Javier Roo
University of Las Palmas de Gran Canaria, Biologia, Department Member
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Senior scientist at GIA with over 17 years of experience in larval nutrition and zootechnology development for comme... moreSenior scientist at GIA with over 17 years of experience in larval nutrition and zootechnology development for commercial and new species. Regular Teacher in The International Master on Aquaculture. In the later years, I was named coordinator of Fast growing species research line, leading different programs for Seriola culture. Also, I have an active interaction with private sector, leading more than 20 RD programs with private companies, mainly producing juveniles under pilot scale level. edit
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Aquaculture and Fishery
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Geography and Humanities
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ABSTRACT Two fresh diets were tested on the biological performance of males and females of Octopus vulgaris under industrial rearing conditions in floating cages. The presence of females could potentially release paralarvae to the natural... more
ABSTRACT Two fresh diets were tested on the biological performance of males and females of Octopus vulgaris under industrial rearing conditions in floating cages. The presence of females could potentially release paralarvae to the natural environment (‘integrated aquaculture’). Octopuses were fed on a single diet of bogue (aquaculture by-product), and on a mixed diet (60–40% crab-bogue), in two trials. In Trial 1 (918 ± 125 g), growth was higher in octopuses fed on the mixed diet (1.9–2.0%d−1) than in those fed on the bogue diet (1.8–1.9%d−1) irrespective of sex, and mortality was 3% regardless of sex and diet. In Trial 2 (1483 ± 269 g), growth was higher in males fed on the mixed diet (1.8%d−1) than in males fed on the bogue diet (1.4%d−1), both higher than females (1.1–1.3%d−1), and mortality was 22–28% regardless of sex and diet. Best biological performance in trial 1 was related to the lack of functional maturation in females, evidence by the low average gonadosomatic index (2.0–3.6%) in comparison with trial 2 (8.8–11.4%), regardless of diet. No correlations between final weight and sexual maturity indices were found, so the length of the rearing period to maximize biomass increment or to release paralarvae depends on functional maturation in females.
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The aim of this study was to evaluate growth, biochemical composition and dietary nutrients utilization in Octopus vulgaris fed on four diets based on bogue Boops boops, from different origin and in two presentations: fresh discarded... more
The aim of this study was to evaluate growth, biochemical composition and dietary nutrients utilization in Octopus vulgaris fed on four diets based on bogue Boops boops, from different origin and in two presentations: fresh discarded bogue (aquaculture by-product) (DB-f), fresh wild bogue (low price trash species) (WB-f), discarded bogue agglutinated moist diet (DB-m) and wild bogue agglutinated moist diet (WB-m). Diets based on DB showed higher lipid content (19–26% dw) than those based on WB (5–6% dw). Octopuses fed on DB-based diets showed higher growth (1.5–1.9% day−1) and higher protein efficiency ratio (0.64–0.69) than those fed on WB-based diet (1.1–1.5% day−1 and 0.36–0.37 respectively), which suggests good utilization of dietary lipids and also a possible protein sparing effect by lipids in O. vulgaris. Octopuses fed on diets presented fresh showed a higher growth (1.9–1.5% day−1) and a higher feed efficiency (62–65%) than those fed on agglutinated diets (1.1–1.5% and 52–60% day−1 respectively). Regarding fatty acids, the digestive gland clearly reflected dietary lipid and fatty acid profile, while muscle showed a more stable composition. Low dietary ARA content reflected in octopus tissues, especially in specimens fed on DB-based diets, which did not seem to affect growth during the experimental period.
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ABSTRACT Most nutritional studies on Octopus vulgaris were based on males to avoid interaction with reproductive processes, focusing on muscle and digestive gland tissues. This study intends to evaluate the effect of two fresh diets, a... more
ABSTRACT Most nutritional studies on Octopus vulgaris were based on males to avoid interaction with reproductive processes, focusing on muscle and digestive gland tissues. This study intends to evaluate the effect of two fresh diets, a fish diet (bogue Boops boops) and a mixed diet (600 g kg−1 crab Portunus pelagicus and 400 g kg−1 bogue), on the biochemical composition of muscle, digestive gland and gonad in males and females of O. vulgaris. Six octopuses per diet were selected (n = 3 per sex) after 60 days of rearing in floating cages. Weight increase was higher in males (3–3.2 kg) than in females (0.9 kg) regardless of diet associated with sexual maturation. Gondosomatic Index in females was 11.3–13.4%. High-lipid content in fish (440 g kg−1 dw) was reflected in digestive gland regardless of the diet, while muscle and testis showed a relatively stable composition. The increase in protein content in the ovary was related to sexual maturation. The low arachidonic content in bogue was reflected in all tissues, with no apparent negative effect on growth and welfare. However, specific retention of arachidonic in the gonads, related to high arachidonic content in crab, underlined the importance of this fatty acid in for gonad development in O. vulgaris.
