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

🌊 Marine Least Concern 🌡️ Tropical

Masked assfish

Bassozetus nielseni Tomiyama, Takami & Fukui, 2018
Max Length
61.5 cm
Max Weight
Lifespan
Trophic Level
3.7
Depth
3155–5440 m
Climate
Tropical
Resilience
Medium
Vulnerability
51.00/100
Typical Length
Depth Zone

📖 Overview

Overview information for Masked assfish is currently being compiled by our editorial team.

Scientific Name
Bassozetus nielseni
Authority
Tomiyama, Takami & Fukui, 2018
Habitat
Marine
Climate
Tropical
IUCN Status
LC
Max Length
61.5 cm
Depth Range
3155–5440 m
Trophic Level
3.7
Resilience
Medium
Vulnerability
51.00/100
Salinity
30–40 ppt

🐟 Physical Description

Dorsal soft rays (total): 122 - 129; Anal soft rays: 101 - 109; Vertebrae: 68 - 71. This species can be distinguished from its congeners by the following set of characters: D 122-129; long rakers on 1st gill arch 11-14; oblique scales 20-25; abdominal vertebrae 13-14; HL 18.1-21.3% SL; body depth at anal-fin origin 8.2-14.6% SL; predorsal length 16.4-20.1% SL; tail length 62.7-68% SL; posterior tip of pelvic-fin rays anterior to anus; one medial basibranchial tooth patch; dorsal margin of sagittal otolith smooth. Colouration: pale yellowish brown fins (preserved condition).Cross section: oval.

🌀 Behaviour

Behavioural data for Masked assfish is currently being reviewed.

🦐 Diet

Diet information for Masked assfish is currently being compiled.

🥚 Reproduction

Reproduction data for Masked assfish is currently being compiled.

🌍 Habitat & Distribution

Marine; bathydemersal; depth range 3155 - 5440 m . Tropical North Atlantic and Western Indian Ocean.

🌿 Ecology

Zone Preferences
🌊 Marine
Trophic Level
3.7±0.6

📐 Morphometrics

Length–Weight Relationship: W = 0.0038 × L3.14 (TL)
Max TL
61.5cm
Dorsal Rays
126
Anal Rays
105
Vertebrae
70

🌡️ Water Parameters & Tolerance

Salinity Range
30–40ppt

🛡️ Conservation Assessment

IUCN Category
Least Concern
Assessment Date
2018

📊 Population Risk & Fisheries

Population Resilience
Medium
Minimum doubling time
Fishing Vulnerability
51.00/100
Moderate-High vulnerability
Trophic Level
3.7
Predator
Climate Zone
Tropical
Described By
Tomiyama, Takami & Fukui, 2018

👥 Community & Contribute

Aquareap Community Observations
0 Observations logged on Aquareap

No observations yet — be the first to log one!

View all observations for Masked assfish ↗
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Spotted incorrect or outdated data?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.