FISHES 165 



at one end, which anchor them securely to solid 

 objects. 



The simplest attempt at nest-making amounts to no 

 more than the excavation of a shallow depression in the 

 sea or river bed. The Salmon, which is both fresh- water 

 and marine, ascends a selected river in the pairing season, 

 and with its fins and body makes a shallow trough for the 

 deposition of the eggs, a labour which leaves lasting 

 evidence upon its scales. The primitive Lampreys, on 

 the other hand, effect nest-building by laboriously lifting 

 stone by stone in their suctorial mouths, male and female 

 combining to lift particularly heavy boulders. 



A further step in nest-making consists in roughly pushing 

 together scraps of weeds, etc., until they form a more or 

 less globular mass, which the male hollows out by tunnelling 

 into and so forming a safe retreat in which his partner 

 can deposit the eggs. The marine Stickleback {Spinachid) 

 and many of our native Wrasses (Labridae) make nests 

 of this description, though in compactness and finish 

 such efforts fall far below the standard of the Common 

 Stickleback (Gasterosteus) of our ponds and ditches. 

 It is noticeable that in by far the larger proportion of such 

 nesting efforts the labour devolves almost entirely on the 

 male, the sexes rarely combining in family duties. Still 

 more rarely do they fall to the female, apart from the actual 

 deposition of the eggs. 



The most popular form of nest-making amongst sea 

 fishes is the selection of a ready-made retreat as offered 

 by a rock cranny or empty mollusc shell. Various 

 Blennies, Bullheads and Sand Gobies, all small coastal 

 fishes abundant between tide limits, habitually make such 



