SOME FRESHWATER AQUARIUM FISHES 



the streams hidden among the weeds and water plants, others under sub- 

 merged boughs to which the nest is attached, or upon stones and project- 

 ing ledges. The building is done solely by the male who assumes bright 

 colorings at this period. All kinds of material are collected and are matted 

 together to form the bottom, and held in place by sand and small pebbles. 

 Leaves, stems, twigs and other available materials are glued together with 

 a mucilagenous substance which is exuded from the body of the fish. 

 Next the sides and roof are formed, leaving only a circular opening through 

 which the female deposits the spawn. The male guards the young fishes, 

 not even permitting the female to approach the nest after spawning. He 

 assaults every living thing that comes into the neighborhood with his 

 sharp dorsal and ventral fins and teeth. About the tenth day after the 

 spawn has hatched, he begins to demolish the nest but keeps vigil over the 

 young for a month or more until they are able to take care of themselves, 

 when both he and the young disappear together. 



There is nothing more interesting in an aquarium than a pair of 

 sticklebacks. They should be supplied with an abundance of building 

 material in the form of aquatic plants, especially myriophyllum, nitella and 

 vallisneria, the long leaves of the latter being especially desirable for the 

 foundation of the nests. 



Three species are generally distributed, the Two-spined Stickleback, 

 Gasterosteus bispinosus; the Four-splned Stickleback, Afeltes quadratus; 

 Fig. 36, and the Ten-spined SitickXthsiC^iL, Pygosteus pungitius. The Four- 

 spined form Is abundant in the Delaware river. 



Daphnia, earthworms, small particles of fresh meat, insects and any of 

 the boiled cereals, sparingly fed, is the best food for the Stickleback in the 

 aquarium. 



THE SUNFISH 



The ordinary sunfish, Eupomotis gibbosus, is one oi the most widely 

 distributed of the freshwater fishes. There are many well-known species 

 which differ principally in their really beautiful markings and the shape of 

 the ear or gill-flap. ■ Nearly all the sunfishes are nest-builder^;., their spawn- 

 ing beds may be recognized by the clean appearance of the gravelly bot- 

 toms of streams and ponds, from which all vegetal matter, mud and peb- 

 bles have been either carefully removed by agitation with the fins and tail, 

 or carried away in the mouths of the fishes. Often the stems of the sur- 

 rounding aquatic plants are trained over the beds to form a perfect bower. 

 After depositing the spawn it is carefully watched by the parent fishes, 



73 



