The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Ángel Guerra - One of the best experts on this subject based on the ideXlab platform.
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First genetic validation and diagnosis of the short-finned squid species of the genus Illex (Cephalopoda: Ommastrephidae)
Marine Biology, 2005Co-Authors: Pilar Martínez, Marcos Pérez-losada, Ángel Guerra, Andrés SanjuanAbstract:Squids of the genus Illex are representative of the family Ommastrephidae and account for 65% of the world’s cephalopod captures. Illex is formed by four taxa distributed throughout the Atlantic Ocean (I. argentinus, I. coindetii, I. illecebrosus and I. oxygonius), whose identification and phylogenetic relationships based on morphological characters remain controversial. Thirty-seven enzyme-coding loci were analysed in 230 individuals from seven populations of Illex and ten specimens of Todaropsis eblanae, which were used as the outgroup. Two to four enzyme loci (ALPDH*, IDHP-1*, MEP* and SOD*) were diagnostic among Illex species depending on the species-pair comparison. Individuals morphologically identified as I. oxygonius were also found genetically distinct, which proves the taxonomic validity of this species. No significant intraspecific genetic heterogeneity was detected within Illex argentinus, I. coindetii and I. illecebrosus (Mean GST= 0.011, 0.003, 0.017, respectively). I. illecebrosus and I. oxygonius were shown as sister species with a close relationship to I. argentinus, whereas I. coindetii formed a different lineage.
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Reproductive biology of the short-finned squid Illex coindetii (cephalopoda, ommastrephidae) of the Northeastern Atlantic
Sarsia, 1996Co-Authors: Ángel F. González, Ángel GuerraAbstract:Abstract For the purposes of this study, 5 311 post recruit of Illex coindetii were collected from the fishery on the Galician shelf, with sizes ranging from 32 to 379 mm dorsal mantle length (ML). Samples were taken monthly from November, 1991 to October, 1992. Sexual maturation, spawning season and population structure of Illex coindetii were analyzed. The spawning season extended throughout the year reaching a peak in July-August, with size at first maturity in males, 128 mm ML and in females, 184 mm ML. Males mature at a smaller size and attain lower size (279 mm ML) than females (379 mm ML). The sex ratio of the whole population sampled was slightly biased towards males, nevertheless monthly variations observed and the ratio obtained (1.09:1) does not suggest that there is spatial segregation by sexes in the fishing ground. From the total sample, 185 males and 281 females, covering the whole range of ML's, were randomly separated out to calculate maturation indices. A correlation between the subjecti...
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Preliminary study of Illex coindetii and Todaropsis eblanae (Cephalopoda:Ommastrephidae) in northern Spanish Atlantic waters
Fisheries Research, 1994Co-Authors: Ángel F. González, Mario Rasero, Ángel GuerraAbstract:Abstract Post-recruit Illex coindetii and Todaropsis eblanae were collected from the fishery on the Galician shelf between November 1991 and April 1992. Maturity was assessed using a maturity scale. Sex ratios, monthly length frequencies distributions and the relationship between dorsal mantle length ( ML ) and body weight ( BW ) of both species were determined. Illex coindetii males were more precocious than females. Mature males and females were found during the entire period sampled, although a considerable maturation peak in April was observed. Todaropsis eblanae males were more precocious than females. The spawning season starts in February and extends at least until April. No distinction is made between the two species of squid in landing statistics. The range of the northern Spanish Atlantic landings from 1980 to 1991 was 490–2352 t.
Minsoo Heu - One of the best experts on this subject based on the ideXlab platform.
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fractionation of exopeptidase from viscera of argentina shortfin squid Illex argentinus
Journal of The Korean Society of Food Science and Nutrition, 2008Co-Authors: Hyesuk Kim, Jinsoo Kim, Minsoo HeuAbstract:For the effective use of exopeptidase from squid viscera as food processing aids, the viscera of Argentina shortfin squid (Illex argentinus) were fractionated by various methods such as acetone treatment, ammonium sulfate treatment, anion exchange chromatography, and gel filtration. The positive exopeptidase fractions were obtained from the fraction II treated by cold acetone (, w/w), the fraction V by ammonium sulfate ( saturation), the fraction II (0.2 M NaCl) by anion exchange chromatography, and the fraction I () by gel filtration. The specific activities of positive fractions from viscera of I llex argentinus against substrates were higher to LeuPNA than to ArgPNA. Total activity and recovery against LeuPNA of positive fraction by gel filtration were 1,867 U and 30.69%, respectively, which were the highest among those of positive fraction. The results suggested that the gel filtration chromatography method was the most efficient method for the fractionation of exopeptidase from viscera of Illex argentinus.
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fractionation of endoprotease from viscera of the argentina shortfin squid Illex argentinus
Korean Journal of Fisheries and Aquatic Sciences, 2008Co-Authors: Hyesuk Kim, Jinsoo Kim, Minsoo HeuAbstract:To evaluate the effective use of endoprotease from squid viscera as a food processing aid, various methods of fractionating endoprotease from viscera of the Argentina shortfin squid (Illex argentinus) were evaluated. The endoprotease-positive fractions of each fractionation were fraction II (30-40%, w/w) with cold acetone, fraction IV (50-60% saturation) with ammonium sulfate, fraction UF with anion exchange chromatography, and fraction II (15-24 kDa) with gel filtration. The specific activities (approximately 25 U/mg) of the fractions using ammonium sulfate and gel filtration were higher than the others. Total azocaseinolytic activity and recovery of the positive fraction using gel filtration were 806.95U and 37.82%, respectively, and were the highest among the positive fractions. Based on the results, gel filtration was the most efficient method for fractionating endoprotease from the viscera of Illex argentinus.
