Mob Rulers And Part-time Cleaners: Two Reef Fish Associations At The Isolated Ascension Island

Isolated oceanic islands may give rise not only to new and endemic species, but also to unique behaviours and species interactions. Multi-species fish interactions, such as cleaning, following, mob-feeding and others are understudied in these ecosystems. Here we present qualitative and quantitative observations on cleaning and mob-feeding reef fish associations at the isolated Ascension Island, South Atlantic Ocean. Cleaning interactions were dominated by juveniles of the facultative fish cleaners Bodianus insularis and Pomacanthus paru, with lesser contributions of Chaetodon sanctaehelenae, Thalassoma ascensionis and the cleaner shrimp Lysmata grabhami. Two types of feeding mobs were consistently identified: less mobile mobs led by the surgeonfish Acanthurus bahianus and A. coeruleus and the more mobile mobs led by the African sergeant Abudefduf hoefleri. This is the first record of A. hoefleri from outside of the Eastern Atlantic and also the first report of this species displaying mob-feeding behaviour. The principal follower of both mob types was the extremely abundant Melichthys niger, but the main aggressor differed: Stegastes lubbocki, a highly territorial herbivore, was the main aggressor of Acanthurus mobs; and Chromis multilineata a territorial fish while engaged in egg parental care, was the principal aggressor towards Abudefduf mobs. Our study enhances the scarce information on reef fish feeding associations at the isolated Ascension Island and at oceanic islands in the Atlantic in general. Copyright © Marine Biological Association of the United Kingdom 201611

Restructuring of the "Macaronesia" biogeografic unit: a marine multi-taxon biogeographical approach

The Azores, Madeira, Selvagens, Canary Islands and Cabo Verde are commonly united under the term “Macaronesia”. This study investigates the coherency and validity of Macaronesia as a biogeographic unit using six marine groups with very different dispersal abilities: coastal fishes, echinoderms, gastropod molluscs, brachyuran decapod crustaceans, polychaete annelids, and macroalgae. We found no support for the current concept of Macaronesia as a coherent marine biogeographic unit. All marine groups studied suggest the exclusion of Cabo Verde from the remaining Macaronesian archipelagos and thus, Cabo Verde should be given the status of a biogeographic subprovince within the West African Transition province. We propose to redefine the Lusitanian biogeographical province, in which we include four ecoregions: the South European Atlantic Shelf, the Saharan Upwelling, the Azores, and a new ecoregion herein named Webbnesia, which comprises the archipelagos of Madeira, Selvagens and the Canary Islandsinfo:eu-repo/semantics/publishedVersio

Predictive Factors Of Species Composition Of Follower Fishes In Nuclear-follower Feeding Associations: A Snapshot Study

