Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

Lipids and their constituent fatty acids are, along with proteins, the major organic constituents of fish, and they play major roles as sources of metabolic energy for growth including reproduction and movement, including migration. Furthermore, the fatty acids of fish lipids are rich in ω3 long chain, highly unsaturated fatty acids (n-3 HUFA) that have particularly important roles in animal nutrition, including fish and human nutrition, reflecting their roles in critical physiological processes. Indeed, fish are the most important food source of these vital nutrients for man. Thus, the longstanding interest in fish lipids stems from their abundance and their uniqueness. This review attempts to summarize our present state of knowledge of various aspects of the basic biochemistry, metabolism, and functions of fatty acids, and the lipids they constitute part of, in fish, seeking where possible to relate that understanding as much to fish in their natural environment as to farmed fish. In doing so, it highli...

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Metabolism and Functions of Lipids and Fatty Acids in Teleost Fish

Unsustainable fishing practices have placed a heavy emphasis on aquaculture to meet the global shortfalls in the supply of fish and seafood, which are commonly accepted as the primary source of health-promoting essential omega-3 (n-3 highly unsaturated fatty acids). However, dietary fish oil is required for the production of omega-3-rich farmed fish and this commodity, in a vicious circle, is at present derived solely from wild fisheries. Decreasing global availability coupled with the highly variable price of this resource has forced the aquaculture industry to investigate the possibilities of alternative dietary lipid sources. This review attempts to compile all principal information available regarding the effects of fish oil replacement for the diets of farmed finfish, analysing the findings using a comparative approach among different cultured fish species. The review initially focuses on the present situation with regard to the production, availability and main nutritional characteristics of fish oil and the principal alternative lipid sources (such as vegetable oils and animal fats). Following this, the effects of fish oil replacement in finfish nutrition on feed quality, fish performance, feed efficiency, fish lipid metabolism, final eating quality and related economic aspects are presented and discussed.

Fish oil replacement in finfish nutrition

Effect of broodstock nutrition on reproductive performance of fish

Myostatin, a member of the transforming growth factor-β (TGF-β) superfamily, has been shown to be a negative regulator of myogenesis. Here we show that myostatin functions by controlling the proliferation of muscle precursor cells. When C2C12 myoblasts were incubated with myostatin, proliferation of myoblasts decreased with increasing levels of myostatin. Fluorescence-activated cell sorting analysis revealed that myostatin prevented the progression of myoblasts from the G1- to S-phase of the cell cycle. Western analysis indicated that myostatin specifically up-regulated p21Waf1, Cip1, a cyclin-dependent kinase inhibitor, and decreased the levels and activity of Cdk2 protein in myoblasts. Furthermore, we also observed that in myoblasts treated with myostatin protein, Rb was predominately present in the hypophosphorylated form. These results suggests that, in response to myostatin signaling, there is an increase in p21 expression and a decrease in Cdk2 protein and activity thus resulting in an accumulation of hypophosphorylated Rb protein. This, in turn, leads to the arrest of myoblasts in G1-phase of cell cycle. Thus, we propose that the generalized muscular hyperplasia phenotype observed in animals that lack functional myostatin could be as a result of deregulated myoblast proliferation.

Myostatin, a negative regulator of muscle growth, functions by inhibiting myoblast proliferation.

Publisher Summary Varying egg quality is one of the limiting factors for successful mass production of fish fry. It may also cause some of the variability in recruitment observed in many wild stocks, since poor egg quality may decrease the survival potential of the hatched larvae. In the literature, the term egg quality has been defined and used in various ways by different authors. Due to the limited knowledge in the field, it has been difficult to pinpoint valid quality criteria. The only definition of egg quality that has general validity is probably the egg's potential to produce viable fry. The egg's potential to produce viable fry is determined by several physical, genetic, and chemical parameters, as well as the initial physiological processes occurring in the egg. If one of the essential factors is lacking, or is incomplete, egg development will fail at some stage. Thus, egg quality should be regarded as determined when the egg has left the female fish and the fertilization process is complete. This definition is, however, of very little practical value, since fry viability obviously cannot be determined before the fry is produced. Good practical criteria for the determination of egg quality should be both possible to identify early in development, and be simple to use. The problems of egg quality have received increasing attention, in relation to cultivation as well as to the assessment of reproduction of wild fishes. This chapter discusses the possible criteria for the determination of quality of fish eggs.

