Papers by Helena Matthews-Cascon
Marine Biology, May 26, 2022
Environments, Jul 14, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Arquivos de Ciências do Mar, Oct 1, 2012
Many studies on Nassariidae have focused on species that live in the intertidal zone, that are ve... more Many studies on Nassariidae have focused on species that live in the intertidal zone, that are very well adapted to scavenger behavior for presenting an ability of chemoreception at a very long distance. The objectives of this study were to record the time spent by Nassarius vibex feeding on the field, to investigate its correlation with the shell size and to analyze the response time to stimulation by the feeding depending on the duration of hunger under laboratory conditions. Five pieces of fish were placed to serve as bait, and every five minutes, from the time of the bait until 50 minutes later, the number of individuals attracted to these was registered. The early feeding of N. vibex was considered when its proboscis was extended on the bait and end when the animal left the bait. This procedure was repeated for 111 individuals distributed in three days of observation, in January, February and March of 2007. Forty individuals divided into four groups of 10 animals each, which were placed in an tank containing 1 liter of seawater, salinity 30 and constant aeration. At the experiment day 0, food was offered to all groups, thus standardizing the level of hunger and every seven days a different group was fed again so that each group fasted for different periods time. In the field, N. vibex had a six-minute period of food consumption, with 76% of individuals feeding for up to 8 minutes. There was no correlation between feeding time and shell length. In the laboratory, the response time to the presence of food depended on the duration of hunger, with the animals that fasted for longer periods responding more quickly to the presence of food.
Arquivos de ciencias do mar, 1986
Arquivos de Ciências do Mar, Jun 1, 2013
Os aspectos reprodutivos do gastrópode Natica marochiensis foram analisados neste estudo com o in... more Os aspectos reprodutivos do gastrópode Natica marochiensis foram analisados neste estudo com o intuito de compreender melhor sua biologia. Para a análise da reprodução fez-se a caracterização das desovas e suas cápsulas de ovos, bem como o acompanhamento do seu desenvolvimento larval. Os animais foram coletados na praia de Melancias, município de Icapuí, durante marés de sizígia. Em seguida foram trazidos para o laboratório e mantidos em aquários de 5 litros, com água e sedimento esterilizado. As desovas postas pelos animais foram separadas em cubas plásticas contendo água do mar e aeração constante. Foram retirados pedaços das desovas de aproximadamente 1 cm, a cada duas horas e observou-se no microscópio o estágio larval, fazendo posteriormente sua caracterização. As larvas de N. marochiensis se desenvolveram rapidamente quando considerando a duração de cada estágio. A clivagem teve duração entre 42-68 horas até o estágio de trocófora. A larva trocófora durou cerca de 6 horas. A larva veliger durou, em média, 8 horas até a completa degeneração da desova.
Neotropical Biology and Conservation, Jul 3, 2015
Veneridae é considerada uma das maiores famílias do Recente, e também uma das mais diversas dentr... more Veneridae é considerada uma das maiores famílias do Recente, e também uma das mais diversas dentro de Bivalvia, distribuindo-se tanto em ambiente marinho quanto estuarino. Estudos de cunho biogeográficos são importantes para manejo e conservação da biodiversidade. O trabalho tem como objetivo inferir os padrões de distribuição latitudinais e longitudinais, reunindo e listando a composição de venerídeos para a costa do Brasil a partir de base secundária de dados. A composição e distribuição geográfica foram determinadas a partir de levantamento bibliográfico, bem como acesso a bancos de dados online, e classificadas em padrões de distribuição atuais (latitudinais e longitudinais). Segundo dados da literatura, registram-se 40 espécies para a família no Brasil, sendo observada semelhança na malacofauna de Veneridae entre Brasil, Caribe e Golfo do México. As espécies de venerídeos foram classificadas em oito padrões latitudinais e cinco longitudinais. O trabalho aponta uma provável distribuição da família e indica a necessidade de aprofundar o conhecimento da malacofauna no país.
