25 research outputs found

    Age, diet, growth and reproduction of a Population of Cobitis paludica (de Buen, 1930) in the Palancar Stream (southwest of Europe, Spain) (Pisces: Cobitidae)

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    A total sample of 99 specimens of the vulnerable fish species Cobitis paludica (de Buen, 1930), was collected on a monthly basis from a tributary of the River Guadalquivir between September 1990 and September 1991. Female longevity was 1 year longer than that of males, the former reaching age-class 5+. The diet of C. paludica consisted mainly of Ostracoda and chironomid larvae, benthic prey of small size and occasionally other resources, such as Macrobiotid eggs spawned during winter. Detritus in gastrointestinal content was scarce, which differs from other populations. Back-calculations of length were performed from scale annuli measurements. The relationship between standard length and scale radius was different for males and females. Females were larger than males of the same age. Both back-calculated length and theoretical length, calculated by applying von Bertalanffy’s model, were larger for females. The relationship between female standard length (SL) and fecundity (F) was log F = 7.465 + 5.5753 log SL

    A software tool for monitoring legal minimum lenght of landings: Case study of a fishery in sourthern Spain

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    Herramienta de interés para el control y la gestión de pesqueríasThe regulation of minimum legal size(MLS) of catches is a tool widely applied in the management of fisheries resources, although the MLS does not always coincide with the length at first maturit(LFM). The optimization of this management tool requires a series of quality control in fish markets and transportation. A software application has been developed to make the control of the landings of several target species easier and faster. In order to test and make this tool operational,six species of commercial interest were selected: four species of fish hand two species of bivalves. It is proposed to estimate the proportion of illegal specimens in the studied lot from the proportion of illegal individuals found in the samples taken from this lot.The input data for the application are the minimum legal size(MLS) of the species and the total length(TL)of each specimen sampled. The out put data is a statistical summary of the percentage of specimens of size less than the legal minimum(TL<=MLS)within different confidence intervals(90%,95% and 99%). The software developed will serve as a fast,efficient and easy to manage tool that allows inspectors to determine the degree of compliance on MLS control and to make a decision supported by statistical proof on fishing goods

    A simple method to estimate the significance level of the catch probability in the catch removal method in riverf ish populations

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    This work presents a method for estimating the signi®cance level of the capture probability when the capture removal method is used in riverine ®sh populations. The method is based on adjustment of the linear relationship between capture probability and an index of capture ef®cacy. With this method the population size, the statistic 2 and the signi®cance level of the capture probability can be estimated. This is a simple technique which can be applied in the ®eld at the time of sampling. It does not require the use of computers and can determine in situ whether the catch is valid to calculate the population density

    Some meristic characteristics of hybrids between Acipenser naccarii and Acipenser baerii

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    The aim of this study was to describe meristic characters of hybrid Acipenser naccarii x A. baeri, to be used as the basis for characterizing hybrid specimens in a complementary manner to as described for A. naccarii by Hernando et al. (1999). Thirty 2+ and 3+ year class individuals from the Region of Lombardy (Italy) were analysed for eight morphological variables (Soljan 1975; Holcick et al. 1989), and weight. Three indices, viz the relative position of barbels (CA), the ratio of snout width to length (FB) (Garrido-Ramos et al. 1997), and the Soljan index (Hernando et al. 1999), were used to characterize hybrids. A descriptive analyses of variables, simple and multiple regression analysis, and principal components relationships, were calculated. The relationships between TI and the indices was described using a stepwise multiple regression analysis: TI = 33.32 - 0.26 CA + 10.49 FB + 74.45 SOLJ (F = 1.96; Df = 3 )

    The performance of three ordination methods

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    The performance of robust principal component analysis (RPCA), detrended correspondence analysis (DCA) and non-metric multidimensional scaling (NMDS) with two demersal fish data sets were assessed in terms of their stability to bootstrap-generated sample variation and the method’s ability to reflect a well-known depth gradient. Stability was assessed for both species and site orderings and configurations, using scaled rank variance (SRV) and Spearman (q) and Procrustes correlations (t0). The NMDS site and species orderings showed the highest stability. DCA performed best in terms of site ordination stability, but NMDS performed best in terms of species ordination stability. In terms of matching the expected ecological variation, NMDS was the most sensitive method for the wider-depth gradient data and DCA was the most sensitive for the narrower-depth gradient data. According to the sensitivity and informative power criteria associated with the stability assessment, t0 was the best methodological approach for site ordinations, and SRV for species ordinations

    Morphometric and genetic analysis as proof of the existence of two sturgeon species in the Guadalquivir river

