Efecto de los misidáceos en la calidad de la puesta en el caballito de mar, Hippocampus hippocampus (Linnaeus, 1758)

[EN]The importance of a suitable feeding in reproduction and spawning quality of teleost fish has been recognized as one of the major ?bottlenecks? in new aquaculture species like seahorses. Mysidacea species has been described as one of the main food for temperate seahorse species (Hippocampus hippocampus and H. guttulatus) in the wild. On the other hand, Artemia has been employed usually as marine food for rearing fish, including seahorses. The aim of this work is to study the effect of two different live preys (Artemia vs Mysis) in spawning quality of H. hippocampus broodstock. The animals were fed two times per day, six times per week. Spawning episodes and larvae quality was recorded. Seahorse fed on mysis showed significantly better results (p<0.05) than Artemia treatment, regarding spawning events, number of offspring?s and size. This fact showed the high potential of mysis as live prey for seahorses or other ornamental species.

Efecto del contenido de DHA en el enriquecimiento de rotíferos sobre la aparición de deformidades esqueléticas en la dorada Sparus aurata (Linnaeus, 1758)

Since sudden mortalities and increased skeletal deformities in gilthead seabream juveniles are currently found in production hatcheries, this study aimed to evaluate the contribution of essential fatty acids, particularly DHA over early feed quality, larval growth, survival and the apparition of skeleton abnormalities in highly commercial interest specie such as Sparus aurata. Sea bream larvae were reared under intensive conditions and fed rotifers enriched with two different enrichment emulsions differing in DHA content. Thus, essential fatty acid composition of rotifers, showed fatty acid profile of enrichment emulsions. The increase in rotifers DHA (10.0 to 25.4% TFA) were also reflected in a higher DHA content in the FA composition of larval fed this rotifers (13.0 to 20.4% TFA) when these preys were the main source of food (14dah). Survival at 50 days after hatching (13.9±4.3) and growth evolution from 3dah until day 50, were similar in both treatments, whereas bone malformations, particularly opercula reduction, and jaw deformities were higher in higher DHA rotifers fed larvae.

Effect of rotifers fatty acid composition on the occurrence of skeletal deformities in red porgy Pagrus pagrus (Linnaeus, 1758)

Red porgy has been proposed as a candidate for diversification of marine aquaculture production (Hernández-Cruz et al., 1999). However, limited larval survival together with the elevated levels of skeletal deformities occurrence (over 50% of the population), under intensive or semi-intensive systems constitute the major bottlenecks for the production of this species at commercial scale (Roo et al., in press). Essential fatty imbalances on early life stages, may alter the osteological development of reared larvae (Cahu et al., 2003). The objective of this study was to determine the effect of rotifers enrichment, particularly on DHA, on growth, survival and occurrence of skeleton deformities in red porgy.

Protocolo de anestesia y recuperación para estudio de morfometría de juveniles de caballito de mar, (Hippocampus hippocampus (Linnaeus, 1758)

Anaesthetic and Recovery Protocol for morfometric study of Atlantic seahorse, Hippocampus hippocampus (Linnaeus, 1758), juveniles. Some morphometric studies in marine organism need anaesthetics in order to avoid animal?s sacrifice and allow its recovery. In this study different natural clove essential concentrations has been tested in Atlantic seahorses, Hippocampus hippocampus (Linnaeus, 1758) aged 13 (trunk length 7,48 ± 1,14 mm) and 22 days (trunk length 9,09 ± 1,62 mm). An inversed relation was observed between anaesthetic concentration and effective time. The concentration allowing measures was 25 ppm. This procedure allowed 100% survival rate.

Efecto de la primera alimentación en la supervivencia y el crecimiento de crías de caballito de mar, Hippocampus hippocampus (Linnaeus, 1758)

[EN]Effects of first feeding on survival and growth of Atlantic seahorse juveniles, Hippocampus hippocampus, (Linnaeus, 1758). In this study, two experimental protocols were tested: a first treatment (RA), in which larvae were fed exclusively on rotifers until day 5, and then on Artemia, and a second treatment (A) where larvae were only fed on Artemia. We attempted to improve survival and growth by comparing different diets in the first days of life. The results showed excellent survival (60% average) and growth in juveniles exclusively fed with Artemia, with better values than those obtained by other authors for this species. In comparison, high mortality and poor growth were observed on the first days in larvae fed rotifers.