Invertebrate Reproduction & Development, 2009
The gastropod Neritina zebra is distributed in Suriname and along the coast of Brazil, where it l... more The gastropod Neritina zebra is distributed in Suriname and along the coast of Brazil, where it lives on muddy bottoms of brackish water environments. The objectives of this study were to describe the spawning of N. zebra and to investigate its embryonic and larval development under laboratory conditions. The egg capsules are oval. The surface of the capsule in contact
Marine Pollution Bulletin, Oct 1, 2018
Journal of Molluscan Studies, Jul 15, 2016
The MacArthur & Wilson theory of island biogeography predicts that the balance between immigratio... more The MacArthur & Wilson theory of island biogeography predicts that the balance between immigration and extinction rates results from the size and degree of isolation of the island. Here, we test this assumption using data from the marine gastropods of Brazilian oceanic islands. Species lists were compiled for Rocas Atoll, the Fernando de Noronha Archipelago, the Sa˜o Pedro and Sa˜o Paulo Archipelago and Trindade Island. These were compared with the predictions of the theory based on the shallow platform area and distance from the mainland (Model 1) and the nearest reef habitat (Model 2). Results corroborated at least in part the assumptions proposed by MacArthur & Wilson. Sa˜o Pedro and Sa˜o Paulo and Fernando de Noronha fitted the equilibrium model of extinction and immigration rates, while Trindade and Rocas Atoll stood out as an exception to Model 1 and to Models 1 and 2, respectively. The relevance of the age of the island and presence of seamount chains is discussed to explain this discrepancy.
Arquivos de Ciências do Mar, Dec 30, 2022
The brachiopod fauna of the South Atlantic is significantly abundant and appears to be predominan... more The brachiopod fauna of the South Atlantic is significantly abundant and appears to be predominantly composed of cosmopolitan species. However, until now there was no record of inarticulate brachiopods of the Family Lingulidae in this region. The present study describes the first occurrence of lingulid brachiopods in the South Atlantic. Seven specimens were collected on the continental shelf of the Maranhão state, Northeastern Brazil, Western South Atlantic. The individuals were identified as belonging to the genus Lingula. Although brachiopods have great dispersion capability durintg their larval phase, the hypothesis that these specimens arrived on the Brazilian coast as a result of human activities cannot be ruled out.
Arquivos de Ciências do Mar, Dec 14, 2017
Ophiuroids of the family Gorgonocephalidae are rare on the Brazilian coast. Thus, only one specim... more Ophiuroids of the family Gorgonocephalidae are rare on the Brazilian coast. Thus, only one specimen of Asteroporpa (Asteroporpa) annulata had previously been registered and deposited in a Brazilian scientific collection. In this paper, we report the occurrence of the species in Brazil based on a single specimen captured in a bottom trawl during the MAR 15 Project of the research vessel (RV) Victor Hensen in November 1990. Our report supports the occurrence of the species in Brazil, represents the first report for the state of Ceará, and reduces the gap in the known distribution of the species.
Herpetology Notes, Aug 12, 2019
This work describes the population biology of the sea hare, Aplysia dactylomela, at two beaches i... more This work describes the population biology of the sea hare, Aplysia dactylomela, at two beaches in Ceará State, Brazil. Their habitats were monthly examined for one-year period, at low tide during daytime and the number, size, spawning and breeding behavior were registered. Feeding habits were determined by observation of seaweed species consumed in the field and by dissecting and examining the gut contents of the sea hares. The results showed that the population density of A. dactylomela in tropical waters from Brazil is much lower than those described for populations of temperate and subtropical regions. This might be explained by the intense sun radiation of tropical regions since the other environmental factors were suitable to their settlement. Despite the low density, A. dactylomela is found throughout the year, with recruitment peaks on February and March. Both population density and animal size were different in the two beaches, what might be due to differences in seaweed abundance and quality, degree of sun exposure and man-caused pollution.
