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🌊 Marine Data Deficient 🌡️ Deep-water

Bighead portholefish

Margrethia obtusirostra Jespersen & Tåning, 1919
Max Length
8.3 cm
Max Weight
-
Lifespan
-
Trophic Level
3.5
Depth
100–1739 m
Climate
Deep-water
Resilience
High
Vulnerability
23.00/100
Typical Length
-
Depth Zone
deep-water

📖 Overview

Usually associated with continental and island slopes . Mesopelagic . Occurs at 100-300 m by day, 200-500 m by night . Feeds on crustaceans and small fishes . Photophore development complete by about 27 mm SL .

Scientific Name
Margrethia obtusirostra
Authority
Jespersen & Tåning, 1919
Habitat
Marine
Climate
Deep-water
Body Shape
Fusiform / normal
IUCN Status
DD
Max Length
8.3 cm
Depth Range
100–1739 m
Latitude
49°S – 33°N
Trophic Level
3.5
Resilience
High
Vulnerability
23.00/100
Salinity
30–40 ppt

🔬 Taxonomy

🐟 Physical Description

Dorsal spines (total): 0; Dorsal soft rays (total): 15 - 16; Anal spines: 0; Anal soft rays: 21 - 26. Yellowish in color, darker dorsally, opercle silver, caudal base and peduncle dark brown . Pectoral and pelvic fins colorless . Dorsal adipose fin present.: fusiform / normal.

🌀 Behaviour

Behavioural data for Bighead portholefish is currently being reviewed.

🦐 Diet

aquatic invertebrates
small fish
algae
detritus

🥚 Reproduction

🐣 Oviparous 📦 Batch Spawner
Spawning Season
spring-summer
Spawn Location
Pelagic
Fertilization
External

🌍 Habitat & Distribution

Marine; bathypelagic; depth range 100 - 1739 m . Deep-water; 33°N - 49°S, 98°W - 154°W south to Morocco including the Azores, Madeira and Canary Islands; off Cape Agulhas, South Africa (Ref.

🌿 Ecology

Zone Preferences
🌊 Marine 🌑 Deep Water
Trophic Level
3.5±0.48
Food Items

crustaceans and small fishes (Ref

📐 Morphometrics

Length–Weight Relationship: W = 0.01122 × L3.04 (TL)
Max TL
8.3cm
Dorsal Rays
16
Anal Rays
24

🌡️ Water Parameters & Tolerance

Salinity Range
30–40ppt

🛡️ Conservation Assessment

IUCN Category
Data Deficient
Assessment Date
2013

📊 Population Risk & Fisheries

Population Resilience
High
Minimum doubling time
Fishing Vulnerability
23.00/100
Low vulnerability
Trophic Level
3.5
Predator
Body Shape
Fusiform / normal
Climate Zone
Deep-water
Latitude Range
33°N – 49°S
Described By
Jespersen & Tåning, 1919

🗺️ Global Occurrence Map

Occurrence records from the Global Biodiversity Information Facility (GBIF) - 84 records indexed .

Occurrence density from GBIF View GBIF records ↗

👥 Community & Contribute

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