TELEOSTEI 257 



There are now 14 fish left in the Portobello Hatchery Tanks, 

 some of them just 24 inches in length, but they show no signs 

 of spawning. I am inclined to think that the difficulty of getting 

 most kinds of sea-fish to spawn in confinement is due to the shallow- 

 ness and consequent lack of pressure of the water in which they are 

 kept. At the spawning season all the large flat-fishes of indigenous 

 species move out of shallow bays and estuaries, and it may be that 

 a pressure of 30 to 40 fathoms of water assists the fish in the 

 extrusion of the ova. We have noticed at the Portobello Hatchery 

 that native flounders (Rhombosolea plebeid) taken at spawning time 

 and placed in our ponds can hold up their ova for weeks. 



It is impossible to say whether the turbot has or has not become 

 established in New Zealand waters. Even if any succeed in spawning 

 their progeny are not likely to be in evidence for some years. 



T.N. Z. I 7 



