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DocumentOther documentRevised stock assessment for the cuttlefish Sepia pharaonis taken off the coast of the People's Democratic Republic of Yemen 1981
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No results found.This paper describes a revised stock assessment for the cuttlefish Sepia pharaonis inhabiting waters off the People's Democratic Republic of Yemen. It differs from earlier assessments in that the male and female cuttlefish are considered separately. -
DocumentOther documentThird report of mesh selection studies conducted in the People's Democratic Republic of Yemen on the cuttlefish Sepia pharaonis 1983
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No results found.The results of a third cod-end mesh selection trial involving the alternate haul method are described. All cod-ends were made from single braided polyetheylene, and the mesh sizes used were 7.0 cm, 10.3 cm, 12.4 cm, 14.1 cm, 15.2 cm, and 16.9 cm; the smallest size being taken as the standard against which the others were compared. The relationship between the 50% selection lengths and mesh sizes, was found not to be different from those of the earlier two trials; combining the results from all t rials gave: 50% selection length (cm) = 2.15 x mesh size (cm) - 9.34; whose correlation coefficient is highly significant (at P<0.05). -
DocumentOther documentSecond report of mesh selection studies conducted in the People's Democratic Republic of Yemen on the cuttlefish Sepia pharaonis 1982
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No results found.This paper describes a repeat of an earlier study by the authors, concerning the mesh selection properties of trawl cod-ends of various mesh sizes on the cuttlefish Sepia pharaonic. A brief resume of the findings is as follows: the estimated 50% selection lengths with 95% confidence limits for single braided polyethylene cod-ends of 12.4 cm, 13.6 cm and 16.8 cm mesh sizes were 17.87+0.28 cm, 20.74+- 0.53 cm and 26.95+-1.07 cm; the 50% selection lengths and selection ranges were very similar to t hose obtained in the earlier study in respect to the 12.4 cm cod-end, but higher in respect to the 13.6 cm cod-end; the 16.8 cm cod-end had not been previously used; the previously held assumption that the 50% selection lengths and cod-end mesh sizes were proportionally related was seen as inappropriate, and hence also the estimation of selection factors; the more appropriate relationship was seen to be one of non-proportional linearity, and the regression equation considered most compatible wit h the observations as 50% selection length (cm)=2.03 mesh size(cm) -7.41; for a chosen value of the 50% selection length, this equation gives substantially different values for the choice of appropriate cod-end mesh size, than the selection factors estimated from the earlier study.
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Book (stand-alone)Manual / guideThe living marine resources of the Western Central Atlantic. Volume 2. Bony fishes part 1 (Acipenseridae to Grammatidae) 2002
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No results found.This is the second of a three volumes field guide that covers the species of interest to fisheries of the major marine resources groups exploited in the Western Central Atlantic. The area of coverage includes FAO Fishing Area 31. The marine resources groups included in this volume are Bony fishes part 1 (Acipenseridae to Grammatidae). The introductory chapter outlines the environmental, ecological and biogeographical factors influencing the marine biota and the basic components of the fisheries in the Western Central Atlantic.See also other volumes related to this series: -
Book (stand-alone)Manual / guide
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Book (stand-alone)Manual / guideThe Living Marine Resources of the Eastern Central Atlantic. Volume 2: Bivalves, gastropods, hagfishes, sharks, batoid fishes, and chimaeras 2016
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No results found.This multivolume field guide covers the species of interest to fisheries of the major marine resource groups exploited in the Eastern Central Atlantic. The area of coverage includes FAO fishing area 34 and part of 47. The marine resource groups included are bivalves, gastropods, chitons, cephalopods, stomatopods, shrimps, lobsters, crabs, hagfishes, sharks, batoid fishes, chimaeras, bony fishes and sea turtles. The introductory chapter outlines the environmental, ecological, and biogeographical factors influencing the marine biota, and the basic components of the fisheries in the Eastern Central Atlantic. Within the field guide, the sections on the re source groups are arranged phylogenetically according to higher taxonomic levels such as class, order, and family. Each resource group is introduced by general re marks on the group, an illustrated section on technical terms and measurements, and a key or guide to orders or families. Each family generally has an account summarizing family diagnostic characters, bi o logical and fisheries in formation, notes on similar families occur ring in the area, a key to species, a check list of species, and a short list of relevant literature. Families that are less important to fisheries include an abbreviated family ac count and no de tailed species in formation. Species in the important families are treated in detail (arranged alphabetically by genus and species) and include the species name, frequent synonyms and names of similar speci es, an illustration, FAO common name(s), diagnostic characters, biology and fisheries in formation, notes on geo graphical distribution, and a distribution map. For less important species, abbreviated accounts are used. Generally, this includes the species name, FAO common name(s), an illustration, a distribution map, and notes on biology, fisheries, and distribution. Each volume concludes with its own index of scientific and common names.