25 results on '"Loligo forbesi"'
Search Results
2. Seasonal movements of veined squid Loligo forbesi in Scottish (UK) waters.
- Author
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Viana, Mafalda, Pierce, Graham J., Illian, Janine, MacLeod, Colin D., Bailey, Nick, Jianjun Wang, and Hastie, Lee C.
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SQUID fisheries , *LOLIGO , *FISHERY resources , *FISH habitats , *SPATIO-temporal variation , *GEOGRAPHIC information systems - Abstract
In order to protect and sustainably manage fishery resource species, it is essential to understand their movements and habitat use. To detect the hypothesised migration of maturing veined squid Loligo forbesi from the west coast of Scotland (UK) to the North Sea and identify possible inshore-offshore movements, we analysed seasonal, spatial and environmental patterns in abundance and size distribution, based on commercial fishery landings data and trawl survey data from Scottish coastal waters (International Council for the Exploration of the Sea, ICES areas IVa, IVb and VIa). A geographic information system (GIS) was used to build monthly contour maps of abundance. Generalised additive mixed models (GAMM) were used to quantify patterns in size distribution and abundance. In most years, there was no evidence of movement from the West to the East coast of Scotland. Evidence of inshore-offshore movements during the life-cycle of the cohort that recruits in autumn (winter breeders) was found instead. The winter breeding cohort appears to spawn in inshore waters and some evidence suggests that the spawning grounds of the summer breeders are also inshore. Across seasons, higher abundance of L. forbesi can generally be found in the north of Scotland at intermediate water depths and in warmer waters. [ABSTRACT FROM AUTHOR]
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- 2009
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3. Application of the Gómez-Muñoz model to estimate catch and effort in squid fisheries in Scotland
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Young, I.A.G., Pierce, G.J., Murphy, J., Daly, H.I., and Bailey, N.
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FISHERIES , *FISHERY management , *AQUATIC resources , *CONFIDENCE intervals - Abstract
Abstract: The Gómez-Muñoz model, which utilises interview data obtained from fishermen, was developed to aid the management of small-scale artisanal fisheries, where there may be a dearth of catch and effort data, and has been successfully used in the estimation of catch per unit effort (CPUE) in this type of fishery in Galicia. The suitability of applying the model to two cases in Scotland, a non-targeted by-catch fishery off the northwest coast of Scotland and a directed squid fishery in the Moray Firth, is explored. The interview information returned from the directed fishery is generally of higher quality. In order to study the model behaviour, an alternative parameterisation is carried out. In general, the model was found to be most sensitive to parameters having a direct effect on catch and effort. Calculated confidence intervals are rather wide but could be improved by refining the interview protocol with emphasis placed on reducing the timing from monthly to weekly. A database of 671 individual vessels’ landings into Scottish ports in 2000 is created and, from this, an index of fishing effort calculated, which displays a close approximation with official data. The results from the by-catch fishery are extrapolated to larger areas. In all cases, the predicted catches are higher than official figures although similar trends are evident. [Copyright &y& Elsevier]
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- 2006
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4. Methionine-rich repeat proteins: a family of membrane-associated proteins which contain unusual repeat regions
- Author
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Weiss, Jamie L., Evans, Nicholas A., Ahmed, Tanweer, Wrigley, Jonathan D.J., Khan, Shukria, Wright, Charles, Keen, Jeffrey N., Holzenburg, Andreas, and Findlay, John B.C.
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PROTEINS , *BIOMOLECULES , *METHIONINE , *GENETIC engineering - Abstract
Abstract: We report the protein isolation, cloning and characterization of members of an unusual protein family, which comprise the most abundant proteins present in the squid eye. The proteins in this family have a range of molecular weights from 32 to 36 kDa. Electron microscopy and detergent solubilization demonstrate that these proteins are tightly associated with membrane structures where they may form tetramers. Despite this, these proteins have no stretches of hydrophobic residues that could form typical transmembrane domains. They share an unusual protein sequence rich in methionine, and contain multiple repeating motifs. We have therefore named these proteins Methionine-Rich Repeat Proteins (MRRPs). The use of structure prediction algorithms suggest very little recognized secondary structure elements. At the time of cloning no sequence or structural homologues have been found in any database. We have isolated three closely related cDNA clones from the MRRP family. Coupled in vitro transcription/translation of the MRRP clones shows that they encode proteins with molecular masses similar to components of native MRRPs. Immunoblot analysis of these proteins reveals that they are also present in squid brain, optic lobe, and heart, and also indicate that MRRP-like protein motifs may also exist in mammalian tissues. We propose that MRRPs define a family of important proteins that have an unusual mode of attachment or insertion into cell membranes and are found in evolutionarily diverse organisms. [Copyright &y& Elsevier]
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- 2005
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5. Application of depletion methods to estimate stock size in the squid Loligo forbesi in Scottish waters (UK)
- Author
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Young, I.A.G., Pierce, G.J., Daly, H.I., Santos, M.B., Key, L.N., Bailey, N., Robin, J.-P., Bishop, A.J., Stowasser, G., Nyegaard, M., Cho, S.K., Rasero, M., and Pereira, J.M.F.
