Time filter

Source Type

Riba I.,Institute Ciencias Marinas Of Andalucia Icman | Riba I.,University of Cadiz | Garcia-Luque E.,University of Cadiz | Maz-Courrau A.,University of Cadiz | And 2 more authors.
Water, Air, and Soil Pollution | Year: 2010

This study assesses the effect of salinity in bioavailability and toxicity of Zn by means of laboratory bioassays by observing contamination in both sediment and water, accumulation of Zn in biological tissues, and histopathological damage in the gills and guts tissues of Ruditapes philippinarum clams, which were exposed to different types of sediments from the Gulf of Cádiz (SW Spain) as well as two dilutions of toxic mud coming from an accidental mining spill. With this objective, the coefficients of distribution (K D) for Zn between overlying water and sediments were calculated, the histopathological frequencies in the tissues of the gills and guts of clams were determined, and the biota-sediment bioaccumulation factors as well as the bioaccumulation factors were quantified in the different stations. Results showed that the greatest histopathological damages appeared when the salinity values decreased. Statistical results showed that salinity was inversely correlated with histopathological damage (p<0.01) for the lesion index for gills. The most outstanding results were observed in the two dilutions of toxic mud (0.3% and 7.9%) at a salinity value of 10. Salinity was inversely correlated with the concentration of Zn in biological tissues (p<0.05) and inversely correlated with the concentration of Zn in water and sediment. Zn mobilization to the overlying water is produced when salinity values decrease. © 2010 Springer Science+Business Media B.V. Source

Perera E.,University of Habana | Perera E.,Institute Ciencias Marinas Of Andalucia Icman | Simon C.,University of Tasmania
Reviews in Aquaculture | Year: 2015

The development of cost-effective and nutritionally adequate formulated feeds is a key step for developing sustainable technologies for new aquaculture species. There has been many research effort for over 30 years on feed development for spiny lobsters, but amazingly, poor performance of formulated feeds remains one of the major obstacles to progressing commercial aquaculture of these crustaceans. This is partially due to a lack of information on how spiny lobsters digest and assimilate formulated feeds. The aim of this review is to integrate recent information on the digestive physiology of spiny lobsters to identify areas where further studies are needed for advancing to more physiologically tailored formulated feeds. Increasing the efficiency of mechanical and chemical digestion is imperative for better digestion of formulated feeds. This is likely to be achieved by improving feed format, reducing the particle size of ingredients, using digestible binders, preprocessing or selecting more soluble macronutrients and supplementing feeds with additives such as pH buffers, emulsifying agents and/or exogenous enzymes. Future research needs to adopt a holistic approach for investigating the digestive processes in spiny lobsters by focusing on digestion as well as downstream processes. The protein-sparing effect of lipids and carbohydrates on spiny lobster metabolism is of a particular significance as the spiny lobster metabolism is strongly directed towards the use of protein. This review provides important insights, practical solutions and key research directions to improve both our understanding of spiny lobster digestive physiology and the performance of formulated feeds for spiny lobsters. © 2015 Wiley Publishing Asia Pty Ltd. Source

Hachero-Cruzado I.,Institute Investigacion Y Formacion Agraria Y Pesquera Of Andalucia Ifapa | Fornies A.,Institute Ciencias Marinas Of Andalucia Icman | Herrera M.,Institute Investigacion Y Formacion Agraria Y Pesquera Of Andalucia Ifapa | Mancera J.M.,University of Cadiz | Martinez-Rodriguez G.,Institute Ciencias Marinas Of Andalucia Icman
Fish Physiology and Biochemistry | Year: 2013

The aims of the present study were to characterize sperm quality and to quantify seasonal changes in sexual hormone (testosterone [T], 11-ketotestosterone [11-KT] and 17,20β-dihydroxypregn-4-en-3-one [17,20β-P]) levels in male brill (Scophthalmus rhombus) plasma, as well as to test a more intensive sampling strategy to establish relationships between sex steroid levels and sperm production parameters. Sperm concentration ranged from 0. 5 to 3. 1 × 109 spermatozoa mL-1, and changes in sperm quality parameters depending on sampling date were observed. Plasma sexual steroid levels remained high and changed in parallel during the spawning season and afterwards decreased to very low levels in summer. The analysis of annual changes of 11-KT and T ratios suggests that 11-KT can be the main circulating androgen for stimulating spermatogenesis in S. rhombus and that T could be involved in the beginning of spermatogenesis through the positive feedback on brain-pituitary-gonad axis. Finally, daily 11-KT and T levels showed similar patterns of variation in males sampled, whereas 17,20β-P amounts showed somewhat opposite trends. These differences could be related with the different role of androgens and progestin during the spermatogenesis. © 2012 Springer Science+Business Media B.V. Source

Pujante I.M.,University of Cadiz | Martos-Sitcha J.A.,Institute Ciencias Marinas Of Andalucia Icman | Moyano F.J.,University of Almeria | Ruiz-Jarabo I.,University of Cadiz | And 2 more authors.
Comparative Biochemistry and Physiology Part - B: Biochemistry and Molecular Biology | Year: 2015

The effects of starvation and re-feeding on metabolites and tissue composition, GH/IGF-I axis, and digestive enzyme activities in juvenile thick-lipped grey mullet (Chelon labrosus) were evaluated. Fish were divided into three feeding groups (n = 72, 82.00 ± 4.09. g initial body mass). The control group was fed 1% of their body mass once a day throughout the experiment with commercial pellets. The other two groups were deprived of feed for 21. days (starved), or re-fed for 7. days after 14. days of food deprivation (re-fed). Full-length cDNAs from pituitary GH and hepatic IGF-I were cloned by screening a cDNA library or by PCR techniques. Furthermore, changes in their mRNA expressions were assessed by real time PCR in specimens maintained under the different feeding patterns. Results showed a negative growth in starved and re-feeding groups. Starvation induced a significant increase in plasma triglycerides as well as a decrease in liver glucose and glycogen. Re-feeding increased plasma glucose, lactate and protein, as well as liver glucose and glycogen. In addition, starvation significantly increased pituitary GH expression, while re-feeding down-regulated it. No significant changes were observed in hepatic IGF-I expression in any dietary treatment. Digestive enzyme activities were not significantly affected either by starvation or by re-feeding. The results of the present work suggest that juveniles of the thick-lipped grey mullet may easily adjust their metabolism under situations characterized by a short-term starvation and re-feeding. © 2014 Elsevier Inc. Source

Marco-Herrero E.,Institute Ciencias Marinas Of Andalucia Icman | Guerao G.,IRTA - Institute of Agricultural-Alimentary Research and Technology | Cuesta J.A.,Institute Ciencias Marinas Of Andalucia Icman
Scientia Marina | Year: 2013

In this study the complete larval development (including four zoeal stages and a megalopa stage) of Dyspanopeus sayi is described and illustrated in detail based on larvae reared in the laboratory. Ovigerous females were collected in Alfacs Bay, Ebro Delta (NW Mediterranean) where the species was recently introduced. These larval stages were compared with others collected in the plankton from the same area, the larval stages described previously for this species and the larval stages of the two other Panopeidae that inhabit the Iberian Peninsula: Panopeus africanus and Rhithropanopeus harrisii. Differences were found in both zoeal and megalopal larval characters between D. sayi and the other two species, which could raise doubt about their placement in the same family. Source

Discover hidden collaborations