Effect of rearing technique over skeletal deformities incidence and osteological development in red porgy Pagrus pagrus (Linnaeus, 1758) larvae

[EN]Red porgy is a candidate species for marine aquaculture diversification.The objective of the present study was to describe the osteological development and the occurrence of skeletal deformities in Pagrus pagrus larvae in relation to the intensification of the rearing system. Fish samples were periodically collected along the development from hatching to juveniles (95days after hatching). Osteological development and the presence of skeleton abnormalities were evaluated. X-ray studies revealed a high number of fish (Semi-intensive:38.8%; Intensive:46.5 %) with skeletal deformities. No significant interaction was found on the incidence of lordosis and fused vertebrae with the rearing tecnique. However, cranial abnormalities and kyphosis incidences were significantly higher in intensive system cultured red porgy. Also, the position of fused vertebrae in this fish was located mainly in the caudal area instead of pre-hemal area for semi-intensive system reared red porgy. Present results, suggest a relationship among feeding sequence, osteological development and deformity incidence and location in red porgy larvae

Experiencias preliminares de cultivo de crías de Hippocampus hippocampus (Linnaeus, 1758) en Gran Canaria

[EN]Seahorses husbandry constitute an innovative aspect on the recovery of wild populations. In this study, two aeration levels were tested (normal and strong) in seahorse juveniles fed on Artemia. Survival and growth were evaluated. The results showed higher survivals (11% average) with strong aerations levels after 90 days. In addition, these juveniles were able to reproduce after 4 months, denoting the early sexual maturation of this species. However, sizes of second-generation larvae at day 0 were smaller compared with those produced by their parents

Crecimiento individual de Octopus vulgaris (Cuvier, 1797) alimentado con pienso húmedo experimental y boga (Boops boops, L. 1758)

[EN]The present work pretends to be the first step towards the development of a commercial diet for Octopus vulgaris. A one month experiment evaluated growth on two treatments, a wet experimental diet and a control (bogue), obtaining a daily growth rate of 1,6 and 16 g/day respectively. Octopuses were tagged and a better growth tendency was found in middle size animals in each experimental tank

Ciclo de vida de la herrera Litohgnathus Mormyrus (Linneaus, 1758) en aguas de las Islas Canarias

[ES] El estudio del ciclo biológico de cualquier población de peces tiene interés desde el punto de vista del conocimiento y, en las poblaciones sometidas a explotación, además desde la perspectiva de la conservación. En el caso de la población de herrera Lithognathus mormyrus de las Islas Canarias, el conocimiento del ciclo de vida cobra una extraordinaria importancia, habida cuenta de los claros síntomas de agotamiento observados en ella. En este trabajo se entrega, para esta población, información relativa a la sexualidad, reproducción, edad y crecimiento, aspectos cuyo conocimiento resulta fundamental para adoptar medidas de gestión dirigidas hacia su recuperación y conservación.

Reproductive biology of Boops boops (Linnaeus, 1758) off Gran Canaria (Canary Islands): a preliminary study

[EN] Preliminary data of the length-weight relationship and reproduction of the bogue Boops boops off Gran Canaria (Canary Islands, Central-east Atlantic) are provided. Two thousand and twenty-one individuals of bogue, ranging from 4 to 34 cm TL, were obtained from purse seine commercial landing. Reproduction parameters as sex determination, duration of spawning season, size at first maturity and GSI variation along time were determinated based on macroscopic evaluation of gonads. The results obtained suggest that bogue is a total spawner, with a long spawning season extending from January to May. Size at first maturity was 16.7 and 17.9 cm TL for males and females, respectively. The length-weight relationship obtained showed a positive allometry in both sexes

Efecto del color del oponente en el comportamiento agresivo del Grapsus grapsus (Linnaeus, 1758) (Crustacea, Decapoda)

[ES] El comportamiento agresivo del cangrejo moro (Grapsus grapsus) ante un modelo de competidor potencial no varió en función del color corporal de este último. No obstante, se observaron cambios en dicho comportamiento en función del tamaño del individuo residente, aumentado la intensidad de los ataques cuanto menores eran las asimetrías en talla