Jordan and Evermann. — Fishes of North America. 747 



1098. GASTEROSTEUS ACt'LEATUS, Linna>us. 



(European Stickleback; Burnstickle.) 



Head 3J to ?>\ ; depth J ; eye 3| to 4 ; snout 3. Body rather stout, head 

 short, snout short, mouth oblique, niaxiUary not reachinff eye; caudal 

 peduncle depressed, keeled or not. Dorsal spines short and stout, usu- 

 ally a little shorter than snout and strongly serrate ; ventral spines about 

 as long as from tip of snout to pupil, serrate on each side, and with strong 

 basal cusp; ventral plate broad and long, longer than ventral spines or 

 about as long as snout and eye; processes from shoulder girdle widely 

 divergent inclosing a large triangular area. Lateral armature variable, 

 the plates 6 to 32, usually none on caudal peduncle ; in fresh-water speci- 

 mens caudal keel generally present but fleshy ; in unarmed specimens the 

 posterior plates when present on the caudal peduncle are much reduced in 

 size. The variation in the sticklebacks of Europe is very great, as w^as 

 pointed out by Day * some years ago. This is also shown by the studies 

 which Dr. Boulenger has recently made of the sticklebacks of England. 

 The various partly naked forms are not susceptible of definition even as 

 varieties. Coasts and streams of northern Europe ; abundant. We 

 include this form in the present memoir on the supposition that the mailed 

 form in Greenland, Gasttrosteus loricatus, Reinhardt, belongs to it. (acu- 

 leatus, spined.) (Eu.) 



Gaglerosletts acideatitg, Linnjjus, Syst. Nat.. Ed. x, 1758, 489, Europe; completely mailed. 

 Gasteiosteus trachurns, CuviEii & Valenciennes, Hist. Nat. Poiss., iv, 481, 1829, France; com- 

 pletely mailed; 31 plates. 

 Gasteriisteus ponlicns, Norpmann, in Demidoff, Voy. Rus9. Merid., iii, SAT, Tauria and Black 



Sea; plates fewer than in aculealuit. 

 Gasteriisleus semiarmatus, CuviEB & Valenciennes, Hist. Nat. Poibs., iv, 493, 18li9, Havre; 14 



plates. 

 Gasleruxteus semiloricalus, Cuvier & Valenciennes, Hist. Nat. Poiss., iv, 494, 1829, Baillon; 13 



plates. 

 Gasterosletis leiunts, CuviER & Valenciennes, Hist. Nat. Poiss., iv, 481, 1829, Seine; 6 plates. 

 f Gasterosteus loricatus, Keinhardt, Fauna Groenlandica, 32, 37, 1837, Greenland; fully armed; 



may be G. hispinosus. 

 Gasterosteus haiUoui, Blanchard, Poissoiis des eaux douces de France, 231, 1866, Abbeville. 

 GastercKleus ueuslriiinus, Blanchard, Poissons des eaux douces de France, 220, 1866, Harfleur; 



armature interrupted. 

 Gasleroslens arijentissimus, Blanciiard, Poissons des eaux douces de France, 232, 1866, Avignon; 



6 plates. 



*Dr. Francis Day observes: "It appears remarkable how many species of sticklebacks have 

 been named, outnumbering even those of the Salmonidie of the fresh waters, and it becomes a 

 first consideration whether any general principles are perceptible in the distribution of these 

 species or varieties. It is in the ocean more than in fresh waters that we must seek the spiny- 

 raj-ed fishes; and similarly it is on tlie seaboards or skirts of the ocean that we must look for 

 sticklebacks in which the armature of tlie sides is most developed (as in the variety trachurns), 

 while such as have the free portion of the tail unarmed are farthest inland or on elevated pla- 

 teaus; while in the center of Ireland I liave captured examples of O. puuijilius in which the arma- 

 ture had so decreased that the ventral spine was entirely absent. It has been poiuted out (Phil. 

 Mas., 185^, V, p. 299) that the variety on the continent witl> the shortest spine or the most 

 defenseless form, comes from Tuscany, and is peculiar to still waters, where it would have the 

 fewest enemies, and here it attains to a preat size. Taking larso numbers of Irish specimens I 

 found considerable difTereiices in the length of the ventral spines and pubic plates, conclusively 

 showing that such characters afford no reliable data. 



" Ilcckel and Kner, in their account of the fishes of Austria, did not admit the foregoing to be 

 more than varieties difTereiitiatcd by the development of the lateral scutes or plates, which they 

 found varied in number between 3 and 28.'" — Day. 



