of the Fishery Board for Scotland. 



147 



fish consumed by the cod are undoubtedly numerous, but they almost all 

 come under the category of casuals, and are not important factors in the 

 present inquiry. 



Finally, then, the statistics brought forward in the present report 

 appear to lead to the following conclusions — 



1. The cod feeds chiefly and constantly on Crustacea, Gadidae, and 

 Pleuronectidae. 



2. Aphrodite (sea mouse) forms an important part of the food in the 

 spring and summer in districts where this form is plentiful. 



3. In the winter the cod is attracted to our shores by the large shoals 

 of herring seeking their spawning ground, and at this time herring and 

 herring ova form the staple food material. 



4. The Echinoderms and Molluscs do not contribute an important part 

 of the food supply. 



5. The cod feeds much more on fish and much less on Echinoderms 

 than is the case with its ally the haddock. 



APPENDIX F.— No. VII. 



NOTES ON THE COPEPODS OF LOCH FYNE. 

 By W. L. Calderwood. 



On all occasions when out sailing from the Board's laboratory at 

 Tarbert, whether amongst the fishing fleets at night or for dredging pur- 

 poses by day, surface netting was engaged in, so that opportunities were 

 not wanting for obtaining specimens of the surface forms to be met with 

 in Loch Fyne. 



When looked at with regard to the food of the herring the surface 

 forms of greatest importance are, without doubt, the copepods, and on 

 that account more attention has been given to them than to any other 

 taken with the surface net. 



As spring advances the copepods appear in greater and greater numbers, 

 until, when the Loch Fyne fishing is at its height — that is to say, when 

 the herring are at their best — the copepods are in vast abundance. At 

 this season the prevailing species is Calanus finmarchicus, which occurs in 

 sufficient numbers in certain places to colour the surface of the water. 

 It is this species which serves as the principal food of the Loch Fyne 

 herring during the summer. 



In all twenty-eight species of copepods were obtained, not a few of 

 which were taken by Mr Scott, who has had charge of the Tarbert labora- 

 tory during the winter months. Of that number we have only been able 

 to identify seven in the stomachs of the Loch Fyne herring, and these were 

 the forms which occurred in greatest abundance, showing that although a 

 large variety of copepods abound, only those are taken which may be said 

 to occur in shoals. The seven species identified were Calanus Jinmarchicus, 

 Metridia armata, Pseudocalanus elongatus, Diets longiremis, Temora 

 longicornis, Centropages typicus, and Centropages liamatus. Subtended 

 is the list of the copepods, together with a short account of those features 

 by which each species can most readily be identified under the microscope 

 without dissection. The system of description is that adopted by Brady 

 in his valuable monograph of British copepoda. 