Egg Quality in Fishes

Cod larvae, Gadus morhua L., were reared in the laboratory and released to a large marine enclosure 4 to 5 days after hatching (6–8° C). The development of the digestive system was studied until day 24 after hatching. Morphological investigations of the jaw apparatus and the digestive tract showed that the larvae are able to absorb ingested food well before exhaustion of the yolk sac. The foregut, and especially the midgut, were particularly active in lipid absorption, and the hindgut was characterized by pinocytotic activity. Duhng the first days of feeding, no distinct prey organisms were observed in the gut, and signs of food absorption in the epithelial cells of the gut were sparse.A distinct red fluorescence, restricted to the hindgut, was observed from day 11 to day 19. On the basis of changes in absorptive pattern in the gut we suggest that changes in digestive and absorptive abilities, as well as in nutritional needs, take place around days 15–17 after hatching.



In starved larvae, signs of degeneration of the gut tissue were first visible in the foregut. By day 9 after hatching, microvilli was degenerated to such an extent that the ability to absorb food must have been severely restricted. If larvae are starved longer than this, they will probably not survive.

Early development of the digestive tract of cod larvae, Gadus morhua L., during start‐feeding and starvation

This study evaluated the effects of fish oil (FO) replacement by vegetable oils [soybean oil (SO), rapeseed oil (RO), linseed oil (LO)] and subsequent feeding with FO on the liver morphology of sea bream A short-term trial (3 months) and long-term trial (6 months) were carried out feeding sea bream with the following experimental diets: FO100%; SO60% + FO40%; RO60% +FO40%; LO60% + FO40%; SO + RO +LO60% + FO40% Finally, all groups from the long-term trial were fed with FO100% for 95 days (washout period) Liver samples were taken for histological and biochemical studies In both the short- and long-term trials, livers of sea bream fed LO60% and SO + RO + LO60% showed a similar hepatic morphology to that observed in fish fed FO100% In contrast, sea bream fed SO60% showed an intense steatosis, with foci of swollen hepatocytes containing numerous lipid vacuoles After the washout period, a considerable reduction of the cytoplasmic vacuolation and the lipid vacuole accumulation were observed in the livers of fish fed the different experimental diets The results of this study suggested that the type of non-essential fatty acid, characteristic of vegetable oils, induces the appearance of steatosis in the following order: linoleic acid > linolenic acid > oleic acid However, the liver alterations found during the experimental periods with vegetable oils are reversible when the fish are re-fed with a balanced diet (FO100%), indicating the non-pathological character of these histological changes

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Histological alterations in the liver of sea bream, Sparus aurata L., caused by short‐ or long‐term feeding with vegetable oils. Recovery of normal morphology after feeding fish oil as the sole lipid source

Morphological aspects of intestinal cells from gilthead seabream (Sparus aurata) fed diets containing different lipid sources