We tested whether habitat, identity, size of nuclear fishes, and intensity of bottom disturbance caused by their foraging can predict the composition of fish followers in nuclear-follower feeding associations. The study was carried out in a stream of the Serra da Bodoquena, Mato Grosso do Sul State, Southwestern Brazil. We performed underwater observational sessions (total 12 h) of such interspecific interactions to obtain data about the identity and abundance of the followers in the association, as well as the identity and size of the nuclear fish. We also evaluated whether different intensities of bottom disturbance due to the nuclear fish foraging and type of habitat may influence interactions. We recorded 38 episodes involving nuclear and follower species. Using a multivariate analysis with distance matrices, we noted that the intensity of bottom disturbance caused by nuclear fishes was the main predictor of the composition of the follower species (r = 0.55, p < 0.01), as well as the identity of the nuclear species, although this latter relation was weak (r = 0.09, p = 0.05). Such results indicate that followers react readily to sediment suspension, which reflects the trophic plasticity and opportunistic foraging characteristic of most tropical freshwater fishes.124913920Abelha, C.F., Agostinho, A.A., Goulart, E., Plasticidade tröfica em peixes de âgua doce (2001) Acta Scientiarum, 23, pp. 425-434Angermeier, P.L., Karr, J.R., Fish communities along environmental gradients in a system of tropical streams (1983) Environmental Biology of Fishes, 9, pp. 117-135Baker, J.A., Foster, S.A., Observations on a foraging association between two freshwater stream fishes (1994) Ecology of Freshwater Fish, 3, pp. 137-139Carvalho, L.N., Zuanon, J., Sazima, I., Natural history of Amazon fishes (2009) Tropical Biology and Conservation Management: Case studies, pp. 113-144. , Del-Claro, K., P. S. Oliveira & V. Rico-Gray (Orgs.), Eolss Publishers Co. Ltd., OxfordCasatti, L., Langeani, F., Silva, A.M., Castro, R.M.C., Stream fish, water and habitat quality in a pasture dominated basin, southeastern Brazil (2006) Brazilian Journal of Biology, 66, pp. 681-696Casatti, L., Romero, R.M., Teresa, F.B., Sabino, J., Langeani, F., Fish community structure along a conservation gradient in Bodoquena Plateau streams, central West of Brazil (2010) Acta Limnologica Brasiliensia, 22, pp. 50-59Costa-Pereira, R., Small fishes follow large mammals suspending sediment (2012) Revista Chilena de Historia Natural, 85, pp. 361-364Frissell, C.A., Iliss, L.J., Warren, C.E., Hurley, M.D., A hierarchical framework for stream habitat classification-viewing streams in a watershed context (1986) Environmental Management, 10, pp. 99-214Fugi, R., Hahn, N.S., Agostinho, A.A., Feeding styles of five species of bottom-feeding fishes of the High Paranâ River (1996) Environmental Biology of Fishes, 46, pp. 297-307Garrone-Neto, D., Sazima, I., The more stirring the better: Cichlid fishes associate with foraging potamotrygonid rays (2009) Neotropical Ichthyology, 7, pp. 499-501Gerking, D.S., (1994) Feeding ecology of fish, , Academic Press, San DiegoGorman, O.T., Karr, J.R., Habitat structure and stream fish communities (1978) Ecology, 59, pp. 507-515Goulding, M., (1980) The fishes and the forest: Explorations in amazon natural history, , University of California Press, BerkeleyKrajewski, J.P., How do follower reef fishes find nuclear fishes? (2009) Environmental Biology of Fishes, 86, pp. 379-387Leitâo, R.P., Caramaschi, E.P., Zuanon, J., Following food clouds: Feeding association between a minute loricariid and a characidiin species in an Atlantic Forest stream, Southeastern Brazil (2007) Neotropical Ichthyology, 5, pp. 307-310Lichstein, J.W., Multiple regression on distance matrices: A multivariate spatial analysis tool (2007) Plant Ecology, 188, pp. 117-131Lowe-McConnell, R.H., (1995) Ecological studies in tropical fish communities, , Cambridge University Press, CambridgeLukoschek, V., McCormick, M.I., A review of multispecies foraging associations in fishes and their ecological significance (2002) Proceedings of the 9th International Coral Reef Symposium, pp. 467-474. , Okinawa, JulyMatsumoto, K., Kohda, M., Differences in feeding associations of benthophagous fishes in two locations (2001) Environmental Biology of Fishes, 61, pp. 111-115Montgomery, W., Interspecific associations of Sea-Basses (Serranidae) in the Gulf of California (1975) Copeia, 1975, pp. 785-787Ott, G.H.F., Fressgemeinschaften zwischen Schmerlen, Grundeln und Karpfenfischen (Cyprinidae) in SilBgewassern Taiwans (2007) Bulletin of Fish Biology, 9, pp. 89-92Rocha, F.C., Casatti, L., Carvalho, F.R., Silva, A.M.S., Fish assemblages in stream stretches occupied by cattail (Typhaceae, Angiospermae) stands in Southeast Brazil (2009) Neotropical Ichthyology, 7, pp. 241-250Sazima, C., Krajewski, J.P., Bonaldo, R.M., Guimarâes, P.R., The goatfish Pseudupeneus maculatus and its follower fishes at an oceanic island in the tropical west Atlantic (2006) Journal of Fish Biology, 69, pp. 883-891Sazima, C., Krajewski, J.P., Bonaldo, R.M., Sazima, I., Nuclear-follower foraging associations of reef fishes and other animals at an oceanic archipelago (2007) Environmental Biology of Fishes, 78, pp. 1-11Strand, S., Following behavior: Interspecific foraging associations among Gulf of California reef fishes (1988) Copeia, 1988, pp. 351-357Teresa, F.B., Carvalho, F.R., Feeding association between benthic and nektonic Neotropical stream fishes (2008) Neotropical Ichthyology, 6, pp. 109-111Teresa, F.B., Romero, R.M., Influence of the riparian zone phytophysiognomies on the longitudinal distribution of fishes: Evidence from a Brazilian savanna stream (2010) Neotropical Ichthyology, 8, pp. 163-170Teresa, F.B., Romero, R.M., Casatti, L., Sabino, J., Habitat simplification affects nuclear-follower foraging association among stream fishes (2011) Neotropical Ichthyology, 9, pp. 121-126Valerio, S.B., Suarez, Y.R., Felipe, T.R.A., Tondato, K.K., Ximenes, L.Q.L., Organization patterns of headwater-stream fish communities in the Upper Paraguay-Paranâ basins (2007) Hydrobiologia, 583, pp. 241-25

