Elasmobranchii (sharks and rays) > Carcharhiniformes
(Ground sharks) > Pentanchidae
Etymology: Bythaelurus: bythos (Gr.), depths of the sea, referring to its deepwater habitat; ailouros (Gr.), cat, probably an allusion to the vernacular “catshark,” so named for its cat-like eyes. (See ETYFish); vivaldii: In honor of Antonio Vivaldi (1678-1741), a “genius composer” of the Baroque era, to express its relationship to B. bachi, named after “sublime genius” Johann Sebastian Bach. (See ETYFish).
Environment: milieu / climate zone / depth range / distribution range
Marine; pelagic-oceanic; depth range ? - 628 m (Ref. 114990). Tropical
Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri
Western Indian Ocean: Off Somalia.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 32.5 cm TL (female)
Morphology | Morphometrics
This species is distinguished by the following characters: body firm and stout (of the presumably adult holotype and slender in supposedly juvenile paratype); snout is long (preorbital length 6.1-6.6% TL) and broad, bell-shaped in dorsoventral view with a distinct lateral indention; the pre-outer nostril length is subequal to internarial space; preorbital snout length is subequal to interorbital space; preoral snout length 1.4–1.8 times in mouth width; eye length 13.9-15.0 times in predorsal distance, 6.8-6.9 times in head length and 1.6-2.3 times eye height; head length 2.6-2.8 times width at level of maximum outer extent of anterior nostrils; head width at the level of maximum outer extent of anterior nostrils, 1.2 times width at level of lateral indention of head, 1.3–1.4 times preorbital length, and 8.5–8.6% TL; the roof of the mouth is loosely set with rather small, knob-like to elongated oral papillae, oral papillae on tongue hardly detectable; pelvic-fin anterior margin 2.0-2.1 times in pectoral-fin anterior margin; first dorsal-fin base 2.2-2.3 times in interdorsal space; length of second dorsal-fin inner margin 1.3-2.3 times in second dorsal-fin height; second dorsal-fin base length 5.3% TL; anal-fin base 0.7-0.8 times interdorsal space; upper jaw with 68-75 and lower jaw with 64 rows of small tri- to pentacuspidate teeth with outer surface of crown furrowed by strong longitudinal ridges from base of cusps to tip and strongly structured by reticulations from basal areas to well into cusps; monospondylous trunk vertebrae centra 38, diplospondylous precaudal centra 43-44, total centra about 135-140; dermal denticles leaf-like to teardrop-shaped on snout and tricuspidate on trunk and tail; reported to have 8–9 dark, broad but inconspicuous transverse bars on the back (preserved coloration plain beige with scattered remains of dark brown); .
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Weigmann, S. and C.J. Kaschner, 2017. Bythaelurus vivaldii, a new deep-water catshark (Carcharhiniformes, Scyliorhinidae) from the northwestern Indian Ocean off Somalia. Zootaxa 4263(1):097-119. (Ref. 114990)
IUCN Red List Status (Ref. 125652)
Threat to humans
CountriesFAO areasEcosystemsOccurrencesIntroductionsStocksEcologyDietFood itemsFood consumptionRation
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82804
= 0.5001 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01000 (0.00244 - 0.04107), b=3.04 (2.81 - 3.27), in cm total length, based on all LWR estimates for this body shape (Ref. 93245
Trophic level (Ref. 69278
): 4.1 ±0.4 se; based on size and trophs of closest relatives
Resilience (Ref. 120179
): Low, minimum population doubling time 4.5 - 14 years (Preliminary low fecundity).
Fishing Vulnerability (Ref. 59153
): Low vulnerability (23 of 100).