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LOLIGO , *LOLIGINIDAE , *FISHING boats , *FISH populations - Abstract
Abundance of the loliginid squid Loligo forbesi in Western and Northern Scottish (UK) waters (ICES fishery subdivisions IVa and VIa) 1989–1998 was estimated using “depletion” methods. Fishery catch and effort data for UK and French fishing vessels were obtained from official government statistics. Biological data were collected during monthly sampling visits to Kinlochbervie (Scotland, UK) fish market. Effects of using different indices for natural mortality and different model fits were evaluated. The results indicate initial (pre-fishing season) annual population sizes in the order of 106 animals. Significant between-year variation in the seasonal pattern of body weight and recruitment indicates that contemporaneous biological data, collected every month (or more frequently) are needed to underpin annual estimates. [Copyright &y& Elsevier]
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- 2004
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6. Metals in squid, Loligo forbesi, adults, eggs and hatchlings. No evidence for a role for Cu- or Zn-metallothionein
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Craig, Stephen and Overnell, Julian
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LOLIGO , *METALS in the body , *METALLOTHIONEIN - Abstract
An adult squid Loligo forbesi had the following metals in its liver/digestive gland: Mn, Fe, Ni, Zn, Cu, As, Cd, Ba and Pb in the range of 1–110 ppm wet wt. Adult mantle muscle, adult eyes, eggs and hatchlings contained a lesser number of these metals at concentrations above 1 ppm. Chromatographic analysis of non-heat-treated cytosols (in the presence of 5 mM 2-mercaptoethanol) gave no evidence for the presence of copper- or zinc-containing fractions with the molecular weights of mollusc metallothioneins in any of the above tissues. Copper and Zn were bound to either the particulate fraction or to very low molecular weight species. [Copyright &y& Elsevier]
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- 2003
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7. Assignment of paternity groups without access to parental genotypes: multiple mating and developmental plasticity in squid.
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Emery, A. M., Wilson, I. J., Craig, S., Boyle, P. R., and Noble, L. R.
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LOLIGO , *ANIMAL courtship , *PHYSIOLOGICAL adaptation - Abstract
Abstract We present a novel approach to investigating sibling relationships and reconstructing parental genotypes from a progeny array. The Bayesian method we have employed is flexible and may be applicable to a variety of situations in addition to the one presented here. While mutation rates and breeding population allele frequencies can be taken into account, the model requires relatively few loci and makes few assumptions. Paternity of 270 veined squid (Loligo forbesi) hatchlings from three egg strings collected from one location was assigned using five microsatellite loci. Paternal and maternal genotypes reconstructed for each of the three strings were identical, strongly indicating that a single female produced the strings that were fertilized by the same four males. The proportion of eggs fertilized was not equal between males in all three strings, with male 1 siring most offspring (up to 68% in string 1), through to male 4 siring the least (as low as 2.4% in string 1). Although temperature had a profound effect on incubation time, paternity did not affect this trait at 12 °C or 8 °C. [ABSTRACT FROM AUTHOR]
- Published
- 2001
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8. Distribution and abundance of the fished population of Loligo forbesi in Scottish waters: analysis of research cruise data.
- Author
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Pierce, G. J., Bailey, N., Stratoudakis, Y., and Newton, A.
