94 



Aquatic JLltt 



which contain amongst their numbers cer- 

 tain viviparous forms are the Scorpae- 

 nidae — a familiar member of which is 

 the common Red Rock cod, Scorpaena 

 cruenta, though itself not viviparous — 

 and the Scombresocidae or Garfishes. In 

 the latter the viviparous members are 

 restricted to fresh water. The family of 

 Blennies {Blenniidae) also contributes its 

 quota to the fishes showing viviparity, 

 and a number of remarkable instances 

 have been at times brought forward. 



As far as our present knowledge car- 

 ries us, viviparous forms of fish life do 



Limia ornata 



not appear to be abundant in the waters 

 of Australia, but at the same time there 

 are some rather striking examples, prom- 

 inent among which are the "Crested 

 Weed-fishes" of the genus Cristiceps. 

 These are usually rock-frequenting fishes 

 of a conformation and color to suit their 

 weedy surroundings. The young are 

 very small at birth. 



A highly interesting viviparous fish is 

 that known as Comephorus. It occurs in 

 the great depths of Lake Baikal, and is 

 remarkable because of the fact that it 

 dies after having given birth to its young. 

 This fish, like many bathybial forms, is 

 practically colorless, and is provided with 

 very large eyes. The skeleton, also, is 

 very thin and papery. 



Amongst viviparous teleostean fishes 

 inhabiting great ocean depths should be 



mentioned the curious forms known 

 under the generic names of Saccogaster, 

 Diplacanthopoma and Hephthocara, the 

 last two of which have been taken in the 

 Indian Ocean at a depth of about iooo 

 fathoms. In another member of the same 

 family, known as Cataetyx messieri, a 

 most remarkable state of affairs has 

 recently been disclosed by Dr. Gilchrist, 

 Marine Biologist at the Cape of Good 

 Hope, The fish referred to, which is a 

 native of the deep seas in the neighbor- 

 hood of South Africa, produces well de- 

 veloped young which are most pro- 

 nounced cannibals, eating each other 

 while still unborn. Though this reads 

 like a fairy story, it is founded on very 

 positive, indisputable evidence. All of 

 these, here mentioned, are closely allied 

 to the family Ophidiidae, of which our 

 Australian Rockling (Genypterus bla- 

 codes) is a familiar member. We are not 

 yet acquainted with the mode of repro- 

 duction of the latter. 



As I before mentioned, most of the 

 sharks and rays are viviparous. Amongst 

 familiar instances of species which occur 

 on the New South Wales coast may be 

 mentioned the large predaceous sharks, 

 such as the "Grey Nurse" (Odontaspis 

 taurus) , the "Tiger" (Galeocerdo ray- 

 neri), and the "whaler" [Carcharias 

 brachyurus). These produce relatively 

 large, well-developed young. The vari- 

 ous Sting-lays (Dasyatis) also may be 

 cited as belonging to this group. 



In regard to the fecundity of vivipar- 

 ous fishes, it may be taken as a rule that 

 they produce comparatively few within 

 one breeding season as compared with the 

 bulk of the oviparous species. But then, 

 as will readily be seen, the risk of de- 

 struction is more and more lessened, in 

 accordance with the degree of advance- 

 ment reached by the embryo, before birth 

 (Concluded on Page 98.) 