Ronald K. O’dor - One of the best experts on this subject based on the ideXlab platform.
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Acid-base regulation in exercising squid (Illex illecebrosus, Loligo pealei).
American Journal of Physiology-Regulatory Integrative and Comparative Physiology, 1991Co-Authors: Hans-otto Pörtner, R G Boutilier, Dale M. Webber, Ronald K. O’dorAbstract:Squid (Illex illecebrosus, Loligo pealei) were cannulated in the vena cava and swum in a Beamish-type respirometer. Gas tensions and acid-base variables as well as octopine levels were estimated in samples of the mantle and of venous blood collected from quiescent, exercised, and recovered animals. When exhausted, both species exhibited a decrease in vena cava oxygen tensions and a slight alkalosis. With high swimming speeds prior to exhaustion in Illex a slight acidosis developed in the blood, which was linked to a severe intracellular acidosis. Generally, the drop in intracellular pH was linearly correlated with octopine accumulation in this species. Metabolic proton (and end-product) release from the mantle, however, was minimal, thus protecting arterial oxygen binding. High PCO2 values in the mantle of both species lead to the conclusion that the vena cava values analyzed in this and all literature studies on unrestrained cephalopods may not reflect the scope of respiratory acid-base changes in venous blood. Although metabolic changes in blood acid-base status are negligible, the respiratory acidification of venous mantle blood may allow for a classical function of Bohr and Haldane effects in these animals.
Ángel F. González - One of the best experts on this subject based on the ideXlab platform.
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Reproductive biology of the short-finned squid Illex coindetii (cephalopoda, ommastrephidae) of the Northeastern Atlantic
Sarsia, 1996Co-Authors: Ángel F. González, Ángel GuerraAbstract:Abstract For the purposes of this study, 5 311 post recruit of Illex coindetii were collected from the fishery on the Galician shelf, with sizes ranging from 32 to 379 mm dorsal mantle length (ML). Samples were taken monthly from November, 1991 to October, 1992. Sexual maturation, spawning season and population structure of Illex coindetii were analyzed. The spawning season extended throughout the year reaching a peak in July-August, with size at first maturity in males, 128 mm ML and in females, 184 mm ML. Males mature at a smaller size and attain lower size (279 mm ML) than females (379 mm ML). The sex ratio of the whole population sampled was slightly biased towards males, nevertheless monthly variations observed and the ratio obtained (1.09:1) does not suggest that there is spatial segregation by sexes in the fishing ground. From the total sample, 185 males and 281 females, covering the whole range of ML's, were randomly separated out to calculate maturation indices. A correlation between the subjecti...
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Preliminary study of Illex coindetii and Todaropsis eblanae (Cephalopoda:Ommastrephidae) in northern Spanish Atlantic waters
Fisheries Research, 1994Co-Authors: Ángel F. González, Mario Rasero, Ángel GuerraAbstract:Abstract Post-recruit Illex coindetii and Todaropsis eblanae were collected from the fishery on the Galician shelf between November 1991 and April 1992. Maturity was assessed using a maturity scale. Sex ratios, monthly length frequencies distributions and the relationship between dorsal mantle length ( ML ) and body weight ( BW ) of both species were determined. Illex coindetii males were more precocious than females. Mature males and females were found during the entire period sampled, although a considerable maturation peak in April was observed. Todaropsis eblanae males were more precocious than females. The spawning season starts in February and extends at least until April. No distinction is made between the two species of squid in landing statistics. The range of the northern Spanish Atlantic landings from 1980 to 1991 was 490–2352 t.
Andrés Sanjuan - One of the best experts on this subject based on the ideXlab platform.
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First genetic validation and diagnosis of the short-finned squid species of the genus Illex (Cephalopoda: Ommastrephidae)
Marine Biology, 2005Co-Authors: Pilar Martínez, Marcos Pérez-losada, Ángel Guerra, Andrés SanjuanAbstract:Squids of the genus Illex are representative of the family Ommastrephidae and account for 65% of the world’s cephalopod captures. Illex is formed by four taxa distributed throughout the Atlantic Ocean (I. argentinus, I. coindetii, I. illecebrosus and I. oxygonius), whose identification and phylogenetic relationships based on morphological characters remain controversial. Thirty-seven enzyme-coding loci were analysed in 230 individuals from seven populations of Illex and ten specimens of Todaropsis eblanae, which were used as the outgroup. Two to four enzyme loci (ALPDH*, IDHP-1*, MEP* and SOD*) were diagnostic among Illex species depending on the species-pair comparison. Individuals morphologically identified as I. oxygonius were also found genetically distinct, which proves the taxonomic validity of this species. No significant intraspecific genetic heterogeneity was detected within Illex argentinus, I. coindetii and I. illecebrosus (Mean GST= 0.011, 0.003, 0.017, respectively). I. illecebrosus and I. oxygonius were shown as sister species with a close relationship to I. argentinus, whereas I. coindetii formed a different lineage.