The Biological Bulletin, Apr 1, 2018
Many invertebrates enclose their embryos within egg capsules, from which the offspring hatch. In ... more Many invertebrates enclose their embryos within egg capsules, from which the offspring hatch. In marine gastropods that brood their egg capsules, hatching could involve radular activity by the mother or by unhatched stages, increased osmotic concentration of the intracapsular fluid, or production of hatching enzymes. The present research sought to determine whether mechanical action by the brooding female or by the encapsulated embryos was involved in the hatching for two sympatric and closely related species of calyptraeid: Crepipatella dilatata, which exhibits direct development without free-living larvae, and Crepipatella peruviana, which releases free-living veliger larvae. We also considered the role that enzymatic action or osmotic changes in the intracapsular fluid might play in hatching. Using scanning electron micrograph analyses, we found no evidence that the well-developed, pre-hatching juvenile radula of C. dilatata played any role in the hatching process and that the radula of C. peruviana did not even develop until long after hatching; so there was no evidence of radular activity involved in the hatching of either species. For C. peruviana, the intracapsular fluid osmolality was always higher than that of the surrounding seawater, suggesting that there is a strong natural water inflow during development. Moreover, when egg capsules of C. peruviana were exposed to lower ambient salinities, the substantial entry of water correlated well with high percentages of hatching, particularly for egg capsules containing advanced veligers, suggesting that an osmotic mechanism may be involved in the hatching process of this species. In contrast, hatching in C. dilatata appeared to be enzymatically mediated.
Scientia Marina, Dec 30, 2006
The influence of abiotic factors on the spatial distribution of the fiddler crabs Uca leptodactyl... more The influence of abiotic factors on the spatial distribution of the fiddler crabs Uca leptodactyla, U. maracoani, U. rapax and U. thayeri was studied in a tropical mangrove of northeast Brazil. Eight transects were delimited in a mangrove area of the Pacoti River. On each transect, three 0.25 m 2 squares were sampled during spring low tide periods from September 2003 to August 2004. The sediment of the squares at each transect was analysed for grain size, organic matter and humidity. Morphology of the second maxilliped was studied considering the number of spoon-tipped setae to help explain the ecological distribution of the species. U. leptodactyla and U. rapax were found living in medium sand, U. thayeri was collected in fine and very fine sand, while U. maracoani was found living in very fine sand. U. leptodactyla showed a negative correlation with organic matter and humidity while U. thayeri showed a positive correlations for both factors. U. maracoani and U. rapax were not correlated with organic matter or humidity. The analysis of the second maxilliped revealed that U. leptodactyla and U. rapax show a high quantity of spoon-tipped setae while U. maracoani and U. thayeri show a greater quantity of plumose setae.
Brazilian Journal of Aquatic Science and Technology, Aug 8, 2016
Known as "ark-shells" and "blood cookles", species of family Arcidade are sessile and it's very c... more Known as "ark-shells" and "blood cookles", species of family Arcidade are sessile and it's very common in tropical seas. The study aiming check the shells morphological metric elements that would help in arcids differentiation (Mollusca: Bivalvia: Arcidae), as well as examine the conchological variations of specimens from North and Northeastern regions of Brazil. The samples available were from malacological collection "Prof. Henry Ramos Matthews" (CMPHRM), of Universidade Federal do Ceará (UFC), wich only the right valve was used. After shells identification, eight measures were taken: hinge length, shell length, position of umbo, umbo height, anterior shell height, middle shell height, posterior shell height and posterior shell length. Those measures are previously known as 'landmarks' of the family. The data were analyzed by statistical packages and shell's mean sizes were consistent with measures presented in the literature. In general, the measures were significant in the differentiation of species. Different specimens with geographical proximity it often have morphological similarity.
Journal of Molluscan Studies, Sep 22, 2018
Encapsulation of embryos in marine gastropods affords protection for the developing young, whethe... more 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.
Journal of the Marine Biological Association of the United Kingdom, Dec 13, 2013
A new species of the family Tritoniidae is described from the tropical South Atlantic Ocean. The ... more A new species of the family Tritoniidae is described from the tropical South Atlantic Ocean. The animal was found off north-east Brazil.Tritonia khaleesisp. nov. is up to 12 mm long, with a slender white body, of which the notum is covered with one broad white band extending from between the eyes and veil to the tail; veil with 4 velar appendages; retractable white rhinophores; rhinophoral sheath with fleshy extension; seven pairs of branchial plumes; the anus is located between the 3rd and 4th gills on the right side, and the genital opening is under the 2nd gill. Internally,T. khaleesisp. nov. is distinguished from other tritoniids by jaws with 10–14 rows of denticles on the inner lips, absence of stomach plates and the radular formula 32 × 2–5.1.1.1.2–5 teeth.Tritonia khaleesisp. nov. is the onlyTritoniathat possesses a unicuspid rachidian tooth as an adult.
Invertebrate Reproduction & Development
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Papers by Helena Matthews-Cascon