Handbook of the marine and freshwater fishes of the British Islands : (including an enumeration of every species) . ales, or may be pro-tected by a series of closely set bony plates, or by variouslydistributed tubercles or spines. All fishes are dioecious(bisexual), the majority being oviparous, but some, in-cluding notably certain representatives of the Shark tribe, OF THE BRITISH ISLANDS. 3 are viviparous, that is, produce their young alive. Thefecundity of fishes is in excess of that of any other divisionof the animal kingdom. The number of eggs contained inthe roe of a single Cod frequentl
Handbook of the marine and freshwater fishes of the British Islands : (including an enumeration of every species) . ales, or may be pro-tected by a series of closely set bony plates, or by variouslydistributed tubercles or spines. All fishes are dioecious(bisexual), the majority being oviparous, but some, in-cluding notably certain representatives of the Shark tribe, OF THE BRITISH ISLANDS. 3 are viviparous, that is, produce their young alive. Thefecundity of fishes is in excess of that of any other divisionof the animal kingdom. The number of eggs contained inthe roe of a single Cod frequently exceeds eight or ninemillions, while the roe of a large Turbot weighing twentypounds was found to contain over fourteen million average number of eggs produced by a Salmon havinga weight of twenty pounds is twenty-seven thousand, andthat of a Herring from twenty to fifty thousand. The number of known species of fish distributed through-out the salt and fresh waters of the globe falls but littleshort of nine thousand, out of which as many as twohundred and thirty-two are included in the fish-fauna of. FIG. I.—AUSTRALIAN MUD-FISH (Ceratodus miolepis). the British Islands. Of these, some twenty-eight or thirtyare inhabitants of purely fresh water, twelve or thirteen are anadromous, migrating periodically from salt to freshwater or the converse, while the remainder are exclusivelymarine forms. The fish class as a whole is sub-divided byour highest authority (see Professor Huxleys Anatomyof Vertebrated Animals ) into as many as six leadingsections or orders. These, commencing with the mosthighly organised, and descending to the lowest or leastspecialised group, take the following sequence : I. TheDipnoi or Mud-fishes ; II. The Teleostei or ordinary bonyfishes ; III. The Ganoidei or Sturgeon tribe ; IV. The Etas-mobranchii, including the Sharks and Rays; V. The B 2 4 MARINE AND FRESHWATER FISHES Marsipobranchii, comprising the Lampreys ; and VI. ThePharyngobranchii, repr
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Keywords: ., bookcentury1800, booksubjectfisheries, booksubjectfishes, bookyea
