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🌊 Marine Data Deficient 🌡️ Tropical

Bach's catshark

Bythaelurus bachi Weigmann, Ebert, Clerkin, Stehmann & Naylor, 2016
Max Length
42.2 cm
Max Weight
-
Lifespan
-
Trophic Level
4.3
Depth
910–1365 m
Climate
Tropical
Resilience
Low
Vulnerability
25.00/100
Typical Length
-
Depth Zone
pelagic

📖 Overview

The females of this species based on total length are mature at 39.2 cm and immature at 36.1 cm, while males are mature at 40.0 cm and immature at 37.6 cm . The size at hatching based on the three post-embryonic specimens is estimated at around 12.0 cm TL .

Scientific Name
Bythaelurus bachi
Authority
Weigmann, Ebert, Clerkin, Stehmann & Naylor, 2016
Habitat
Marine
Climate
Tropical
IUCN Status
DD
Max Length
42.2 cm
Depth Range
910–1365 m
Trophic Level
4.3
Resilience
Low
Vulnerability
25.00/100
Salinity
30–40 ppt

🐟 Physical Description

This species is distinguished by the following characters: body firm and stout (slender in juveniles); snout long, preorbital length 4.7-7.6% TL and has a broad, bell-shaped in dorsoventral view with distinct lateral indention; pre-outer nostril length 1.1-1.9 times internarial space; preorbital snout length 0.7-1.0 times interorbital space; preoral snout length 1.0-1.9 times in mouth width; eye length 9.0-13.0 times in predorsal distance, 3.6-5.4 times in head length and 1.4-4.1 times eye height; head length 1.8-2.7 times width at level of maximum outer extent of anterior nostrils; head width at level of maximum outer extent of anterior nostrils 1.1-1.5 times width at level of lateral indention of head, 1.1-1.8 times preorbital length, and 7.2-10.0% TL; its tongue and roof of mouth densely set with oral papillae of distinct size, which are partially very large and conglomerated from several single papillae; pelvic anterior margin 1.1-2.1 times in pectoral-fin anterior margin; first dorsal-fin base 1.0-1.8 times in interdorsal space; length of second dorsal-fin inner margin 0.5-1.9 times in second dorsal-fin height; length of second dorsal-fin base 6.7-9.7% TL; anal-fin base 0.7-1.3 times interdorsal space; upper jaw with 70-84 and lower jaw with 60-76 rows of small tri- to pentacuspidate teeth with outer surface of crown furrowed by strong longitudinal ridges and structured by reticulations in basal areas; monospondylous trunk vertebrae centra 38-43, diplospondylous precaudal centra 33-43, total centra 124-132; dermal denticle morphology highly diverse in different body areas and post-embryonic specimens with very characteristic double row each of about 20 distinctly enlarged, blunt, spatulate, cross-based dermal denticles along dorsal trunk; claspers rather long and very thick, inner margin length 10.6-11.3% TL, base width 2.3-3.1% TL; no clasper hooks, cover rhipidion and pseudosiphon very large, envelope elongated. Colouration: body and fins plain beige to light grayish-brown, slightly brighter on ventral side Cross section: flattened.

🌀 Behaviour

Behavioural data for Bach's catshark is currently being reviewed.

🦐 Diet

small fish
crustaceans
cephalopods

🥚 Reproduction

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

🌍 Habitat & Distribution

Marine; pelagic-oceanic; depth range 910 - 1365 m . Tropical; 32°S - 34°S, 43°E - 46°E Indian Ocean: Madagascar Ridge at Walters Shoals.

🌿 Ecology

Zone Preferences
🌊 Marine 🐟 Pelagic
Trophic Level
4.3±0.5

📐 Morphometrics

Length–Weight Relationship: W = 0.00347 × L3.09 (TL)
Max TL
42.2cm

🌡️ Water Parameters & Tolerance

Salinity Range
30–40ppt

🛡️ Conservation Assessment

IUCN Category
Data Deficient
Assessment Date
2018

📊 Population Risk & Fisheries

Population Resilience
Low
Minimum doubling time
Fishing Vulnerability
25.00/100
Low vulnerability
Trophic Level
4.3
Apex / Top predator
Climate Zone
Tropical
Described By
Weigmann, Ebert, Clerkin, Stehmann & Naylor, 2016

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