Elasmobranchii (sharks and rays) > Carcharhiniformes
(Ground sharks) > Scyliorhinidae
Etymology: .tenuicephalus: Name from Latin 'tenuis' for slender and 'cephalus" for head; referrring to the remarkably narrow head and snout of this species.
species (lat. tenuis = slender, cephalus = head).
Environment: milieu / climate zone / depth range / distribution range
Marine; pelagic-oceanic; depth range 463 - 550 m (Ref. 106604), usually - m (Ref. ). Tropical; 0°C -
Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri
Western Indian Ocean: off Tanzania and Mozambique.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 300 cm TL male/unsexed; (Ref. 106604)
Morphology | Morphometrics
This species is distinguished from its congeners by the following characters: slender head and snout, only slightly bell-shaped in dorsoventral view without distinct lateral indention (vs. distinctly bell-shaped snouts with a strong lateral indention anterior to outer nostrils); has broader claspers in adult males, the base width 2.1% TL (vs. 1.51.8% TL of congeners in the western Indian Ocean); further differs from B. clevai by having a smaller maximum size and a color pattern of fewer and smaller blotches, larger oral papillae, a shorter snout, and broader claspers without knob-like apex and with a smaller envelope and a subtriangular (vs. subrectangular) exorhipidion; differs from B. hispidus by having a longer snout, a longer dorsal-caudal space, broader clasper without knob-like apex, and fewer vertebral centra; differs from B. lutarius by having a smaller maximum size and has a blotched (vs. largely plain) coloration, numerous (vs. lacking) oral papillae, shorter anterior nasal flaps, a longer caudal fin, a shorter pelvic anal space, and shorter and broader claspers (Ref. 104913).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Kaschner, C.J., S. Weigmann and R. Thiel, 2015. Bythaelurus tenuicephalus n. sp., a new deep-water catshark (Carcharhiniformes, Scyliorhinidae) from the western Indian Ocean. Zootaxa 4013(1):120-138. (Ref. 104913)
IUCN Red List Status (Ref. 124695)
Threat to humans
CountriesFAO areasEcosystemsOccurrencesIntroductionsStocksEcologyDietFood itemsFood consumptionRation
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 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
): 5.0 ±0.5 se; based on size and trophs of closest relatives
Resilience (Ref. 120179
): Very Low, minimum population doubling time more than 14 years (Preliminary K or Fecundity.).
Vulnerability (Ref. 59153
): Very high vulnerability (85 of 100) .