Biologia e abundância do camarão Plesionika edwardsii (Brandt, 1851) nos Açores

Dissertação de Mestrado, Estudos Integrados dos Oceanos, 15 de Janeiro de 2009, Universidade dos Açores.

Feeding strategy and trophic ontogeny in Scorpaena maderensis (Scorpaeniformes: Scorpaenidae) from the Azores, NE Atlantic

Copyright © 2014 Société Française d'Ichtyologie.

A trophic analysis of target species of macrobenthos in a subtropical coast community: a taxa relationship essay

Studies on the feeding habits of aquatic organisms are a requirement for the management and sustainable use of marine ecosystems. The aim of the present research was to analyze the habits and trophic similarities of decapods, starfish and fish in order to propose trophic relationships between taxa, using Hennigian methods of phylogenetic systematics. This new grouping hypothesis, based on shared and exclusive food items and food types, corresponds to the broad taxonomic groups used in the analysis. Our results indicate that algae, Mollusca, Polychaeta, Crustacea, Echinodermata and Actinopterygii are the most exploited common resources among the species studied. Starfish were differentiated from other organisms for being stenophagic, and were grouped for feeding on bivalve mollusks. A larger group of fish and crustaceans shares algae and mainly crustaceans as food items. A third group united all eight species of Actinopterygii. This largest subgroup of fish is typically carnivorous, feeding on Anthozoa and a great quantity of Crustacea. Synodus foetens has a special position among fishes, due to its unique feeding on nematodes. A Euclidean distance dendrogram obtained in a previous publication grouped S. foetens with starfish. That result was based on a few non-exclusive shared similarities in feeding modes, as well as on shared absences of items, which are not an adequate grouping factor. Starfish are stenophagic, eating bivalves almost exclusively. Synodus foetens and Isopisthus parvipinnis have restricted food items, and are thus intermediary in relation to starfish, decapods, and other fish, which are euryphagous. The trophic cladogram displays details of food items, whether or not shared by all species. The resulting trophic analysis is consistent with known historical relationships.

Ecologia alimentar e biometria de duas espécies de raias de espinho dos Açores : uma análise ecológica e perspetiva para turismo subaquático

Dissertação de Mestrado em Gestão e Conservação da Natureza.

First report of ciguatoxins in two starfish species : Ophidiaster ophidianus and Marthasterias glacialis

Ciguatera fish poisoning (CFP) is a syndrome caused by the ingestion of fish contaminated with Ciguatoxins (CTXs). These phycotoxins are produced mainly by dinoflagellates that belong to the genus Gambierdiscus that are transformed in more toxic forms in predatory fish guts, and are more present in the Indo-Pacific and Caribbean areas. It is estimated that CFP causes per year more than 10,000 intoxications worldwide. With the rise of water temperature and anthropogenic intervention, it is important to study the prevalence of CFP in more temperate waters. Through inter- and subtidal sampling, 22 species of organisms were collected, in Madeira and Azores archipelagos and in the northwestern Moroccan coast, during September of 2012 and June and July of 2013. A total of 94 samples of 22 different species of bivalves, gastropods, echinoderms and crustaceans where analyzed by Ultra Performance Liquid Chromatography-Mass Spectometry-Ion Trap-Time of Flight (UPLC-MS-IT-TOF) and Ultra Performance Chromatography- Mass Spectrometry (UPLC-MS). Our main aim was to detect new vectors and ascertain if there were some geographical differences. We detected for the first time putative CTXs in echinoderms, in two starfish species—M. glacialis and O. ophidianus. We detected differences regarding uptake values by organisms and geographical location. Toxin amounts were significant, showing the importance and the need for continuity of these studies to gain more knowledge about the prevalence of these toxins, in order to better access human health risk. In addition, we suggest monitoring of these toxins should be extended to other vectors, starfish being a good alternative for protecting and accessing human health risk.

Water treatments in semi-closed cooling circuits and their impact on the quality of effluents discharged by CERN

Dissertação apresentada à Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia do Ambiente, Gestão de Sistemas Ambientais

Water treatments in semi-closed cooling circuits and their impact on the quality of effluents discharged by CERN

Mestrado integrado em Engenharia do Ambiente, perfil: Gestão de Sistemas Ambientais

