Recursos de colección

Repositorio da Universidade dos Açores (9.269 recursos)

O Repositório Institucional da Universidade dos Açores desenvolvido no âmbito do projecto RCAAP.

ARQ - CBM - Número 18A

Mostrando recursos 1 - 14 de 14

  1. A visual survey of the inshore fish communities of Gran Canaria (Canary Islands).

    Hajagos, Janos G.; Van Tassel, James L.
    An in situ visual survey technique (5 minutes and 100 m2 area) was used to assess the inshore fishes off Gran Canaria. In 1996, 211 visual surveys were conducted at 7 localities. Locations differed significantly among each other with regards to the number of species per survey (ANOVA: p < 0.01). The five most abundant species were Chromis limbatus, Boops boops, Pomadasys incisus, Abudefduf luridus, and Thalassoma pavo with respective mean abundances of 65.6, 37.4, 16.7, 8.7, and 4.5 per 100 m2. Detrended Correspondence Analysis, a multivariate ordination technique showed that the major determinant of community structure is substrate type....

  2. Potential flight range of Snow Buntings Plectrophenax nivalis occurring in the Azores in late March : a first analysis.

    Bolton, Mark; Medeiros, Renata; Fraga, Helder
    It has been known for many decades that Snow Buntings occur with some regularity in the Azores archipelago in winter, with flocks numbering up to 20 individuals on occasion. The majority of records are from the islands of Corvo and Faial. The origin and fate of these individuals is unknown and it is unclear whether the regular occurrence of such groups represents a wintering strategy, or rather, whether these birds have been blown off the course of their usual migration route. Seven individuals from a flock of ten Snow Buntings known to have been present on the island of Faial between...

  3. First record of the crabs Pirimela denticulata (Montagu, 1808) and Xaiva biguttata (Risso, 1816) (Crustacea: Decapoda) from the Azores.

    Vieira, Carla M.; Morato, Telmo
    The crabs Pirimela denticulata (Montagu, 1808) and Xaiva biguttata (Risso, 1816) identified in stomach contents of striped red mullet, Mullus surmuletus (Linnaeus, 1758) are recorded for the first time in Azorean waters, extending their known distribution range. A total of 59 individuals of P. denticulata and 12 of X. biguttata were identified in 22 and 10 mullets, respectively.

  4. On some interesting opisthobranchs (Mollusca, Gastropoda) from the Azores.

    Fontes, Jorge; Tempera, Fernando; Wirtz, Peter
    The nudibranch Eubranchus farrani Alder and Hancock, 1844 is recorded from the Azores for the first time. The presence of the sacoglossan Placida cremoniana (Trinchese, 1892) in the Azores is confirmed. Pleurobranchus sp. from the Azores, Madeira and the Canary Islands is compared with P. garciagomesi Cervera et al. 1996; it probably is an undescribed species.

  5. New records of marine invertebrates from the Cape Verde Islands.

    Wirtz, Peter
    The anthozoan Pseudocorynactis caribbeorum den Hartog, 1980, the polychaete Lygdamis wirtzi Nishi and Núñez, 1999, the cirriped Oxynaspis celata Darwin, 1852, the cephalopod Octopus macropus (Risso, 1826), and the phoronid Phoronis australis Haswell, 1883 are recorded from the Cape Verde Islands for the first time.

  6. Impact of swordfish fisheries on sea turtles in the Azores.

    Ferreira, Rogério L.; Martins, Helen R.; Silva, Alexandre A.; Bolten, Alan B.
    The surface longline fishery around the Azores targets swordfish (Xiphias gladius). Bycatch from this fishery includes loggerhead sea turtles (Caretta caretta) and occasionally leatherback sea turtles (Dermochelys coriacea) that are either hooked or entangled in the lines. Hooks are generally set at depths of 15-50 m and baited with squid, mackerel, or sometimes with shark meat. The size classes of loggerhead sea turtles caught ranged from 41.3 to 65.4 cm curved carapace length and constitutes the largest size class of loggerheads occurring in the Azores. The impact on this size class affects the survival of the southeastern United States (SEUS) population of loggerheads...

  7. Staining techniques for ageing tope shark, Galeorhinus galeus (Linnaeus, 1758), from the Azores : a comparison based on precision analysis.

    Duarte, Pedro N.; Silva, Alexandre A.; Menezes, Gui M.; Pinho, Mário Rui
    A vertebrae sample of tope shark, Galeorhinus galeus (Linnaeus, 1758), stratified by sizeclasses,was used to test between different staining techniques of enhancing vertebral growth ring visibility. Four techniques were tested: alizarin red, silver nitrate and cobalt nitrate staining, and the “deep-coned vertebrae” technique. The latter was discarded due to its unsuitability for tope shark vertebrae. The cobalt nitrate original protocol was modified. Upon staining, each vertebra was subject to three replicated independent readings, by a single reader. Within-reader consistency and bias of growth ring counts determination were evaluated using four different precision indices: percent of agreement (PA), average percent error...