Patterns Of Shell Utilization And Selection In Two Sympatric Hermit Crabs (anomura: Diogenidae) In South-eastern Brazil

The present study evaluated shell utilization and preference of two sympatric hermit crab species, Calcinus tibicen and Clibanarius antillensis, from Ilha Galheta de Dentro, Vitória Bay, south-eastern Brazil. Distribution of individuals and use and availability of shells were estimated in the field, where microhabitat and shell partitioning were demonstrated between the two species of crabs. Calcinus occurred in higher numbers in the infralittoral fringe and shallow subtidal, while Clibanarius was found mainly in the midlittoral zone. The crabs used shells of different architectures and sizes. Calcinus used mainly globose and low spired shells (Tegula viridula and Cymatium parthenopeum), while Clibanarius utilized predominantly the elongated and high spired ones (mainly Cerithium atratum). Clibanarius used shells with smaller volume, weight, and aperture. Free access experiments were conducted in the laboratory and showed that Calcinus and Clibanarius had a high satisfaction rate, i.e. only 50% of the crabs exchanged their shells. From those that exchanged, they chose shells with higher internal volume than that used in the field, while shell weight did not present any increase. Clibanarius was found in shells closer to the preferred ones and in a very different proportion from shell availability, contrasting to Calcinus, which followed shell availability instead of their preferences. Shell internal volume was more important as a choice factor than the weight for both hermit crab species, showing that crabs optimized shell volume in relation to shell weight in the free access experiments.80610531059Bach, C.B., Hazlett, B., Rittschof, D., Effects of interspecific competition on fitness of the hermit crab Clibanarius tricolor (1976) Ecology, 57, pp. 579-586Bertness, M.D., Shell preference and utilization patterns in littoral hermit crabs of the Bay of Panama (1980) Journal of Experimental Marine Biology and Ecology, 48, pp. 1-16Bertness, M.D., Pattern and plasticity in tropical hermit crab growth and reproduction (1981) American Naturalist, 117, pp. 754-773Bertness, M.D., Conflicting advantages in resource utilization: The hermit crab housing dilemma (1981) American Naturalist, 118, pp. 432-437Bertness, M.D., Shell utilization, predation pressure, and thermal stress in Panamanian hermit crabs: An interoceanic comparison (1982) Journal of Experimental Marine Biology and Ecology, 64, pp. 159-187Busato, P., Benvenuto, C., Gherardi, F., Competitive dynamics of a Mediterranean hermit crab assemblage: The role of interference and exploitative competition for shells (1998) Journal of Natural History, 32, pp. 1447-1451Conover, M.R., The importance of various shell characteristics to the shell-selection behaviour of hermit crabs (1978) Journal of Experimental Marine Biology and Ecology, 32, pp. 131-142Elwood, R.W., Neil, S.J., (1992) Assessments and decisions: A study of information gathering by hermit crabs, , London: Chapman & HallFloeter, S.R., Nalesso, R.C., Padrões de utilização de conchas e distribuição espacial em duas espécies simpatricas de caranguejos-ermitões (Crustacea, Anomura) na Ilha Galheta de Dentro-Baía de Vitória, ES (1998) Anais do IV Simpósio de Ecossistemas Brasileiros, ACIESP