Diagnosis: Salmo pallaryi differs from all other Salmo species and archaic trouts, except for S. platycephalus, by the overall dusky brown or blackish colour pattern, without contrasting colouration on trunk and fins in adults; it is most easily distinguished from S. platycephalus by the deep and narrow, sometimes pointed snout and large orbit, 25-31% of head length vs. the broad and flat snout and small orbit, 22% of head length, and more numerous scales, usually 18-20 vs. 16, between adipose fin and lateral line; it differs further in having number of anal fin pterygiophores 12-14, other Salmo species and archaic trouts have 10-12 (Ref. 55619).
Description: Snout blunt in females, moderately acute in males; snout length slightly shorter than horizontal orbit diameter; mouth terminal or slightly inferior; maxilla plus supramaxilla short with convex to straight upper margin, rarely extending to vertical of posterior margin of orbit (Ref. 55619). Large orbit, 25-31% of head length (Ref. 55619, 94556). Body variable both in depth and width; fins with rounded tips in most females and acute tips in most males (Ref. 55619). Number of pored scales in lateral line 105-114; 150-160 scales on longitudinal line; 25-26 scales above lateral line and 35-40 scales below lateral line; 17-21 scales from base of adipose fin to lateral line (Ref. 55619, 94553, 94556). Gill rakers externally on the first gill-arch numerous and slender, 7-10 and 11-13 on upper and lower limb respectively; left side branchiostegals most commonly 13, right side 10-12 (Ref. 55619). Anal fin iv-vi,8-10; dorsal fin v-vii,7-9; pelvic fin i,8-10; pectoral fin i,11-13; pectoral fin appendage on both sides or on left or right side; caudal fin with 15 and 12-14 upper and lower procurrent rays respectively in addition to 19 principal rays (Ref. 55619). Two epurals, 4-6 expanded neural spines; posterior margin of hypural complex often slightly concave with rounded postero-dorsal and ventral corners; vertebral count 56-59, 33-36 abdominal and 21-24 caudal vertebrae (Ref. 55619). Frontal broad at level of sphenotic, tapering evenly anteriorly giving cranium a triangular shape from above; rostral cartilage slightly concave or notched anteriorly; bone usually referred to as dermethmoid or supramesethmoid composed of two parts, jointed by flexible commissure; premaxilla slender with small mesial pocket for the rostral cartilage; maxilla with small teeth and short strongly inflected premaxillary process; small but distinct gap between palatine teeth and teeth on vomer head; vomerine longitudinal tooth row extending to posterior edge of vomer; glossohyal originally with four pairs of strong teeth; shape and number of infraorbitals different on left and right side (Ref. 55619).
Colouration: In preservative, small specimens with remnants of about 10-12 parr marks, larger specimens with overall dull, brownish or blackish colouration; ventral side lighter compared to sides of body and back; fins without any contrasting markings; sides of the head sometimes with traces of darker spots or a marbled pattern (Ref. 55619). Small dark spots on opercle (Ref. 94553).