Browsing by Author "Wirtz, Peter"
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- Alarm reaction and absence of alarm reaction to simulated predation on conspecifics in two temperate sea urchin speciesPublication . Wirtz, Peter; Duarte, JoanaBody fluids released by prey can signal the presence of a nearby predator. Numerous aquatic organisms show alarm responses to body fluids of conspecifics (reviewed by Chivers & Smith 1998, and by Ferrari et al. 2010). For nine sea urchin species, an alarm response to the smell of crushed conspecifics or the smell of extracts of conspecifics has been shown (Snyder & Snyder 1970, Mann et al. 1984, Parker & Shulman 1986, Campbell et al. 2001, Hagen et al. 2002, Vadas & Elner 2003). Two sea urchin species also responded to extracts from other species of the same genus (Parker & Shulman 1986). The sea urchins either moved to nearby shelter or moved away from the direction of the extract. We tested the two common, temperate eastern Atlantic sea urchins Arbacia lixula and Sphaerechinus granularis for the presence of such alarm reactions to simulated predation on conspecifics. (Introduction)
- Apletodon gabonensis, a new species of clingfish (Teleostei: Gobiesocidae) from Gabon, eastern Atlantic OceanPublication . Fricke, Ronald; Wirtz, PeterThe clingfish Apletodon gabonensis sp. nov. is described on the basis of seven specimens and colour photographs from Gabon, eastern Atlantic Ocean. The species is small, apparently not exceeding 20 mm total length; it is characterized by having 5 dorsal-fin rays, 4-5 anal-fin rays, 25-27 pectoral-fin rays, head width in males 2.6-4.7 in SL, anus in males with urogenital papilla present but not pronounced; snout long, broad, anteriorly truncate in male, narrower and rather pointed in female; preorbital length 1.8-3.8 in head length; conspicuous maxillary barbel absent in both sexes; disc with 10-12 rows of papillae in region A, 5 rows of papillae in region B, and 5-7 rows of papillae in region C. The new species is compared with the other species of the genus; a key to the males of the 6 known species of the eastern Atlantic genus Apletodon is presented.
- Atlantic reef fish biogeography and evolutionPublication . Floeter, S. R.; Rocha, L. A.; Robertson, D. R.; Joyeux, J. C.; Smith-Vaniz, W. F.; Wirtz, Peter; Edwards, A. J.; Barreiros, João P.; Ferreira, C. E. L.; Gasparini, João L.; Brito, A.; Falcón, J. M.; Bowen, B. W.; Bernardi, G.AIM: To understand why and when areas of endemism (provinces) of the tropical Atlantic Ocean were formed, how they relate to each other, and what processes have contributed to faunal enrichment. RESULTS: Phylogenetic (proportion of sister species) and distributional (number of shared species) patterns are generally concordant with recognized biogeographical provinces in the Atlantic. The highly uneven distribution of species in certain genera appears to be related to their origin, with highest species richness in areas with the greatest phylogenetic depth. Diversity buildup in Atlantic reef fishes involved (1) diversification within each province, (2) isolation as a result of biogeographical barriers, and (3) stochastic accretion by means of dispersal between provinces. The timing of divergence events is not concordant among taxonomic groups. The three soft (non-terrestrial) inter-regional barriers (mid-Atlantic, Amazon, and Benguela) clearly act as ‘filters’ by restricting dispersal but at the same time allowing occasional crossings that apparently lead to the establishment of new populations and species. Fluctuations in the effectiveness of the filters, combined with ecological differences among provinces, apparently provide a mechanism for much of the recent diversification of reef fishes in the Atlantic.
- Caprellid (Crustacea) - holothurian (Echinodermata) associations in the AzoresPublication . Wirtz, PeterDescreve-se para as águas açoreanas associações entre os caprelídeos Caprella stella e Phtisica marina (já encontrados em associação com estrelas-do-mar nos Açores) e o pepino-do-mar Holothuria tubulosa. Os caprelídeos foram encontrados em grandes grupos (mais que 20 indivíduos) na superfície do pepino-do-mar. Isto é o primeiro registo de uma associação entre caprelídeos e um pepino-do-mar.
