478 Transactions. 



has been carried on by the Commission, it may be stated that the 

 total output of fry for 1904 was 1,267,343,025, including both 

 indigenous and introduced fresh- and salt-water fishes. 



Many of the declining fishing industries, such as the salmon, 

 lobster, and shad, have been revived, and new industries created 

 by means of artificial propagation. 



Such is a brief outUne of the history of the work in other 

 countries, from which it will be seen that it is only a little over 

 forty years since the floating nature of the majority of the eggs 

 of marine fishes was first discovered. 



An account of the marine fish-hatchery and biological station 

 established in 1904 at Portobello is published in the New Zealand 

 Institute Transactions, vol. xxxviii. In this paper Mr. G. M. 

 Thomson has given a history of the movement to establish a 

 station, together with a statement of its objects and details of 

 construction, and a report of the work undertaken during 1904. 

 The following notes practically constitute a continuation of 

 Mr. Thomson's paper. 



The Gurnard {Trigla kumu). 



Although fairly abundant around various parts of the coast, 

 this fish is seldom caught by the local trawlers, and then generally 

 only singly or in pairs. 



On the 5th March about two thousand eggs were taken from 

 a female on board the s.s. " Napier," off Otago Heads. We 

 were fortunate in securing a male fish in the next haul, and the 

 eggs were impregnated and brought to the station. The egg 

 (Plate XVII, figs, a, b, c, d, e, f, g) is the largest marine fish-egg 

 secured up to the present time, and is 1-7 mm. in diameter. 

 It is of the buoyant or pelagic type, spherical and transparent, 

 with (chiefly) a single large oil-globule, but in some cases three 

 or four, which soon appear to merge into one. This oil-globule 

 is at first of a bright- orange colour, and gives the eggs a bright 

 and conspicuous appearance when floating in a mass on the 

 surface of the water. The colour gradually fades, and by the 

 time the embryo is ready for hatching the colour has entirely 

 disappeared, the eggs hatch on the seventh day, at an average 

 temperature of 9° C. 



The gurnard is probably a summer spawner, as the eggs 

 were collected when the M^ater had reached its highest tempera- 

 ture. The larva (Plate XVIII, figs, h c, d, e) is about 4 mm. 

 in length ; the pigmentation is black and yellow, and the 

 yolk-sac large and interspersed with the same black-and-yellow 

 markings. By the second day the yolk-sac has appreciably 

 diminished in size, and the larvae become more active. The 



