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Part 111. — Thirteenth Annual Report 



VII. — LIST OF THE PELAGIC OVA, LARVAE, AND YOUNG 



FISHES PROCURED BY THE s.s. 'GARLAND,' AND 

 BOAT ' DALHOUSIE.' By H. Chas. Williamson, M.A., B.Sc, 

 St Andrews Marine Laboratory. 



The following lists contain a record of the ova and young fishes 

 captured in the tow-nets of the ' Garland,' in the Firth of Forth and St 

 Andrews Bay from January to June 1895, aud in the Moray Firth in 

 July 1894. The eggs were, in many cases, examined in the fresh con- 

 dition. The collections from some stations were, however, preserved in a 

 mixture, consisting of equal parts of methylated spirit (about 94 per 

 cent.) and 2 per cent, acetic acid. Before preservation in the mixture, 

 the ova were fixed with picro-hydrochloric acid (saturated solution of 

 picric acid, in 5 per cent, solution of hydrochloric acid). The larvae were 

 preserved in spirit. While the classification of the live eggs is usually 

 attended with comparatively little difficulty, it is by no means always 

 easy to separate the ova after preservation. This difficulty is most felt 

 in cases where the collection includes the eggs of different gadoids.* It 

 is always possible to readily classify certain of tlie preserved ova, but 

 there are usually a number of eggs which give rise to difficulty, either 

 through unequal shrinkage, or from the obliteration of diagnostic features, 

 such as pigment, markings on yolk, &c. The oil-globule present in 

 certain eggs is of great service in the separation of the ova. The total 

 number of eggs of any one species in a collection is, therefore, in the 

 case of the preserved ova, approximate. The presence of the species 

 recorded is certain ; the exact number of the ova of any one species it 

 is impossible to fix. 



The tow-nets of the ' Garland ' are usually down for two hours ; on 

 short stations, for a less period. 



Plaice. — The earliest date on which ova were obtained in the tow- 

 nets was 8th February, when two eggs of plaice were procured on Station 



VIII. , Forth. On 6th March, the eggs of a number of other species were 

 found on Station VIII., Forth. In addition to the ova of the plaice, 

 the eggs of haddock, green cod (saithe), long-rough dab, and flounder 

 were there obtained in fairly large numbers. The eggs of* the plaice 

 were found in the Forth until 23rd April, in varying numbers ; in no 

 collection were there more than fifteen eggs. In St Andrews Bay, the 

 largest number of plaice ova (thirty-eight) was procured on Station II., 

 on 14th March. The last date, upon which the tow-net was used in 

 the bay during April, was the 8th. The ova. of the plaice were found 

 on that occasion. 



Haddock. — The first egg of the haddock was obtained in the Forth, 

 Station VII., on 11th February. They continued to appear in the 

 tow-nets until 22nd April, on which date they were procured on Station 



IX. They were found in the greatest numbers on the 19th and 20th 

 of March, when Stations V., VII., VIII., and IX. were examined. 



Cod. — The ova of the cod were present in the tow-nets in greatest 

 abundance in the month of April. They were first obtained on Station 

 III., St Andrews Bay, on 14th March. 



Whiting. — The ova of the whiting were found in great numbers on 

 the stations of the Forth, especially so during the month of April. The 

 first ova of this species were obtained on Station II., St Andrews Bay, 

 on 14th March. They were very common during April and May. 



* Vide "On the Variation in Size of certain Pelagic Ova." Thirteenth Report 

 Scottish Fishery Board, p. 271. 



