Edible Fishes of New South Wales. 



Class.— PISCES. 



Fishes are cold-blooded Vertebrate Animals, which are almost exclusively 

 adapted for an aquatic existence ; which almost invariably respire by means 

 of specialized organs, known as gills or Iranchice, these being persistent 

 throughout life and the functional agents by which the oxygen is dissolved 

 from the surrounding water ; which have the limbs for the most part modified 

 into paired fins — the pectorals taking the place of the mammalian arm, the 

 ventrals that of the lower limb — supplemented by unpaired fins — the dorsal, 

 anal, and caudal — situated on the median axis of the body, and chiefly used 

 for the pui'poses of keeping the body erect and as organs of progression, the 

 latter function being in most fishes wholly confined to the caudal ; which 

 have the heart divided into two cavities, one auricle and one ventricle only ; 

 and which are scaleless, partially or wholly scaled, or protected by osseous 

 plates. 



Fishes are for the most part oviparous ; some, however, are ovoviviparous, 

 both methods being not uncommonly present in members of the same family ; 

 for instance, our familiar Bleuniid genus Cristicepsis strictly ovoviviparous, 

 while the equally common allied genus Peiroscirtes is as strictly oviparous. 



Subclass I.— TELEOSTEI. 



Skeleton osseous. I^rain distinct. Skull possessing cranial bones. Ver- 

 tebra? completely formed: the vertebral column bony, or with a bony plate 

 posteriorly, diphycercal, or homocercal. Branchiae free : the water dis- 

 charged through a single aperture, Avhich is protected by a bony gillcover, 

 Eranchiostegal rays present. Heart with a non-contractile bulbus arteri- 

 osus, having a pair of proximal valves. Optic nerves decussating. Intes- 

 tines without spiral valve. 



Order l.—ACANTIIOFTEUYGIL 



Part of the dorsal, anal, and ventral fins unarticulated, forming spines. 

 Hypopharyngeal bones generally separated. Airbladder, when present, 

 without pneumatic duct in the adult. 



In several families of Acanthopterygian Fishes no true spines are present. 

 Among the families which are included in the New South Wales fauna, the 

 Trichonotidce with Hemerocoetes and the Gohiesocidcs with D/pIoerepis, both 

 containing small species of no commercial value, may be mentioned as typical 

 of this modification. 



Eefering to this, Gunther (Study of Fishes, p. 374) remarks : — " The 

 Aeanthopterygians do not form a perfectly'' natural group, some heteroge- 

 neous elements being mixed up with it ; neither are the characters by which 



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