Ecological Impact of the Invasive European Flounder (Platichthys Flesus) on the Native European Plaice (Pleuronectes Platessa) on Nursery Grounds in Iceland

Total Page:16

File Type:pdf, Size:1020Kb

Ecological Impact of the Invasive European Flounder (Platichthys Flesus) on the Native European Plaice (Pleuronectes Platessa) on Nursery Grounds in Iceland Master’s thesis Ecological impact of the invasive European flounder (Platichthys flesus) on the native European plaice (Pleuronectes platessa) on nursery grounds in Iceland Theresa Henke Advisor: Guðbjörg Ásta Ólafsdóttir, Ph.D. University of Akureyri Faculty of Business and Science University Centre of the Westfjords Master of Resource Management: Coastal and Marine Management Ísafjörður, May 2018 Supervisory Committee Advisor: Guðbjörg Ásta Ólafsdóttir, Ph.D. Reader: Camille Leblanc, Ph.D. Program Director: Catherine Chambers, Ph.D. Theresa Henke Ecological impact of the invasive European flounder (Platichthys flesus) on the native European plaice (Pleuronectes platessa) on nursery grounds in Iceland 45 ECTS thesis submitted in partial fulfilment of a Master of Resource Management degree in Coastal and Marine Management at the University Centre of the Westfjords, Suðurgata 12, 400 Ísafjörður, Iceland Degree accredited by the University of Akureyri, Faculty of Business and Science, Borgir, 600 Akureyri, Iceland Copyright © 2018 Theresa Henke All rights reserved Printing: Háskólaprent, Reykjavík, May 2018 ii Declaration I hereby confirm that I am the sole author of this thesis and it is a product of my own academic research. __________________________________________ Theresa Henke iii iv Abstract In recent years the number of invasive species that have been introduced to new environments has strongly increased, and their further distribution may be favored by both anthropogenic influence and climate change. In 1999, the European flounder (Platichthys flesus), a flatfish species native to central European coasts, was first identified in the southwest of Iceland at the mouth of the Ölfusa river and has since then spread around the whole country. This project investigated the ecological impact of juvenile flounder on juveniles of the native European plaice (Pleuronectes platessa) on nursery grounds. The work focused on two sampling sites representing early and more recent flounder establisment; the fjords Borgarfjörður and Önundarfjörður, respectively. Fish were caught with a beach seine between July and September 2017. Species composition and juvenile size were measured, and stomach content analysis was used to determine niche widhts of each species and overlap in feeding patterns between species. Flounder was present in all collected samples, but both species composition and length distribution of flounder and plaice varied between sites and sampling time. Significant diet overlap between species was observed for some samples, particularly between 1+ flounder and 0+ plaice, which indicates potential for competition between species. Together with observed direct predation of 1+ flounder on 0+ plaice, the presence of the invasive species is likely to have a negative impact on the native plaice population. Differences between the sites of early and more recent invasion could not clearly be linked to the time since invasion. This project highlights that the management of invasive species needs to be improved, especially in locating and restricting pathways of introduction as well as in early detection and rapid response strategies. Útdráttur Á síðustu árum hefur flutningu tegunda út fyrir náttúleg heimkynni aukist mjög. Margvíslegt rask á búsvæðum svo og loftslagsbreytingar auka líkur á útbreiðslu þessarra framandi tegunda í nýjum heimkynnum. Árið 1999, fannst flundra (Platichthys flesus), flatfiskur með náttúrulega dreifingu við strendur mið Evrópu, við Ölfusárósa. Flundran hefur síðan dreifst víða um land. Í þessu verkefni eru rannsökuð möguleg áhrif flundruseiða á seiði skarkola (Pleuronectes platessa) á uppeldisstöðvum. Sýnataka fór að mestu fram á tveimur svæðum sem endurspegla eldra og nýlegra landnám flundrunar; í Borgarfirði og í Önundarfirði. Seiði voru veidd með landnót frá júlí og fram í september 2017. Tegundasamsetning á hverjum stað var metin, lengd seiðanna mæld og þau vigtuð og magainnihald greint til að ákvarða vistbreidd tegundanna og skörun í fæðuvist. Flundra veiddist við alla sýnatöku en bæði tegundasamsetning og stærð seiða beggja tegunda var breytileg eftir svæðum og tíma. Marktæk skörun í fæðuvist var á milli flundru og skarkola seiða, mest áberandi á milli 1+ flundru og 0+ skarkola. Þá kom í ljós að 1+ flundruseiði eru afræningjar á 0+ skarkolaseiði. Það er því talið líklegt að tilkoma flundru hafi neikvæð vistfræðileg áhrif á skarkola á uppeldisstöðvum. Það komu hinsvegar ekki fram sterkar vísbendingar um mun á milli svæða eftir tíma frá landnámi flundrunnar. Niðurstöður þessa verkefnis sýna að það er mikilvægt að og hefja virka stýringu ágengra tegunda við Ísland m.a. með því að greina helstu flutningsleiðir, bæta snemmtæka greiningu framandi tegunda og þróa viðbragðsáætlun. v vi Table of Contents Abstract .............................................................................................................................. v Table of contents ................................................................................................................ vii List of figures ..................................................................................................................... x List of tables ....................................................................................................................... xi Acknowledgments .............................................................................................................. xii 1. Introduction ................................................................................................................... 