Ambiente: milieu / zona climatica / distribuzione batimetrica / gamma di distribuzione
Ecologia
marino; acqua dolce; salmastro demersale; catadromo (Ref. 138280). Temperate; 68°N - 35°N, 175°W - 120°W
North America: Bristol Bay and Aleutian Islands, Alaska to northern California, USA. Isolated populations in lower Kobuk River (Alaska), Cultus Lake (British Columbia, Canada), and Lake Washington (USA) (Ref. 27547).
Dimensione / Peso / Età
Maturità: Lm ?  range ? - ? cm
Max length : 17.0 cm TL maschio/sesso non determinato; (Ref. 5723); common length : 6.0 cm TL maschio/sesso non determinato; (Ref. 12193); Età massima riportata: 8 anni (Ref. 27547)
Spine dorsali (totale) : 8 - 10; Raggi dorsali molli (totale) : 17 - 20; Spine anali: 0; Raggi anali molli: 12 - 15; Vertebre: 34 - 38. Distinguished by having only a single pore on the tip of the chin, no palatine teeth and no pronounced gap between 1st and 2nd dorsal fins (Ref. 27547). Dark brown to greenish or grayish on back and sides, with darker blotches; sides lighter, ventral areas white; usually two or three dark saddle-like blotches below soft part of dorsal fin; dark bars on dorsal, anal, pectoral and caudal fins; orange edge on spiny dorsal fin of spawning males (Ref. 27547).
Body shape (shape guide): elongated.
Adults inhabit gravel and rubble riffles of medium to large rivers and rocky shores of lakes (Ref. 5723). They occasionally enter estuaries (Ref. 5723) and nearshore coastal water (Ref. 43939). They feed mostly at night and mostly on aquatic insects and benthic invertebrates (Ref. 27547). Generally solitary but large aggregations have been noted (Ref. 27547). Adults make regular seasonal migrations associated with spawning (Ref. 27547). Considered a forage fish for some salmonids (Ref. 1998).
Adults make regular seasonal migrations associated with spawning. They move downstream to estuaries or at least to lower reaches of rivers in the spring, mostly at night (Ref. 27547). Eggs are deposited on the undersurface of a rock, in adhesive masses (Ref. 1998). Over 7,000 eggs have been found in a single nest, suggesting that a male may spawn with several females (Ref. 1998, 27547). The male guards the nest until all eggs have hatched (Ref. 1998, 27547). A reverse, upstream migration of yearlings and adults occur in late summer to early winter, from August to December (Ref. 27547).
Page, L.M. and B.M. Burr, 1991. A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston. 432 p. (Ref. 5723)
Stato della Lista Rossa IUCN (Ref. 130435: Version 2025-2 (Global))
Minaccia per l'uomo
Harmless
Usi umani
Pesca: di nessun interesse
Strumenti
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Fonti Internet
Stime basate su modelli
Indice di diversità filogenetica (Fonte Biblio. 82804) |
PD50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high]. |
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Bayesian length-weight
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a=0.00832 (0.00340 - 0.02033), b=3.16 (2.98 - 3.34), in cm total length, based on LWR estimates for this Genus-body shape (Ref. 93245). |
Livello trofico (Fonte Biblio. 69278) |
3.2 ±0.3 se; based on diet studies. |
Resilienza (Fonte Biblio. 120179) |
Medio, tempo minimo di raddoppiamento della popolazione 1.4 - 4.4 anni (tm=3; tmax=8; Fec=100). |
Vulnerabilità della pesca (Ref. 59153) |
Low to moderate vulnerability (34 of 100). 🛈 |