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The objective of this study was to determine the effect of dietary vitamin E on gilthead seabream (Sparus aurata) growth and survival, at two different highly unsaturated fatty acids (HUFAs) levels. Eighteen days old gilthead seabream... more
The objective of this study was to determine the effect of dietary vitamin E on gilthead seabream (Sparus aurata) growth and survival, at two different highly unsaturated fatty acids (HUFAs) levels. Eighteen days old gilthead seabream larvae were fed four formulated experimental diets combining two different dietary levels of HUFAs (M: medium 2.5 + 1.5, DHA + EPA, H: high 5 + 2.5 DHA + EPA g per 100 g) with two different levels of vitamin E (M: medium 540 mg kg−1, H: high 2900 mg kg−1): MM, MH, HM, HH (HUFA/vitamin E). After 2-week feeding trial, the average survival rate was 52.6% and there were no significant differences found among treatments. Increase in vitamin E up to high level markedly improved larval growth, particularly when dietary HUFA levels were lower, suggesting a higher protection value when these fatty acids are more limiting. At medium dietary HUFA levels, increase in vitamin E from medium to high level enhanced larval growth performance in terms of total length. Moreover, increase in vit E enhanced HUFAs content in the larval polar lipids denoting the anti-oxidative effect of vitamin E.
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Food Science, Biology, Aquaculture, Vitamin E, Fisheries Sciences, and 3 moreVitamin, Parus, and Larva
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Materials and methods Most marine fish larvae require high amounts of n-3 HUFA (highly unsaturated fatty acids) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)(Watanabe, 1982; Izquierdo, 1996), while studies focusing... more
Materials and methods Most marine fish larvae require high amounts of n-3 HUFA (highly unsaturated fatty acids) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)(Watanabe, 1982; Izquierdo, 1996), while studies focusing the value of arachidonic ...
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Geography and Humanities
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... Materias : 251092 Acuicultura marina. Fecha de publicación : 2009. Fecha de depósito: 29-jul-2011. Tipo de documento: Póster. Resumen : Octopus vulgaris on-growing in floating cages is a promising activity implemented in ...
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The reverse osmosis seawater desalination plants open-intake requires different strategies of pre-treatment to reduce the biofouling and scaling. The UltraFiltration (UF) technology is a recent application to this process. In this work,... more
The reverse osmosis seawater desalination plants open-intake requires different strategies of pre-treatment to reduce the biofouling and scaling. The UltraFiltration (UF) technology is a recent application to this process. In this work, some alternatives to chemical products reducing in chemically enhanced backwash (CEB) and clean in place (CIP) of a UF rack have been studied. Mainly the sodium hypochlorite consumption, due to its biofouling precursor effect over reverse osmosis membranes. For this purpose, the optimal filtration time has been studied, to get the highest water production prior to the CIP, as well as some modifications in the conventional CIP's, modifying the duration of the stages of the same. The results were compared with the current mode of daily operation of the CEB. The results show that a reduction of up to 60% in the amount of sodium hypochlorite per cubic meter of water produced employed in UF CEB's, mini CIP's and CIP's can be achieved. Howe...
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PO Box 56, E-35200 Telde, Las Palmas, Canary Islands, Spain. Phone number: 34 928 13 29 00/04. Fax: 34 928 13 20 08. E-mail: juanestefanell@iccm.rcanaria.es 2 IES Maritimo Pesquero de Las Palmas. Simon Bolivar, 15. E-35007, Las Palmas. 3... more
PO Box 56, E-35200 Telde, Las Palmas, Canary Islands, Spain. Phone number: 34 928 13 29 00/04. Fax: 34 928 13 20 08. E-mail: juanestefanell@iccm.rcanaria.es 2 IES Maritimo Pesquero de Las Palmas. Simon Bolivar, 15. E-35007, Las Palmas. 3 CANEXMAR. Palangre s/n nave 1, Castillo del Romeral. San Bartolome de Tirajana, Las Palmas. Effect of sex ratio on growth and survival in Octopus vulgaris (Cuvier, 1797) reared in floating cages.