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LOLIGO ,SQUIDS ,TRAWLING ,FISHERIES - Abstract
Length-frequency data on squid (Loligo forbesi) collected during trawling surveys in Scottish waters from 1980 to 1994 were analysed to describe temporal and spatial patterns in abundance and to examine the prospects for using survey abundance to forecast fishery abundance. Loligo was patchily distributed in space and time. Distribution patterns in the North Sea in February appeared to be strongly related to bottom temperature (squid avoided waters <7°C) and, to a lesser extent, salinity (more squid in more saline water). For other areas and times, no temperature or salinity data were available, but there were trends for squid on the west coast to be more abundant in westerly areas and higher latitudes, and for squid at Rockall to be more abundant in shallow water. Inter-annual trends in abundance differed between the North Sea, west coast and Rockall, but average survey abundances for the North Sea and west coast tended to be positively correlated. For the North Sea and west coast, survey abundance was positively correlated with fishery abundance for the same month and area, and average abundance for the February North Sea survey was a reasonable predictor of commercial CPUE in the autumn of the same year (the peak of the fishery). Some of the observed trends were consistent with the existence of a stock-recruitment relationship but may indicate that abundance in a given calendar year is linked to climatic factors. [ABSTRACT FROM PUBLISHER]
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- 1998
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9. Diet of the squid Loligo forbesi Steenstrup (Cephalopoda: Loliginidae) in Irish waters.
- Author
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Collins, M. A., De Grave, S., Lordan, C., Burnell, G. M., and Rodhouse, P. G.
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Stomach contents of Loligo forbesi obtained from commercial landings and research cruises in Irish waters and the Irish Sea were examined. A total of 62.3% of stomachs were empty. Fish remains occurred in 73.7% of all full or partially full stomachs, with crustaceans and cephalopods occurring in 26.4% and 7.5% respectively, L. forbesi was found to consume a wide range of fish and crustacean prey. Sagittal otoliths were used to identify fish species, and vertebrate to identify families. The most frequent species by per cent occurrence sprat (Sprattus sprattus), poor cod (Trisopterus minutus), Norway pout (T. esmarkii), and transparent goby (Aphia minuta). Crustaceans were the main prey item is squid of less than 100 mm mantle length, together with small clupeids and gobies. the predominant prey of medium-sized squid (100–220 mm) was found to be gadoid and clupeid fish, while gadoids and other cephalopods were the main prey of larger squid (>220 mm). Seasonal differences in the diet were apparent but were shown to be influenced by seasonal changes in squid size. [ABSTRACT FROM PUBLISHER]
- Published
- 1994
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10. Recruitment, maturation, and spawning of Loligo forbesi Steenstrup (Cephalopoda: Loliginidae) in Irish waters.
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Collins, M. A., Burnell, G. M., and Rodhouse, P. G.
- Abstract
A number of reproductive indices were compared with a subjective maturity scale for assessment of Loligo forbesi maturity. The ratio between nidamental gland length and mantle length corresponded well with female maturation, as did the ovary mass-soma mass and nidamental gland mass-soma mass ratios. For males, the ratio between spermatophoric complex mass and somatic mass was found to be the most suitable for maturity assessment. The timing of recruitment and maturation of L. forbesi in Irish waters was described from the size and maturity of squid in commercial landings in the south of Ireland during the years 1991–1993. Immature squid first appeared in commercial catches in July and August, and this represented the main period of recruitment. A second period of recruitment was apparent in December 1991, but was not identified in the 1992–1993 season. Mature females were present in the commercially exploited population between November and April, with a small number also found in the summer. The abundance of egg masses was used to indicate timing of spawning. Egg masses recovered from the Cork coast indicated that peak spawning occurred during the winter months, but continued on a small scale for much of the year. [ABSTRACT FROM PUBLISHER]
- Published
- 1995
- Full Text
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11. SEASONAL VARIATIONS IN BIOCHEMICAL COMPOSITION OF LOLIGO FORBESI (CEPHALOPODA: LOLIGINIDAE) IN THE MEDITERRANEAN SEA AND THE GULF OF SUEZ, EGYPT.
