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W. Gregory Hood - One of the best experts on this subject based on the ideXlab platform.

  • Landscape allometry: from tidal channel hydraulic geometry to benthic ecology
    Canadian Journal of Fisheries and Aquatic Sciences, 2002
    Co-Authors: W. Gregory Hood
    Abstract:

    The use of hydraulic geometry and other geomorphic indices has been recommended for habitat restoration and creation of estuarine tidal channels. Although such an approach provides design guidance for tidal channel form, it does not provide guidance for the ecological consequences of channel form. This study investigates the potential link - age of the scaling of tidal channel form with ecological patterns and processes in estuarine tidal channels of the lower Chehalis River, Washington, U.S.A. Ebb tide surface velocity was related to channel size, as was exit time and export probability of tiny drogues, which mimic floating allochthonous detritus. Consequently, the amount of organic material in channel sediments scaled negatively with channel size as did the abundance of benthic surface deposit feeders. These observations suggest that the highest concentrations of Fish Feeding in estuarine tidal channels may be in smaller channels or in the smaller and more distal portions of large channels. Scaling of ecological patterns and processes with tidal channel size may be an example of a more general ecological scaling with landscape form, i.e., landscape allometry.

  • Landscape allometry: from tidal channel hydraulic geometry to benthic ecology
    Canadian Journal of Fisheries and Aquatic Sciences, 2002
    Co-Authors: W. Gregory Hood
    Abstract:

    The use of hydraulic geometry and other geomorphic indices has been recommended for habitat restoration and creation of estuarine tidal channels. Although such an approach provides design guidance for tidal channel form, it does not provide guidance for the ecological consequences of channel form. This study investigates the potential link - age of the scaling of tidal channel form with ecological patterns and processes in estuarine tidal channels of the lower Chehalis River, Washington, U.S.A. Ebb tide surface velocity was related to channel size, as was exit time and export probability of tiny drogues, which mimic floating allochthonous detritus. Consequently, the amount of organic material in channel sediments scaled negatively with channel size as did the abundance of benthic surface deposit feeders. These observations suggest that the highest concentrations of Fish Feeding in estuarine tidal channels may be in smaller channels or in the smaller and more distal portions of large channels. Scaling of ecological patterns and processes with tidal channel size may be an example of a more general ecological scaling with landscape form, i.e., landscape allometry.

Enric Cortes - One of the best experts on this subject based on the ideXlab platform.

Kjell B. Døving - One of the best experts on this subject based on the ideXlab platform.

  • Taste preferences in Fishes
    Fish and Fisheries, 2003
    Co-Authors: Alexander O. Kasumyan, Kjell B. Døving
    Abstract:

    The Fish gustatory system provides the final sensory evaluation in the Feeding process. Unlike other vertebrates, the gustatory system in Fish may be divided into two distinct subsystems, oral and extraoral, both of them mediating behavioural responses to food items brought in contact with the Fish. The abundance of taste buds is another peculiarity of the Fish gustatory system. For many years, morphological and electrophysiological techniques dominated the studies of the Fish gustatory system, and systematic investigations of Fish taste preferences have only been performed during the last 10 years. In the present review, basic principles in the taste preferences of Fish are formulated. Categories or types of taste substances are defined in accordance with their effects on Fish Feeding behaviour and further mediation by the oral or extraoral taste systems (incitants, suppressants, stimulants, deterrents, enhancers and indifferent substances). Information on taste preferences to different types of substances including classical taste substances, free amino acids, betaine, nucleotides, nucleosides, amines, sugars and other hydrocarbons, organic acids, alcohols and aldehydes, and their mixtures, is summarised. The threshold concentrations for taste substances are discussed, and the relationship between Fish taste preferences with Fish systematic position and Fish ecology is evaluated. Fish taste preferences are highly species-specific, and the differences among Fish species are apparent when comparing the width and composition of spectra for both the stimulants and the deterrents. What is evident is that there is a strong similarity in the taste preferences between geographically isolated Fish populations of the same species, and that taste preferences are similar in males and females, although at the individual level, it may vary dramatically among conspecifics. What is noteworthy is that taste responses are more stable and invariable for highly palatable substances than for substances with a low level of palatability. Taste preferences as a function of pH is analysed. There is a good correspondence between development of the gustatory system in Fish ontogeny and its ability to discriminate taste properties of food items. There is also a correspondence between oral and extraoral taste preferences for a given species; however, there is no correlation between smell and taste preferences. Taste preferences in Fish show low plasticity (in relation to the diet), appear to be determined genetically and seem to be patroclinous. Fish Feeding motivation and various environmental factors like water temperature and pollutants such as heavy metals and low pH water may shift Fish taste preferences. Comparisons between bioassay and electrophysiological data show that palatability is not synonymous with excitability in the gustatory system. The chemical nature of stimulants and deterrents in various hydrobionts is outlined. The significance of basic knowledge in Fish taste preferences for aquaculture and Fisheries is emphasised.

Sergio R. Floeter - One of the best experts on this subject based on the ideXlab platform.

