Reproductive activity and biochemical composition of the pullet carpet shell <i>Venerupis senegalensis</i> (Gmelin, 1791) (Mollusca: Bivalvia) from Ria de Aveiro (northwestern coast of Portugal)

Abstract

SUMMARY: The present study characterizes the reproductive cycle of Venerupis senegalensis (=V. pullastra) from Ria de Aveiro (Portugal) as well as its nutrient storage and exploitation strategy. The reproductive cycle followed a seasonal cycle that correlated negatively with sea surface temperature, and comprised a ripe stage in winter followed by a spawning period that began in late winter and ended in the early summer. This extended spawning may be an advantageous strategy for the species because it ensures a continuous supply of settlers. Gametogenesis began in late summer/early autumn and intensified with the decrease in temperature during autumn. The condition index increased even during the spawning period, which indicates that there is rapid recovery and that reserves are accumulated during late summer and used later in the gametogenic process. Proteins did not contribute significantly to gametogenesis and the glycogen pattern is typical of conservative species, since gametogenesis depends largely on the amount of glycogen stored. The lipid storage and utilization cycle showed that gametogenesis took place in autumn/winter and that energy reserves were accumulated in summer.Keywords: pullet carpet shell, Venerupis senegalensis, biochemical composition, condition index, reproductive cycle.RESUMEN: Actividad reproductiva y composición bioquímica de la almeja babosa Venerupis senegalensis (Gmelin, 1791) (Mollusca: Bivalvia) de la Ría de Aveiro (costa noroeste de Portugal). -El presente estudio caracteriza el ciclo reproductivo de Venerupis senegalensis (= V. pullastra) en la Ría de Aveiro (Portugal) así como su estrategia de almacenamiento y explotación de los nutrientes. El ciclo reproductivo de esta especie sigue un ciclo estacional que se correlaciona negativamente con la temperatura del agua del mar, que coincide con un estado de madurez en el invierno, seguido de un periodo de desove que se inicia a finales de invierno y termina a principios del verano. Este periodo de puesta prolongado puede ser una estrategia ventajosa para la especie, ya que garantiza un suministro continuo de larvas. La gametogénesis comenzó a finales del verano/inicios de otoño y se intensificó con la disminución de la temperatura durante el otoño. El aumento del índice de condición, todavía durante la puesta, indica una recuperación rápida y una acumulación de reservas a finales del verano, que serán utilizadas en el siguiente proceso de gametogénesis. Las proteínas no contribuyen significativamente a la gametogénesis y el ciclo de glucógeno es típico de las especies conservadoras, una vez que la gametogénesis depende, en gran medida, de la cantidad de glucógeno almacenado. El almacenamiento de lípidos y su utilización indica la gametogénesis en el otoño/invierno, así como el proceso de acumulación de energía en verano.Palabras clave: almeja babosa, Venerupis senegalensis, composición bioquímica, índice de condición, ciclo reproductivo. June 2011, 217-226, Barcelona (Spain) Scientia Marina 75(2)

The effect of density in larval rearing of the pullet carpet shellVenerupis corrugata(Gmelin, 1791) in a recirculating aquaculture system

“…In Portugal, V. corrugata populations declined during the last decades due to overfishing and recruitment failure, even in areas where this species was once abundant, such as in Ria de Aveiro and Ria Formosa lagoons. Indeed, Ria Formosa population density has decreased below a threshold level, such that natural recovery does not appear to be possible (Joaquim, Matias, Ramos, Moura, Arnold, Chícharo & Gaspar ). Despite the high market demand and high commercial value of this species, this decline has led to an abandonment by local fishermen.…”

Broodstock conditioning of the Portuguese oyster (Crassostrea angulata, Lamarck, 1819): influence of different diets

“…However, the evolution observed in the gonadal development and condition index of the individuals fed Diet 1 suggests that in case of nutritional stress, reproduction seems to be a priority and oysters allocate some available energy to this process to ensure the viability of the species (Joaquim et al . ).…”

“…The biochemical composition of the diet influences the physiology of bivalves, particularly if a minor component is lacking. However, the composition of the specific forms of major components (proteins, carbohydrates and total lipids) can also be of influence (Matias, Joaquim, Leitão & Massapina ; Joaquim, Matias, Ramos, Moura, Arnold, Chícharo & Gaspar ). Lipids are usually used as an energy source during gametogenesis (Holland ; Martínez, Aguilera & Mettifogo ; Delgado, Pérez‐Camacho, Labarta & Fernández‐Reiriz ) and constitute the principal nutritional reserve in oocytes and larvae, conditioning their viability (Matias, Joaquim, Ramos, Sobral & Leitão ).…”

Elemental composition and bioaccessibility of farmed oysters (Crassostrea gigas) fed different ratios of dietary seaweed and microalgae during broodstock conditioning

“…On the one hand, it is known that the dietary nutritional profile influences the physiology of bivalves, having typically a strong effect on proteins, carbohydrates, and lipids (Joaquim et al, 2011;Matias, Joaquim, Leitão, & Massapina, 2009). On the other hand, bivalves are known to be accumulators of mineral elements, including some contaminants.…”