Elasmobranchii (sharks and rays) >
Rajiformes (Skates and rays) >
Arhynchobatidae (Softnose skates)
Etymology: Rioraja: Latin, rivus = river (in Greek, rheo) + Latin, raja, -ae = ray, fish.
Eponymy: Jean Louis Rudolphe Agassiz (1807–1873) was a Swiss-American geologist, glaciologist and zoologist whose speciality was ichthyology. [...] (Ref. 128868), visit book page.
More on authors: Müller & Henle.
Environment: milieu / climate zone / depth range / distribution range
Ecology
Marine; demersal; depth range ? - 130 m (Ref. 26375). Subtropical
Southwest Atlantic: Espírito Santo, Brazil to Argentina.
Length at first maturity / Size / Weight / Age
Maturity: Lm 42.5, range 39 - 45.7 cm
Max length : 33.0 cm WD male/unsexed; (Ref. 26408)
A coastal species found on sand, mud or gravel bottoms (Ref. 26375). Feeds on crustaceans, mollusks and fishes (Ref. 26375). Oviparous (Ref. 50449). Eggs have horn-like projections on the shell (Ref. 205).
Oviparous, paired eggs are laid. Embryos feed solely on yolk (Ref. 50449).
McEachran, J.D. and K.A. Dunn, 1998. Phylogenetic analysis of skates, a morphologically conservative clade of elasmobranchs (Chondrichthyes: Rajidae). Copeia 1998(2):271-290. (Ref. 27314)
IUCN Red List Status (Ref. 130435: Version 2024-1)
Threat to humans
Harmless
Human uses
Fisheries: commercial
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Estimates based on models
Preferred temperature (Ref.
123201): 10.4 - 22.6, mean 14.8 °C (based on 300 cells).
Phylogenetic diversity index (Ref.
82804): PD
50 = 1.0000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00490 (0.00312 - 0.00769), b=3.02 (2.89 - 3.15), in cm total length, based on LWR estimates for this species & (Sub)family-body (Ref.
93245).
Trophic level (Ref.
69278): 3.6 ±0.0 se; based on diet studies.
Resilience (Ref.
120179): Low, minimum population doubling time 4.5 - 14 years (Assuming fecundity<100).
Fishing Vulnerability (Ref.
59153): Moderate to high vulnerability (52 of 100).
Nutrients (Ref.
124155): Calcium = 43 [7, 197] mg/100g; Iron = 0.911 [0.243, 2.649] mg/100g; Protein = 17.3 [14.6, 19.8] %; Omega3 = 0.522 [0.178, 1.883] g/100g; Selenium = 16.5 [4.9, 49.3] μg/100g; VitaminA = 16.8 [6.1, 46.1] μg/100g; Zinc = 0.769 [0.367, 1.401] mg/100g (wet weight);