  8. New records and notes on little known shrimps (Crustacea, Decapoda) from Azorean waters.

    Udekem d'Acoz, Cédric d’; Pinho, Mário Rui; Melo, Octávio; Gonçalves, João M.; Martins, Helen R.
    Five species of shrimps (Crustacea, Decapoda) are recorded for the first time from the Azores: Funchalia villosa (Bouvier, 1905), Parapasiphae sucatifrons S.I. Smith, 1884 Heterocarpus ensifer A. Milne-Edwards, 1881, Heterocarpus laevigatus Bate, 1888 and Plesionika williamsi Forest, 1964. The variability of Plesionika gigliolii (Senna, 1903) and its relationship with P. sindoi (Rathbun, 1906) are discussed.

  9. Remarks on the genera Balssia Kemp, 1922 and Acanthonyx Latreille, 1828 in the Azores, and first record of Calappa tuerkayana Pastore, 1995 (Crustacea, Decapoda) in the Atlantic Ocean.

    Udekem d'Acoz, Cédric d'
    The morphology of the Azorean populations of the caridean shrimp Balssia gasti (Balss, 1921) is here examined. This species, which was not previously recorded from the Azores, proves to have a spectacular variability in the development of dorsal carapace processes. The variability of the Azorean majid crabs of the genus Acanthonyx is also studied. Comparison with Mediterranean Acanthonyx lunulatus (Risso, 1816) show some morphological differences but also an important overlap in characters. The Azorean Acanthonyx are therefore identified as A. lunulatus. The Azorean Acanthonyx also show some similarities with the poorly known species Acanthonyx brevifrons A. Milne-Edwards, 1869 from the Cape Verde Islands, a species of uncertain validity....

  10. Fish larvae and zooplankton biomass around Faial Island (Azores archipelago). A preliminary study of species occurrence and relative abundance.

    Sobrinho-Gonçalves, Luis; Isidro, Eduardo
    Plankton hauls were conducted off Faial island (Azores archipelago, NE Atlantic), to a depth of 100 m, between February and June 1998, covering the spawning period of a number of commercially important fish species. Seventy-three fish larvae taxa were identified, of which 51 were quantified, one of them a new record for the region, Glossanodon leioglossus (Valenciennes, 1848). The fish larvae community was dominated by mesopelagic and bathypelagic elements (namely Myctophidae and Gonostomatidae), a typical oceanic island environment composition. Total zooplankton showed a biomass peak in May that could correspond to the Spring “bloom”. However, the fish larvae showed an abundance minimum in...

  11. Zooplankton biomass, abundance and diversity in a shelf area of Portugal (the Berlenga Marine Natural Reserve).

    Pardal, Miguel; Azeiteiro, Ulisses M.
    During November 1997 and May 1998, zooplankton samples were collected with other environmental data along the shelf area of Berlenga marine natural reserve (MNR) (NW Portugal). Copepods contributed > 70 % to the total zooplankton community. In November the dominant species of copepods were Paracalanus parvus, Temora stylifera and Centropages chierchiae with larvaceans and the cladocerans Penilia avirostris also abundant. The meroplankton was dominated by echinoderms. In May the dominant species of copepods were Pseudocalanus elongatus and Acartia clausi, Centropages typicus, and Calanus helgolandicus, with barnacle larvae and the pisces larvae also abundant. The islands influence was represented in the results by the increase in diversity and meroplankton’s relative...

  12. The occurrence of the Monarch butterfly, Danaus plexippus L. in the Azores, with a brief review of its biology.

    Neves, Verónica C.; Fraga, João C.; Schäfer, Hanno; Vieira, Virgílio; Bívar de Sousa, A.; Borges, Paulo A. V.
    The Monarch butterfly, Danaus plexippus L. (Lepidoptera, Nymphalidae), has been an occasional visitor to the Azores. However, during the last two decades it has become a resident species in these islands and has adapted its behaviour to the geographic conditions of this new habitat, feeding on Gomphocarpus fruticosus (L.) Aiton fil. (Asclepiadaceae). The first confirmed breeding of this butterfly in the Azores (Faial island) is reported here and dates from the summer of 1994. However, previous sightings of only a very few adult individuals indicate that there was already a small resident population before 1994. Breeding was confirmed in three additional sites: on...

  13. The genus Sapromyza (Insecta, Diptera) in Madeira.

    Báez, Marcos
    The genus Sapromyza in Madeira is revised and six new species are described: S. imitans n. sp., S. biscoitoi n. sp., S. mauli n. sp., S. laurisilvae n. sp., S. inconspicua n. sp. and S. ultima n. sp.

  14. A new subspecies of Orthotylus junipericola Linnavuori, 1965 (Insecta, Heteroptera) from the Azores.

    Ribes, Jordi; Borges, Paulo A. V.
    Orthotylus (Parapachylops) junipericola attilioi n.ssp. is described from Terceira (Azores), based on a single male specimen collected in the Azorean endemic tree Juniperus brevifolia. O. (Parapachylops) junipericola Linnavuori, 1965 is a “Rassenkreis” with seven known geographic races with an Atlanto-mediterranean distribution. O. (Parapachylops) junipericola attilioi n.ssp. is the eighth subspecies described from this species, being the most occidental taxon. The new subspecies, O. (Parapachylops) junipericola attilioi n.ssp., was sampled in a biodiversity hotspot from the Azores, Biscoito da Ferraria Natural Forest Reserve of “climax pattern of indigenous forest”.

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