Metamorphosis and the transition from larvae or embryos to juveniles in fishes are important in order to answer, for example, questions about: (1) life-history styles and their modifications in evolutionary perspective and within current environmental demands; (2) the development and application of fisheries recruitment models, (3) the use of ontogenetic scales for interspecific comparisons, (4) the identification of ontogenetic shifts in resource use, and (5) the discovery of evolutionary interrelationships of species or genera. This volume is dedicated to recent studies and reviews of existing knowledge on this insufficiently-addressed area of ichthyology. Most of the papers in this volume were presented in Bratislava, Slovakia, at the 1st International Workshop of the Fish Ontogeny Network of Europe (FONE) in September 1997, a meeting sponsored in part by the European Commission. This volume emphasizes an integrated approach to the study of fish ontogeny, which is a process during which one event is related to another and everything is related to everything else, encompassing physiology, morphology, behaviour and niche. Within this comprehensive perspective, the papers in this volume are grouped along four major themes: reflections on early ontogeny and metamorphosis, organism-environment relationships, ontogeny of predator-prey interactions, and behaviour and ontogeny. Among other issues, the papers consider topics such as whether one can identify when fish metamorphosis ends, whether the larva period begins with hatching or with the onset of exogenous feeding, whether fish ontogeny is saltatory' or gradual', and whether larvae are eliminated in some fishes with direct development. The keynote paper of this volume reviews the main topics within contemporary paradigms and the final paper concludes that the onset of the juvenile period can be identified in some species, but precision remains problematic, emphasizing the need for further research in this dynamic area of fish biology.

Zusammenfassung
Among other issues, the papers consider topics such as whether one can identify when fish metamorphosis ends, whether the larva period begins with hatching or with the onset of exogenous feeding, whether fish ontogeny is saltatory' or gradual', and whether larvae are eliminated in some fishes with direct development.

Inhalt
Prelude: looking at early development in fishes.- Keynote presentation.- Alternative ways to become a juvenile or a definitive phenotype (and on some persisting linguistic offenses).- 1. Reflections on early ontogeny and metamorphosis.- Features of transition from larva to juvenile in fishes with different types of early ontogeny.- Thyroxine as a mediator of metamorphosis of Atlantic halibut, Hpppoglossus hippoglossus.- Early development of the sofie, Chondrostoma toxostoma.- The reproductive biology and early ontogeny of the mouthbrooding Banggai cardinalfish, Pterapogon kauderni (Perciformes, Apogonidae).- The onset of the juvenile period in carp, Cyprinus carpio: a literature survey.- 2. Organism-environment relationships.- Morphometry of the stone loach, Barbatula barbatula: do mensural characters reflect the Species' life history thresholds?.- Correspondence between ontogenetic shifts in morphology and habitat use in minnow Phoxinus phoxinus.- Fish, flows and flood plains: links between freshwater fishes and their environment in the Murray-Darling River system, Australia.- Comparison of growth plasticity in the laboratory and field, and implications for the onset of juvenile development in sofie, Chondrostoma toxostoma.- 3. Ontogeny of predator-prey interactions.- A review of predation impact by 0+ fish on zooplankton in fresh and brackish waters of the temperate northern hemisphere.- Seasonal and diel utilisation of inshore microhabitats by larvae and juveniles of Leuciscus cephalus and Leuciscus leuciscus.- Seasonal shifts in day-time resource use of 0+ barbel, Barbus barbus.- Vertical distribution and feeding activity of metamorphosing sole, Solea solea, before immigration to the Bay of Vilaine nursery (northern Bay of Biscay, France).- 4. Behaviour andontogeny.- Ontogeny of aggressive behaviour in schools of yellowtail, Seriola quinqueradiata.- School formation and concurrent developmental changes in carangid fish with reference to dietary conditions.- Ontogeny of diel pattern of stream-margin habitat use by emerging brown trout, Salmo trutta, in experimental channels: influence of food and predator presence.- Size-based variation in somatic energy reserves and parental expenditure by male smallmouth bass, Micropterus dolomieu.- To be a juvenile and not to be a larva: an attempt to synthesize.- Species and subject index.