1 1.1 Goal of this study ........................................................................................... 3 2. Theoretical background ............................................................................................... 5 2.1 Invasive species ............................................................................................. 5 2.1.1 Definition and trends around the world ........................................ 5 2.1.2 The pathways of introduction of invasive species ......................... 6 2.1.3 The influence of Climate Change on invasive species .................. 7 2.1.4 Impacts of invasive species.............................................................. 8 2.1.5 Invasive species in Iceland .............................................................. 12 2.1.6 Management of invasive species ..................................................... 13 2.2 Pleuronectiformes ......................................................................................... 15 2.3 European flounder (Platichthys flesus) ....................................................... 16 2.3.1 Distribution of flounder .................................................................. 16 2.3.2 Life-history traits of flounder ......................................................... 16 2.3.3 Invasion of flounder in Iceland ...................................................... 19 2.3.4 Economic value of flounder ............................................................ 20 2.4 European plaice (Pleuronectes platessa) ..................................................... 21 2.4.1 Distribution of plaice ....................................................................... 21 2.4.2 Life-history traits of plaice.............................................................. 21 vii 2.4.3 Economic value of plaice ................................................................. 24 3. Methods .......................................................................................................................... 25 3.1 The study system .......................................................................................... 25 3.2 Study sites...................................................................................................... 26 3.3 Sampling ........................................................................................................ 28 3.4 Laboratory analysis ...................................................................................... 28 3.5 Stomach content analysis ............................................................................. 29 3.6 Age determination ........................................................................................ 29 3.7 Statistical analysis ........................................................................................ 30 3.7.1 Shannon-Wiener Index to determine niche width ...................... 30 3.7.2 Simplified Morisits Index to determine niche overlap ................ 30 3.7.3 Principal Component Analysis (PCA) .......................................... 31 3.7.4 Generalized Linear Mixed Model (GLMM) ................................ 31 4. Results ............................................................................................................................ 33 4.1 Species identification ................................................................................... 33 4.2 Length distribution ...................................................................................... 34 4.3 Determination of age classes for both species ............................................ 35 4.4 Sympatric occurrence of plaice and flounder ............................................ 36 4.5 Stomach content analysis ............................................................................. 38 4.5.1 Diet items ....................................................................................... 38 4.5.2 Principal
Recommended publications
  • Beaver Street Fisheries, Inc
    Why Participate? How ODP Works What's Included? About Us News Beaver Street Fisheries, Inc. Beaver Street Fisheries is a leading importer, manufacturer and distributor of quality frozen seafood products from the USA and around the world. With headquarters in Jacksonville, Florida, a vertically integrated supply chain, and the advantage of both on-site and off-shore processing capabilities, Beaver Street Fisheries offers a wide variety of products, competitive pricing, and can satisfy the diverse needs of wholesale, retail, institutional and foodservice operators. The success and reputation that Beaver Street Fisheries enjoys is attributed to its dedication to undeniable quality, efficient, and attentive service and the disciplined exercise of a single principle, "Treat the customer as you would a friend and all else will follow.” 2019 Number of Wild Caught Number of Certified Number of Fisheries in a Number of Farmed Species Used Fisheries FIP Species Used 21 16 11 3 Production Methods Used · Bottom trawl · Purse seine · Longlines · Rake / hand gathered / · Dredge · Handlines and pole-lines hand netted · Pots and traps · Farmed Summary For over seventy year, Beaver Street Fisheries has always been a leader in the seafood industry, and we understand that we have a global responsibility to support and sustain the earth and its ecosystems. As part of our commitment to sustainability and responsible sourcing, we work closely with our supply chain partners to embrace strategies to support the ever-growing need for responsible seafood from around the world. We do this by working with standard-setting organizations for wild caught and aquaculture seafood. Additionally, we have partnered with Sustainable Fisheries Partnership (SFP) to help us develop and implement fishery improvement projects for both wild and farmed raised species.
