92 MARKETABLE BRITISH MARINE FISHES 



eggs inside with his pectoral fins. But the sea stickleback makes 

 a nest by binding loosely together the fronds of growing sea- 

 weeds by means of a thread which he spins from his own body. 

 It has recently been proved that this thread is a secretion from 

 the kidneys, which is produced only in the breeding season. 



The mode in which the eggs are protected in the pipe-fishes 

 is still more remarkable. They might fitly be called the 

 kangaroo-fishes, but the pouch is in the male parent instead of 

 the female. The male in the common or larger brown pipe- 

 fish, and in the broad-nosed pipe-fish, which is green in colour, 

 has a pouch beneath the tail behind the vent. The pouch is 

 formed by two long thick folds of skin which meet in the middle 

 line, but are not joined together. Into this pouch the eggs are 



Fig. 43. — Butter Fish with its mass of spawn; after Holt. 



received when shed by the female, the male fertilising them at 

 the same time, and there they remain until they are hatched, 

 when the young pipe-fishes, which are about an inch and a half 

 long and similar to their parents, escape. In the snake pipe- 

 fish, the body of which is smooth and rounded, there is no 

 pouch, but the eggs are attached to the skin of the male in front 

 of the vent. One species called the worm pipe-fish is very 

 small and slender, and is often found under stones at low tide, 

 on the south coast. 



It has been mentioned that the eggs of the gobies are 

 attached not simply by an adhesive surface but by special 

 threads or fibres. Such special modes of attachment of varying 

 kinds occur in the eggs of other fishes. In some adhesive eggs 

 of the ordinary kind there are indications that the egg-membrane 



