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Ivone Figueiredo – One of the best experts on this subject based on the ideXlab platform.

  • Sex steroids of black scabbardfish, Aphanopus carbo, in relation to reproductive and migratory dynamics
    Aquaculture and Fisheries, 2020
    Co-Authors: Inês Farias, João Delgado, Elsa Couto, Neide Lagarto, Adelino V.m. Canario, Ivone Figueiredo

    Abstract:

    Abstract Black scabbardfish, Aphanopus carbo, is a commercially important species that takes distant migrations throughout its life cycle. Sex steroids were measured by radioimmunoassay in the blood plasma of specimens caught off the Madeira Archipelago and mainland Portugal to link this species migratory path with its reproductive cycle. Furthermore, a pilot study using Mozambique tilapia (Oreochromis mossambicus) was designed to evaluate the effect of sample freshness on steroid levels because black scabbardfish blood was collected at separate times after specimens were caught. The changes in T and 11-KT concentrations between the time of blood extraction and the time after preservation did not statistically differ among the different methods applied. Therefore, measured black scabbardfish steroid concentrations were directly used in the subsequent data analyses. In females, E2 and in T concentrations peaked at a late stage of vitellogenesis. E2 concentration was significantly different between females caught off each area. Clustering E2 and T concentrations from all developing females resulted in the separation of two distinct groups, independently of their geographical area. In males, T and 11-KT were not significantly different between maturity stages. The hepatosomatic index of males caught off mainland Portugal was relatively high. This may reflect a mechanism for storing energy that will later be consumed during migration to the spawning grounds. The trend of sex steroids concentrations throughout the sexual maturation of the species is consistent with the morphological indicators and shows evidence of the reproductive and migratory pattern hypothesised for the black scabbardfish in NE Atlantic.

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  • and
    , 2015
    Co-Authors: Ivone Figueiredo, Pedro Bordalo Machado, Leonel Serrano Gordo

    Abstract:

    Deep-water sharks represent a major percentage of the total annual elasmobranch landings in mainland Portugal, primarily comprising Portuguese dogfish (Centroscymnus coelolepis), Leaf-scale gulper shark (Centrophorus squamosus) and Gulper shark (Centrophorus granulosus). These species are usually taken as by-catch from fisheries targeting other species. The present work describes the main characteristics of the fisheries for the three species mentioned above that take place mainly from Sesimbra and Peniche. Sesimbra accounts for nearly 50 % of the deep-water sharks landings in mainland Portugal and deep-water sharks constitute a by-catch of the black scabbardfish (Aphanopus carbo) fishery and in Peniche, a by-catch of multispecies artisanal fisheries. The focus was placed on a comparative analysis of the fishing regimes adopted at these two ports

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  • A State Space Model Approach for Modelling the Population Dynamics of Black Scabbardfish in Portuguese Mainland Waters
    CIM Series in Mathematical Sciences, 2015
    Co-Authors: Isabel Natário, Ivone Figueiredo, M. Lucília Carvalho

    Abstract:

    Black scabbardfish (Aphanopus carbo Lowe, 1839) is a widely distributed species across the Atlantic ocean. In Portuguese mainland waters the existing specimens are immature (not able to reproduce). It is admitted that they have migrated from the West of the British Isles and that they remain in the area for some years, until they attain an adequate size or physiological conditions which allow them to migrate and reproduce elsewhere.The present study aims to model the dynamics of the population of black scabbardfish living in the International Council for the Exploration of the Seas Division IXa, for which disaggregated data are available, although within the context of a larger population. With this purpose, a state-space model is used, which enables the estimation of the unknown abundance (latent process) by exploring its dependency relationship with the observational data on the species fishing landings in that area. The population is partitioned into length groups and the population evolution process is subdivided into biological related subprocesses.The estimation is achieved within a Bayesian paradigm, where all the available biological information is incorporated in the prior distributions of the parameters of the subprocesses. Later, short-term trajectories of the population living in IXa are studied, via simulations that are constructed based on different management scenarios.

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João Delgado – One of the best experts on this subject based on the ideXlab platform.