    [Show full text]
  • The Landing Obligation and Its Implications on the Control of Fisheries
    DIRECTORATE-GENERAL FOR INTERNAL POLICIES POLICY DEPARTMENT B: STRUCTURAL AND COHESION POLICIES FISHERIES THE LANDING OBLIGATION AND ITS IMPLICATIONS ON THE CONTROL OF FISHERIES STUDY This document was requested by the European Parliament's Committee on Fisheries. AUTHORS Ocean Governance Consulting: Christopher Hedley Centre for Environment, Fisheries and Aquaculture Science: Tom Catchpole, Ana Ribeiro Santos RESPONSIBLE ADMINISTRATOR Marcus Breuer Policy Department B: Structural and Cohesion Policies European Parliament B-1047 Brussels E-mail: [email protected] EDITORIAL ASSISTANCE Adrienn Borka Lyna Pärt LINGUISTIC VERSIONS Original: EN ABOUT THE PUBLISHER To contact the Policy Department or to subscribe to its monthly newsletter please write to: [email protected] Manuscript completed in September 2015. © European Union, 2015. Print ISBN 978-92-823-7938-7 doi:10.2861/694624 QA-02-15-709-EN-C PDF ISBN 978-92-823-7939-4 doi:10.2861/303902 QA-02-15-709-EN-N This document is available on the Internet at: http://www.europarl.europa.eu/studies DISCLAIMER The opinions expressed in this document are the sole responsibility of the author and do not necessarily represent the official position of the European Parliament. Reproduction and translation for non-commercial purposes are authorized, provided the source is acknowledged and the publisher is given prior notice and sent a copy. DIRECTORATE-GENERAL FOR INTERNAL POLICIES POLICY DEPARTMENT B: STRUCTURAL AND COHESION POLICIES FISHERIES THE LANDING OBLIGATION AND ITS IMPLICATIONS ON THE CONTROL OF FISHERIES STUDY Abstract This study reviews the impacts of the new Common Fisheries Policy (CFP) rules requiring catches in regulated fisheries to be landed and counted against quotas of each Member State ("the landing obligation and requiring that catch of species subject to the landing obligation below a minimum conservation reference size be restricted to purposes other than direct human consumption.
    [Show full text]
  • Fishery Management Plan for Groundfish of the Bering Sea and Aleutian Islands Management Area APPENDICES
    FMP for Groundfish of the BSAI Management Area Fishery Management Plan for Groundfish of the Bering Sea and Aleutian Islands Management Area APPENDICES Appendix A History of the Fishery Management Plan ...................................................................... A-1 A.1 Amendments to the FMP ......................................................................................................... A-1 Appendix B Geographical Coordinates of Areas Described in the Fishery Management Plan ..... B-1 B.1 Management Area, Subareas, and Districts ............................................................................. B-1 B.2 Closed Areas ............................................................................................................................ B-2 B.3 PSC Limitation Zones ........................................................................................................... B-18 Appendix C Summary of the American Fisheries Act and Subtitle II ............................................. C-1 C.1 Summary of the American Fisheries Act (AFA) Management Measures ............................... C-1 C.2 Summary of Amendments to AFA in the Coast Guard Authorization Act of 2010 ................ C-2 C.3 American Fisheries Act: Subtitle II Bering Sea Pollock Fishery ............................................ C-4 Appendix D Life History Features and Habitat Requirements of Fishery Management Plan SpeciesD-1 D.1 Walleye pollock (Theragra calcogramma) ............................................................................