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Master Universitario International en Acuicultura. Trabajo presentado como requisito parcial para la obtencion del Titulo de Master Universitario Internacional en Acuicultura, otorgado por la Universidad de Las Palmas de Gran Canaria... more
Master Universitario International en Acuicultura. Trabajo presentado como requisito parcial para la obtencion del Titulo de Master Universitario Internacional en Acuicultura, otorgado por la Universidad de Las Palmas de Gran Canaria (ULPGC), el Instituto Canario de Ciencias Marinas (ICCM), y el Centro Internacional de Altos Estudios Agronomicos Mediterraneos de Zaragoza (CIHEAM)
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Geography and Humanities
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Argyrosomus regius is a new species of interest in aquaculture. Nevertheless, few are the works published on this species and less even in larvae culture and weaning. In this study an experiment was carried out, in tanks of 15 Ls, with... more
Argyrosomus regius is a new species of interest in aquaculture. Nevertheless, few are the works published on this species and less even in larvae culture and weaning. In this study an experiment was carried out, in tanks of 15 Ls, with larvae of 15 days of life, to which 4 different protocols for their weaning were applied. The best growth results were observed with Treatment 1 and the worse ones with Treatment 3, nevertheless in the survival rate the opposite occurs
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Oceanography and Biology
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Documentación científica de la ULPGC en abierto.
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Abstract The main objective of this study was to determine the effect of two feeding additives (cMOS: Actigen®, Alltech Inc., USA) and a phytogenic specifically designed for reducing ectoparasite incidence, combining garlic and labiatae... more
Abstract The main objective of this study was to determine the effect of two feeding additives (cMOS: Actigen®, Alltech Inc., USA) and a phytogenic specifically designed for reducing ectoparasite incidence, combining garlic and labiatae herbal extracts (HERB; Delacon, Austria) on growth performance, stress and immune response of greater amberjack (Seriola dumerili) before and after an experimental parasitization with the skin ectoparasite Neobenedenia girellae, a monogenean with high incidence on Seriola cultured in sea cages. Two parallel trials were conducted in order to determine the effect of 70 days of functional diets supplementation (0.2% cMOS and 200 ppm HERB) on greater amberjack: a) Growth performance and stress resistance and b) disease resistance against N. girellae. Additionally, in order to evaluate the effects of the dietary supplements pre- and post- parasitization challenge against N. girellae, the expression of some immune-related genes was evaluated. The relative expression of Il-1β, piscidin, hepcidin, IgT, tnf-α, muc-2, cathelicidin, complement c3, cd8, and caspase-3 was determined in skin. The activity of protease and lysozyme in serum and skin mucus were also evaluated, as well as parasite load and parasite total size. The use of both functional additives did not affect fish growth performance. However, the dietary supplementation of HERB significantly (p In general, greater amberjack supplementation with cMOS and HERB at the dose used in the present study was effective for reducing stress and for increasing the skin associated lymphoid tissue (SALT) immune response against N. girellae during the infection process.
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Skull, pectoral and pelvic fin bone structures in longfin yellowtail Seriola rivoliana were studied from 3.43 ± 0.15 to 16.20 ± 0.73 mm standard length (SL) specimens. The S. rivoliana skull started to mineralize with the appearance of... more
Skull, pectoral and pelvic fin bone structures in longfin yellowtail Seriola rivoliana were studied from 3.43 ± 0.15 to 16.20 ± 0.73 mm standard length (SL) specimens. The S. rivoliana skull started to mineralize with the appearance of the parasphenoid and maxillary by 3.43 ± 0.15 mm SL at the neurocranium and jaw regions, respectively. The first pectoral structure to mineralize was the cleithrum at 3.75 ± 0.14 mm SL shortly followed by the supracleithrum and posttemporal. The pelvic fin started by 6.16 ± 0.32 mm SL with the spine and continued with the soft rays and basipterygium. The present study determined the onset of the skull, pectoral and pelvic fin mineralization. These results might be used as a reference for future studies in S. rivoliana or related species.