Preface. List of Contributors. 1 Introduction (The Editors). 1.1 References. 2 Abiotic Factors (B.R. Howell and S.M. Baynes). 2.1 Introduction. 2.2 Oxygen and oxygen consumption. 2.3 Ammonia. 2.4 Temperature. 2.5 Salinity. 2.6 Hydrogen sulphide. 2.7 Light. 2.8 Algae blooms. 2.9 Site selection. 2.10 References. 3 Microbial Interactions, Prophylaxis and Diseases (O. Vadstein, T.A. Mo and O. Bergh). 3.1 Fish--microbe interactions and implications in aquaculture. 3.2 Viral diseases: diagnosis. 3.3 Bacterial diseases: diagnosis. 3.4 Parasitic protists and metazoans: diagnosis, prophylaxis and treatment. 3.5 A strategy for microbial control. 3.6 Improving environmental conditions. 3.7 Improving the resistance of the fish. 3.8 Closing remarks. 3.9 References. 4 Live Food Technology of Cold--Water Marine Fish Larvae (Y. Olsen). 4.1 Introduction. 4.2 Cultivation systems. 4.3 Production of rotifers. 4.4 Production of Artemia. 4.5 Marine copepods. 4.6 Concluding remarks. 4.7 References. 5 Brood Stock and Egg Production (D. Pavlov, E. Kjorsvik, T. Refsti and O. Andersen). 5.1 Reproductive strategies. 5.2 Gonad maturation. 5.3 Brood--stock management and egg production. 5.4 Egg quality. 5.5 Sperm production and quality. 5.6 Selective breeding. 5.7 Modern biotechnology and aquaculture. 5.8 References. 6 From Fertilisation to the End of Metamorphosis--Functional Development (E. Kjorsvik, K. Pittman and D. Pavlov). 6.1 Intervals of fish ontogeny and definitions of the organism. 6.2 Egg classification. 6.3 Insemination and fertilisation. 6.4 Embryonic development and hatching. 6.5 From hatching to metamorphosis. 6.6 Functional development of organ systems from hatching to metamorphosis. 6.7 Hatchery design. 6.8 Critical aspects of larval cultivation. 6.9 References. 7 First Feeding Technology (Y. Olsen, T. van der Meeren and K.I. Reitan). 7.1 Introduction. 7.2 Nutritional requirements of marine fish larvae. 7.3 Definitions and system description. 7.4 Larval rearing in a nature--like systemsa . 7.5 Larval first feeding in intensive systems. 7.6 Concluding remarks. 7.7 References. 8 Weaning and Nursery (J. Stoss, K. Hamre and H. Ottera). 8.1 Introduction. 8.2 Developmental aspects of digestion in marine fish larvae. 8.3 Nutrition. 8.4 Microparticulate diets. 8.5 Weaning and nursery stage, practical aspects. 8.6 References. 9 On--Growing to Market Size (M. Jobling). 9.1 Introduction. 9.2 Analysis of feeds and feedstuffs. 9.3 Protein requirements and sources. 9.4 Lipids and lipid requirements. 9.5 Carbohydrates. 9.6 Micronutrients: vitamins and minerals. 9.7 Feed types and formulations. 9.8 Feeding regimes and practices. 9.9 Growth and feed conversion. 9.10 Nutrient deposition and body composition. 9.11 Concluding comments. 9.12 References. 10 The Status and Perspectives for the Species (T. Svasand, H.M. Ottera, G.L. Taranger, M. Litvak, A.B. Skiftesvik, R.M. Bjelland, D.A. Pavlov, J.Chr. Holm, T. Harboe, A. Mangor--Jensen, B. Norberg and B. Howell). 10.1 Atlantic cod. 10.2 Haddock. 10.3 Hake. 10.4 Wolf--fish. 10.5 Halibut. 10.6 Turbot. 10.7 Sole. 11 Marine Stock Enhancement and Sea--Ranching (T. Svasand and E. Moksness). 11.1 Introduction. 11.2 Stock enhancement and sea--ranching in Europe and North America. 11.3 Stock enhancement and sea--ranching in Asia. 11.4 Prospects and limitations of enhancement and sea--ranching. 11.5 Recommendations and guidelines. 11.6 References. 12 New Species in Aquaculture: Some Basic Economic Aspects (R. Engelsen, F. Asche, F. Skjennum and G. Adoff). 12.1 Introduction. 12.2 Cod. 12.3 Haddock. 12.4 European hake. 12.5 Wolf--fish. 12.6 Halibut. 12.7 Turbot. 12.8 Sole. 12.9 Conclusions. 12.10 References. Index.

Elin Kjørsvik

Papers

Egg Quality in Fishes

Early development of the digestive tract of cod larvae, Gadus morhua L., during start‐feeding and starvation

Histological alterations in the liver of sea bream, Sparus aurata L., caused by short‐ or long‐term feeding with vegetable oils. Recovery of normal morphology after feeding fish oil as the sole lipid source

Morphological aspects of intestinal cells from gilthead seabream (Sparus aurata) fed diets containing different lipid sources

Culture of cold-water marine fish