381 research outputs found
First record of Alosa fallax (LacépÚde, 1803) (Teleostei: Clupeiformes:Clupeidae) in the Azores Archipelago, Portugal (NE Atlantic)
Copyright © 2014 All rights reserved.This note reports the first record of Alosa fallax (LacĂ©pĂšde, 1803) in the Azores Archipelago (NE Atlantic, Portugal). Being an anadromous species, this occurrence is quite unexpected since there are no suitable breeding habitats for this species in these volcanic islands, isolated and river less. Although A. fallax is known to migrate offshore, it has never been previously reported in oceanic environments. We discuss this occurrence and theorize on the possibility of the speciesâ being found in Madeira, another Macaronesian Archipelago, albeit much older and closer to European coasts and thus more suitable to be crossed by A. fallax during their migration routes in pelagic environments. With this record, the number of Clupeid fishes for Azorean waters increases to two, the other being the well known and resident Sardina pilchardus
Notes on the feeding habits of Gaidropsarus guttatus (Collett, 1890) from Faial Island, Azores, NE Atlantic, PT
Copyright © 2014 SociĂ©tĂ© Française dâIchtyologie.Gaidropsarus guttatus est un prĂ©dateur nocturne des fonds rocheux des Ăźles de MacaronĂ©sie. Il nâexiste pas dâĂ©tude sur lâĂ©cologie alimentaire de cette espĂšce et cet article apporte les toutes premiĂšres informations, sur la base dâun Ă©chantillon de 82 individus capturĂ©s Ă lâĂźle de Faial, aux Açores (Portugal). Les prĂ©lĂšvements ont Ă©tĂ© rĂ©alisĂ©s entre aoĂ»t 1997 et avril 1999 dans des mares intertidales et en zone subtidale jusquâĂ une profondeur de 10 m. Sur les 82 spĂ©cimens collectĂ©s, 95% dâentre eux prĂ©sentaient des aliments dans lâestomac, totalisant 303 proies de 11 taxons diffĂ©rents. Les proies les plus frĂ©quentes Ă©taient des dĂ©capodes (45%), notamment le crabe Pachygrapsus marmoratus (24%). Les poissons tĂ©lĂ©ostĂ©ens reprĂ©sentaient 17% de toutes les proies identifiĂ©es. La prĂ©sence significative de proies benthiques et dâalgues dans les contenus stomacaux de G. guttatus suggĂšrent que cette espĂšce est un prĂ©dateur opportuniste qui utilise la succion pour capturer ses proies.ABSTRACT: Gaidropsarus guttatus is a nocturnal predator that dwells in rocky bottoms of Macaronesian coastal areas. There are no studies as yet on the feeding ecology of this species. This paper describes the feeding habits of this quite unknown species, based on a sample from Faial Island, Azores, Portugal. This sample is composed of 82 specimens collected between August 1997 and April 1999, both in intertidal pools and sub-tidal shallow waters (max. depth 10 m). 95% of sampled stomachs contained food items totaling 303 preys from 11 different taxa. Most important items were decapoda (45%), from which Pachygrapsus marmoratus (24%) showed to be clearly a dominant prey. Teleost fish represented 17% of all prey items. The significant presence of benthonic species and algae in their stomach contents do suggest that G. guttatus is an opportunistic suction feeder predator
Occurrence of Grammicolepis brachiusculus Poey, 1873 (Pisces: Grammicolepididae) in the Azores Archipelago
Three specimens of Grammicolepis brachiusculus were caught by the commercial bottom hand and longline fisheries off Terceira and Faial Islands, Azores Archipelago. This is the first record of the species for the region, and one of few ever caught in the NE Atlantic
Habitat use by the juvenile dusky grouper Epinephelus marginatus and its relative abundance, in Santa Catarina, Brazil
