Ana Neves

Molecular barcoding of north-east Atlantic deep-water sharks: species identification and application to fisheries management and conservation

Two genera of elasmobranchii, Centrophorus and Centroscymnus, include species that represent the highest landings of deep-water sharks caught by fishing fleets operating in the north-east Atlantic. There are morphology-based identification problems among and within genera, and landings of processed shark products further prevent an objective assessment of these species. The present study is the first attempt to test the suitability of using a DNA barcode approach to discriminate accurately among the four most important commercial deep-water shark species: Centrophorus squamosus, Centrophorus granulosus, Centroscymnus coelolepis and, recently discovered in Portuguese ports, Centroscymnus owstoni. Sequence analyses of the mitochondrial DNA cytochrome c oxidase subunit I (COI) gene revealed low levels of haplotypic and genetic diversities. Higher levels of inter-specific relative to intra-specific divergences allowed discrimination among species, which form reciprocally monophyletic clades. Inclusion of published COI sequences from other species within the same genera revealed haplotype sharing among species, which calls into question the current taxonomy and accuracy of fisheries data available. Amplification of the COI gene coupled with MboI restriction digests was found to be a fast and inexpensive strategy to resolve within genera identification problems. Molecular barcoding constitutes a critical tool for the assessment and implementation of urgent management policies for this group of species.

The use of caudal thorns for ageing Raja undulata from the Portuguese continental shelf, with comments on its reproductive cycle

The present study focuses on age estimation, with reproductive information contributing to the better understanding of the growth and the biology of Raja undulata. In the age and growth study, two calcified structures were used: caudal thorns and central vertebra. Results of readings showed that there were no significant differences in age estimates between the two structures. Both von Bertalanffy and Gompertz growth models were fitted to size-at-age data by sex and geographical area. No significant differences were found between sexes for the two models but significant differences were found between geographical areas (P = 0.05). The Gompertz growth function was selected as the best model to describe R. undulata growth because it presented the best fit and the most reasonable biological estimates. Reproductive analysis indicates one annual breeding season for R. undulata. The differences found in the estimates of length at first maturity between geographical areas (TL50% = 838 mm in Peniche and 762 mm in Algarve for females and TL50% = 781 mm in Peniche and 736 mm in Algarve for males), together with the regional differences found between growth parameters estimates (P = 0.05), may reflect the existence of different local populations of R. undulata on the Portuguese continental shelf.

Discriminating bluemouth, Helicolenus dactylopterus (Pisces: Sebastidae), stocks in Portuguese waters by means of otolith shape analysis

ana neves, vera sequeira, ines farias, ana rita vieira, rafaela paiva and leonel serrano gordo Faculdade de Ciencias da Universidade de Lisboa, Departamento de Biologia Animal & Centro de Oceanografia, Bloco C2, Campo Grande, 1749-016 Lisboa, Portugal, Unidade de Recursos Marinhos e Sustentabilidade, Instituto de Investigacao das Pescas e do Mar (IPIMAR–INRB), Avenida Brasilia, 1449–006 Lisboa, Portugal

Distribution patterns and reproduction of the cuttlefish, Sepia officinalis in the Sado estuary (Portugal)

The cuttlefish (Sepia officinalis) is the most important traditional fishing activity in the Sado estuary. In order to analyse the spatial and temporal distribution patterns and to study the reproductive cycle of this species, twenty sampling areas were towed along the estuary on a monthly basis from May 2001 to April 2002. The higher densities were obtained in summer and autumn in the lower and southern area of the estuary while spring showed the higher biomass. Mature individuals prevailed in the inner zone of the estuary during spring while juveniles were dominant in autumn and concentrated in the lower part of the estuary. Almost all individuals leave the estuary during winter. The weight-length relationship was significantly different according to sex, beingfemales heavier than males for individuals larger than 106 mm. Sex-ratio was similar to 1:1 in every season. Females had high values of gonadosomatic index during the spawning season with a major peak in June, while males showed similar values throughout the spawning season. The length at first maturity was estimated at 80 mm mantle length (ML) for females and 59 mm ML for males. In the Sado estuary only one generation of cuttlefish breeders were found with an average of 110 mm ML for males and 122 mm ML for females, which is consistent with breeders in their first year.

