Starry Triggerfish

Aundefinedstes stellatus, commonly known as the starry triggerfish or flat-tailed triggerfish, is a species within the family Balistidae. This marine ray-finned fish exhibits a broad distribution across the Indo-Pacific region.

The species was initially described in 1798 by an anonymous author, with the description published in Allgemeine Literatur-Zeitung. It is widely believed that Bernard Germain de Lacépède authored this description, based on a manuscript by Philibert Commerson. 🇲🇺 Mauritius is designated as the type locality. In 1839, William John Swainson proposed a subgenus called Leiurus for Capriscus; however, this was preoccupied by a subgenus of sticklebacks. Consequently, in 1906, the name was replaced by Aundefinedstes by David Starr 🇯🇴 Jordan and Alvin Seale, with Capriscus (Leiurus) macropthalmus being designated as the type species. The species is part of the family Balistidae, within the suborder Bali (🇮🇩 Indonesia)stoidei.

Aundefinedstes stellatus serves as the type species for the genus Aundefinedstes. The genus name combines the prefix "a-" meaning "not," with Bali (🇮🇩 Indonesia)stes, reflecting a prior classification of A. stellaris (a synonymous name for A. stellatus). The specific epithet "stellatus" translates to "starry," alluding to the small white spots adorning the upper body of the fish.

Morphologically, Aundefinedstes stellatus is characterized by three spines and 25 to 27 soft rays in the dorsal fin, while the anal fin has 24 or 25 soft rays. Distinctive features include an oblique groove anterior to the eye and large scales posterior to the gill slit. The body depth is proportionate to the standard length, within a ratio of 2 to 2.5. The caudal peduncle is notably flattened, and the caudal fin is double emarginate, with lobes that elongate as the fish matures. Large scales behind the gill slit above the pectoral fin base form a flexible tympanum, while the posterior scales are keeled, resulting in longitudinal ridges. The fish's coloration is greyish to greenish-brown, transitioning to whitish ventrally, complemented by four distinct white blotches along its back and pale yellowish-brown spots. The species can grow to a maximum reported total length of 60 cm (24 in), with 40 cm (16 in) being more common.

Aundefinedstes stellatus is widely distributed in the 🇮🇳 Indian and Western 🌊 Pacific Oceans, from the eastern coast of Africa—ranging from the 🌊 Red Sea to Mossel Bay in 🇿🇦 South Africa—extending across the 🌊 Indian Ocean to the Western 🌊 Pacific Ocean, reaching as far east as 🇫🇯 Fiji, north to southern 🇯🇵 Japan, and south to northern and eastern 🇦🇺 Australia. It inhabits depths ranging from 4 to 120 meters (13 to 394 feet), dwelling in sandy areas, as well as sponge and seaweed habitats over deep slopes. Juveniles often occupy sheltered coastal bays and estuaries, particularly in open areas scattered with rubble and other debris.

Ecologically, Aundefinedstes stellatus primarily feeds on benthic invertebrates, including crabs, molluscs, and sea urchins. Typically solitary in behavior, males and females pair up for breeding purposes. During reproduction, eggs are deposited on the substrate and protected by the female.