CHAPTER XIX 



THE SEA-ANEMONES AND THEIR ALLIES COELENTERA 



LEAVING some more difficult forms we may pass finally to the 

 sea-anemones and their allies, forms which always strongly 

 attract the aquarium-keeper. As a general rule, the animals 

 belonging to this great alliance are conspicuous and easily seen, 

 as compared with the shy and retiring worms. The meaning of 

 this is that they characteristically bear tentacles furnished with 

 stinging cells, which cause them to be disdained as food by most 

 other animals, especially fish. They thus do not need to seek 

 shelter like the edible forms. We shall begin this series with the 

 sea-anemones proper, because they are the most familiar forms. 

 The number of those available varies very greatly with the 

 particular part of the coast studied, persons placed on the south- 

 west coast being far more favoured in this respect than those 

 on the eastern side of Great Britain. Only a few of the commoner 

 forms can be mentioned by name, but those specially interested 

 should endeavour to obtain a copy of Gosse's Sea- Anemones, 

 which can sometimes be picked up cheaply from a second-hand 

 bookseller, and has fine coloured plates. 



Commonest and most suitable for the aquarium is the smooth 

 anemone (Actinia mesembryanthemum), which occurs in red, green 

 and brown varieties, and can always be recognised by the row 

 of blue beads to be seen at the base of the tentacles, when these 

 are fully expanded. These blue beads are clusters of stinging 

 cells. To obtain specimens of this anemone for the aquarium it 

 is only necessary to search under overhanging rocks in the shore 

 pools, choosing if possible forms attached to small stones or to 

 shells, so that the animal need not be disturbed. If such a speci- 

 men cannot be found, great care should be taken in detaching the 

 base from the rocks, for if this be injured the anemone will not 

 thrive in captivity. 



162 