Alergia a Perceves no Contexto da Síndrome Ácaros-Crustáceos-Moluscos-Baratas

Introdução: A tropomiosina dos invertebrados é o pan-alergénio que une crustáceos, moluscos, aracnídeos, insectos e parasitas, encontrando-se significativa homologia de sequência entre as proteínas dos vários grupos. Os perceves são um tipo de crustáceo particularmente apreciado e consumido no nosso país; no entanto, a alergia a este crustáceo é uma situação bastante rara da qual só existe um trabalho publicado na literatura. Caso clínico: Apresentamos o caso de uma criança do sexo masculino, de 9 anos de idade, com asma brônquica, rinoconjuntivite alérgica e eczema atópico, sensibilizada a ácaros e baratas. Aos 7 anos, 10 minutos após a primeira ingestão de perceves, refere síndrome de alergia oral, angioedema periorbitário e rinoconjuntivite. Aos 8 anos, ocorreram 4 episódios semelhantes após ingestão de caracol, camarão, lula e choco (referindo ingestão prévia destes alimentos sem queixas). Aos 9 anos, refere episódio de urticária da face e angioedema periorbitário com inalação de vapores de cozedura de camarão. Foram realizados testes cutâneos por prick que se revelaram positivos para perceves, camarão, caracol, lula, choco, polvo e amêijoa em natureza, e para gamba, caranguejo e mexilhão com extractos comerciais. Os doseamentos de IgE específica sérica revelaram-se positivos para camarão, caracol, lula, polvo e amêijoa, bem como para perceves e tropomiosina recombinante. Foi efectuado SDS-PAGE immunoblotting com extracto de perceves que revelou várias fracções alergénicas com grande variação de pesos moleculares (19-88 kDa); foi ainda efectuado estudo de inibição com D. pteronyssinus, que inibiu várias fracções fixadoras de IgE no extracto de perceves. Discussão: Apresenta-se um caso raro de uma criança, com quadro de alergia respiratória associada a sensibilização a ácaros e baratas, com alergia alimentar a crustáceos –incluindo a perceves – e moluscos gastrópodes, bivalves e cefalópodes. Foram caracterizados os alergénios implicados na alergia a perceves e demonstrada a presença da tropomiosina como alergénio implicado, bem como a reactividade cruzada entre estes crustáceos e os ácaros.

Heavy metal contamination in seafood and consumer exposure in the Gulf Cooperation Council

Dissertação para obtenção do Grau de Mestre em Tecnologia e Segurança Alimentar

The seasonal diet of Aequidens tetramerus (Cichlidae) in a small forest stream in the Machado River basin, Rondônia, Brazil

Trophic relationships in fish communities are affected by the availability of resources, which in turn is affected by spatial and temporal variations throughout the year. The aims of this study were to characterize the diet of A. tetramerus in a streamlet in the north of Brazil and compare its composition in different hydrological seasons (wet and dry seasons). Collections were performed every two months from October 2011 to September 2012 with the aid of seine nets, hand net and fishing traps in the streamlet located in the Machado River drainage basin in the Rondônia state. Most of the specimens collected were quite small (< 40 mm) and had empty stomachs. Our results showed that A. tetramerus feeds on a wide variety of items of plant origin, such as algae, seeds and leaves, as well as items of animal origin, including bryozoans, crustaceans, fish scales, terrestrial insects and detritus. The data also indicated higher consumption of aquatic insects than other food items, suggesting a primarily insect-based diet. Items of plant and allochthonous origin were consumed more in the wet season than in the dry season, but there were no seasonal differences in the consumption of animal and autochthonous items.

Crustáceos no cerrito Ariano Souza, Rio Grande, Rio Grande do Sul e distribuição de Callinectes sapidus (Brachyura, Portunidae)

While all species of the genus Callinectes Stimpson, 1860 have a continuous distribution on the Atlantic coast of the Americas, Callinectes sapidus Rathbun, 1896 is the only one with disjunct distribution. Considering that this species was introduced in Europe and Japan, it has been suggested that the occurrence of C. sapidus on the southern coast of Brazil was due to the transport by ballast water. In the archaeological site Ariano Souza, located in the estuary of the Patos Lagoon (southern Brazil), remains of crustaceans, including claws of approximately two thousand years ago, were found. A preliminary analysis of this material showed Callinectes chelae. Because this archaeological site is located inside the estuary, it has been hypothesized that these chelae belong either to C. sapidus or to C. danae Smith, 1869. A comparison between pincers collected in the archaeological and pincers of these two species (90 dactyls, 30 of each type) was performed. The analysis (ANOVA) considered the variability of seven characters of the dactyls, and demonstrated the existence of two groups. Results showed that the measured characters suffice to separate these species, and indicated that the material found in the archaeological site belongs to C. sapidus. The hypothesis of the introduction of C. sapidus in the area is rejected. The possible biogeographic history of the species is discussed.

