CHAPTER X 
EELS AND CAT-FISHES 
BY W. P. PYCRAFT, A.LS., F.Z.S. 
ELS, like flat-fishes, show plainly, in the shape of their bodies, a remarkably perfect 
adaptation to their environment. They are burrowing fishes, passing much of their time 
buried in the mud, and leaving little more than the head exposed. In accordance with 
this habit, the body is very long and round, and lacks both the hinder paired fins, and scales. 
When swimming, the body is propelled by rapid undulations, the movement being from side to 
side, it may be remarked, instead of up and down, as in the ‘ serpentine” movements of snakes. 
Whether all the fishes commonly regarded as eels really belong to this family or not is 
a moot-point. It is possible that the eel shape has been independently acquired by unrelated 
forms as a result of adaptation to a similar mode of life. But as the group now stands it 
embraces several distinct types,—the COMMON FRESH-WATER EELS; numerous marine species, 
such as CONGERS, SERPENT-EELS, DEEP-SEA EELS, and PAINTED EELS; and the fresh-water 
ELECTRIC EELS. 
The RIVER-EELS and CONGERS are perhaps the best known, and are also highly important 
food-fishes. That they are fishes of comparatively slow growth seems to be shown by the 
Photo by N. Laxcarnick) 
EELS 
Two species are shown in this photograph 
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