ARQ - Life and Marine Sciences
Permanent URI for this community
Browse
Browsing ARQ - Life and Marine Sciences by Author "Afonso, Pedro"
Now showing 1 - 4 of 4
Results Per Page
Sort Options
- Acoustic tag retention of the Mediterranean slipper lobster Scyllarides latus (Latreille, 1802) in the AzoresPublication . Schmiing, Mara; Afonso, PedroMoulting, growth and retention of externally attached acoustic tags were studied in ten Mediterranean slipper lobsters, Scyllarides latus (Latreille, 1802). Animals were kept in a cage at 20 m depth in Faial Island, Azores, over a period of nine months. No negative effects of tag attachment on moult or behaviour were detected, but a negative effect on growth cannot be excluded. Moulting was correlated with ambient water temperature and resulted in an increase of approximately 7% in mean size and 17% in mean weight. The results demonstrate that the use of externally attached acoustic transmitters in this species is adequate for medium-term movement studies but not for longer-term annual studies, due to the rate of molting.
- Coastal marine fishes of São Tomé Island (Gulf of Guinea).Publication . Afonso, Pedro; Porteiro, Filipe M.; Santos, Ricardo S.; Barreiros, João P.; Worms, Jean; Wirtz, PeterSince the early works of Balthazar Osório, at the turn of the century, only few papers have been published on the ichthyofauna of São Tomé island. The papers dealing with these fishes were compilations of previous works or the results of a few scientific expeditions (e.g. "Galathea" and "Calypso"). In this paper, we present the results of several surveys carried out from the island over the last decade, together with an annotated revision of the known bibliography for the area. The result is an inventory of the coastal fish of São Tomé island. Our records (124 species belonging to 59 families) are based on fish captured, photographed or observed whilst diving and also on those landed by local artisanal fishermen. In this paper we report a total of 185 confirmed coastal species and 67 families. Twenty-seven of these are reported for the first time for the area, and three other unidentified species may represent new species to science. The best represented families are Carangidae (14 species), Serranidae (11 species), Gobiidae and Scombridae (8 species each). Despite its proximity to the African Continent, it is clear that these islands harbour a particular fish fauna, including several amphiatlantic species, which, in the eastern Atlantic, occur only around oceanic islands (e.g., Epinephelus ascencionis, Paranthias furcifer, Mulloidychtis martinicus, Bodianus pulchellus, Chromis multilineata, Gnatholepis thomsoni, Melychthis niger). The coastal ichthyodiversity of São Tomé is apparently poorer than that of the adjacent coasts, showing a significant influence of the islands further west, St. Helena and Ascencion.
- The singlespot frogfish Antennarius radiosus (Lophiiformes, Antennariidae), a valid member of the ichthyofauna of the AzoresPublication . Porteiro, Filipe M.; Afonso, PedroThe big-eyed frogfish Antennarius radiosus Garman, 1896 is confirmed as a valid record for the Azores. A revision of the historical records confirms three valid species of frogfishes from the Azores (A. radiosus, A. nummifer, Histrio histrio). Two species (A. senegalensis, A. pardalis or A. multiocellatus) require confirmation.
- Summer aggregations of the common eagle ray, Myliobatis aquilaPublication . Afonso, Pedro; Rodrigues, Nuno V.The aggregation of multiple individuals is a long known behaviour in a variety of elasmobranchs, including reef sharks (Speed et al. 2011), hammerhead sharks (Klimley & Nelson 1984), whale sharks (Hoffmayer et al. 2007), devilrays (Ward-Page et al. 2013; Sobral & Afonso 2014), stingrays (Semeniuk & Rotley 2008), eagle rays (Silliman & Gruber 1999) and cownose rays (Smith et al. 1987). Various functions have been hypothesised to explain these aggregations, including feeding (e.g. Wilson et al. 2001; Rohner et al. 2013), courtship or mating (Whitney et al. 2004; Dudgeon et al. 2008), and cleaning stations (Dewar et al. 2008). However, apart from the obvious cases whenever individuals directly engage in reproductive activities, the social functions that these aggregations might serve are not understood or even described. […].