- 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.
- Crustaceans associated with Cnidaria, Bivalvia, Echinoidea and Pisces at São Tomé and Príncipe islandsPublication . Wirtz, Peter; Udekem d'Acoz, Cédric d’Symbiotic crustaceans were searched for at sea anemones (Actiniaria), encrusting anemones (Zoantharia), horny coral (Gorgonaria), black coral (Antipatharia), bivalves (Bivalvia), and sea urchins (Echinoidea) at São Tomé and Príncipe Islands (Gulf of Guinea, eastern central Atlantic). Sixteen species of crustaceans were found in association with these invertebrate hosts; eleven of them were new records for the area and two species, belonging to the genera Hippolyte and Heteromysis, were new for science. The thalassinid Axiopsis serratifrons was occasionally associated with an undescribed species of gobiid fish.
- Eight gastropods new for the marine fauna of Madeira.Publication . Wirtz, PeterThe prosobranchs Architectonica nobilis and Smaragdia viridis and the opisthobranchs Arminia maculata, Cyerce cf. graeca, Elysia papillosa, Petalifera petalifera, Pleurobranchaea meckeli and Pleurobranchus testudinarius are recorded from Madeira Island for the first time.
- First record of the Sculptured Mitten Lobster Parribacus antarcticus (Crustacea, Decapoda, Scyllaridae) from the Cabo Verde Islands (eastern Atlantic)Publication . Freitas, Rui; Wirtz, PeterThe lobster genus Parribacuscontains six living and one fossil species (Holthuis 1991; Chan 2010; Nyborg & Garassino 2017). In the Atlantic Ocean, only one living species is known, Parribacus antarcticus(Lund, 1793); it has been recorded in the western Atlantic from Florida to Brazil and recently also from the mid-Atlantic island of Ascension (Brown et al.2016). It is nocturnal and is often found hiding in crevices during daytime (Holthuis 1991). We here note the presence of Parribacus antarcticusat the Cabo Verde Islands, the first record of the species from the eastern Atlantic.
- First record of the starfish Goniaster tesselatus at Madeira IslandPublication . Wirtz, Peter; Machado, JorgeNumerous new records of marine species have been made at Madeira Island in recent years (e. g. Ramalhosa et al. 2014, 2017, Wirtz 2020 a, Wirtz & Araujo 2021). Some of these species appear to have extended their range northwards (e. g. Wirtz & Berenger 2017, Schäfer et al. 2019, Wirtz 2021), possibly due to global warming (Siemer et al. 2021). Eleven shallow-water starfish species are known from Madeira Island (Wirtz 2020 b). We report here on one more species previous, unrecorded for Madeiran waters.
- First record of the Starry Weever Trachinus radiatus (Cuvier, 1829) from the Madeira archipelagoPublication . McIvor, Ashlie J.; Wirtz, PeterThe Starry Weever (Trachinus radiatus, Cuvier 1829) is one of nine extant species of the Trachinidae family, which typically inhabit sandy-bottomed environments. This species is widespread throughout the Mediterranean Sea and in the Eastern Atlantic from continental Portugal to Angola, including the Canary Islands (Seret & Opic 2011; Smith, 2016). It has, however, not yet been recorded from the Azores, Madeira, and the Cabo Verde Islands. Carneiro et al. (2019) mentioned a museum specimen allegedly from Madeira Island in the Paris Natural History Museum (MNHN-IC-2005-2436,1925) but this specimen is not from Madeira, it is from Casablanca fish market (Iglesias pers. comm. To the second author). We herein provide the first true record of T. radiatus from the Madeira archipelago, in the Northeast Atlantic Ocean.