Fourhorn sculpin

📖 Overview

Occurs in cold brackish and moderately saline water near the coast . Enters coastal rivers and may occur as far as 120 miles inland . Landlocked in lakes . Maximum depth reported at 100m . Benthic . Movements are limited to short onshore-offshore seasonal movements and mass movements of fry into shallow water in autumn . Moreover, there are no migrations of large numbers; movement into freshwater and long distances up rivers are apparently undertaken by relatively few individuals at a time . Diurnal from November to April but is largely nocturnal the rest of the year . Feeds on small crustaceans, fishes and molluscs . Spawning takes place in shallow waters, male digs a groove in the gravel where pairing and egg laying occur. Move to deeper water in the spring, where they stay in summer . Landlocked populations are locally threatened .

🔬 Taxonomy

🐟 Physical Description

Dorsal spines (total): 7 - 9; Dorsal soft rays (total): 13 - 16; Anal spines: 0; Anal soft rays: 13 - 17; Vertebrae: 37 - 42. Identified by the four bony protuberances on the top of the head (the protuberances are smaller in females and young and absent in the freshwater form), the chainlike lateral line, the sharp spines on the preoperculum, and the absence of palatine teeth . Gill rakers reduced to rounded, spiny protuberances . Soft dorsal often much enlarged in adult males; caudal truncate to slightly rounded . Young gray above, with three or four dark saddles below dorsal fins and a dark spot on dorsal side of caudal peduncle; adults are darker; spiny dorsal fin dusted with black; soft dorsal, anal, pectoral and caudal fins have dark bars; pelvic fins pale .: fusiform / normal.

🌀 Behaviour

Behavioural data for Fourhorn sculpin is currently being reviewed.

🦐 Diet

🥚 Reproduction

Males become territorial and aggressive toward other males with the approach of the spawning season. Two or three days prior to spawning, the females become restless and swim about between short periods of rest. When a female swims over a male, he undulates his body from side to side and raises his spiny dorsal fin, If the female comes to rest near the male, he moves close to her in a series of short darts. Both then fan rhythymically with their pectoral fins, making a hole. The pair lie side by side, with the male's caudal fin twisted under that of the female. The male make rhythmic motions toward the female with his tail, and the motions apparently stimulate her to release her eggs . After spawning the female leaves the nest; the eggs are fanned and guarded by the male until hatching which occurs in the spring .

🌍 Habitat & Distribution

Marine; freshwater; brackish; demersal; depth range 0 - 100 m . Polar; 83°N - 41°N, 180°W - 180°E central Finland and Karelia (Ref.

🌿 Ecology

📐 Morphometrics

🌡️ Water Parameters & Tolerance

🛡️ Conservation Assessment

📊 Population Risk & Fisheries

🐠 Related Species

🔍 Similar Species

👥 Community & Contribute