  • Mob rulers and part-time cleaners: two reef Fish associations at the isolated Ascension Island
    Journal of the Marine Biological Association of the United Kingdom, 2016
    Co-Authors: R. A. Morais, SCOTT BEDARD, Juan P. Quimbayo, Sergio R. Floeter, Luiz A Rocha, Carlos E. L. Ferreira, J. Brown, Ivan Sazima
    Abstract:

    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 cleanersBodianus insularisandPomacanthus paru, with lesser contributions ofChaetodon sanctaehelenae, Thalassoma ascensionisand the cleaner shrimpLysmata grabhami. Two types of Feeding mobs were consistently identified: less mobile mobs led by the surgeonFishAcanthurus bahianusandA. coeruleusand the more mobile mobs led by the African sergeantAbudefduf hoefleri. This is the first record ofA. hoeflerifrom 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 abundantMelichthys niger, but the main aggressor differed:Stegastes lubbocki, a highly territorial herbivore, was the main aggressor ofAcanthurusmobs; andChromis multilineataa territorial Fish while engaged in egg parental care, was the principal aggressor towardsAbudefdufmobs. 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.

  • Herbivory drives large‐scale spatial variation in reef Fish trophic interactions
    Ecology and Evolution, 2014
    Co-Authors: Guilherme O. Longo, Carlos E. L. Ferreira, Sergio R. Floeter
    Abstract:

    Trophic interactions play a critical role in the structure and function of ecosystems. Given the widespread loss of biodiversity due to anthropogenic activities, understanding how trophic interactions respond to natural gradients (e.g., abiotic conditions, species richness) through large-scale comparisons can provide a broader understanding of their importance in changing ecosystems and support informed conservation actions. We explored large-scale variation in reef Fish trophic interactions, encompassing tropical and subtropical reefs with different abiotic conditions and trophic structure of reef Fish community. Reef Fish Feeding pressure on the benthos was determined combining bite rates on the substrate and the individual biomass per unit of time and area, using video recordings in three sites between latitudes 17°S and 27°S on the Brazilian Coast. Total Feeding pressure decreased 10-fold and the composition of functional groups and species shifted from the northern to the southernmost sites. Both patterns were driven by the decline in the Feeding pressure of roving herbivores, particularly scrapers, while the Feeding pressure of invertebrate feeders and omnivores remained similar. The differential contribution to the Feeding pressure across trophic categories, with roving herbivores being more important in the northernmost and southeastern reefs, determined changes in the intensity and composition of Fish Feeding pressure on the benthos among sites. It also determined the distribution of trophic interactions across different trophic categories, altering the evenness of interactions. Feeding pressure was more evenly distributed at the southernmost than in the southeastern and northernmost sites, where it was dominated by few herbivores. Species and functional groups that performed higher Feeding pressure than predicted by their biomass were identified as critical for their potential to remove benthic biomass. Fishing pressure unlikely drove the large-scale pattern; however, it affected the contribution of some groups on a local scale (e.g., large-bodied parrotFish) highlighting the need to incorporate critical functions into conservation strategies.

Alexander O. Kasumyan - One of the best experts on this subject based on the ideXlab platform.

  • Taste preferences in Fishes
    Fish and Fisheries, 2003
    Co-Authors: Alexander O. Kasumyan, Kjell B. Døving
    Abstract:

    The Fish gustatory system provides the final sensory evaluation in the Feeding process. Unlike other vertebrates, the gustatory system in Fish may be divided into two distinct subsystems, oral and extraoral, both of them mediating behavioural responses to food items brought in contact with the Fish. The abundance of taste buds is another peculiarity of the Fish gustatory system. For many years, morphological and electrophysiological techniques dominated the studies of the Fish gustatory system, and systematic investigations of Fish taste preferences have only been performed during the last 10 years. In the present review, basic principles in the taste preferences of Fish are formulated. Categories or types of taste substances are defined in accordance with their effects on Fish Feeding behaviour and further mediation by the oral or extraoral taste systems (incitants, suppressants, stimulants, deterrents, enhancers and indifferent substances). Information on taste preferences to different types of substances including classical taste substances, free amino acids, betaine, nucleotides, nucleosides, amines, sugars and other hydrocarbons, organic acids, alcohols and aldehydes, and their mixtures, is summarised. The threshold concentrations for taste substances are discussed, and the relationship between Fish taste preferences with Fish systematic position and Fish ecology is evaluated. Fish taste preferences are highly species-specific, and the differences among Fish species are apparent when comparing the width and composition of spectra for both the stimulants and the deterrents. What is evident is that there is a strong similarity in the taste preferences between geographically isolated Fish populations of the same species, and that taste preferences are similar in males and females, although at the individual level, it may vary dramatically among conspecifics. What is noteworthy is that taste responses are more stable and invariable for highly palatable substances than for substances with a low level of palatability. Taste preferences as a function of pH is analysed. There is a good correspondence between development of the gustatory system in Fish ontogeny and its ability to discriminate taste properties of food items. There is also a correspondence between oral and extraoral taste preferences for a given species; however, there is no correlation between smell and taste preferences. Taste preferences in Fish show low plasticity (in relation to the diet), appear to be determined genetically and seem to be patroclinous. Fish Feeding motivation and various environmental factors like water temperature and pollutants such as heavy metals and low pH water may shift Fish taste preferences. Comparisons between bioassay and electrophysiological data show that palatability is not synonymous with excitability in the gustatory system. The chemical nature of stimulants and deterrents in various hydrobionts is outlined. The significance of basic knowledge in Fish taste preferences for aquaculture and Fisheries is emphasised.