Environment: milieu / climate zone / depth range / distribution range
; marino; acqua dolce; salmastro demersale; distribuzione batimetrica 2 - 25 m (Ref. 55207), usually 2 - 6 m (Ref. 55207). Subtropical; 0°C - ; 39°N - 17°N, 100°W - 75°W (Ref. 55207)
Western Atlantic: Chesapeake Bay to southern Florida in the USA and the Gulf of Mexico. Records from South America doubtful (Ref. 7251).
Length at first maturity / Size / Peso / Age
Maturity: Lm 22.0, range 22 - 23 cm
Max length : 61.0 cm WD maschio/sesso non determinato; (Ref. 6902); common length : 27.0 cm WD maschio/sesso non determinato; (Ref. 6902); common length :39 cm WD (female); peso massimo pubblicato: 4.9 kg (Ref. 40637)
Morfologia | Morfometria
Prominent triangular snout. Broadly rounded outer corners of disc. Upper surface brown or yellowish brown, paler toward margins of disc. Lower surface white (Ref. 6902). Few scapular spines. Middorsal row of spines present, but few on tail beyond pelvic fins (Ref. 7251).
Adults inhabit coastal waters, including estuaries and lagoons (Ref. 12951) and ascend rivers (Ref. 12951). They feed on tube anemones, polychaete worms, small crustaceans, clams, and serpent stars (Ref. 12951). Ovoviviparous (Ref. 50449). Parturition occurs in July and August (Ref. 27549). Litters of 2-3 pups; gestation 4 months (Ref. 114953).
Life cycle and mating behavior
Maturità | Riproduzione | Deposizione | Uova | Fecundity | Larve
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). Distinct pairing with embrace (Ref. 205).
Robins, C.R. and G.C. Ray, 1986. A field guide to Atlantic coast fishes of North America. Houghton Mifflin Company, Boston, U.S.A. 354 p. (Ref. 7251)
IUCN Red List Status (Ref. 124695)
Threat to humans
Pesca: di nessun interesse
Estimates based on models
Preferred temperature (Ref. 115969
): 23.2 - 27, mean 25.5 °C (based on 272 cells).
Phylogenetic diversity index (Ref. 82805
= 0.5039 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00646 (0.00265 - 0.01571), b=3.06 (2.86 - 3.26), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic level (Ref. 69278
): 3.5 ±0.42 se; based on food items.
Resilienza (Ref. 120179
): Molto basso, tempo minimo di raddoppiamento della popolazione più di 14 anni (K=0.26-0.31; Fec assumed <10).
Vulnerability (Ref. 59153
): Very high vulnerability (76 of 100) .
Nutrients (Ref. 124155
): Calcium = 46.6 [6.6, 268.1] mg/100g ; Iron = 1.23 [0.22, 4.59] mg/100g ; Protein = 21 [18, 23] % ; Omega3 = 0.522 [0.157, 1.602] g/100g ; Selenium = 21.3 [4.3, 85.8] μg/100g ; VitaminA = 13.4 [2.9, 63.7] μg/100g ; Zinc = 0.87 [0.22, 3.41] mg/100g (wet weight); based on nutrient studies.