Publicações, 104, pp. 349-355Fotheringham, N., Population consequences of shell utilization by hermit crabs (1976) Ecology, 57, pp. 570-578Gherardi, F., Competition and coexistence in two Mediterranean hermit crabs, Calcinus ornatus (Roux) and Clibanarius erythropus (Latreille) (Decapoda, Anomura) (1990) Journal of Experimental Marine Biology and Ecology, 143, pp. 221-238Gherardi, F., Nardone, F., The question of coexistence in hermit crabs: Population ecology of a tropical intertidal assemblage (1997) Crustaceana, 70, pp. 608-629Gleibs, S., Mebs, D., Sequestration of a marine toxin (1998) Coral Reefs, 17, p. 338Hazlett, B.A., Social behavior of the Paguridae and Diogenidae of Curaçao (1966) Studies on Fauna of Curaçao, 88, pp. 1-143Hazlett, B.A., The behaviour ecology of hermit crabs (1981) Annual Review of Ecology and Systematics, 12, pp. 1-22Kellogg, C.W., Gastropod shells: A potentially limiting resource for hermit crabs (1976) Journal of Experimental Marine Biology and Ecology, 22, pp. 101-111Kellogg, C.W., Coexistence in a hermit crab ensemble (1977) Biological Bulletin. Marine Biological Laboratory, Woods Hole, 153, pp. 133-144Krebs, C.J., (1989) Ecological methodology, , New York: Harper Collins PublishersLeite, F.P.P., Turra, A., Gandolfi, S.M., Hermit crabs (Crustacea: Decapoda: Anomura), gastropod shells and environmental structure: Their relationship in south-eastern Brazil (1998) Journal of Natural History, 32, pp. 1599-1608Lively, C.M., A graphical model for shell-species selection by hermit crabs (1988) Ecology, 69, pp. 1233-1238Osorno, J.L., Fernandez-Casillas, L., Rodriguez-Juarez, C., Are hermit crabs looking for light and large shells? Evidence from natural and field induced shell exchanges (1998) Journal of Experimental Marine Biology and Ecology, 222, pp. 163-173Reese, E.S., Shell selection behaviour of hermit crabs (1962) Animal Behaviour, 10, pp. 347-360Scully, E.P., The effect of gastropod shell availability and habitat characteristics on shell utilization by the intertidal hermit crab Pagurus longicarpus Say (1979) Journal of Experimental Marine Biology and Ecology, 37, pp. 139-152Scully, E.P., The effects of shell availability on intraspecific competition in experimental populations of the hermit crab, Pagurus longicarpus Say (1983) Journal of Experimental Marine Biology and Ecology, 71, pp. 221-236Spight, T.M., Availability and use of shells by intertidal hermit crabs (1977) Biological Bulletin. Marine Biological Laboratory, Woods Hole, 152, pp. 120-133Turra, A., Leite, F.P.P., Clustering behaviour of hermit crabs (Decapoda, Anomura) in an intertidal rocky shore at São Sebastião, southeastern Brazil (2000) Revista Brasileira de Biologia, 60, pp. 1-6Turra, A., Leite, F.P.P., Shell utilization patterns of tropical intertidal hermit crabs. I. The case of Grande Beach Journal of Crustacean BiologyVance, R.R., Competition and mechanism of coexistence in three sympatric species of intertidal hermit crabs (1972) Ecology, 53, pp. 1062-1074Vance, R.R., The role of shell adequacy in behavioral interactions involving hermit crabs (1972) Ecology, 53, pp. 1076-1083Wilber, T.P., Herrnkind, W., Rate of new shell acquisition by hermit crabs in a salt marsh habitat (1982) Journal of Crustacean Biology, 2, pp. 588-592Zar, J.H., (1999) Biostatistical analysis, 4th ed., , New Jersey: Prentice-Hal