Spatial and temporal distribution of decapod larvae in the subtropical waters of the Arvoredo archipelago, SC, Brazil

The present paper aims to describe the temporal and spatial distribution of the composition and abundance of Decapoda larvae in the shallow waters around Arvoredo Marine Biological Reserve. Stomatopod occurrence is also discussed. Plankton samples were collected at five sites around the Arvoredo Island every two months for one year from May, 2002 to April, 2003. Thirty-nine morphotypes, 11 genus and 4 species (Artemesia longinaris Bate, 1888, Hexapanopeus schmitii Rathbun, 1930, Menippe nodifrons Stimpson, 1859 and Pleoticus muelleri Bate, 1888) were identified, among them only two morphotypes of Stomatopoda larvae, and the remainder Decapoda larvae. Brachyuran zoeae were the most abundant group and they were well represented by Portunidae and Xanthidae zoeae. Lucifer sp. and Caridea zoeae were the most abundant non-brachyuran taxa. Decapod larvae were observed to occur at all sampling sites, however the spatial distribution demonstrated a general tendency to greater abundance and diversity at the southern sites of the Island. Decapoda and Stomatopoda larvae occurred throughout the year, showing that reproduction is continuous, but that larval input in planktonic community was significantly higher during autumn and spring.

Diet of the ichthyofauna associated with marginal vegetation of a mangrove forest in southeastern Brazil

The objective of this study was to analyze the diet of fish species that use the mangrove vegetation for shelter and feeding in a river southeastern Brazil. The fieldwork, including collecting and underwater observations, was carried out in the dry (July and August 2004) and in the rainy season (February and March 2005) in order to assess the existence of seasonal variation in the diets. Seven kinds of food items were consumed, two of plant origin and five of animal origin. Crustaceans predominated in the diet of most species, either in the form of unidentified fragments or discriminated in eight groups. The predominance of species using mainly a single food source (crustaceans, principally Ostracoda and Tanaidacea) and the existence of seasonal variation in the diets of some species became very evident in the analysis food niche breadth, with a predominance of dietary specialists. In the Rio da Fazenda mangrove, the submersed marginal vegetation was used by the ichthyofauna as a locale for foraging, and principally as cover by bottom-feeding species. These species may be using the vegetation for protection from aerial and aquatic predators, or even from the pull of the current during the turn of the tide. In the study area, the great diversity of crustaceans constitutes an important food source for most fish species which adjusted their diet according to seasonal changes in food availability and to interactions with other species.

Gonad development in females of fiddler crab Uca rapax (Crustacea, Brachyura, Ocypodidae) using macro and microscopic techniques

The morphology of the ovaries in Uca rapax (Smith, 1870) was described based on macroscopic and microscopic analysis. Females were collected in Itamambuca mangrove, Ubatuba, state of São Paulo, Brazil. In the laboratory, 18 females had their ovaries removed and prepared for histology. Each gonad developmental stage was previously determined based on external and macroscopic morphology and afterwards each stage was microscopically described. The ovaries of U. rapax showed a pronounced macroscopic differentiation in size and coloration with the maturation of the gonad, with six ovarian developmental stages: immature, rudimentary, developing, developed, advanced and spent. During the vitellogenesis, the amount of oocytes in secondary stage increases in the ovary, resulting in a change in coloration of the gonad. Oogonias, primary oocytes, secondary oocytes and follicular cells were histologically described and measured. In female’s ovaries of U. rapax the modifications observed in the oocytes during the process of gonad maturation are similar to descriptions of gonads of other females of brachyuran crustaceans. The similarities are specially found in the morphological changes in the reproductive cells, and also in the presence and arrange of follicle cells during the process of ovary maturation. When external morphological characteristics of the gonads were compared to histological descriptions, it was possible to observe modifications that characterize the process in different developmental stages throughout the ovarian cycle and, consequently, the macroscopic classification of gonad stages agree with the modifications of the reproductive cells.

Diet of Cnesterodon decemmaculatus (Poeciliidae) and Jenynsia multidentata (Anablepidae) in a hypertrophic shallow lake of Uruguay

Diet of Cnesterodon decemmaculatus (Jenyns, 1842) and Jenynsia multidentata (Jenyns, 1842) were analysed in Lake Rodó, an urban hypertrophic lake from Montevideo, Uruguay. Both species displayed omnivory. The most consumed items for C. decemmaculatus were zooplankton, periphyton, phytoplankton and detritus; the diet of J. multidentata included zooplankton, insects, crustaceans and juvenile fish. Our results suggest that both species could be acting as facultative planktivores. The fish community of this lake is characterised by the dominance of C. decemmaculatus and J. multidentata. Under this condition, predation on large-bodied zooplankton could indirectly be contributing to maintain a high phytoplankton abundance and a low water transparency.