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Kilada, Raouf and Riad, Rafik
- Abstract
The aim of this work was to investigate the seasonal variability in the biochemical composition in both sexes of Loligo forbesi, (Streenstrup 1856) in two locations in Egypt: the Mediterranean Sea off the coasts of Alexandria and north of the Gulf of Suez. The study is also aimed to document for the first time the fatty acids composition in both sexes in each location. There was a significant difference in the seasonal variations of total protein (P = 0.0001), total lipids (P = 0.036) and total carbohydrates (P = 0.009). Also, there was a significant difference in total lipids (P = 0.008) between sexes. Total lipids and protein declined from spring to summer and then increased in fall before they decrease again in the winter in males and females. Meanwhile, the concentration of total carbohydrates in females decreased from spring to fall then increased slightly in winter. There was a negative correlation between Gonado Somatic Index and Nidamental gland Somatic Index and each of total protein and lipids in different sexes (P = 0.01), which was not the case with total carbohydrates (P = 0.1). Seasonal fluctuations in biochemical content were attributable to the reproductive state of the animal. Although there was no significant difference in either total saturated lipids or total unsaturated lipids among the two sexes or between the two locations (P > 0.05), variations were observed in some fatty acids. The most predominant saturated fatty acid was palmitic acid (C16:0), comprising 68% to 73% for both sexes and locations. Most of the monounsaturated content was present as Cis-Pentadecanoic (C15:1) and palmiboleic (C16:1). Omega 3-poly-unsaturated fatty acids, which include linolenic, EPA, and DHA comprised ~80% of total poly-unsaturated fatty acids. [ABSTRACT FROM AUTHOR]
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- 2008
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12. First field observation of naturally-laid eggs of Loligo forbesi (Cephalopoda: Myopsida), through a remotely operated vehicle in the Azores.
- Author
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Carreira, Gilberto P., Pham, Christopher K., Tempera, Fernando, Gonçalves, João M.A., and Porteiro, Filipe M.
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SQUIDS , *CEPHALOPODA , *EGGS , *WATER depth , *REPRODUCTION - Abstract
An egg mass of Loligo forbesi was observed in the field for the first time while conducting a remotely operated vehicle dive at a depth of 370 m, off the São Jorge Island (Azores, north-east Atlantic). This observation allowed the confirmation of two hypotheses previously suggested for the reproduction of this species: (i) that in the Azores this species spawns deeper than the previously recorded 144 m; and that (ii) it is likely that this species prefers to spawn within cavities. The way the observed egg strings suspended from the roof of a cavity, underneath a rocky block, surrounded by sediment, is a feature that interestingly seems to be shared between L. forbesi (in the Azores, all the previous naturally-laid egg masses were recovered from within cavities) and L. vulgaris that inhabit shallower waters off the Madeira archipelago. [ABSTRACT FROM AUTHOR]
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- 2011
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13. Methionine-rich repeat proteins: a family of membrane-associated proteins which contain unusual repeat regions
- Author
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Andreas Holzenburg, Jonathan D.J. Wrigley, Charles Wright, Jamie L. Weiss, Jeffrey N. Keen, Tanweer Ahmed, Nicholas A. Evans, Shukria Khan, and John B. C. Findlay
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Repetitive Sequences, Amino Acid ,Protein family ,Molecular Sequence Data ,Biophysics ,Biology ,Eye ,Biochemistry ,Methionine ,Non-histone protein ,Protein purification ,Animals ,Tissue Distribution ,Amino Acid Sequence ,Structural motif ,Squid ,Protein secondary structure ,Peptide sequence ,Cells, Cultured ,Loligo forbesi ,Cell Membrane ,Loligo pealei ,Decapodiformes ,Membrane Proteins ,Cell Biology ,Molecular biology ,Transmembrane domain ,Membrane protein - Abstract
We report the protein isolation, cloning and characterization of members of an unusual protein family, which comprise the most abundant proteins present in the squid eye. The proteins in this family have a range of molecular weights from 32 to 36 kDa. Electron microscopy and detergent solubilization demonstrate that these proteins are tightly associated with membrane structures where they may form tetramers. Despite this, these proteins have no stretches of hydrophobic residues that could form typical transmembrane domains. They share an unusual protein sequence rich in methionine, and contain multiple repeating motifs. We have therefore named these proteins Methionine-Rich Repeat Proteins (MRRPs). The use of structure prediction algorithms suggest very little recognized secondary structure elements. At the time of cloning no sequence or structural homologues have been found in any database. We have isolated three closely related cDNA clones from the MRRP family. Coupled in vitro transcription/translation of the MRRP clones shows that they encode proteins with molecular masses similar to components of native MRRPs. Immunoblot analysis of these proteins reveals that they are also present in squid brain, optic lobe, and heart, and also indicate that MRRP-like protein motifs may also exist in mammalian tissues. We propose that MRRPs define a family of important proteins that have an unusual mode of attachment or insertion into cell membranes and are found in evolutionarily diverse organisms.