    [Show full text]
  • The State of Mediterranean and Black Sea Fisheries 2018
    Food and Agriculture General Fisheries Commission for the Mediterranean Organization of the Commission générale des pêches United Nations pour la Méditerranée ISSN 2413-6905 THE STATE OF MEDITERRANEAN AND BLACK SEA FISHERIES 2018 Reference: FAO. 2018. The State of Mediterranean and Black Sea Fisheries General Fisheries Commission for the Mediterranean. Rome, Italy. pp. 164. THE STATE OF MEDITERRANEAN AND BLACK SEA FISHERIES 2018 FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Rome, 2018 Required citation: FAO. 2018. The State of Mediterranean and Black Sea Fisheries. General Fisheries Commission for the Mediterranean. Rome. 172 pp. The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations (FAO) concerning the legal or development status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. The mention of specifc companies or products of manufacturers, whether or not these have been patented, does not imply that these have been endorsed or recommended by FAO in preference to others of a similar nature that are not mentioned. The views expressed in this information product are those of the author(s) and do not necessarily refect the views or policies of FAO. ISBN 978-92-5-131152-3 © FAO, 2018 Some rights reserved. This work is made available under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 IGO licence (CC BY-NC-SA 3.0 IGO; https://creativecommons.org/licenses/by-nc-sa/3.0/igo/legalcode/legalcode).
    [Show full text]
  • Identification of Larvae of Three Arctic Species of Limanda (Family Pleuronectidae)
    Identification of larvae of three arctic species of Limanda (Family Pleuronectidae) Morgan S. Busby, Deborah M. Blood & Ann C. Matarese Polar Biology ISSN 0722-4060 Polar Biol DOI 10.1007/s00300-017-2153-9 1 23 Your article is protected by copyright and all rights are held exclusively by 2017. This e- offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com”. 1 23 Author's personal copy Polar Biol DOI 10.1007/s00300-017-2153-9 ORIGINAL PAPER Identification of larvae of three arctic species of Limanda (Family Pleuronectidae) 1 1 1 Morgan S. Busby • Deborah M. Blood • Ann C. Matarese Received: 28 September 2016 / Revised: 26 June 2017 / Accepted: 27 June 2017 Ó Springer-Verlag GmbH Germany 2017 Abstract Identification of fish larvae in Arctic marine for L. proboscidea in comparison to the other two species waters is problematic as descriptions of early-life-history provide additional evidence suggesting the genus Limanda stages exist for few species. Our goal in this study is to may be paraphyletic, as has been proposed in other studies.
    [Show full text]
  • Case Study Price Structure in the Supply Chain for Plaice in the Netherlands
    Case study Price structure in the supply chain for plaice in the Netherlands Last update: May 2016 Maritime Affairs and Fisheries Contents SUMMARY ...................................................................................................................................... 1 0 TASK REMINDER – SCOPE AND CONTENT .................................................................................. 2 0.1 CASE STUDY SCOPE ............................................................................................................................. 2 0.2 CONTENT OF THE DOCUMENT ............................................................................................................... 2 1 DESCRIPTION OF THE PRODUCT................................................................................................ 3 1.1 BIOLOGICAL AND COMMERCIAL CHARACTERISTICS .................................................................................... 3 1.2 CATCHES AND AVAILABILITY OF PLAICE ................................................................................................... 5 2 THE EU MARKETS FOR PLAICE ................................................................................................... 9 2.1 STRUCTURE OF THE EU MARKET ........................................................................................................... 9 Apparent market by Member State ....................................................................................... 9 Imports ................................................................................................................................
    [Show full text]
  • Fisheries Update for Monday August 26, 2019 Groundfish Harvests
    Fisheries Update for Monday August 26, 2019 Groundfish Harvests through 8/17/2019, IFQ Halibut/Sablefish & Crab Harvests through 8/26/2019 Fishing activity in the Bering Sea /Aleutian Islands A season Groundfish Fisheries for the week ending on August 17, 2019, last week's Pollock harvest slowed down with an 8,000MT reduction from the previous week. The Pollock 8 season harvest is 60% completed thru last week. Last week's B season Pollock harvest came in at 48, 126MT fishing has .slowed down last week. The total groundfish harvest last week was 58,255MT (130million pounds). We are seeing increased effort in the Aleutian Islands on Pacific Ocean Perch last week's harvest of 1 ,938MT and Atka mackerel1 ,816MT. Halibut and Sablefish harvest statewide continues to see increased harvests, The Halibut harvest is 11.8 million pounds harvested 67% of the allocation has been taken. The Sablefish IFQ harvest is at 13.8 million pounds landed, the season is 53% of the allocation has been completed; Unalaska has had 46 landings for 820, 1171bs of Sablefish. Aleutian Island Golden King Crab allocation opened on July 15th with and allocation of 7.1 million pounds we have 4 vessels registered to fish the allocation. The Eastern District allocation is set at 4.4 million pounds and has had 7 landing for and estimated total of 600,000 to 800,000 harvested. The Western District at 2.7 million pounds there have been 5 landings for and estimated 200,000 to 250,0001bs harvested. For the week ending August 17, 2019 the Groundfish landings, showed a harvest of 58,255MT landed (130million pounds) most of last week's harvest was Pollock 48, 126MT (107 million pounds).
