FEEDING OF MARINE ANIMALS 



20I 



of branching tentacles around their mouths, have an original 

 manner of feeding (Fig. 43). The tentacles are usually- 

 projected out of the rock and, as they are covered with slime, 

 food quickly collects upon them ; but there are no cilia 

 to carry the food to the mouth, instead the tentacles are 

 deliberately curved inwards 

 and pushed to their fullest 

 extent into the mouth and 

 then slowly withdrawn, the 

 food being scraped off by 

 means of a pair of short 

 Y-shaped tentacle sat the side 

 of the mouth. One tentacle 

 after another is pushed into 

 the mouth in regular sequence 

 and sucked clean — exactly 

 like a child sucking jam off 

 its fingers ! One of the marine 

 snails called Vermetus, feeds 

 in a manner peculiar to itself. 

 It has largely lost the power 

 of movement but uses the 

 mucus, which such creatures 

 normally employ to lubricate 

 their movements, to catch its 

 food, throwing out a sheet of 

 sticky mucus in which fine 

 particles and animals are 

 entangled, and after a time 

 drawing this with the col- 

 lected food back into its mouth. 



Fig. 43. — The seacucumber, Cucumaria, 

 feeding (x £). 



BURROWERS AND SCRAPERS 



A great many animals (such as worms, and sea cucumbers) 



