248 ACANTHOPTERTGII. 



Habits. — This is a marine species, the limit of whose existence has been 

 erroneously fixed at one year (Lloyd). Occasionally it strays into brackish waters, 

 and has been said to have ascended a short distance up rivers, but this is denied 

 by most authors. But its most common residence appears to be along the bases of 

 sea-weed covered rocks, or among the stems of fuci at the sea bottom, although 

 it is sometimes found in rock pools and under stones between tide marks. It 

 feeds on worms, small Crustacea, the eggs and fry of other fish, and animal 

 substances. Yarrell found in them numerous examples of the opossum shrimp, 

 Mysis. At the Westminster Aquarium (Dec. 1879) some might occasionally be 

 seen floating along in a perpendicular manner, the head being uppermost : or else 

 quite still on some marine plant, retaining the same position, or the head might be 

 occasionally downwards. They do not move their fin rays in the rapid manner 

 of the Hippocampus. Couch observed one under the influence of teiTor change 

 from a dark olive with golden sides to a pale hue, and so remain for eighteen hours. 



Means of capture. — Dredging, trawling, shrimp nets, and found under stones 

 and among sea-weed at low water. 



Breeding. — In spring in some quiet spot as a harbour or place where the water 

 is pure but the locality sheltered from the violence of the waves, or even between 

 tidemarks where the nest may be left uncovered for two or three hours at a time. 

 The form of the whole structure is pear-shaped and about the size of a man's fist. 

 Admiral Milne, in the Edinburgh Philosophical Journal, writing on fishes' 

 nests evidently refers to that of the fifteen-spined stickleback. Dr. Swainson 

 considered them to have been constructed by gobies, but Mr. Maclaren had 

 assured him that he had watched the stickleback in the act of making them. 

 In an aquarium this fish commences constructing its nest in the spring, but 

 it is never completed. The fifteen-spined stickleback usually chooses as a 

 foundation for its nest the over-hanging branch of a sea-weed, and one was 

 observed to have selected the loose end of a rope, from which the separated strands 

 hung at about a yard below the surface over a depth of four or five fathoms. 

 Either the materials at hand are employed or the fish collects some of the softer 

 sea-weeds which it joins together with so much of the coralline tufts, Janice, as 

 will be suSicient to afford the required firmness. It stitches the materials together 

 with a thread, the material employed being very elastic and which has been 

 likened in appearance to silk. This nest is watched over by the parent fish, 

 supposed to be the male, which does not leave its station but continues guard for 

 three or four weeks until the young are able to shift for themselves. 



As food. — It is worthless, while its sides are too well protected even for bait. 

 It is used as manure and for obtaining oil from. 



Hahitat. — From the coasts of northern Europe, especially the North Sea. and 

 Baltic : in vast numbers off Holland : along the coasts of Prance : it is found 

 round the British Isles, also ofi the English Channel to the Bay of Biscay. 



In the Orkneys and Zetland it is very frequent. It breeds at Wick (Peach) : 

 common among the pools at Banff (Edward) : at Peterhead (Tarrell) : Aberdeen 

 (Sim). Only two instances have been recorded from the Moray Firth (Gordon, 

 Zool. 1852, p. 3458) : abundant in rock pools at St. Andrew's (Mcintosh): 

 Firth of Forth (Neill). By no means uncommon on the coast of Berwickshire 

 (Johnston) : similarly numerous along that of Yorkshire (Yorkshire Vertebrata) : 

 at Yarmouth it has been said to be rare (Paget) : it is uncommon along the Sussex 

 coast : at Weymouth it is abundant around the quays (P. Gosse) : Plymouth and 

 south coast (Parfitt) : Dawlish : and common in Cornwall (Cornish Fauna) : a 

 local example exists in the Weston-super-Mare Museum : and the fry have been 

 observed on the coast of Anglesea (Donovan). 



In Ireland it is found all round the island, most being taken on the south coast 

 where sprat fishing is most practised. Thompson had examples from Eathlin in 

 the north : Down and Antrim : Bundoran on the west and Youghal on the south. 



The example figured, life size, was from Shoreham. It attains to at least 7 

 inches in length. 