Copyright © 2003 aqua, International Journal of Ichthyology.The dusky grouper (Epinephelus marginatus) is a species whose stock management deserves special attention. It has an important role in hard-bottom ecosystems and, as a protogynous hermaphrodite; it is especially susceptible to overfishing. Data on the speciesâ use of habitat, and on the way environmental and behaviour parameters influence its abundance can help to improve management and conservation strategies. The aim of this study was to evaluate the influence of bottom type, temperature and species behaviour on the abundance of E. marginatus, using a quadrate for visual census. An area of 80 mq., divided between rocky shore, rocky outcrop and sandy habitats was surveyed monthly. Densities of juveniles were: 1.16 groupers mËÂČ over the rocky shore and 1.47 groupers mËÂČ over the rocky outcrop, while no groupers were found over sand. Analysis of the yearly variation in abundance revealed a migratory pattern of dispersal and gathering. All size groups observed in this study were below the first maturation length.RĂSUMĂ: Le mĂ©rou Epinephelus marginatus est une espĂšce dont la gestion du stock rĂ©clame une attention spĂ©ciale. Son rĂŽle est important dans les Ă©cosystĂšmes Ă fonds durs et en tant quâhermaphrodite protogyne ; il est particuliĂšrement sensible Ă la supĂȘche. Des donnĂ©es sur lâutilisation de lâhabitat par lâespĂšce et sur la façon dont les paramĂštres dâevironnement et de comportement dĂ©terminant sa frĂ©quence peuvent aider Ă amĂ©liorer les stratĂ©gies de gestion et de prĂ©servation. Lâobjectif de cette Ă©tude consiste Ă Ă©valuer lâimpact di tye de substrat, de la tempĂ©rature et du comportement de lâespĂšce sur lâabondance de E. margiantus, Ă lâaide dâun quadrat de recensement visuel. Une surface de 80mÂČ, composĂ©e de littoral rocheux, dâaffleurements rocheux et dâhabitats sableux, a Ă©tĂ© contrĂŽlĂ©e mensuellement. Les densitĂ©s de juvĂ©niles Ă©taient de: 1,16 mĂ©rous au mËÂČ sur le littoral rocheux et de 1.47 au mËÂČ sur les affleurements, alors quâils nâapparaissaient pas sur les fonds sableux. Lâanalyse de la variation annuelle en abondance a rĂ©vĂ©lĂ© un schĂ©ma migratoire de dispersion et de rassemblement. Tous les groupes observĂ©s dans cette Ă©tude avaient une taille infĂ©rieure Ă celle de la premiĂšre maturation
Juvenile Sphyraena viridensis, preyed by the lizard fish Synodus saurus. A new predatory association from the Azores
Copyright © 2008 SociĂ©tĂ© Française dâIchtyologie.Les juvĂ©niles de Sphyraena viridensis, proies de Synodus saurus, une nouvelle association prĂ©dateur-proie aux Açores. Au cours dâun travail sur lâĂ©cologie (comportement, alimentation et reproduction) du poisson lĂ©zard, Synodus saurus, aux Açores (Atlantique NE) nous avons dĂ©couvert, dans plusieurs contenus stomacaux, des exemplaires postlarvaires et des juvĂ©niles de la bĂ©cune Ă bouche jaune Sphyraena viridensis. Non seulement cette dĂ©couverte nous a permis dâobtenir, pour la premiĂšre fois, des postlarves de cette espĂšce de barracuda mais nous avons rĂ©ussi Ă dĂ©crire une action de prĂ©dation dâun poisson Ă©pibenthique envers une espĂšce pĂ©lagique
Stratégie alimentaire et ontogénie trophique de Scorpaena maderensis (Scorpaeniformes: Scorpaenidae) des Açores, Atlantique NE
Copyright © 2014 SociĂ©tĂ© Française d'Ichtyologie.Feeding habits of Scorpaena maderensis Valenciennes, 1833 from the Azores archipelago were investigated. The stomach contents of 245 specimens, collected between August 1997 and July 1999, were analysed. Decapod crustaceans and teleost fishes constitute the main food items, revealing a high level of specialization by S. maderensis. Ontogenic shifts and seasonal changes in the diet composition were observed, unveiling the adaptability and opportunistic predatory behaviour of this scorpaenid.RĂSUMĂ: Les habitudes alimentaires de Scorpaena maderensis Valenciennes, 1833 de l'archipel des Açores ont Ă©tĂ© Ă©tudiĂ©es. Les contenus stomacaux de 245 spĂ©cimens, rĂ©coltĂ©s entre aoĂ»t 1997 et juillet 1999, ont Ă©tĂ© analysĂ©s. Les crustacĂ©s dĂ©capodes et les tĂ©lĂ©ostĂ©ens sont les principales proies de S. maderensis, indiquant un fort degrĂ© de spĂ©cialisation chez cette espĂšce. Des changements ontogĂ©nĂ©tiques et saisonniers de la composition du rĂ©gime alimentaire rĂ©vĂšlent lâadaptabilitĂ© et le comportement prĂ©dateur opportuniste de ce scorpaenidĂ©
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