Fishes of the JVestern North Atlantic 505 



mouth and the less blunt snout; although the maximum numbers of dorsal and anal 

 rays and of gill rakers average more in alpinus than m fontinalis,^ the overlap here is 

 too wide for these numerical differences to serve as a reliable basis for separation. 

 Neither is the shape of the caudal fin a safe clue to identity, for while the concavity 

 is somewhat less deep on the average among fontinalis'^ than among sea-run alpinus, it 

 is deeper in some freshwater trout from Labrador (seen by me) than in some alpinus 

 from eastern Greenland. 



Both the fontinalis complex and the alpinus complex include populations that 

 spend their entire life in fresh water, as well as populations that spawn in fresh water 

 but spend a part of the year in brackish or salt water, just as salmon do. It is with 

 these migratory populations alone that we are concerned here. 



Both complexes tend to vary widely in color and body proportions and in the 

 sizes to which they grow in different localities, as is reflected in the names under 

 which they have appeared in scientific literature (see Synonyms, pp. 523, 541). In 

 the case of fontinalis, these local varieties seem so clearly to be a result of en- 

 vironment that only one of the forms in question, agassizii Garman 1885, has been 

 recognized as a separate species, by Jordan, et al. (4J : 60), but doubtfully so in my 

 opinion. 



"The various forms of charr allied to Salvelinus alpinus (Linnaeus) present a . . . 

 confused picture to the systematist, for a myriad of forms, described and undescribed, 

 exist" (Walters, yi: 274); views have differed widely as to how many of these 

 deserve recognition as distinct species or as subspecies. On the one hand, six separate 

 species were listed for North America by Jordan, et al. {43: 60—61), 15 for the British 

 Isles by Regan (5^; 82—85), and 16 for the Soviet Union and adjacent countries by 

 Berg (in yi: 274). On the other hand, Goode {26: 501), following von Siebold's lead 

 {^g: 285—288) and finding it "difficult to believe that every little lake or group of lakes 

 in Europe possesses a well characterized species of fish," tentatively regarded the charrs 

 of Europe as representing a single highly variable species. This viewpoint is further 

 exemplified by Smitt's union of all charrs of Scandinavia, from both fresh and salt 

 water, in the single species, umbla Linnaeus, with alpinus Linnaeus and salvelinus 

 Linnaeus rated as synonyms (6j: 841). 



In view of this diversity of opinion as to the systematic status of the freshwater 

 charrs of the alpinus complex from different parts of the world, it is fortunate for pres- 

 ent purposes that sea-going populations of the western North Atlantic appear clearly 

 to represent a single species that seems to be identical to the common sea-run charr 

 of Greenland. This was described by Fabricius in 1780 as Salmo carpio {22: 170); 

 but this name had been previously applied by Linnaeus to one of the European 

 freshwater charrs (1758: 309). To replace carpio for our fish, Kendall {44: 507), 



3. S . fontinalis : dorsal rays 9-14, anal rays 8-12, gill rakers on first arch 4-8+ 7-9; alpinus: dorsal rays 9-15, anal rays 

 8-14, gill rakers usually 6-8+ 12-16, with a total of 13-22 reported. For meristic counts for sea-run trout of the 

 Moser River, Nova Scotia, compared with several populations of freshwater fontinalis, see Wilder {78: 186, tab.8); 

 for fontinalis compared with alpinus, see Vladykov {67: 909-912). 



4. The anglers' name, Square-tail Trout, is based on the contrast between fontinalis and Cristi-vomer namaycush (p. 453). 