Distribution and abundance patterns of decapod crustaceans in the Sado estuary, Portugal

[The decapod crustacean community of the Sado estuary was sampled monthly, between May 2001 and April 2002, using a 4 m beam trawl with 10 mm mesh size. The assemblage was composed of 33 species (9 Natantia and 24 species of Reptantia). Only 5 species (Crangon crangon, Macropodia rostrata, Pilumnus hirtellus, Carcinus maenas, and Liocarcinus navigator) were present in more than 40% of the samples. Few species dominated the community: C. crangon and C. maenas were the most important species in numbers (accounting for 63% and 17% of the total number of individuals, respectively), while C. maenas, Maja brachydactyla, and C. crangon dominated in biomass (73%, 9%, and 8%, respectively). A marked spatial and seasonal pattern was noticed: the inner areas, with shallower depth, less water transparency, and lower salinity, presented a high abundance of C. crangon, while in the outer areas a more diverse assemblage was found. In spring and summer, species richness increased, mainly in the lower estuary. The dominant species Crangon crangon and Carcinus maenas were more abundant in winter. A comunidade de crustaceos do estuario do sado foi amostrada mensalmente, entre Maio de 2001 e Abril de 2002, com recurso a um arrasto de vara com 4 m de largura e com uma malha da rede de 10 mm. Foram identificadas 33 especies (9 especies de Natantia e 24 de Reptantia). Apenas 5 especies (Crangon crangon, Macropodia rostrata, Pilumnus hirtellus, Carcinus maenas e Liocarcinus navigator) estiveram presentes em mais de 40% das amostras. Poucas especies dominaram a comunidade: C. crangon e C. maenas foram as mais importantes em numero de individuos (representando 63% e 17% do total de individuos capturados, respectivamente), enquanto C. maenas, Maja brachydactyla e C. crangon dominaram em biomassa (73%, 9% e 8%, respectivamente). Foi registado um padrao espacio-temporal bem marcado: as areas mais a montante, com menor profundidade, transparencia da agua e salinidade, apresentaram uma abundância elevada de C. crangon, enquanto nas areas mais proximas da embocadura foi encontrada uma comunidade mais diversificada. Na Primavera e no Verao verificou-se um aumento da riqueza especifica, especialmente no estuario inferior. As especies dominantes Crangon crangon e Carcinus maenas foram mais abundantes no Inverno., The decapod crustacean community of the Sado estuary was sampled monthly, between May 2001 and April 2002, using a 4 m beam trawl with 10 mm mesh size. The assemblage was composed of 33 species (9 Natantia and 24 species of Reptantia). Only 5 species (Crangon crangon, Macropodia rostrata, Pilumnus hirtellus, Carcinus maenas, and Liocarcinus navigator) were present in more than 40% of the samples. Few species dominated the community: C. crangon and C. maenas were the most important species in numbers (accounting for 63% and 17% of the total number of individuals, respectively), while C. maenas, Maja brachydactyla, and C. crangon dominated in biomass (73%, 9%, and 8%, respectively). A marked spatial and seasonal pattern was noticed: the inner areas, with shallower depth, less water transparency, and lower salinity, presented a high abundance of C. crangon, while in the outer areas a more diverse assemblage was found. In spring and summer, species richness increased, mainly in the lower estuary. The dominant species Crangon crangon and Carcinus maenas were more abundant in winter. A comunidade de crustaceos do estuario do sado foi amostrada mensalmente, entre Maio de 2001 e Abril de 2002, com recurso a um arrasto de vara com 4 m de largura e com uma malha da rede de 10 mm. Foram identificadas 33 especies (9 especies de Natantia e 24 de Reptantia). Apenas 5 especies (Crangon crangon, Macropodia rostrata, Pilumnus hirtellus, Carcinus maenas e Liocarcinus navigator) estiveram presentes em mais de 40% das amostras. Poucas especies dominaram a comunidade: C. crangon e C. maenas foram as mais importantes em numero de individuos (representando 63% e 17% do total de individuos capturados, respectivamente), enquanto C. maenas, Maja brachydactyla e C. crangon dominaram em biomassa (73%, 9% e 8%, respectivamente). Foi registado um padrao espacio-temporal bem marcado: as areas mais a montante, com menor profundidade, transparencia da agua e salinidade, apresentaram uma abundância elevada de C. crangon, enquanto nas areas mais proximas da embocadura foi encontrada uma comunidade mais diversificada. Na Primavera e no Verao verificou-se um aumento da riqueza especifica, especialmente no estuario inferior. As especies dominantes Crangon crangon e Carcinus maenas foram mais abundantes no Inverno.]

The gelatinous matrix of the teleost Helicolenus dactylopterus dactylopterus (Delaroche, 1809) in the context of its reproductive strategy

Abstract The bluemouth, Helicolenus dactylopterus dactylopterus (Pisces: Sebastidae), is a zygoparous species with internal fertilization that stores the spermatozoa in crypts within the female ovaries. It spawns gelatinous egg masses that were investigated in this study. Histological analysis confirmed that the ovarian wall and peduncular epithelia play an important role in the production of this gelatinous matrix that contained both oocytes and embryos. Cleavage and blastulae were the most frequent embryonic development stages observed and the tail bud was the latest stage reached. The chemical composition of the matrix was also investigated, revealing that water and proteins are the major components of this substance. This is the first study exclusively dedicated to the investigation of the composition, function and importance of the gelatinous matrix of H. d. dactylopterus in the context of its reproductive strategy.

Reproductive strategy of the female deep-water shark birdbeak dogfish, Deania calcea : lecithotrophy or matrotrophy?