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    Morphometric and genetic methods were used to identify two sturgeon species, Acipenser naccarii Bo- naparte, 1836, and A. sturio Linnaeus, 1758, captured in some of the principal rivers of the Iberian Peninsula, including the Guadalquivir. After measuring 25 Iberian specimens from a ®shery and several Spanish and Por- tuguese museums and applying stepwise discriminant analysis (SDA), four specimens preserved in di erent museums [two specimens from the Guadalquivir river (EBD-8173 and EBD-8174), one specimen from the Tagus river (MUC1) and one specimen from the Mondego river (MUC46B)], as well as ®ve specimens captured in the Guadalquivir river in the 1940s but not preserved (CM1, CM2, CM3, CM4 and CM5), were identi®ed as A. naccarii. After cloning and character- isation of a satellite-DNA family, HindIII, from A. naccarii genome, its absence from the genome of A. sturio was determined. Using this satellite-DNA as a genetic marker and by means of dot-blotting, we dem- onstrate that the DNA of the two specimens captured during the mid-1970s in the Guadalquivir river cross- hybridised with HindIII satellite-DNA sequences of A. naccarii. We conclude that A. naccarii is autochtho- nous to the Iberian Peninsula and is not, as was previ- ously believed, endemic to the Adriatic Sea

    Trophic relationships in an intertidal rockpool fish assemblage in the gulf of Cádiz (NE Atlantic)

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    Many species of littoral fish that live in rocky substrates are syntopic, sharing the same coastal habitat. They have similar feeding behaviours and use small hollows as places to hide and spawn. In the present study, we identified a total of 16 resident fish species in a rockpool assemblage in the Gulf of Cádiz and studied their patterns of co-occurrence. The dietary analysis performed showed the occurrence of 2 mainly herbivorous species (Lipophrys canevae and Parablennius sanguinolentus), 8 mainly carnivorous species with a percentage occurrence of algae in the diet below 10% (Gobius paganellus, Gobius cobitis, Gobius bucchichi, Clinitrachus argentatus, Tripterygion delaisi, Lepadogaster lepadogaster, Lepadogaster purpurea and Lepadogaster candolii), and 6 species that are carnivorous in the earlier phases of their lives and gradually increase the proportion of algae in their diet (Lipophrys pholis, Paralipophrys trigloides, Parablennius incognitus, Salaria pavo, Coryphoblennius galerita and Symphodus roissali). The dietary overlap among the different species does not explain the different patterns of abundance found among co-occurring species. In the present study, the common use of abundant resources coupled with specialized use of other types of resources was observed, and this allows the different species to minimise the effects of possible trophic competition

    Revista de Vertebrados de la Estación Biológica de Doñana

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    Página 298 con error de impresiónEstudio cariológico en dos especies de Serránidos del Mediterráneo (Peces: PerciformesRelaciones morfométricas de Atherina boyeri Risso (Pisces: Atherinidae) de la laguna de Zoñar (Córdoba, España)Contribución al conocimiento de la biometríay osteología de Barbus barbus bocagei, Steindachner, 1866 (Pisces: CyprinidaeLa actividad de la salamandra, Salamandra salamandra (L.), en Galicia.Estudios sobre el sapo corredor (Bufo calamita) en el Sur de España.1. BiometríaEstudios sobre el sapo corredor (Bufo calamita) en el Sur de España. II. AlimentaciónBiología de la reproducción de Rana iberica Boulenger 1879 en zonas simpátridas con Rana temporaria Linneo, 1758Nuevos datos sobre la distribución geográfica de Lacerta monticola cantabrica Mertens, 1929. (Sauria, lacertidae).Datos sobre Lacerta monticola Boulenger, 1905 (Saurio: lacertidae)en el oeste del Sistema Central.Nueva especie de Anolis (lacertilia, Iguanidae) para CubaEtograma cuantificado del cortejo en Falco naumannOntogénesis del comportamiento predador en Falco naumanniContaminación xenobiótica del Parque Nacional de Doñana. 1. Residuos de insecticidas organoclorados, bifenilos policlorados y mercurio en anseriformes y gruiformesReproducción del críalo (Clamator glandarius) en Sierra Morena CentraNidificación de Picus viridis en taludes de arcilla en Ramblas de Guadix (Granada)Comportamiento del calamón Porphyrio porphyrio (Linnaeus, 1758) en Doñana, Marismas del GuadalquiviBiología y ecología de la malvasía (Oxyura leucocephala) en Andalucía.On the differential diet of Carnivora in islands:a method for analysing it and a particular case.Notas sobre la distribución pasada y actual del meloncillo Herpestes ichneumon (L.) en la Península IbéricaEstructuración de las interacciones en una camada de lobos (Canís lupus)Nuevos datos sobre la distribución del Cottus gobio L. (pisces, cottidae) en EspañaSobre la alimentación de Callopistes maculatus (Reptilia,teiidaeObservación de Lacerta lepida depredando un nido de Alectoris rufaNueva cita del galápago leproso Mauremys leprosa (Scheigger, 1812) en los pirineosPrimera cita de Psammodromus hispanicus (Fitzinger) para GaliciaSobre la presencia de Gallotia (=Lacerta) atlantica (Peters y Doria, 1882) en Gran CanariaNota sobre las Lacerta monticola Boulenger, 1905 de las zonas del norte de GaliciaPrimeras notas herpetológicas de la provincia de Soria.Datos sobre selección de hábitat y ecología alimenticia del porrón pardo (Aythya nyroca)Probable nueva área de cría del pechiazul (Luscinia svecica cyanecula) en el sistema central. PerisPredación de Falco peregrinus y Falco subbuteo sobre quirópterosResultados de la producción de Oxyura leucocephala en el año 1981 en las lagunas de Zóñar y el rincónAnálisis de la dieta de Tyto alba en un medio árido antropógeno de los alrededores de Almería¿Son Eudocimus ruber y E. albus distintas especies?EL Estornino pinto (Sturnus vulgaris) en Canarias: nueva especie nidifiante en el archipiélagoDatos sobre la alimentación otoñal del cárabo (Strix aluco) en la sierra de CádizObservación primaveral de rapaces y otras aves en el páramo del estado de Mérida (Venezuela).Murciélago hematófago (Desmodus rotundus) parasitando a un chigüire (Hidrochoerus hydrochaeris)Observaciones sobre la reproducción del zacatuche o teporinho Romerolagus diazi (Mammalia: lagomorpha)Estudio electroforético de hemoglobinas y esterasas sanguíneas en Rhinolophus ferrumequinum (Chiroptera: rhinolophidae) y de hemoglobinas en Tadaria taeniotis (chiroptera: molossidae)Peer reviewe

