Elasmobranchii (sharks and rays) >
Rhinopristiformes (Shovelnose rays) >
Rhinobatidae (Guitarfishes)
Eponymy: Dr Johann Horkel (1769–1846) was a German physician and botanist who had an example of this species, preserved in alcohol, that he provided to the authors. [...] (Ref. 128868), visit book page.
More on authors: Müller & Henle.
Environment: milieu / climate zone / depth range / distribution range
Ecology
Marine; demersal; oceanodromous (Ref. 51243); depth range 1 - 150 m (Ref. 114953). Subtropical; 24°S - 41°S, 63°W - 55°W (Ref. 114953)
Western South Atlantic: From Rio de Janeiro to Argentina.
Size / Weight / Age
Maturity: Lm ? range ? - ? cm
Max length : 138 cm TL male/unsexed; (Ref. 57911); common length : 60.0 cm TL male/unsexed; (Ref. 6077)
Nostrils are longer, crown is flat transversely or even slightly convex, tubercles in median row are larger, thorn like, numerous. Origin of first dorsal is posterior to the tips of pelvic fins, equal to the base of first dorsal. Upper surface uniform olive gray or chocolate brown, without pale or dark markings. Snout with an oval sooty patch (Ref. 6902).
Found from the coast line to the continental edge. Females mature at ca. 90 cm TL (Ref. 114953). Feeds on crustaceans, cephalopods, polychaetes and small fishes. Ovoviviparous (Ref. 50449). Produces litters of 4-12 pups (Ref. 114953).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Exhibit ovoviparity (aplacental viviparity), with embryos feeding initially on yolk, then receiving additional nourishment from the mother by indirect absorption of uterine fluid enriched with mucus, fat or protein through specialised structures (Ref. 50449).
Compagno, L.J.V., 1999. Checklist of living elasmobranchs. p. 471-498. In W.C. Hamlett (ed.) Sharks, skates, and rays: the biology of elasmobranch fishes. Johns Hopkins University Press, Maryland. (Ref. 35766)
IUCN Red List Status (Ref. 130435: Version 2024-1)
Threat to humans
Harmless
Human uses
Fisheries: commercial
Tools
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Internet sources
Estimates based on models
Preferred temperature (Ref.
123201): 11.6 - 22.7, mean 15.6 °C (based on 248 cells).
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5039 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00282 (0.00134 - 0.00591), b=3.12 (2.95 - 3.29), in cm total length, based on LWR estimates for this Genus-body shape (Ref.
93245).
Trophic level (Ref.
69278): 3.8 ±0.49 se; based on food items.
Resilience (Ref.
120179): Very Low, minimum population doubling time more than 14 years (Fec=4-12).
Fishing Vulnerability (Ref.
59153): Very high vulnerability (83 of 100).
