of the Fishery Board for Scotland. 



13 



The Distribution, Food, and Growth of the Angler. 



In another paper Dr. Wemyss Fulton describes the results of an 

 investigation of the distribution, rate of growth, and food of the 

 angler or frog-fish (Lophius piscatorius), one of the principal 

 enemies of the edible fishes. In the course of the trawling investi- 

 gations conducted on board steam-trawlers fishing from Aberdeen, 

 1956 specimens were taken, of which 1549 were caugho in the 

 Moray Firth. The proportional abundance of this fish was found 

 to be gi eater in Aberdeen Bay and the Moray Firth than in the 

 more distant grounds in deeper water off the Shetlands. As is the 

 case with so many other fishes, the young forms were absent from 

 the collections or only scantily represented, a circumstance believed 

 to be mainly due to their preference for rocky and rough ground, 

 where algae grow and furnish shelter and protection, and where the 

 trawl cannot be used. The smallest described was five inches in 

 length, which is among the smallest on record. 



The observations on the rate of growth were made by the com- 

 parison of a series of measurements of specimens taken at different 

 seasons, and indicate that at an approximate age of six months the 

 angler has a mean length of about six inches and three-eighths, at 

 one year and six months a mean length of about a foot, and at two 

 years and six months an average length of about eighteen inches. 

 The males probably reach maturity when four years of age, and the 

 females a year later with a larger size. 



In determining the nature of the food the stomachs of 541 anglers 

 were examined, and of these 261, or 48 '2 per cent., were empty. 

 Of the remainder, fish in some form or another were found in 269, 

 cephalopods alone in ten, and a shore crab in one. The proportion 

 of flat-fishes distinguished was 29*6 per cent., and of round-fishes 

 70'3 per cent., and it was found that the principal fishes preyed 

 upon were whitings, sand-eels, haddocks, common dabs, and herrings, 

 but the proportions varied on different grounds and at different 

 seasons. Very few of the anglers contained large fishes in their 

 stomachs. Even the largest seem to live for the most part on small 

 and young fishes ; some of the smallest of the anglers, however, had 

 swallowed fishes almost as long as themselves. It is probable that 

 the piscivorous habit is adopted at a very early stage. 



The Food of Fishes. 



Dr. Thomas Scott contributes to this Eeport a paper giving the 

 results of his continued investigations on the food of fishes as deter- 

 mined by the examination of the contents of their stomachs. The 

 food of twenty-two species of fishes is dealt with, including the cat- 

 fish, the king-fish, the silver smelt, the Norway pout, skates, and 

 dog-fishes. It is interesting to notice that the observations on the 

 contents of the stomachs of the dog-fishes show that while these 

 predaceous forms live to a large extent on the herring, they also 

 prey upon round fishes and flat-fishes, the remains of whitings, coal- 

 fish, dabs, and lemon soles being obtained in them. 