    Revista de Vertebrados de la Estación Biológica de Doñana

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    Tiempo y orden de aparición de las escamas en el salmón del Atlántico (Salmo salar)Estudios sobre el sapo corredor (Bufo calamita) en el sur de España.III. ReproducciónInfluencia de las carecterísticas del medio acuático sobre las poblaciones de larvas de anfibios en lala Reserva Biológica de Doñana(Huelva, EspañaDieta de la cigüeñuela (Himantopus himantopus) en las salinas del estuario del GuadianaOrientación y selección del lugar del nido en el gorrión moruno (Passer hispaniolensis)la avifauna de las Vegas Bajas del Guadianala reproducción de la malvasía (Oxyura leucocephala) en el sur de la provincia de Córdoba, España.La alimentación de la curruca cabecinegra (Sylvia melanocephala, Gmelin 1788) en olivares de la provincia de Jaén (otoño-invierno)Consideraciones sobre el efecto de los conejos y los grandes herbívoros en los pastizales de la Vera de DoñanaAnálisis factorial de las expresiones faciales del babuino sagrado (Papio hamadryas)Contaminación xenobiótica del Parque Nacionalde Doñana. II. Residuos de insecticidas organoclorados, bifenilos policlorados, (PGBs) y metales pesados en Falconiformes y StrigiformesTransferencia total y del y bioacumulación de mercurio y metilmercurio en ecosistemas del Parque Nacional de DoñanaNota sobre la alimentación de larvas de anfibios: I. Pleurodeles waltl en charcas temporaleNota sobre nuevas especies parasitada por el críalo (Clamator glandarius) en EspañaEstructura de la jerarquización en la predación de huevos y pichones en Spheniscus magellanicusPasser domesticus, nueva specie para Bolivia¿Están realmente subalimentados los cernícalos primilla en el valle del Guadalquivir durante el periodo no reproductor?.Nidificación del paiño común (Hydrobates pelagicus) en las Islas Canarias.Nuevos datos sobre la presencia del visón europeo (Mustela lutreola L.) en NavarraLa población de gamos del Parque Nacional de Doñana en 1979Puntualización a la nota "predacción de Falco peregrino y Falco subbuteo sobre quirópteros" de Aymerich y García de Castro aparecida en el vol. 9 de esta revista.Peer reviewe

    Artisanal fishing in Andalusia: A statistical study of the fleet

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    Andalusia is a region of Spain with an area of some 90,000 km2 and almost 900 km length of coastline. It has an important tradition in the fishing industry that makes it one of the areas of the European Union where fisheries policies have a great significance for the population. The present statistical study deals comprehensively with the so-called "artisanal fleet", especially in respect of data on the typology of vessels (construction particulars) and on the extractive effort made (distances and depths where they fish, duration of fishing voyages, the fishing gear used and target species), with the aim of presenting a new approach in the policies for regulating this important fisheries sector.Safety at sea Fisheries management Andalusia Spain
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