Resolution of the Acroteriobatus leucospilus species complex, with a redescription of A. leucospilus (Norman, 1926) and descriptions of two new western Indian Ocean species of Acroteriobatus (Rhinopristiformes, Rhinobatidae)

Abstract Recent sampling efforts and examinations of museum material provided evidence for a complex species within Acroteriobatus leucospilus (Norman, 1926). The present manuscript contains redescription A. involving the syntypes additional material, as well formal descriptions two new Giltay, 1928. All specimens both were found in western Indian Ocean. Individuals first species, hereafter referred to andysabini sp. nov., identified originating from Madagascar, second stehmanni only off Socotra Islands at junction between Gulf Aden Arabian Sea. Both appear be endemic respective region allopatric occur coastal waters least 80 m 43 depth, respectively. They differ number characteristics including maximum size coloration fresh. nov. is large growing more than 100 cm total length (TL) with elongated bluish-gray spots on snout giving “stripe-nosed” appearance; numerous small pectoral, pelvic, dorsal, caudal fins; brown trunk fin bases; lateral tail folds striped orange white; ventral surface largely white but V-shape pattern faint dark speckled black tip. ~62 TL sparse patterning circular confined tip, posterior pectoral-fin margins, pair midbody, few pelvic-fin rather indistinct larger spots, white. medium-sized ~96 similar uniformly or blue brown. Taxonomical differences include nasal lamellae counts (42–48 vs. 43–48 37–41 ), angle (76–85° 71–77° 68–81°), dorsal head (24.2–33.5% 17.2–22.8% 24.0–29.2% TL). A key given time.