- Published
- 2005
14. The life history of Loligo vulgaris and Loligo forbesi (Cephalopoda: Loliginidae) in Galician waters (NW Spain)
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Francisco Rocha and Ángel Guerra
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Loligo ,Loligo forbesi ,biology ,Life cycle ,Zoology ,Aquatic Science ,biology.organism_classification ,Spawn (biology) ,Loligo vulgaris ,Fishery ,Spain ,Spermatophore ,Seasonal breeder ,Sexual maturity ,European squid ,Loliginidae ,Sex ratio - Abstract
27 páginas, 11 figuras, 7 tablas, The population biology of Loligo vulgaris and Loligo forbesi in Galician waters is described based on monthly samples from the fishery obtained during the period February 199 l-June 1992. Maturity was assessed using a maturity scale and indices. The estimated number of oocytes in mature females varied from 782 to 21 885 in L. vulgaris and from 1317 to 14 956 in L. forbesi, and showed a slight positive correlation with the length of the mantle (ML) for both species. Oocytes in the ovaries fall into three discrete size classes, which suggests that L. vulgaris and L.forbesi are intermittent or multiple spawning species. In L. vulgaris males mature at two different modal sizes, hence perhaps at two different ages, while in L. forbesi this occurs in both males and females. Males mature earlier in the season than females in both species. The maximum number of spermatophores found was 1010 and 1000 in two L. vulgaris males with 119 mm and 400 mm ML respectively, and 1035 in a L. forbesi male with 150 mm ML. In both species, spermatophore length increases with ML. Loligo forbesi males maturing at a larger size produce fewer but larger spermatophores than those maturing at a small size. Loligo vulgaris spawn throughout the year, but the period of more intensive spawning extends from December to April. The breeding season ofL. forbesi extends from December to May, the more intensive spawning extending from December to February. Sex ratios were variable for both species. Age and growth for both species and sexes were estimated by examining growth increments in the statoliths. Like-sized individuals had different ages in both species. The life span of L. vulgaris was estimated at about l year while L. forbesi seems to reach an age of 15-16 months. A list of prey species found in gastric contents of both species is given. The diet of L. vulgaris comprises fish (86.8%), cephalopods (6.0%), crustaceans (3.0%) and polychaetes (1.8%), and the diet of L. forbesi includes fish (75.6%), crustaceans (18.5%) and cephalopods (4.4%)., This work was funded by the Commission of the European Communities within the frame of this EEC research programme in the fisheries sector (FAR, contract no. MA 1.146).
- Published
- 1994
15. Migration and distribution of the veined squid, Loligo forbesi, in Scottish (UK) waters
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Viana, Mafalda, Pierce, Graham, and Dias, Manuel Afonso
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Pescas ,Distribuição ,Lula ,Loligo forbesi ,Protecção ,Escócia ,Gestão da produção ,Teses ,Recursos pesqueiros - Abstract
Dissertação de mest., Biologia Marinha, 2007, Universidade do Algarve, Faculdade de Ciências do Mar e do Ambiente In order to protect and sustainably manage fishery resources, it is essential to understand the temporal and spatial utilization of habitats of the target species. A Geographic Information System and length frequency analysis were used, in both fishery and survey data, to detect Loligo forbesi migration patterns from west to east coast of Scotland and inshore-offshore movements. Although the migration between west coast and North Sea is not evident, it is possible that veined squid performs an inshore movement in summer/autumn and offshore in winter/spring to complete their life cycle. Two distinct migratory behaviours between the two cohorts of Scottish veined squid is also a possibility, one cohort can be resident in inshore waters while the other migrates to offshore waters in winter and spring. The environmental reasons for such movements were examined using a generalized additive mixed model (GAMM) that suggested that distance to coast is the most important variable affecting size distribution in almost all seasons; however abundance distribution seems to be influenced with the same importance by sea surface temperature, depth and distance to coast. L. forbesi also revealed an optimal peak of abundance in waters at ~11oC, 200m depth and 