HERRING, GA8PEREAU, SHAD AND OTHER CLUPEOIDS 



105 



SESSIONAL PAPER No. 22a 



inclies. The sprat, wiiich. on hatching out is only about half the size of the herring 

 and one-third the size of the shad, is believed to reach a length of 3 inches in one year, 

 in its second year it is said to be 4| inches and in its third year 5| inches long, while 

 the pilchard, which reseiubles the sprat in so many points in its embryonic and larval 

 life-history, is believed to grow much faster during its post-larval life. Professor A. F. 

 Marion declared that the rate of growth is half an inch (1cm.) per month, so that the 

 translucent larva i inch long on hatching becomes a post-larval fish 1 to 1| inches 

 long (20 to 40 mm.) when between one and two months old — a view very difficult to 

 favour. The famous French authority holds that when 140 to 150 mm. they are ready 

 to spawn and are not more than one year old. As compared with other Clupeoids a 

 growth of a centimetre a month is of course unusually rapid. Mr. J. T. Cunningham 

 obtained specimens which were only 8*5 mm. long (J inch), and according to Marion's 

 calculations these were less than one month old, while his other specimens (Mar. Biol. 

 Assoc. Journal, Vol. II., p. 161, PI X., fig. 3) would be five months old;, and the same 

 size as the sea-herring at that age. Pilchards 3 to 4 inches long are abundant in Octo- 

 ber Mr. M. Dunn has recorded, and, at Marion's rate of growth, would be the fry of 

 March or April ova; but on the Cornish coast, June, or even earlier, appears to be the 

 spawning period, and it is impossible until more extended work has been done to accur- 

 rately decide the rate of growth. It may be added that the southern or Mediterr- 

 anean sardine is a smaller form (6 to 7^ inches) than the northern sardine which ranges 

 from 9 to 10 inches when adult, a size which corresponds with the Canadian pilchard 

 (Olupanodon coeruleus Girard), of which mature specimens studied by me ranged from 

 209 to 237 mm. (8i to 9i inches). 



The rate of growth is of first importance, as it is a guide to the age at which the . 

 various species of the herring family reproduce. The matter is one upon which author- 

 ities differ greatly. The common sea-herring was supposed by Professor Huxley to 

 reach maturity in its first year, as De Oaux had ventured to surmise before.* Mitchell 

 held that maturity was reached in eighteen months, while Meyer favoured the second 

 year, when the fish he thought were 8 inches long, but at the present time the prevail- 

 ing opinion is that in the third or fourth year these fish reach the spawning condition as 

 Sundevall, Ljungmann, Jenkins and others hold. Such a form as the dwarfed Caspian 

 herring is of course exceptional, and is found to be ripe when only 4^ or 4| inches long, 

 while land-locked herring such as the variety in the Windebyer Noor, near Kiel, 

 spawns when 5-| inches long, and in its third year after being hatclhed. /The Baltic 

 herring spawn when 7 inches long. The sprat, a species only one-third the size of the 

 shad, and half the size of the average herring and gaspereau, spawns when 5| inches 

 long (i.e., in its third year), that species being 3 inches long in its first year and 4| 

 in its second year. 



The movements of the young clupeoids, larval and post-larval, are interesting, 

 and while much variety of opinion has existed amongst authorities, there is now a 

 consensus of view which may be summarized as follows: The young fry, when newly 

 hatched and far more delicate and translucent than most other fishes in the sea or in 

 rivers, lie on the bottom for some time. The shad, it is true, was stated by Mr. Seth 

 Green, to seek the main current in midwater in the rivers where it is hatched. ^ How 

 different this (he said) from the young trouts that lie almost helpless for 45 days 

 and then are fain to hide behind roots and stone ! Whereas these minute, transparent, 

 gelatinous things, push boldly for the deep swift current, where they are too insignifi- 

 o|nt to be attacked by the great fishes.' It may be pointed out that, when liberated 

 from the Seth Green hatching boxes, anchored in a current, the fry were bound to 

 take to the swift water, ' with their heads up stream,' such delicate organisms being 

 carried by the current away from the shallows. My own examination of the spawn- 

 ing grounds and ^ nurseries ' on the St. John river convinced me that the pebbly shores 



* Professor Huxley, in his famous address at Norwich Fishery Exhibition, April, 1881, on 

 • The Herring,' admitted he had overestimated the rate of growth, in view of the results of the 

 Baltic Cpmmission investigations. 