Little information is available on the maternal–embryonic relationships among sharks. Birdbeak dogfish ( Deania calcea ) has been described as ovoviviparous, but this term comprises a wide range of forms on how the embryos are nourished including lecithotrophy and matrotrophy. To evaluate the maternal–embryonic relationship in birdbeak dogfish we have analysed chemical features (fatty acid composition and mercury (Hg) levels) and biological characteristics (egg and embryo dry weight variation, uterus characterization). Monounsaturated fatty acids were the dominant fatty acids in eggs while polyunsaturated fatty acids (PUFA) were the dominant fatty acids in both pregnant females and embryos. Significant differences were found among eggs, embryos and pregnant females for all fatty acids groups with the exception of saturated fatty acids for embryos and pregnant females. The principal components analysis revealed that embryos are particularly related to n-6 PUFA and pregnant females with n-3 PUFA. A close relationship exists between the Hg level of pregnant females and the Hg level of their embryos which indicates that there is a transfer of mercury from maternal sources. The comparison of the mean dry weight between eggs and embryos showed a gain of 3.8% obtained in the embryos. Histological sections of the uteri of pregnant females showed a high level of both superficial and inner vascularization in the uterine villi as well as the presence of secretor cells. Until now, the importance of this species maternal contribution and interference for the embryos development has never been documented. However, the biological and chemical results observed in the present work show that there is a matrotrophic strategy for the birdbeak dogfish.

Feeding habits of the cuttlefish Sepia officinalis during its life cycle in the Sado estuary (Portugal)

The importance of cephalopods in marine ecosystems is well recognized as they serve as important predators and prey in many food chains. During a 1-year period, cuttlefish were monthly sampled in five areas throughout the Sado estuary, and the stomachs of 445 individuals were examined. Significant changes in the diet according to their life stage were revealed, but similar food habits were presented by males and females. Juvenile individuals (the smaller ones with no visible distinct gonads) preyed mainly upon small crustaceans, while the immature ones (maturity stages I and II) had the most diverse diet with brachyurans as the major prey group. The mature individuals (maturity stages III and IV) showed a clear preference for larger crabs and fishes. Although the cuttlefish are known for their opportunistic feeding behaviour, a preference for some prey according to length and behaviour could be perceived during this study. Seasonal differences in the diet were mostly due to the variation of individuals according to their maturity stage during the year.

Diversity of sexual strategies of fish species caught by bottom trawl off the western Iberian Peninsula

Abstract Samples of boarfish Capros aper, small red scorpionfish Scorpaena notata and comber Serranus cabrilla were collected from monthly by-catch samples on board commercial trawlers off the western coast of Portugal. A histological approach was undertaken to study each species’ reproductive strategy and annual sexual cycle. Temporal variations of the gonadosomatic index and of two condition indices (hepatosomatic and Fultons K) were also analysed. Results showed that C. aper and S. notata are gonochoristic whilst S. cabrilla is a simultaneous hermaphrodite. Fertilization is external and development of secondary growth follicles is asynchronous in the three species. Mass atresia characterized the end of the spawning season in S. notata and S. cabrilla. In C. aper a high prevalence of atresia was observed throughout the year and was not attributed to regressing or regenerating phases or skip spawning events. The main spawning season of the three species was in the summer and it is suggested that spawning is related to upwelling. During the summer, the spawning interval was 1.09, 1.23 and 1.84 days for S. cabrilla, S. notata and C.aper, respectively. The results of this study indicate potential plasticity and environmental adaptation of sexual strategies.

Therapeutic activity of superoxide dismutase-containing enzymosomes on rat liver ischaemia-reperfusion injury followed by magnetic resonance microscopy

&NA; Liver ischaemia‐reperfusion injury (IRI) may occur during hepatic surgery and is unavoidable in liver transplantation. Superoxide dismutase enzymosomes (SOD‐enzymosomes), liposomes where SOD is at the liposomal surface expressing enzymatic activity in intact form without the need of liposomal disruption, were developed with the aim of having a better insight into its antioxidant therapeutic outcome in IRI. We also aimed at validating magnetic resonance microscopy (MRM) at 7 T as a tool to follow IRI. SOD‐enzymosomes were characterized and tested in a rat ischaemia‐reperfusion model and the therapeutic outcome was compared with conventional long circulating SOD liposomes and free SOD using biochemical liver injury biomarkers, histology and MRM. MRM results correlated with those obtained using classical biochemical biomarkers of liver injury and liver histology. Moreover, MRM images suggested that the therapeutic efficacy of both SOD liposomal formulations used was related to prevention of peripheral biliary ductular damage and disrupted vascular architecture. Therefore, MRM at 7 T is a useful technique to follow IRI. SOD‐enzymosomes were more effective than conventional liposomes in reducing liver ischaemia‐reperfusion injury and this may be due to a short therapeutic window. Graphical abstract Figure. No caption available.