Environment: milieu / climate zone / depth range / distribution range
Οικολογία
Θαλασσινό(ά); Γλυκού νερού; Υφάλμυρο βενθικό(ς); κατάδρομος (Ref. 51243). 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).
Μέγεθος / Βάρος / Age
Maturity: Lm ? range ? - ? cm
Max length : 17.0 cm TL αρσενικό/απροσδιόριστο; (Ref. 5723); common length : 6.0 cm TL αρσενικό/απροσδιόριστο; (Ref. 12193); μεγ. αναφερόμενη ηλικία: 8 έτη (Ref. 27547)
Ραχιαίες άκανθες (συνολικά) : 8 - 10; Μαλακές ραχιαίες ακτίνες (συνολικά) : 17 - 20; Εδρικές άκανθες: 0; Μαλακές εδρικές ακτίνες: 12 - 15; Σπόνδυλοι: 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).
Inhabits gravel and rubble riffles of medium to large rivers and rocky shores of lakes (Ref. 5723). Occasionally enters estuaries (Ref. 5723) and nearshore coastal water (Ref. 43939). Feeds mostly at night and mostly on aquatic insects and benthic invertebrates (Ref. 27547). Generally solitary but large aggregations have been noted (Ref. 27547). Makes 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)
IUCN Red List Status (Ref. 130435)
Threat to humans
Harmless
Human uses
αλιεία: χωρίς ενδιαφέρον
Εργαλεία
Special reports
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Διαδικτυακές πηγές
Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00676 (0.00300 - 0.01523), b=3.17 (2.98 - 3.36), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
Τροφικό Επίπεδο (Ref.
69278): 3.2 ±0.3 se; based on diet studies.
Ελαστικότητα (Ref.
120179): Μεσαίο(α), ελάχιστος χρόνος για διπλασιασμό πληθυσμού 1,4 - 4,4 έτη (tm=3; tmax=8; Fec=100).
Fishing Vulnerability (Ref.
59153): Low vulnerability (10 of 100).
