36 



As to the lower animal life in this locality, I shall mention here only 

 that the prawn {Palæmon Fabricii) lives and breeds in the basin in great 

 numbers, while it is not found at ah along the shores outside the harbour. 

 This is one example showing how quickly an animal will make its appearance, 

 when the conditions of its existence are fortheoming. 



I shall add that it was not knowu at all that the prawn was living here 

 in nnmbers, till the Biologicai Station arrived at Frederikshavn. 



Of other species of prawns we find here also, thougli in much smaller 

 numbers, Palæmon squilla and the shrimp [Crangon vulgaris). 



The common Crab [Carcinus mcenas) is found here in great numbers. 



2. The open Cattegat. 



a. The Sand-Banks. 



The low water on the above-mentioned sand-banks, along the open 

 shores, is a favourite dwelling-place of the tender fry of several species of fish. 

 As the scanty vegetation (a few bushes of bladder-kelp) afiords only few piaces 

 of refuge for these animals, it is of great importance to their safety when they 

 have, in their capability of changiug colour, a meaus of accommodating them- 

 selves to the appearance of the bottom. This is the case with the fry of several 

 of our flat-fishes which, when they have come out of the pelagic eggs that are 

 floating in the water, seek refuge on the sand-banks. 



To these fiat-fishes beloug: 

 The Plaice {Pleuronectes platessa). The eggs are met with already in February, 

 March, and April, in the sea; and in the first days of May the little 

 newly hatched young ones (the 0-group) are first appearing on the very 

 lowest water on the shores; but they do not occur more commonly in 

 here till the end of the month or the beginning of June. As they grow 

 larger, they go out a little farther, but in August the c. 5 months old 

 fish are still met with on 1 — 3 feet of water; they are then about 2 

 inches long. 



Besides the fry of the year, some of the young fish from the pre- 



ceding year (I-group) are generally living on the deepest piaces of this 



locality. 



The Flounder [Pleuronectes flesus), the 0-group as well as the I-group, and 



sometimes a few still older specimens. The fry of the year is in Au- 



