310 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



weighting it down with pebbles. He then escorts 

 one or a succession of females to this nest, and 

 each of them deposits about 100 to 150 eggs in the 

 central cavity. The male then enters the nest 

 to fertilize the eggs, which stick in clumps to each 

 other and to the nest. Incubation occupies 6 to 

 10 days, during which period the male guards the 

 nest, driving away intruders large or small. He 

 tears down the nest when hatching-time ap- 

 proaches, but he continues to guard the fry 

 until these can shift for themselves. Many 

 males die after spawning. Those that survive 

 go back to sea in summer; the females, too. 



Figure 168.— Egg. 



Figure 169. — Larva, newly hatched, 4.3 mm. 



Figure 170. — Larva, 6.3 mm. 



Three-spined stickleback (Gasterosteus aculeatus). 

 After Kuntz and Radcliffe. 



The young fish are 4.25 to 4.5 mm. long when 

 hatched. The yolk sac is absorbed in three or 

 four days; when a week old they are almost 8 mm. 

 long; and the fry are of adult form with fins and 

 spines fully formed when 6 weeks old, and 14 to 

 16 mm. long. 67 They are 1% to 2 inches (40-50 



mm.) long when 2 years old, 2 to 2% (50-55 mm.) 

 at 3 years, according to European studies. 



General range. — Coasts and fresh waters of the 

 northern hemisphere; from Labrador, the Strait 

 of Belle Isle and northern Newfoundland to lower 

 Chesapeake Bay on the eastern coast of America, 

 and represented on the northwestern coast by a 

 form (Gasterosteus cataphractus Pallas 1811) that 

 probably is identical with the Atlantic species. 

 Its European range is from northern Norway and 

 Iceland to Spain, the Mediterranean, and the 

 Black Sea. 



Occurrence in the Gulf of Maine. — This stickle- 

 back is very plentiful all around the shores of the 

 Gulf from Nova Scotia to Cape Cod, living 

 indifferently in brackish water and in salt. The 

 ditches and creeks of the tidal marshes, brackish 

 ponds and lagoons, rock pools, and weedy shores 

 in shallow water are its favorite habitats. It 

 may be found practically anywhere in such places, 

 often in great numbers and in company with other 

 sticklebacks, for it is the commonest of its tribe in 

 the Gulf, as it is about Woods Hole. And so 

 many of them drift out to sea around the shores 

 of the open Gulf that we have taken them on the 

 eastern part of Georges Bank; over German Bank; 

 in the western basin off Cape Cod; near the Isles 

 of Shoals; off Seguin Island; and off Matinicus 

 Island. In the Bay of Fundy, however, they are 

 known only close to land and in the mouths of 

 estuaries. 



Importance. — This little fish is of no commercial 

 value in America. In Scandinavia, however, it 

 is sometimes seined in such quantities that it is 

 worth boiling down for oil. 



Two-spined stickleback Gasterosteus wheatlandi 

 Putnam 1867 68 



Jordan and Evermann, 1896-1900, as Gasterosteus gladiun- 

 cul-us Kendall, p. 2836. 



Description.- — This stickleback is said to differ 

 from the three-spined stickleback in having a 

 deeper body, fewer fin rays (9 or 10 dorsal and 

 7 or 8 anal) ; fewer dermal plates (5 or 6 as against 

 28 to 33); a caudal peduncle without keels; and a 

 strong cusp both above and below at the base of 



" Figures of stages in development of this fish are given by Kuntz and 

 Radcliffe (Bull. U. S. Bur. Fish., vol. 35, 1918, p. 131); A. Agassiz (Proe. 

 Amer. Acad. Arts Soi., vol. 17, 1882, p. 288, plate 9), and by Ehrenbaum (Nor- 

 disches Plankton, vol. 1, 1905-1909, p. 319). 



M This is the Gasterosleus blaculeatus of MitchUl 1815 and Storer 1867; 

 bispinosus of Walbaum 1792; gladiunculus of Kendall 1896, but not the O. 

 bispinosus of Jordan and Evermann 189G, which is a variety of Q. aculeatus. 

 For the reason for using the specific name wheatlandi, see Hubbs, Occasional 

 Papers, Museum of Zoology, University of Michigan, No. 200, 1925. 



