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

🌊 Marine Least Concern 🌡️ Deep-water

Risso's smooth-head

Alepocephalus rostratus Risso, 1820
Max Length
50 cm
Max Weight
-
Lifespan
23 yrs
Trophic Level
3.7
Depth
300–2250 m
Climate
Deep-water
Resilience
Very low
Vulnerability
60.00/100
Typical Length
-
Depth Zone
deep-water

📖 Overview

Risso's smooth-head (Alepocephalus rostratus) is a ray-finned fish of the family Alepocephalidae. It inhabits marine (saltwater) waters in deep-water environments. This species can reach a maximum total length of 50 cm. It occurs at depths between 300 and 2250 metres. With a trophic level of 3.7, it is a mid-level predator. It is assessed as Least Concern on the IUCN Red List.

Scientific Name
Alepocephalus rostratus
Authority
Risso, 1820
Habitat
Marine
Climate
Deep-water
Body Shape
Elongated
IUCN Status
LC
Max Length
50 cm
Lifespan
23 years
Depth Range
300–2250 m
Latitude
17°S – 64°N
Trophic Level
3.7
Resilience
Very low
Vulnerability
60.00/100
Salinity
30–40 ppt

🐟 Physical Description

Dorsal spines (total): 16 - 20; Anal spines: 17 - 20. : elongated.

🌀 Behaviour

Behavioural data for Risso's smooth-head is currently being reviewed.

🦐 Diet

aquatic invertebrates
small fish
algae
detritus

🥚 Reproduction

Size at Maturity
27.7cm TL

🌍 Habitat & Distribution

Marine; bathydemersal; depth range 300 - 2250 m . Deep-water; 64°N - 17°S, 22°W - 22°E northeast Atlantic and western Mediterranean to Cape Verde (Ref.

🌿 Ecology

Zone Preferences
🌊 Marine 🌑 Deep Water
Trophic Level
3.7±0.2
Food Items

pelagic crustaceans like euphausiids, decapods and mysids (Ref

📐 Morphometrics

Length–Weight Relationship: W = 0.00316 × L3.17 (TL)
Max TL
50cm
Dorsal Spines
18
Anal Spines
19

🌡️ Water Parameters & Tolerance

Salinity Range
30–40ppt

🛡️ Conservation Assessment

IUCN Category
Least Concern
Assessment Date
2012

📊 Population Risk & Fisheries

Population Resilience
Very low
Minimum doubling time
Fishing Vulnerability
60.00/100
High vulnerability
Trophic Level
3.7
Predator
Body Shape
Elongated
Climate Zone
Deep-water
Latitude Range
64°N – 17°S
Described By
Risso, 1820

👥 Community & Contribute

Aquareap Community Observations
0 Observations logged on Aquareap

No observations yet - be the first to log one!

View all observations for Risso's smooth-head ↗
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Spotted incorrect or outdated data?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.