504 Part III. — Twentieth Annual Report 



Sand Smelt. Atherina presbyter, Cuv. 



Twelve Sand Smelts, part of a small lot captured in Inverneil Bay on 

 October 31st, 1899, were recently examined. The length of the speci- 

 mens ranged from 5| to 8|- centimetres, and the stomachs of every one of 

 the twelve examined contained Copepods in considerable abundance. 

 One stomach was fairly well filled with Oiihona sp. ; one contained 

 Oitliona sp. and fragments of an insect ; but in the other ten the food 

 consisted of nearly equal numbers of Oitliona and Acartia. In one of 

 these ten there were also the remains of a few larval decapod Crustacea, 

 and in another a young Galaniis finmarchicus. The Oitlionas contained 

 in these stomachs appeared to be the one known as 0. spinifrons (or 0. 

 helgolandica) ; the Acartia was A. clausi. 



Grey Mullet. Mugil eJielo, Cuv. 



In the summer of 1900 three Grey Mullets were captured in the 

 salmon fishers' nets in the Bay of Nigg, near Aberdeen ; two were taken 

 on June 20th and one on July 4th, but only one stomach (one of the two 

 captured in June) contained food, and this consisted almost entirely of 

 Rhuoselenia ; there was a considerable quantity of these organisms in 

 this stomach, and mixed up with them were a few common Copepods — 

 Calanoids. 



ThPvBE-spined Stickleback. Gasterosteus aculeatus, L. 



Twenty-nine specimens of these Sticklebacks have been examined, one 

 from the Bay of Nigg, two from the Moray Firth, and twenty-six from 

 Loch of Loirston — within three or four miles from Aberdeen. The food 

 observed in the stomach of the specimen from the Bay of Nigg consisted 

 entirely of marine Copepods belonging to the Harpacticidse, and they 

 included Ectinosoma sp., Stenlielia sp., Daetylopus tisboides, and 

 Harpactieus sp. (probably H. fulvus) ; this Stickleback measured Q^^ 

 centimetres in length. 



The stomachs of the two specimens from the Moray Firth contained 

 small flat-fishes partly digested, and young Mysidfe. A number of 

 Copepods, chiefly Ectinosoma, were also observed in one of them, as well 

 as a few larval BaJani (cypris stage). These two specimens of 

 Gasterosteus measured &-^^ and 6| centimetres in length respectively. 



The twenty-six specimens from Loch of Loirston ranged from about 

 3| to 5 centimetres in length, but the length of most of them did not 

 exceed 4| centimetres. The stomachs of all the specimens, with only 

 one or two exceptions, contained Entomostraca in fewer or larger 

 numbers. Cyclops serrulatus and Bosmina longirostris Avere the two 

 species most frequently noticed ; the names of the others will be found in 

 the tabulated list. Insect larvfe wea.'e observed in a number of the 

 stomachs, and every one of these fishes was infested with cestoid parasites 

 {Scliistocephalus), the body cavity of the fish being in some instances 

 crammed with them ; eight comparatively large ScJiistocephali were taken 

 from the body cavity of a Stickleback scarcely 5 centimetres in length. 



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