  • Two sympatric, not externally discernible, and heavily exploited deepwater species with coastal migration during spawning season: implications for sustainable stocks management of Aphanopus carbo and Aphanopus intermedius around Madeira
    Canadian Journal of Fisheries and Aquatic Sciences, 2020
    Co-Authors: Joana Vasconcelos, João Delgado, Paulo Henriques, Ricardo Sousa, Antonieta Amorim, Rodrigo Riera

    Abstract:

    Several artisanal fisheries target deepwater species. These stocks are highly sensitive to overfishing because of their slow growth and late maturation. This vulnerability is higher if species conc…

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  • Sex steroids of black scabbardfish, Aphanopus carbo, in relation to reproductive and migratory dynamics
    Aquaculture and Fisheries, 2020
    Co-Authors: Inês Farias, João Delgado, Elsa Couto, Neide Lagarto, Adelino V.m. Canario, Ivone Figueiredo

    Abstract:

    Abstract Black scabbardfish, Aphanopus carbo, is a commercially important species that takes distant migrations throughout its life cycle. Sex steroids were measured by radioimmunoassay in the blood plasma of specimens caught off the Madeira Archipelago and mainland Portugal to link this species migratory path with its reproductive cycle. Furthermore, a pilot study using Mozambique tilapia (Oreochromis mossambicus) was designed to evaluate the effect of sample freshness on steroid levels because black scabbardfish blood was collected at separate times after specimens were caught. The changes in T and 11-KT concentrations between the time of blood extraction and the time after preservation did not statistically differ among the different methods applied. Therefore, measured black scabbardfish steroid concentrations were directly used in the subsequent data analyses. In females, E2 and in T concentrations peaked at a late stage of vitellogenesis. E2 concentration was significantly different between females caught off each area. Clustering E2 and T concentrations from all developing females resulted in the separation of two distinct groups, independently of their geographical area. In males, T and 11-KT were not significantly different between maturity stages. The hepatosomatic index of males caught off mainland Portugal was relatively high. This may reflect a mechanism for storing energy that will later be consumed during migration to the spawning grounds. The trend of sex steroids concentrations throughout the sexual maturation of the species is consistent with the morphological indicators and shows evidence of the reproductive and migratory pattern hypothesised for the black scabbardfish in NE Atlantic.

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  • Deep stocks avoid competition migrating horizontal and vertically: The example of two scabbardfishes (Aphanopus spp.) targeted by long-liners in grounds next to an oceanic archipelago
    Regional Studies in Marine Science, 2019
    Co-Authors: Joana Vasconcelos, João Delgado, Paulo Henriques, Ricardo Sousa, Antonieta Amorim, Rodrigo Riera

    Abstract:

    Abstract Fishing is occurring all over the globe, with an increase trend of exploiting deep stocks. Several species are currently targeted from the deep ocean, and some artisanal fisheries developed fishing gears, e.g. long lines, with limited impact to the environment but scarce information is available on biological aspects of these exploited stocks. In the Macaronesian region and specifically in Madeira archipelago, two Aphanopus sympatric species have been extensively exploited for decades but no detailed information is available on the spatial and vertical distribution of both species (Aphanopus carbo and Aphanopus intermedius). Currently, they represent an important percentage of landings from artisanal fishermen of Madeira (27% of the total catches in 2017). We herein observed that they showed a pattern of depth segregation, where adults of both species are more abundant (ca. 80%) at deeper seafloor (> 2500 m). A. intermedius was more numerous in fishing areas with greater seafloor depth (> 4500 m) compared to A. carbo. This pattern may be explained by a food source overlap between both species, and also the vertical segregation within the same species may be considered as a pattern to avoid cannibalism. Also, migration patterns were found in both species being more pronounced for A. intermedius where > 86% of individuals were collected offshore (> 12 n.m.). The present results constitute a step forward to start developing integrative management actions to preserve stocks of both species in the medium and long term in the study region.

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James C Chubb – One of the best experts on this subject based on the ideXlab platform.

  • Larval trypanorhynchs (Platyhelminthes: Eucestoda: Trypanorhyncha) from black-scabbard fish,
    EDP Sciences, 2014
    Co-Authors: G Costa, C J Veltkamp, James C Chubb

    Abstract:

    Four different types of trypanorhynch postlarvae were found attached to the stomach mucosa, external stomach wall or free in the body cavity of two marine fishes from Madeira, namely black-scabbard fish, Aphanopus carbo and oceanic horse mackerel, Trachurus picturatus. Morphological features shown by SEM indicated that the postlarvae belonged to the species Tentacularia coryphaenae, Sphyriocephalus tergestinus, Nybetinia lingualis and possibly N. yamagutii. Prevalence [mean intensity (range)] of T. coryphaenae, S. tergestinus and Nybetinia spp. in A. carbo (n = 135) was 12.6 % [1.65 ± 1.27 (1-6)], 5.9 % [1.57 ± 0.79 (1-3)] and 2.2 % [1.33 ± 0.58 (1-2)] respectively. The prevalence of T. coryphaenae and S. tergestinus showed some seasonality, with a rise in prevalence of T. coryphaenae corresponding to a decrease in prevalence of S. tergestinus. However these differences were not significant. In T. picturatus (n = 304) only N. lingualis was found at a prevalence of 9.6 %. Both S. tergestinus and N. lingualis were recovered only from the stomach mucosa or external stomach wall, while T. coryphaenae was observed either attached to the stomach mucosa or free in the visceral cavity of the fish. The paper presents the first scanning electron micrographs (SEM) of Sphyriocephalus tergestinus and a new geographical record of N. lingualis in T. picturatu

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  • larval trypanorhynchs platyhelminthes eucestoda trypanorhyncha from black scabbard fish Aphanopus carbo and oceanic horse mackerel trachurus picturatus in madeira portugal
    Parasite, 2003
    Co-Authors: G Costa, C J Veltkamp, James C Chubb

    Abstract:

    Quatre sortes de trypanorhynques postlarvaires ont ete trouvees fixees a la paroi externe de l’estomac ou a l’etat libre dans la cavite generale de deux especes de poissons marins provenant de Madere : le sabre noir, Aphanopus carbo et le chinchard du large, Trachurus picturatus. Les caracteristiques morphologiques, etudiees au microscope a balayage indiquent que les posilarvae appartiennent aux especes suivantes : Tentacularia corypnaenae Sphyriocephalus tergestinus, Nybelinia lingualis et enfin probablement N. yarragutii. Le taux d’infestation [intensite moyenne (range)] de T. coryphaenae, S. tergestinus et Nybelinia spp. chez A. carbo (n = 135) est respectivement de 12.6 % [1.65 ± 1.27(1-6)], 5.9 % [1.57 ± 0.79 (1-3)] et 2.2 % [1.33 ± 0.58 (1-2)]. la prevalence de T. coryphaenae et S. tergestinus semble fluctuer selon les temperatures saisonnieres. avec une hausse de la prevalence de T. coryphaenae correspondant a la baisse de la prevalence de S. tergestinus. Neanmoins, ces differences ne sont pas significatives. Chez T. pictutatus, N. lingualis a une prevalence de seulement 9.6 % (n = 304). S. tergestinus et N. lingualis ont ete retrouves seulement dans l’estomac ou dans sa paroi externe alors que l’on constate que le T. coryphaenae se trouve soit fixe a l’estomac soit a l’etat libre dans la cavite viscerale du poisson. Ce travail presente les premieres images realisees en microscopie a balayage de S. tergestinus et une nouvelle mention geographique sur la presence de N. lingual chez T. picluratus.

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  • Cystacanths of Bolbosoma vasculosum in the black scabbard fish Aphanopus carbo, oceanic horse mackerel Trachurus picturatus and common dolphin Delphinus delphis from Madeira, Portugal.
    Journal of Helminthology, 2000
    Co-Authors: G Costa, James C Chubb, C J Veltkamp

    Abstract:

    Cystacanths of the acanthocephalan, Bolbosoma vasculosum Rudolphi 1819, were found to be encapsulated in the connective tissues of the viscera of the black scabbard fish, Aphanopus carbo and oceanic horse mackerel, Trachurus picturatus from Madeira, Atlantic Ocean. Juvenile worms were obtained from the intestine of a stranded common dolphin, Delphinus delphis , also from Madeira. Cystacanths were 11–15 mm long, with a proboscis of 18–19 longitudinal rows, eight hooks per row, and two sets of trunk spines. Overall, the morphology and dimensions of the proboscis, neck and trunk corresponded to previous descriptions. Scanning electron microscopy of the proboscis structures and trunk spines is provided for the first time. The prevalence of B. vasculosum in A. carbo increased with fish length. There were no statistical differences in the prevalence and intensity of infection between seasons. The intensity of infection was similar for male and female fishes, but there were significant differences in relation to length, longer fishes having heavier infections. Aphanopus carbo from Madeira represents a new host record and a new geographic location for B. vasculosum.

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