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Part III. — Twenty-fifth Annual Report 



herrings sent from Stornaway, which is a West Coast station (see notes 

 under Stornoway). It is an interesting question why the Hyperiidse 

 should so frequently occur in the stomachs of East Coast herrings and so 

 sparingly in those from the West Coast. 



3rd — The Copepoda. The most important of the Copepod species as 

 herring food is undoubtedly Calainis. It will be observed that the 

 name given in my list to this form is Calanus helgolandicus, Claus, but 

 after all it may only be a smaller form of Calanus jinmarchicus, Gunner, 

 for, with the exception of size, the differences between them is not very 

 marked, and a familiarity with the two forms is necessary to enable one 

 to separate them — but this is a question that need not be discussed 

 here. 



Calanus is usually observed in greater quantity in stomachs of West 

 Coast herrings, and especially of those from the Clyde and Loch Fyne, 

 than in those from East Coast fishes, and it is noteworthy that the species, 

 though common enough in the Firth of Forth, appears to form a very 

 small portion of the food of herrings captured in that estuary. In Brook 

 and Calderwood's paper Copepoda are recorded on only two occasions 

 from herrings sent from the Firth of Forth, and they were not observed 

 at all in the stomachs of the herrings sent from Anstruther and 

 examined for this paper. Calanus has been obtained in the stomachs of 

 Loch Fyne and Clyde herrings, frequently in considerable quantity, 

 from April till November, in those from Stornoway in May and 

 June, and in those from Shetland in April. Other species of Copepoda 

 are sometimes observed in the stomachs of herrings, i.e. Centropages 

 hamatus and typicus, Temora longicornis, Metridia lucens, Pseudocalanus 

 elongatus, Acartla sp. and Oithona similis, but seldom in any quantity, 

 and are only of interest as bearing on the extensive bill of fare from 

 which the herring may select its food. 



4th — Schizopoda. All the Schizopoda found in the stomachs of 

 herrings caught off the Scottish coasts are, with few exceptions, members 

 of the family Euphausiidae, and belong to one or other of the three 

 genera Nydiphanes, Rhoda (better known perhaps as Boreophausia) and 

 Thysanoessa. On the other hand, Schizopoda belonging to the family 

 Mysidae such as Schistomysis spiritus, Norman, and Macromysis 

 flexuosa (0. F. Miiller), which at times are met with in swarms, and 

 other species of less frequent occurrence as Leptomysis gracilis, 

 Gastrosaccus spinifer, but which are also widely diffused in our coastal 

 waters, are rarely observed amongst the food of herrings. The only 

 Schizopod mentioned by Brook and Calderwood, other than species 

 belonging to the Euphausiidae, is a Siriella, and it is recorded from 

 the stomach of a herring from Tarbert, Lower Loch Fyne. One notable 

 characteristic of the Euphausiidae is that they all possess phosphorescent 

 organs, which appear to be entirely wanting in the Mysidae. This 

 power of becoming luminous which the Euphausiidae possess may explain 

 to some extent why they receive so much attention from the fish, while 

 the others are as seldom found in their stomachs. 



The Euphausiidae may be considered as equal to or even of greater 

 importance than the Calanoida as a food supply for herring both on the 

 East and West Coasts. Moreover, they have been observed in the 

 stomachs of herrings more or less all through the year from January to 

 December, though they appear to be more commonly met with during 

 the earlier and later months of the year. 



The Schizopod most in evidence, and most frequently recorded as 

 herring food, is Nyctiphanes norvegica (M. Sars), while Thysanoessa and 

 Rhoda are only occasionally mentioned; these two forms may, however, 



