Further Growth; Breeding-age; Moulting. 241 



It is then somewhere about a quarter of an inch long ; later 

 on it begins to change its habits, moves towards the shores and 

 shallows, where it becomes a ground feeder. Whilst in the 

 /oi ; a, and immediately succeeding larval stages they can be 

 obtained numerously in the surface tow-net. After an interval 

 we find the young shrimps of half an inch upwards among the 

 pools on our muddy flats, as has already been described. We 

 get them from early spring, all during summer till late autumn. 

 During winter, or with an early spell of sharp, frosty weather, 

 their presence descends to zero. Their summer growth is 

 manifest, and they attain 1 inch to H inches ere shoaling off to 

 deeper water. 



The smallest size of females with abdominal eggs that we 

 have noticed have been 1| inches in length ; at 2 inches they 

 are quite numerous. Taking progressive growth into con- 

 sideration, it may be inferred these are not less than 12, say, 

 rather, 15 months old ; though maturity and eggs within the 

 ovary necessarily have been earlier. The large females pre- 

 sumably have attained several years of age ; but how long they 

 may ultimately live would be haphazard guess.* 



Exuviation. This, otherwise casting of the skin or moulting, 

 is common to the Crustacea, and the shrimp is no exception. In 

 former years, when the smacks had wells, it was a regular 

 occurrence for the men when cleaning them out to get almost a 

 shovelful of the shrimps' skins, the residue of their moultings. 

 These were found more particularly in the spring never in the 

 height of summer but a fair amount occasionally towards 

 the autumn season. 



In absence of wells, their moulting deceptively appears less 

 pronounced, only because, the shrimps coming on deck in a 

 heap, those with soft carapace are quickly passed over, almost 

 unnoticed. As soon as the rough hand-culling is finished the 



* Ehrenbaum holds that the N. German shrimps are productive at a year old, and 

 those at 2-2j inches ho reckons are 15 to 18 months of age. He expresses doubts 

 whether they ever attain more than three years, though the 2}-3-inch sized females 

 may be three years. We are inclined to think the 3J-3J inch specimens obtained by us 

 must have been nigh four years old or over. 



