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Squalus mahia Viana, Lisher & Carvalho, 2017

Malagasy skinny spurdog
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Native range | All suitable habitat | Point map | Year 2050
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Squalus mahia   AquaMaps   Data sources: GBIF OBIS
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Classification / Names Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa

Elasmobranchii (sharks and rays) > Squaliformes (Sleeper and dogfish sharks) > Squalidae (Dogfish sharks)
Etymology: Squalus: Genus name from Latin 'squalus' meaning shark (Ref. 6885, 27436);  mahia: Name from Malagasy 'mahia' meaning skinny or very thin, referring to the particular morphological features of this species; noun in apposition..

Issue
Species information for completion.

Environment: milieu / climate zone / depth range / distribution range Ecology

Marine; pelagic-oceanic; depth range 55 - 500 m (Ref. 116247), usually 202 - 390 m (Ref. 116247). Tropical

Distribution Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri

Western Indian Ocean: restricted distribution from Socotra Islands and northern Madagascar to Algoa Bay, Eastern Cape in South Africa.

Size / Weight / Age

Maturity: Lm ?  range ? - ? cm
Max length : 50.0 cm TL male/unsexed; (Ref. 116247); 59.0 cm TL (female)

Short description Identification keys | Morphology | Morphometrics

This species is distinguished from its congeners by the following characters: a slender body with a narrow caudal fin, pointed dorsal and ventral caudal tips, and dermal dentils with markedly slender crowns; it is clearly distinct from its regional congeners S. acanthias, S. acutipinnis, Squalus cf. blainvillei, Squalus cf. mitsukurii, S. megalops, by having a ventral caudal lobe which is mostly white with a black caudal blotch near lower caudal origin; differs from S. megalops by having a more elongated first dorsal fin spine, with length 4.9% TL (4.2-5.1%) and corresponding to 0.6 (0.5-0.7) times the height of first dorsal fin in adult specimens (vs. 2.7-3.7% TL, 0.3-0.4 times in S. megalops), slender and upright dorsal fins (vs. wide and low), postventral caudal margins not uniformly white (vs. uniformly white); it differs from S. brevirostris and S. acanthias by its greater preoral length, its length 9.5-11.1% TL (vs. 8.5-9.1% TL for brevirostris and 8.3-9.2% TL for acanthias); differs from S. brevirostris and S. crassispinus by the thickness of its first dorsal fin spine of adults, base length 0.8-1.0% TL (vs. 0.5-0.7% TL for brevirostris and 1.1-1.3% TL for crassispinus); adults of Squalus mahia differs from S. acanthias and S. crassispinus by its first dorsal fin anterior margin length 10.5-12.2% TL (vs. 6.8-9.8% TL for acanthias and 12.6-12.9% TL for crassispinus); differs from S. acanthias and S. margaretsmithae by its greater prespiracular length. 12.4-13.7% TL (vs. 10.7-12.0% TL for acanthias and 11.5-12.3% TL for margaretsmithae); differs from S. chloroculus, S. edmundsi, S. lalannei, S. mitsukurii, S. montalbani, S. nasutus by having a smaller snout with prenarial length shorter than distance from nostril to upper labial furrow, and unicuspid and lanceolate dermal dentils (vs. prenarial length greater than distance from nostril to upper labial furrow, and tricuspid and rhomboid dermal dentils) (Ref. 116247).

Biology     Glossary (e.g. epibenthic)

A mesopelagic species, where its distribution indicates that it is a warmer-water species associated with the Mozambique and Agulhas currents (Ref. 116247).

Life cycle and mating behavior Maturities | Reproduction | Spawnings | Egg(s) | Fecundities | Larvae

Main reference Upload your references | References | Coordinator : Compagno, Leonard J.V. | Collaborators

Viana, S.T. d. F.L., M.W. Lisher and M.R. de Carvalho, 2017. Two new species of short-snouted dogfish sharks of the genus Squalus Linnaeus, 1758, from southern Africa (Chondrichthyes: Squaliformes: Squalidae). Mar. Biodiv. 1-28. (Ref. 116247)

IUCN Red List Status (Ref. 130435)

  Data deficient (DD) ; Date assessed: 01 August 2019

CITES

Not Evaluated

CMS (Ref. 116361)

Not Evaluated

Threat to humans

  Harmless





Human uses

FAO - Publication: search | FishSource |

More information

Trophic ecology
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Ecology
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Length-length rel.
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Internet sources

AFORO (otoliths) | Aquatic Commons | BHL | Cloffa | BOLDSystems | Websites from users | Check FishWatcher | CISTI | Catalog of Fishes: genus, species | DiscoverLife | ECOTOX | FAO - Publication: search | Faunafri | Fishipedia | Fishtrace | GenBank: genome, nucleotide | GloBI | Google Books | Google Scholar | Google | IGFA World Record | MitoFish | Otolith Atlas of Taiwan Fishes | PubMed | Reef Life Survey | Socotra Atlas | Tree of Life | Wikipedia: Go, Search | World Records Freshwater Fishing | Zoobank | Zoological Record

Estimates based on models

Phylogenetic diversity index (Ref. 82804):  PD50 = 0.5000   [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00339 (0.00162 - 0.00707), b=3.10 (2.93 - 3.27), in cm total length, based on LWR estimates for this Genus-body shape (Ref. 93245).
Trophic level (Ref. 69278):  4.2   ±0.3 se; based on size and trophs of closest relatives
Resilience (Ref. 120179):  Low, minimum population doubling time 4.5 - 14 years (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref. 59153):  Moderate vulnerability (44 of 100).