25miles far from coast. De modo a proteger e gerir de forma sustentável os recursos pesqueiros é essencial compreender como as espécies alvo utilizam os seus habitats temporal e espacialmente. Na lula riscada (Loligo forbesi) da Escócia isto é bastante importante uma vez que não existe qualquer medida de gestão da sua pesca, além do tamanho mínimo da malha das redes de arrasto. L. forbesi, encontra-se principalmente em águas costeiras, e nas águas escocesas apresenta duas coortes com dois períodos de desova e duas épocas de recrutamento. Diferentes estudos demonstraram que várias espécies de lulas fazem migrações de curta escala, de perto para longe da costa, e de grande escala, Este-Oeste ou Norte-Sul, e.g. a L. forbesi de Inglaterra. Estas movimentações poderão ser causadas por condições ambientais, nomeadamente pela temperatura e pela profundidade, uma vez que a abundância de várias espécies de lulas é influenciada por estas mesmas condições ambientais. Deste modo, os objectivos da presente tese são (1) verificar se L. forbesi faz migrações da costa Oeste para a costa Este da Escócia, no Inverno, para desovar e da costa Este para a Oeste, na Primavera, tal como sugerido por estudos anteriores; (2) detectar as eventuais migrações da L. forbesi da Escócia para zonas afastadas da costa e caso estes movimentos existam, verificar qual a sua relação com o ciclo de vida da espécie e; (3) verificar quais as razões ambientais que levam as lulas a migrar, dando ênfase à sua relação com a temperatura superficial do mar (SST), profundidade e distância à costa. Para testar as hipóteses, foram utilizados dados de cerca de 20 anos da espécie L. forbesi, fornecidos pelo Fisheries Research Services, provenientes de desembarques comerciais e de navios de investigação. Estes foram primeiro utilizados num Sistema de Informação Geográfica (SIG) e em análises de frequência de comprimentos para verificar a existência de uma migração entre a costa Este e Oeste da Escócia. Estas análises demonstraram que a migração entre a costa Oeste e Este não é evidente, mas comportamentos migratórios diferentes entre coortes podem ocorrer, uma vez que alguns dos mapas de SIG exibem dois picos distintos de abundância em certos anos e meses. Outra explicação pode ser que a população de L. forbesi de Inglaterra, migre em certos anos mais para Norte que o habitual entrando no território escocês devido a condições ambientais mais favoráveis. Os mesmos dados foram utilizados para construir gráficos de abundância e frequência de comprimentos contra a distância à costa onde os arrastos foram feitos. Estes gráficos mostram que é possível que esta espécie migre para águas costeiras no Verão e Outono e para águas mais longínquas durante o Inverno e Primavera, com a finalidade de completar o seu ciclo de vida. A coorte que desova no Verão deverá fazê-lo em zonas costeiras assim como o seu recrutamento no Outono. Contudo, o local de desova da coorte de Inverno e as áreas de recrutamento na primavera não são claros. A hipótese de dois comportamentos migratórios distintos entre as duas coortes de L. forbesi da Escócia é também uma possibilidade: enquanto uma coorte é residente em águas costeiras a outra migra para longe da costa durante o Inverno e a Primavera, ou chega a estas águas longe da costa vindo de áreas ainda mais distantes como os Rockall Banks. As razões ambientais para tais movimentos foram examinadas em R, com um modelo aditivo generalizado misto (GAMM), uma extensão do GAM, e com uma componente temporal (ano) como variável aleatória. Esta análise demonstrou que a distância à costa é a variável mais importante a afectar a distribuição por tamanhos, contudo, a distribuição da abundância parece ser influenciada igualmente pela SST, profundidade e distância à costa. A relação entre cada uma destas variáveis ambientais e o comprimento do manto da espécie em estudo varia consoante a estação do ano: e.g. no Inverno e Primavera quanto maior for o comprimento do manto mais próximo da costa se encontram as lulas, contudo, no Verão esta relação parece ser inversa. A influência destas variáveis na abundância é bastante uniforme ao longo dos diferentes meses: quanto menor a distância à costa maior será a abundância de lulas, até aos 200m de profundidade, quanto maior é a profundidade maior é a abundância e a abundância tem ainda um pico em águas com cerca de 10ºC. L. forbesi revelou, deste modo, ter um possível óptimo ambiental em águas escocesas com aproximadamente 10oC, 200m de profundidade e próximo da costa.
