, as observed by CD. A 3D structure model of ADEL was created and shows two domains connected by a short loop. Domain A is composed of a flat three-stranded and a curved five-stranded β-sheet, while domain B presents a flat three-stranded and a curved four-stranded β-sheet. Molecular docking revealed favorable binding energies for interactions between lectin and galacturonic acid, lactose, galactosamine, and galactose. Moreover, ADEL was able to agglutinate and inhibit biofilm formation of Staphylococcus aureus, suggesting that this lectin may be a potential alternative to conventional use of antimicrobial agents in the treatment of infections caused by Staphylococcal biofilms.

Of 45 species of nemerteans reported for the Brazilian coast, only two were recorded from Brazil's Northeast coast. Here we report seven new records for the state of Ceará, in Northeast Brazil: Tubulanus rhabdotus Côrrea, 1954, Carinomella cf. lactea Coe, 1905, Baseodiscus delineatus (Delle-Chiaje 1825), Cerebratulus cf. lineolatus Coe, 1905, Cerebratulus sp. 1, Cerebratulus sp. 2 and Lineidae sp. 1. Specimens were collected at the following beaches: Praia dos Dois Coqueiros, Praia do Pacheco, Pecém harbor, Praia da Pedra Rachada and Praia do Guajiru. T. rhabdotus is a new record for Northeast Brazil, Carinomella cf. lactea and Cerebratulus cf. lineolatus are new records for the South Atlantic Ocean and both genera are new records for Brazil.

This is the first report on imposex occurrence in Pugilina morio. Imposex levels in P. morio from Ceará River Estuary were assessed by a non-lethal method. The obtained imposex parameters were: percentage = 37.1 %, female penis length index (FPLI) = 0.93 mm, relative penis length index (RPLI) = 6.5 %, and vas deferens sequence index (VDSI) = 1.0. Because imposex is induced by tributyltin, and P. morio is widely distributed on the East coast of South America, the species can be used as a tributyltin contamination sentinel in these estuaries. Additionally, a non-lethal method of evaluating imposex minimized the impact on the population of P. morio from sample collection, as all organisms were returned to the environment.