Time filter

Source Type

Lourenco S.,University of Lisbon | Moreno A.,Unidade de Recursos Marinhos e Sustentabilidade | Narciso L.,University of Lisbon | Gonzalez A.F.,CSIC - Institute of Marine Research | Pereira J.,Unidade de Recursos Marinhos e Sustentabilidade
Fisheries Research | Year: 2012

Octopus vulgaris is an important fisheries resource, particularly in Iberian waters. Species life cycle is short with capacity to adapt to different environmental conditions and, considered a simultaneous terminal spawner. Data on maturation and other biological parameters collected from January 2007 to November 2010 are used to define spawning seasons for octopus landed by the small-scale trap fisheries in two oceanographically distinct Portuguese coastal areas: the northwest coast (western Iberia upwelling system) and the south coast (Gulf of Cadiz system). On a monthly basis, we followed the proportion of mature individuals, and the Gonad-Somatic and Hayashi Indices. Length-weight relationship, weight-at-maturity, body condition and energy allocation were other biological parameters studied. Spawning season was markedly different in both areas. The northwest population spawns from March to July, in synchrony with the northwest coast upwelling season, and the south coast population spawns mainly in summer, between August and September. A less intense spawning peak in early spring is present occasionally in the south coast. Weight-at-maturity is geographically indistinct, but in both areas males mature at smaller sizes than females. Body condition increases significantly during maturation and mass allocation for reproduction results indicate that males and females channel energy to reproduction from several sources. © 2012 Elsevier B.V.


Sequeira V.,University of Lisbon | Vila S.,University of Girona | Neves A.,University of Lisbon | Rifes P.,University of Lisbon | And 5 more authors.
Marine Biology Research | Year: 2011

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. © 2011 Taylor & Francis.


Moura T.,Unidade de Recursos Marinhos e Sustentabilidade | Moura T.,University of Lisbon | Serra-Pereira B.,Unidade de Recursos Marinhos e Sustentabilidade | Serra-Pereira B.,University of Lisbon | And 2 more authors.
Journal of Zoology | Year: 2011

Sperm storage in males and females was studied for the deepwater shark Portuguese dogfish Centroscymnus coelolepis. In males, sperm is stored in the seminal vesicle from early maturity stages until mating. The epithelium of the seminal vesicle secretes an acid mucopolysaccharide that might preserve sperm until it is released. The oviducal gland (OG) presents the four distinct zones described for other elasmobranchs: club, papillary, baffle and terminal. Mature, pregnant, resting and regenerating females are able to store sperm in the terminal zone. Sperm was found within sperm storage tubules (SSTs), involved by a secretory matrix. The localization of SSTs deeper in the OG suggests long-term sperm storage, which is in agreement with the long reproductive cycle described for this species. Sperm storage is an advantage for this deepwater species that presents sexual segregation and lives in a food-constrained environment, increasing the efficiency in reproduction. © 2011 The Authors. Journal of Zoology © 2011 The Zoological Society of London.


Moura T.,Unidade de Recursos Marinhos e Sustentabilidade | Moura T.,University of Lisbon | Nunes C.,Unidade de Recursos Marinhos e Sustentabilidade | Bandarra N.,Unidade de Valorizacao dos Produtos da Pesca e da Aquicultura | And 2 more authors.
Marine Biology | Year: 2011

The embryonic development and the level of dependency of the embryos from the maternal organism were investigated for Centroscymnus coelolepis. During the development, there is a 22-32% loss of organic matter and gains of 95-122% and 29-46% on moisture and inorganic matter, respectively. Only 28-48% of the initial yolk energy is conserved in embryos, being the remaining used in catabolism. In late pregnancy, the epithelium thickness of uterine villi decreases and vascularity increases. Results suggest that only water and minerals are transferred from the mother to the embryos. Monounsaturated fatty acids are the main type of fatty acids representing 48% of the total yolk fatty acid content, followed by polyunsaturated (30%) and saturated fatty acids (18-21%). © 2010 Springer-Verlag.

Loading Unidade de Recursos Marinhos e Sustentabilidade collaborators
Loading Unidade de Recursos Marinhos e Sustentabilidade collaborators