STICKLEBACKS AND FLUTE- MOUTHS. 405 



fighting, the males make full use of the formidable spines on the back, with which 

 they have been seen to rip open the body of an antagonist. The most interesting 

 trait in the economy of sticklebacks is, however, undoubtedly the nest-building 

 habit of many of the species. In the sea-stickleback the nest is composed of a 

 mass of pendent seaweeds, bound together by a silk-like thread into a pear-shaped 

 form, in the centre of which are deposited the eggs. Such a nest has been known 

 to be guarded for a period of upwards of three weeks by the male parent fish ; and 

 when it sustained any damage, by which the eggs were exposed to view, the 

 watchful guardian set about repairing the mischief with the greatest despatch and 

 energy, thrusting its nose deep into the structure, and pushing and pulling the 

 materials till all was once more sound. The following account of the nesting of 

 the three-spined stickleback in an aquarium was forwarded by a correspondent to 

 Frank Buckland. On this occasion the male " selected a spot nearly in the centre 

 of the trough, and busily set to work to make a collection of delicate fibrous 

 materials, placed on the ground, and matted into an irregularly circular mass, 

 somewhat depressed, and upwards of an inch in diameter, the top being covered 

 with similar materials, and having in the centre a rather large hole. His work 

 was commenced at noonday, and was completed, and the eggs deposited by half- 

 past six in the afternoon. Nothing could exceed the attention from this time 

 evinced by the male fish. He kept constant watch over the nest, every now and 

 then shaking up the materials and dragging out the eggs, and then pushing them 

 into their receptacle again, and tucking them up with his snout, arranging the 

 whole to his mind, and again and again adjusting it till he was satisfied ; after 

 which he hung or hovered over the surface of the nest, his head close to the 

 orifice, the body inclined upwards at an angle of about 45, fanning it with the 

 pectoral fins, aided by a side-motion of the tail. This curious manoeuvre was 

 apparently for the purpose of ventilating the spawn; at least by this means a 

 current of water was made to set in towards the nest, as was evident by the 

 agitation of particles of matter attached to it. This fanning or ventilation was 

 frequently repeated every day till the young were hatched; and sometimes the 

 fish would dive head foremost into his nursery and bring out a mouthful of sand, 

 which he would carry for some distance and discharge with a puff! At the end 

 of a month the young ones were first perceived. The nest was built on the 23rd 

 of April, the young appeared first on May 21. Unremitting as had been the 

 attention of this exemplary parent up to the time of the hatching of the eggs, he 

 now redoubled his assiduity. He never left the spot either by day or night ; and 

 during the daytime he guarded it most pertinaciously, allowing nothing to 

 approach. . . . The fry were at first so minute and transparent that they were 

 scarcely perceptible, and it was only by a slight fluttering motion their position 

 could be occasionally discovered ; otherwise it was impossible to detect them." 



Although the name of pipe-fishes is frequently applied to the 

 members of the second family of the group under consideration, it 

 is better to restrict that term to the Syngnathidce (described in the sequel), and 

 take that of flute-mouths for those to be now noticed. As a family, the flute- 

 mouths are readily distinguished from the sticklebacks by the production of the 

 bones of the muzzle into a long tube, terminated by a small mouth ; and likewise 