    [Show full text]
  • Plaice (Pleuronectes Platessä) Contents
    1-group plaice (Pleuronectes platessä) Contents Acknowledgements:............................................................................................................ 1 Abstract:.............................................................................................................................3 Chapter 1: General introduction.....................................................................................................4 Chapter 2: Fin-ray count variation in 0-group flatfish: plaice (Pleuronectesplatessa (L.)) and flounder (Platichthys flesus ( L.)) on the west coast of Ireland..............................15 Chapter 3: Variation in the fin ray counts of 0-group turbot (Psetta maxima L.) and brill (Scophthalmus rhombus L.) on the west coast of Ireland: 2006-2009.......................... 28 Chapter 4: Annual and spatial variation in the abundance length and condition of turbot (.Psetta maxima L.) on nursery grounds on the west coast of Ireland: 2000-2007.........41 Chapter 5: Variability in the early life stages of juvenile plaice (.Pleuronectes platessa L.) on west of Ireland nursery grounds; 2000 - 2007........................................................64 Chapter 6: The early life history of turbot (Psetta maxima L.) on nursery grounds along the west coast of Ireland: 2007 -2009, as described by otolith microstructure.............85 Chapter 7: The feeding ecology of 0-group turbot (Psetta maxima L.) and brill (Scophthalmus rhombus L.) on Irish west coast nursery grounds.................................96 Chapter
    [Show full text]
  • How Benthic Habitats and Bottom Trawling Affect Trait Composition in the Diet of European Plaice (Pleuronectes Platessa) in the North Sea
    HOW BENTHIC HABITATS AND BOTTOM TRAWLING AFFECT TRAIT COMPOSITION IN THE DIET OF EUROPEAN PLAICE (PLEURONECTES PLATESSA) IN THE NORTH SEA Jacqueline Eggleton, Kenny A.J., Bolam S.G., Depestele J., Garcia C. IFS10, Saint Malo 11th-16th November 2017 ‘Integrating the role of marine benthic ecosystems in fisheries management’ Two fundamental questions confronted by fisheries scientists: 1. To what extent do commercial fish target their prey? 2. Do the impacts of bottom trawling on benthic assemblages contribute to sustaining these populations ? Need to understand links (as trophic interactions) between populations of demersal fish species and potential benthic invertebrate prey (food) which live on or in the seabed Our questions 1. Do commercial fish species target different benthic prey? 2. Do commercial fish species target benthic prey differently in different habitats? 3. Do commercial fish species target benthic prey that are resistant or favoured by fishing pressure? To provide functional links between predator and prey we use biological traits analysis (BTA) What data do we need? 1. What fish are eating Fish stomachs 2. Habitat information at the scale of the fishery Habitat map What data do we need? 1. What fish are eating Fish stomachs 2. Habitat information at the scale of the fishery Habitat map 3. An indication of fishing pressure VMS/Logbook 4. Information on the benthic fauna living in and on the seabed Fish stomachs ICES year of the stomach 1991 North Sea, Skagerrak and Kattegat ICES rectangle scale (30 x 30 nautical miles)
    [Show full text]
  • Recycled Fish Sculpture (.PDF)
    Recycled Fish Sculpture Name:__________ Fish: are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. At 32,000 species, fish exhibit greater species diversity than any other group of vertebrates. Sculpture: is three-dimensional artwork created by shaping or combining hard materials—typically stone such as marble—or metal, glass, or wood. Softer ("plastic") materials can also be used, such as clay, textiles, plastics, polymers and softer metals. They may be assembled such as by welding or gluing or by firing, molded or cast. Researched Photo Source: Alaskan Rainbow STEP ONE: CHOOSE one fish from the attached Fish Names list. Trout STEP TWO: RESEARCH on-line and complete the attached K/U Fish Research Sheet. STEP THREE: DRAW 3 conceptual sketches with colour pencil crayons of possible visual images that represent your researched fish. STEP FOUR: Once your fish designs are approved by the teacher, DRAW a representational outline of your fish on the 18 x24 and then add VALUE and COLOUR . CONSIDER: Individual shapes and forms for the various parts you will cut out of recycled pop aluminum cans (such as individual scales, gills, fins etc.) STEP FIVE: CUT OUT using scissors the various individual sections of your chosen fish from recycled pop aluminum cans. OVERLAY them on top of your 18 x 24 Representational Outline 18 x 24 Drawing representational drawing to judge the shape and size of each piece. STEP SIX: Once you have cut out all your shapes and forms, GLUE the various pieces together with a glue gun.