- Published
- 2007
16. Signs of an extended and intermittent terminal spawning in the squids Loligo vulgaris Lamarck and Loligo forbesi Steenstrup (Cephalopoda: Loliginidae)
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Francisco Rocha and Ángel Guerra
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0106 biological sciences ,Gonad ,media_common.quotation_subject ,Ovary (botany) ,Aquatic Science ,NW Atlantic ,010603 evolutionary biology ,01 natural sciences ,Spawning patterns ,medicine ,14. Life underwater ,Mating ,Loliginidae ,reproductive and urinary physiology ,Ecology, Evolution, Behavior and Systematics ,media_common ,Loligo ,Loligo forbesi ,biology ,urogenital system ,010604 marine biology & hydrobiology ,Reproduction ,biology.organism_classification ,Cephalopod ,Fishery ,Loligo vulgaris ,medicine.anatomical_structure - Abstract
13 páginas, 7 figuras, 2 tablas, The reproductive pattern of Loligo vulgaris and Loligo forbesi was studied on the basis of gonad maturation, mating and spawning in males and females of both species which were present off the northwest coast of Spain (Galicia), between February 1991 and February 1993. The mature females of both species have several modes of egg sizes and developmental stages within the ovary. Several signs indicate that both female Loligo vulgaris and L. forbesi undergo partial ovulation at the time of spawning, the spawning period being relatively long, although in no case representing the greatest fraction of the animal's life before death. Egg-laying occurring in separate batches and somatic growth between egg batchs has not been observed. This reproductive pattern is defined as intermittenterminaspawning. Some other terms describing different cephalopod reproductive strategies are also defined., This work was financed by two projects under the auspices of the European Union (FAR, MA.1.146 and AIRl-CT92-0573).
- Published
- 1996
17. Morphometric variation in Loligoforbesi and Loligo vulgaris: regional, seasonal, sex, maturity and worker differences
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Roger S. Thorpe, Peter Boyle, Graham J. Pierce, Lee C. Hastie, Ángel Guerra, and F.Godfrey Howard
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Maturity (geology) ,Loligo ,Multivariate analysis ,Loligo forbesi ,biology ,Ecology ,Aquatic Science ,Seasonality ,biology.organism_classification ,medicine.disease ,Population structure ,Seasonal dynamics ,Loligo vulgaris ,Variation (linguistics) ,medicine ,Sexual maturity ,Mollusca ,Meristics - Abstract
22 páginas, 3 figuras, 17 tablas, 1 apéndice, Morphometric variation in the squid Loligoforbesi was investigated to quantify effects of region, season, sex and maturity. Practical exercises were carried out using this species and the congeneric Loligo vulgaris to evaluate differences in measurements by different workers. The utility of meristic characters was also examined. Consistent significant differences were found between measurements by different workers, although this problem may be reduced with experience and many of the differences were small compared with observed differences between areas, particularly differences between Loligoforbesi from the Azores and elsewhere (Scotland, Spain, Portugal). Body shape in Loligoforbesi varied significantly in relation to maturity stage and, to a lesser extent, with season. Multivariate analysis of morphometric characters for samples collected in Scottish waters over 12 months revealed no consistent differences between localities. In contrast, there were marked differences between Loligoforbesi from the Azores and those from UK waters. If future studies on geographic variation in loliginids are to make use of morphometric characters, they should be based on simultaneous sampling to minimise effects of season and maturity, and all measurements on a single character should be made by a single worker., This work was funded by the Commission of the European Communities within the frame of the EEC research programme in the fisheries sector (FAR, Contract No. MA 1.146). Data collection by AG and FGH in 1989 was supported by the Spanish Ministry of Education and Science and the British Council under the British/Spanish Joint Research Programme (Acciones Integradas 1989/90).
- Published
- 1994
18. The Spanish fishery for Loligo: recent trends
- Author
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Pilar Sánchez, Ángel Guerra, and Francisco Rocha
- Subjects
Loligo ,Squid ,Loligo forbesi ,Overfishing ,biology ,Trawling ,Fishing ,Aquatic Science ,Seasonality ,medicine.disease ,biology.organism_classification ,Fishery ,Loligo vulgaris ,Mediterranean sea ,Oceanography ,Geography ,Spain ,biology.animal ,medicine ,Mollusca - Abstract
14 páginas, 9 figuras, 1 tabla, The Spanish fishery for the loliginid squids Loligo vulgaris and Loligo forbesi is described, with particular emphasis on the period 1983-1991. During this period the landings of squid in Spain stayed at a relatively constant level of around 2200 t. The value of the Spanish squid landings increased throughout the 1980s and amounted to £9.7 million in 1991. The two species of squid are not treated separately in the official statistics, and therefore the percentage corresponding to each is unknown; nevertheless, in the maritime regions of the Mediterranean, L. vulgaris is practically the only species landed, while in Atlantic regions, both are landed, although L. vulgaris is more abundant than L. forbesi. Particular attention is paid to the analysis and description of fisheries and squid landings in Galicia (northwest Spain) and Catalonia (northeast Spain), during the period 1980- 1991. In both regions, part of the landings correspond to trawling and purse-seine fisheries targeting finfish, where squid is caught as a by-catch. There are also important seasonal artisanal fisheries where the target species is squid. Landings have shown a marked seasonality; being more plentiful in summer and autumn. This resource does not show signs of overfishing. The present methods of fishing management are discussed, and proposals are put forward to modify some of these in order to avoid catching immature individuals of less than 200 mm mantle length., This work was funded by the Commission of the European Communities within the frame of this EEC research programme in the fisheries sector (FAR, contract no. MA. 1.146)
- Published
- 1994
19. Genetic variation in the neritic squid Loligo forbesi (Myopsida: Loliginidae) in the northeast Atlantic Ocean
- Author
-
Thorpe, J. P., Pierce, G. J., Boyle, P. R., Brierley, A. S., and Clarke, M. R.
