The Eel

1. Body Structure and Functions.- 1.1 Skeleton.- 1.1.1 Skull.- 1.1.2 Pectoral girdle.- 1.1.3 Vertebral column.- 1.1.4 Fins.- 1.2 Skin and musculature.- 1.2.1 Structure and function of the skin.- 1.2.2 Scales.- 1.2.3 Pigmentation.- 1.2.4 Teeth.- 1.2.5 Musculature.- 1.3 Respiratory organs and swimbladder.- 1.4 Feeding and organs of digestion.- 1.4.1 The gastrointestinal tract.- 1.4.2 Pancreas.- 1.4.3 Liver and gall bladder.- 1.5 Circulation of the blood.- 1.5.1 Cardiovascular system.- 1.5.2 Blood.- 1.6 Urinogenital system.- 1.6.1 The kidneys.- 1.6.2 The gonads.- 1.7 The endocrine system.- 1.7.1 The pituitary gland.- 1.7.2 The thyroid gland.- 1.7.3 The urohypophysis.- 1.7.4 The interrenal tissue (adrenocortical homologue).- 1.7.5 Ultimobranchial bodies.- 1.7.6 Corpuscles of Stannius.- 1.7.7 Thymus gland.- 1.7.8 The kidney.- 1.8 Nervous system and sense organs.- 1.8.1 The brain.- 1.8.2 Eye.- 1.8.3 Olfaction.- 1.8.4 Hearing and the lateral line sense organs.- 2. Eel Species, their Developmental Stages and their Distribution.- 2.1 The European and American eels A. anguilla and A. rostrata.- 2.1.1 Spawning grounds and larval forms.- 2.1.2 Continental distribution.- 2.2 Indo-Pacific species.- 2.2.1 The south-east African region: A. marmorata, A. nebulosa labiata, A. mossambica and A. bicolor.- 2.2.2 The temperate north Pacific zone: The Japanese eels A. japonica and A. marmorata.- 2.2.3 The south-east Pacific species from the temperate zone: A. australis and A. dieffenbachi.- 2.2.4 The tropical eels A. celebesensis, A. megastoma, A. interioris, A. ancestralis, A. nebulosa, A. marmorata, A. reinhardti, A. borneensis, A. bicolor, A. obscura.- 2.3 Zoogeographical relationships.- 3. Post-Larval Ecology and Behaviour.- 3.1 The glass eel and elvers : their migration on the Continental shelf and into freshwaters.- 3.1.1 Migration in the sea.- 3.1.2 The movement into freshwater.- 3.1.3 Human intervention.- 3.2 Migration of pigmented young eels.- 3.2.1 Dependence on environmental factors.- 3.2.2 Human involvement in the ascent of young eels.- 3.3 The 'Yellow eel' stage to the 'Silver eel' stage.- 3.3.1 Feeding.- The period of activity and food intake-Seasonal variations in diet-Choice of food and body size-Choice of food and head width-The dependence of diet on food availability-Choice of food.- 3.3.2 Age and growth.- Methodological problems-Differences in growth between males and females and the age and length at which migration begins-Head width and growth-Differences in growth due to environmental factors-Interspecific differences in growth-Theoretical pattern of growth-Length and weight.- 3.3.3 Location, habitat and behaviour patterns.- Refuge in tubes and hollows, and contact with members of the same species-Water depth-Survival in air-Localization and homing.- 3.4 Silver eel migration.- 3.4.1 Seasonal variation.- 3.4.2 Variations in the time of day, and the influence of light.- 3.4.3 Correlation with lunar phases.- 3.4.4 Hydrological and meteorological factors.- Low pressure areas-Water level and currents in rivers-Tidal currents-Wind and currents-Temperature and depth-Salinity.- 3.4.5 In subterranean waters.- 3.4.6 In the sea, with special reference to the Baltic.- 3.4.7 Behaviour and speed.- 4. Fishing Yields.- 4.1 The development of eel fisheries.- 4.2 Annual and regional fluctuations in yield.- 4.2.1 Variations over the whole North Sea region.- 4.2.2 The effect of differing proportions of males and females on variations in catch size along the southern coast of the Baltic and in inland waters.- 4.2.3 The relationship between the west wind and glass eel invasions.- 4.2.4 The influence of seasonal temperature levels.- 4.2.5 Catch variations in Canada.- 4.3 Variation in catch size throughout the year.- 4.4 Population density and catch sizes from an economic and ecological viewpoint.- 4.4.1 Regional differences.- 4.4.2 The eel in competition with other fishes and with crustaceans.- 4.4.3 Improving yields by stocking.- 4.4.4 Summary of yield and stocking success.- 5. Fishing Methods.- 5.1 Eel traps.- 5.1.1 Eel baskets.- 5.1.2 Fyke nets.- 5.1.3 Pound nets.- 5.2 Stow nets.- 5.2.1 Staked stow nets.- 5.2.2 Anchored stow nets.- 5.2.3 Otterboard stow net.- 5.3 Permanent eel traps.- 5.3.1 Eel weirs in rivers.- 5.3.2 Eel traps in streams and rivers.- 5.4 Seines and trawls.- 5.5 Angling and line fishing.- 5.6 Lift nets, spears and other equipment.- 5.7 The use of electricity.- 5.8 Combination with light.- 6. Eel Culture and Live Storage.- 6.1 Eel farming in Japan.- 6.1.1 The importance of eel farming.- 6.1.2 Pond systems and yields.- 6.1.3 Rearing techniques.- 6.1.4 Feeding.- 6.1.5 Profit and expenditure.- 6.2 Experiments on eel farming in Europe.- 6.3 Live storage.- 7. Diseases, Parasites and Injuries.- 7.1 Virus and bacterial diseases.- 7.1.1 Cauliflower disease.- 7.1.2 Fresh-and saltwater eel diseases Freshwater eel disease-Saltwater eel disease.- 7.2 Infestation by fungi, protozoa and metazoa.- 7.3 Teratological and other defects.- 8. Trade and Processing.- 8.1 International trade.- 8.2 Prices.- 8.3 Quality.- References.