262 Sticklebacks and other Nest-making Fish. 



young fry. Tlie negroes of Demerara, where these Hassars, 

 as they are called, are found, very readily catch the fish by 

 putting their hands into the water near the nest, when the 

 parent fish rushes furiously at them, and is thus captured. Dr. 

 John Hancock, who has given an interesting account of these 

 Hassars, one of which he calls the Flat-headed, the other the 

 Round-headed Hassar, thus speaks of the nests : — " The 

 Round-head forms its nest of grass, the Mat-head of leaves. 

 Both at certain seasons burrow in the bank. They lay their 

 eggs only in wet weather. I have been surprised to observe 

 the sudden appearance of numerous nests in a morning after 

 rain occurs, the spot being indicated by a bunch of froth, 

 which appears on the surface of the water over the nest. 

 Below this are the eggs, placed on a bunch of fallen leaves, or 

 grass, if it be the littoral species, which they cut and collect 

 together. By what means this is effected seems rather myste- 

 rious, as the species are destitute of cutting teeth. It may 

 possibly be by the use of their serrator arms, which form the 

 first ray of the pectoral fins." The Callichthys, another genus 

 of this family, manifests the same care for its young. 



The stickleback, the especial subject of this paper, is the 

 three-spined species {Gasterosteus aculeatus, Lin.). Yarrell 

 enumerates several species of this fish, but Mr. Couch* regards 

 most of these as mere varieties, and recognizes only three 

 species, viz., the one just named, the ten-spined (G. pungitius, 

 Lin.), and the fifteen-spined stickleback (G. Spinachia, Lin.), 

 a species entirely marine. All these, I believe, are nest- 

 builders. There is no doubt whatever 'about two of them, for 

 the nests of both have been seen by several observers, but I 

 cannot call to mind at present any notice of the nest of G. 

 pungitius. This species is not uncommon in ditches, and I 

 have often found specimens, but hitherto have searched in vain 

 for their nests. The three-spined sticklebacks are inhabitants 

 of both salt water and fresh. Mr. Couch, one of our best 

 authorities on all that relates to the habits of fish, remarks 

 that " they do not in preference frequent the open sea, and 

 that a quiet union of the sea water with the fresh appears the 

 most congenial with their nature — as we may judge by the 

 abundance to be met with in such situations." The same 

 author states that so numerous are they, that " in some places 

 they are employed for the purpose of feeding ducks and pigs ; 

 and sometimes they are drawn on shore in such heaps as to 

 serve for manure, for which purpose they are said to be of 

 considerable value — a fact not improbable, when, according to 

 Lacepede, they are known to afford, by pressure, a good supply 



* Fishes of the British Isles, i. pp. 167 — 184. Groombridge and Sons. 



