Himantura australis Last, White & Naylor, 2016
Australian whipray

Family:  Dasyatidae (Stingrays), subfamily: Urogymninae
Max. size:  140 cm WD (female)
Environment:  pelagic-neritic; marine; depth range - 45 m,
Distribution:  Western Central Pacific: confined to the Australasian Plate, from off Papua New Guinea and northern Australia, from Shark Bay (off Western Australia) to Brisbane (off Queensland) (Ref. 110363). Also Ref. 114953.
Diagnosis:  This species is distinguished by the following set of characters: the disc is weakly rhomboidal; preorbital snout is moderately short, its length 19-22% DW and rather broad, angle 117-127°, with a distinct apical lobe; lateral apices are narrowly rounded; the orbits moderately large, usually strongly protruding (particularly in young); 1-2, mostly heart-shaped suprascapular denticles which are not preceded before and after by a row of smaller primary denticles; secondary denticle band is developed before birth; dorsal surface of juveniles (smaller than 370 mm DW) are dark spotted or with spots and weak reticulations, subadults and adults (exceeding 390 mm DW) are more strongly reticulated; dorsal tail of juveniles has 3 rows of spots before caudal sting, faint dark saddles beyond sting (no alternating black and white bands on tail); tail uniformly dark ventrally; 146-152 pectoral-fin radials; 123 vertebral centra (excluding synarcual), 24 including synarcual 124 (Ref. 110363) Description: Similar to another Australasian species H. leoparda, but differ in coloration with Himantura australis having a more reticulated pattern on the dorsal disc in adults, with few suprascapular denticles and with broader snout in young and mostly in adults. It differs from H. undulata in having smaller reticulations, less elongated snout, and absence of a pair of pearl-shaped suprascapular denticles which are characteristic of H. undulata (Ref. 110363).
Biology:  Depth distribution is not well documented, but this species is primarily in shallow water from near the shore to at least 45 m depth (Ref. 110363). Enters estuaries and brackish water (Ref. 114953). The largest specimen (140 cm WD) is a pregnant female with 2 embryos (30 cm WD) (data not year published); the smallest confirmed adult male is 112 cm WD (Ref. 110363); born at ca. 29 cm WD. Produces litters up to 4 pups (Ref. 114953).
IUCN Red List Status: Least Concern (LC); Date assessed: 09 February 2021 Ref. (130435)
Threat to humans:  harmless


Source and more info: www.fishbase.org. For personal, classroom, and other internal use only. Not for publication.