FEEDING HABITS OF MACKEREL. 397 



made, however, viz. in July, the heavy summer drift fishery was far on 

 the decline* and line fishing had commenced, an indication that the 

 fish liad begun to take prey of larger type. 



With further reference to the feeding habits of mackerel and herring, 

 in this instance kept in captivity at the Brighton Aquarium, the writer 

 is indebted to Mr. E. W. Cowley, the Superintendent, for the following 

 note. 



This observer states : " The herring and mackerel are usually taken 

 from the sea in October and November with the .seine net, which is 

 drawn on to the beach. They are then conveyed to the Aquarium in 

 cans the size of an ordinary sanitary bin, about 20 or 30 in each can. 

 Special care is taken to see that the ca*ns are not overcrowded, the 

 fish are not handled in any way, and conveyed to the tanks with the 

 greatest possible speed. Even with these precautions we consider 

 ourselves fortunate in saving 10% of the original catch. After they 

 are placed in the tanks great care has to be exercised to see that the 

 fish are in no way disturbed until they are acclimatized ; but we have 

 not found it necessary to darken the tanks. 



"In the case of the herring and mackerel we find that the placing of 

 a rock in the centre of the tank assists them considerably, unless of 

 course a tank 120 feet long is provided. 



" We feed both species upon sand-hoppers and small shrimps, alive if 

 possible, and vary the diet from time to time with whiting cut up into 

 small pieces. Of course great care has to be used not to overfeed them. 



"The feeding is done at regular times, viz. 12 noon and 4 p.m. I 

 have repeatedly noticed that the fish seem to know the time of feeding, 

 for at these hours they are always on the alert. Before the food falls 

 to the bottom of the tank it is devoured, and even when only a few 

 shrimps or sand-hoppers are left, the fish will dart hither and thither 

 after them. 



" Usually we keep the herring and mackerel in separate tanks, but 

 since last month (i.e. October, 1911) we have had them mixed, and I 

 notice that they are swimming intermingled. 



" During the summer months they both swim nearer to the surface 

 than in the winter, but they never seek the bottom, being continually 

 in motion, night and day. Otherwise there is no difference in their 

 summer and winter movements. The temperature of the water in the 

 tanks, which hold about 3000 gallons, is not so variable, I should 

 think, as that of the open sea. 



" Usually the mackerel live about two to three years, but we have 

 kept herring from four to five years. No examples have ever been 



* Vide "Weekly JIarket Reports," Fish Trades Gazette. 



