New 🐟 Mercury Safety Guide & Omega-3 Rankings Updated for 2026. View Omega-3 Rankings →

💧 Freshwater Least Concern 🌡️ Temperate

Mountain Galaxias

Galaxias olidus Günther, 1866
Max Length
10.7 cm
Max Weight
-
Lifespan
4 yrs
Trophic Level
2.9
Depth
0–1 m
Climate
Temperate
Resilience
High
Vulnerability
19.00/100
Typical Length
7 cm
Depth Zone
-

📖 Overview

Facultative air-breathing in the genus ; Adults live mainly in small, clear, flowing streams with gravel or sand bottoms from near sea level to about 1800 m elevation. May be cryptic, living among log debris and boulders, or sometimes found in loose shoals in more open conditions. Also occur in small upland tarns where they may be found shoaling in open water. Tolerant of very cold water, they have been collected from a tarn surrounded by deep snow. Life cycle (maximum life span of about 4 years) is restricted to fresh water. Feed on benthic and drifting invertebrates. Mature individuals breed in spring (sometimes extending to autumn); adults move upstream into shallow riffle areas to lay their demersal, adhesive eggs over rocky bottoms .

Scientific Name
Galaxias olidus
Authority
Günther, 1866
Habitat
Freshwater
Climate
Temperate
IUCN Status
LC
Max Length
10.7 cm
Lifespan
4 years
Depth Range
0–1 m
Trophic Level
2.9
Resilience
High
Vulnerability
19.00/100
Water Temp
4–30 °C
Salinity
0–0.5 ppt

🐟 Physical Description

Dorsal soft rays (total): 7 - 12; Anal soft rays: 8 - 14; Vertebrae: 49 - 60. This species is distinguished by the following set of characters and careful comparison with the diagnoses, descriptions and geographical distributions of the other species: some populations, or individuals within a population, have a series of small, closely-spaced and short, distinct mid-lateral black bars, usually extending from near the pectoral fin base posteriorly to past the pelvic fin base, though equally as often, absent; body depth at vent moderately shallow (8.3-16.9 % SL); caudal peduncle length similar to that of caudal fin, relatively shortish, but moderately deep; dorsal midline usually partly flattened anteriorly from above pelvic fins; trunk with dorsal and ventral profiles relatively gently and evenly arched; interorbital often relatively flat though sometimes slightly to strongly convex; nostrils short to moderately long, usually non-visible from ventral view; mouth generally terminal, occasionally slightly sub-terminal; lower jaw shorter than upper jaw; caudal peduncle flanges usually low and long. generally reaching to, or near, the anal fin base; anal fin origin usually under 0.68 (0.21-1.14) distance posteriorly along dorsal fin base; pyloric caecae 1, more often 2, of moderate length (mean length of 3.1 % SL); gill rakers variable, short to moderately long and stout to moderately thin; expanded caudal fin rays usually equal to body depth through pectoral fin base, occasionally wider or narrower; lamina of paired fins oriented anterio-ventrally to ventrally; raised lamellae can be present on ventral surface of rays, and if so, weakly to strongly developed .Cross section: compressed.

🌀 Behaviour

Behavioural data for Mountain Galaxias is currently being reviewed.

🦐 Diet

aquatic invertebrates
small fish
algae
detritus

🥚 Reproduction

🐣 Oviparous
Spawning Season
spring
Spawn Location
Substrate
Fertilization
External

🌍 Habitat & Distribution

Freshwater; benthopelagic; depth range 0 - 1 m . Temperate; 4°C - 30°C

🌿 Ecology

Zone Preferences
💧 Freshwater
Trophic Level
2.9±0.49
Food Items

benthic and drifting invertebrates

📐 Morphometrics

Length–Weight Relationship: W = 0.00468 × L3.07 (TL)
Max TL
10.7cm
Dorsal Rays
10
Anal Rays
11
Vertebrae
55

🌡️ Water Parameters & Tolerance

Temperature Range
4–30°C
Salinity Range
0–0.5ppt

🛡️ Conservation Assessment

IUCN Category
Least Concern
Assessment Date
2019

📊 Population Risk & Fisheries

Population Resilience
High
Minimum doubling time
Fishing Vulnerability
19.00/100
Low vulnerability
Trophic Level
2.9
Omnivore / Planktivore
Climate Zone
Temperate
Described By
Günther, 1866

👥 Community & Contribute

Aquareap Community Observations
0 Observations logged on Aquareap

No observations yet - be the first to log one!

View all observations for Mountain Galaxias ↗
Suggest an Edit

Spotted incorrect or outdated data? Submit a correction and our editorial team will review it. Approved edits go live within 48 hours.

Link to a scientific paper, FishBase, or other authoritative source
Report an Issue

Found a factual error, broken data, or inappropriate content? Let us know and we will investigate promptly.