PARENTAL CARE AMONG FRESH-WATER FISHES. 495 



The three-spined sticklebacks {Gasterostens) , ten or many spined 

 sticklebacks {Pygosteus), and those with four or five dorsal sj^ines 

 reclinable directly backward (Ei/cdiia) belong to it. 



One peculiar American tyiDe, the A]}eltines, have the pelvic bones 



Fig. 82.— Four-spined Stickleback {AikUck Fig. SZ.—ApdlcK. I'el- 



quadracus). After Storer. vis below. 



obtuse behind, lateral bars, and between them an unarmed belly. 



A third type, the Sphu(c/ui/ie.s, have the pelvic bones loosely con- 

 nected in front only and the ventral fins inserted farther l)ack than 

 ill the others; the body is also more elongated, the snout extends 

 forward in a somewhat tubiform manner, and the (h)rsal spines are 

 more numerous. 



The most generally difjtributed and characteristic of the genera 

 and that to which the largest species except Spinach ia belong is Gas- 

 terosteiis, or the three-spined sticklebacks. The body is comparatively 

 high and has a fusiform contour, there are two large free spines on the 

 back and a smaller one in front of the fin, and the ventral spines are 

 considerably behind the roots of the pectorals and under the inter- 

 space between the first and second dorsal spines. The most com- 

 mon species — common to Europe and America — is the Gasterosteus 

 aadentns. 



Almost any permanent body of water, however small, may har- 

 bor some. In the words of Smitt, " It is often met with in collections 

 of water so small and so isolated that it appears difficult, if not 

 impossible, to explain the manner in which it has been conveyed 

 thither, or the sources from which it derives its support. It is 

 fondest of calm water, and in summer frequents shallow spots close 

 inshore, especially where the sunshine has full play. Here it leads 

 a merry life, and one may often see it leap several centimeters out 

 of the water, while at other times it keeps still at the same spot, as 

 though there were nothing in the world to disturb it. But in a 

 moment it is all life and spirit and darts off with the speed of an 

 arrow. In stormy weather it is tossed on the waves and has thus been 

 cast even into a boat. Toward autumn it retires to deeper spots on the 

 shores of channels, estuaries, or larger inlets. In late autumn and at 

 the beginning of winter, however, it roams about in large companies." 

 It then prepares for winter quarters ; " when the cold is most severe, 

 it probably lies packed in large shoals at the bottom." 