    [Show full text]
  • Information in Support of the Identification of Ecologically
    Canadian Science Advisory Secretariat (CSAS) Research Document 2018/027 Central and Arctic Region Information in Support of the Identification of Ecologically Significant Species, Functional Groups and Community Properties (ESSCP) in the Western Arctic Biogeographic Region D.G. Cobb1, S. MacPhee1, J. Paulic1, K. Martin1, V. Roy2, J. Reist1, C. Michel1, A. Niemi1, E. Richardson3, and A. Black4 1Fisheries and Oceans Canada Freshwater Institute 501 University Crescent Winnipeg, MB, R3T 2N6 2Canadian Museum of Nature PO Box 3443, Station D Ottawa, ON, K1P6P4 3Environment and Climate Change Canada Eastgate Offices 9250 – 49th Street Edmonton, AB, T6B 1K5 4Environment and Climate Change Canada 1125 Colonel By Drive Ottawa, ON, K1A 0H3 November 2020 Foreword This series documents the scientific basis for the evaluation of aquatic resources and ecosystems in Canada. As such, it addresses the issues of the day in the time frames required and the documents it contains are not intended as definitive statements on the subjects addressed but rather as progress reports on ongoing investigations. Published by: Fisheries and Oceans Canada Canadian Science Advisory Secretariat 200 Kent Street Ottawa ON K1A 0E6 http://www.dfo-mpo.gc.ca/csas-sccs/ [email protected] © Her Majesty the Queen in Right of Canada, 2020 ISSN 1919-5044 Correct citation for this publication: Cobb, D.G., MacPhee, S., Paulic, J., Martin, K., Roy, V., Reist, J., Michel, C., Niemi, A., Richardson, E., and Black, A. 2020. Information in Support of the Identification of Ecologically Significant Species, Functional Groups and Community Properties (ESSCP) in the Western Arctic Biogeographic Region. DFO Can.
    [Show full text]
  • Taste Preferences in Fish
    FISH and FISHERIES, 2003, 4, 289^347 Taste preferences in ®sh Alexander O Kasumyan1 & Kjell B DÖving2 1Department of Ichthyology,Faculty of Biology,Moscow State University,119992 Moscow,Russia; 2Department of Biology, University of Oslo, N-0136 Oslo, Norway Abstract Correspondence: The ¢sh gustatory system provides the ¢nal sensory evaluation in the feeding process. Alexander O Unlike other vertebrates, the gustatory system in ¢sh may be divided into two distinct Kasumyan, Department of subsystems, oral and extraoral, both of them mediating behavioural responses to food Ichthyology,Faculty items brought incontact withthe ¢sh.The abundance of taste buds is anotherpeculiarity of Biology,Moscow of the ¢sh gustatory system. For many years, morphological and electrophysiological State University, techniques dominated the studies of the ¢sh gustatory system, and systematic investiga- 119992 Moscow, tions of ¢sh taste preferences have only been performed during the last 10 years. In the Russia E-mail: present review,basic principles in the taste preferences of ¢sh are formulated. Categories alex_kasumyan@ or types of taste substances are de¢ned in accordance with their e¡ects on ¢sh feeding mail.ru behaviour and further mediation by the oral or extraoral taste systems (incitants, sup- pressants, stimulants, deterrents, enhancers and indi¡erent substances). Information Received17July 2002 on taste preferences to di¡erent types of substances including classical taste substances, Accepted3April 2003 free amino acids, betaine, nucleotides, nucleosides, amines, sugars and other hydrocar- bons, organic acids, alcohols and aldehydes, and their mixtures, is summarised. The threshold concentrations for taste substances are discussed, and the relationship between ¢sh taste preferences with ¢sh systematic positionand ¢sh ecology is evaluated.
    [Show full text]