OF THE CORNISH PILCHARD FISHERY. 



7 



observer situated at Milford in August of the same year, 

 Phaeocystis occurred in abundance along the coastal waters 

 of South Wales and the adjacent area, whereas at this time 

 from our personal observation it had entirely disappeared from 

 St. Ives Bay. The periodic occurrence of this species has 

 already been described by Dr. L. H. Gough,^^ but it ma\' 

 here be remarked that the estimation of its frequency, and in 

 fact its correct determination when occurring in stomach 

 material and preserved plankton samples, is at all times 

 difficult. 



M. Casimir Cepede's finding of Phaeocystis pouchefi 

 (Har.y'* in the stomach contents of fish examined in the spring 

 of 1906, agrees with our own observations made upon mackerel 

 and pilchard in April, 1906, and March and April, 1907. 



The available observations lending support to the theory 

 that this particular type of food on the other hand may be 

 H alosphaera vindis are fewer in number, and none of the 

 Continental authors hitherto cited make mention of the 

 occurrence of the species in material examined. In April, 

 1906, it was observed in more or less regular abundance in 

 plankton collected on the Western mackerel grounds, and 

 was occasionally observed in the stomach contents of a few 

 pilchards taken in the mackerel nets. 



An examination of the plankton tables for those Inter- 

 national Cruise Stations situated in the near vicinity to the 

 pilchard fishery area shows that the species is of far less fre- 

 quent occurrence than Phaeocystis in the first half of the year, 

 and that it does not belong to the group of organisms known 

 as " periodic plankton." 



Passing now to a general (X)nsideration of the food of the 

 pilchard, as determined from the observations obtained during 

 the present enquiry, it may first be stated that the fish from 



1'^ L. H. (j()u^»'h, "R<"p. on the Plankton of the Knff. Channel," Inter. Inv. 

 Mar. I^iol. Ass. Rep. i, p. 330. 



1^ Note. — The determination of the species, occurring- at the Inter. Cruise 

 Stations was for some time incorrect [vide Gough, op. cit. p. 339), and it is 

 possible that a similar error may here exist, since the identificaton was per- 

 formed on stomach material. 



15 Vide Bullen, G. E., "Plankton Studies in relation to the Western 

 Mackerel Fishery," Table No. i, 



C 