- Subjects
BIOLOGICAL variation ,BIOLOGICAL classification - Published
- 1995
20. Flexible reproductive strategies in the squid Loligo forbesi
- Author
-
Hastie, L. C., Boyle, P. R., and Pierce, G. J.
- Subjects
MARINE biology - Published
- 1995
21. Geographic variation in Loligo forbesi in the northeast Atlantic Ocean: analysis of morphometric data and tests of causal hypotheses
- Author
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Jamieson, R., Pierce, G. J., Boyle, P. R., Brierley, A. S., Guerra, A., Hastie, L. C., Thorpe, R. S., and Avila, P.
- Subjects
GEOGRAPHY - Published
- 1994
22. Naar aanleiding van een Loligo - rugschilden - invasie op Terschelling
- Subjects
Loligo vulgaris ,Loligo forbesi ,rugschilden ,Loligo ,Terschelling - Published
- 1979
23. The γ-subunit of the principal G-protein from squid (Loligo forbesi) photoreceptors contains a novel N-terminal sequence
- Author
-
Alan Carne, N J P Ryba, John B. C. Findlay, J.Shaun Lott, John D.D. Pottinger, and Jeffrey N. Keen
- Subjects
Molecular Sequence Data ,Invertebrate vision ,Biophysics ,Sequence alignment ,Biology ,Biochemistry ,Protein structure ,Protein sequencing ,Structural Biology ,GTP-Binding Proteins ,Complementary DNA ,biology.animal ,Heterotrimeric G protein ,Genetics ,Animals ,Photoreceptor Cells ,Amino Acid Sequence ,Molecular Biology ,Peptide sequence ,Squid ,Loligo forbesi ,Base Sequence ,Sequence Homology, Amino Acid ,Nucleic acid sequence ,Decapodiformes ,Molecular cloning ,Cell Biology ,DNA ,Blotting, Northern ,G-protein subunit - Abstract
The squid (Loligo forbesi) visual system presents as accessible a system for study of G-protein mediated signal transduction as the vertebrate rod outer segment with the added advantage that the major G-protein is a member of the Gq-class. Here the cDNA clone encoding the gamma-subunit of this G-protein is reported, thereby completing the molecular cloning of the heterotrimeric G-protein. The deduced protein structure of G-gamma has relatively little sequence identity with known mammalian counterparts particularly in comparison with the relatively high degree found for both the alpha- and beta-subunits of this protein. In particular, the N-terminus of the squid visual G-gamma contains a repetitive, highly charged region, rich in lysine and glutamate, that has no parallel in other G-proteins. The amino acid sequence of a number of peptides derived by chemical cleavage of G-gamma accounted for much of the protein sequence predicted from the cDNA, including the unusual N-terminal region.
- Full Text
- View/download PDF
24. Naar aanleiding van een Loligo - rugschilden - invasie op Terschelling
- Author
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Hoeksema, Bert, Hoeksema, D., and Staff publications
- Subjects
Loligo vulgaris ,Loligo forbesi ,rugschilden ,Loligo ,Terschelling - Published
- 1979
25. Tintenfisrhvorkommen vor der nordamerikanischen Ostküste
- Author
-
Schöne, Rüdiger
- Subjects
stock monitoring ,Loligo forbesi ,biology ,North Atlantic ,Loligo pealei ,Fisheries ,cephalopods ,fishing grounds ,Loligo vulgaris ,short finned squid ,German fishery ,distribution area ,long finned squid ,Illex illecebrosus - Abstract
Johann Heinrich von Thunen-Institute, Federal Research Institute for Rural Areas, Forestry and Fisheries began publishing the Informationen aus der Fischereiforschung – Information on Fishery research in 2010
- Published
- 1975
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