Desjardin's Sailfin Tang

Species and Taxonomy

Zebrasoma desjardinii, commonly referred to as the 🌊 Red Sea sailfin tang, Desjardin's sailfin tang, 🇮🇳 Indian sailfin tang, or 🇮🇳 Indian sailfin surgeonfish, is a marine ray-finned fish categorized within the family Acanthuridae. This family includes surgeonfishes, unicornfishes, and tangs. The species is primarily located in the 🌊 Indian Ocean.

Historical Taxonomy

Initially described in 1836 as Acanthurus desjardinii by the English zoologist Edward Turner Bennett, with 🇲🇺 Mauritius identified as the type locality, Zebrasoma desjardinii was once considered conspecific or synonymous with Zebrasoma velifer. The genera Zebrasoma and Paracanthurus constitute the tribe Zebrasomini within the subfamily Acanthurinae, as per the 5th edition of "Fishes of the World."

Etymology

The specific name desjardinii honors the French zoologist Julien Desjardins, who resided in 🇲🇺 Mauritius for an extended period and contributed a collection of fishes to the British Museum of Natural History, including the type specimen of this species.

Morphological Characteristics

Zebrasoma desjardinii is characterized by a high dorsal fin, comprising 4 spines and between 27 to 31 soft rays, with the longest soft ray being about half the standard length. The anal fin features 2 spines and between 22 to 24 soft rays. The species has a deep body with a standard length that is 1.8 to 2 times its depth. The maximum published total length is 40 cm (16 in). The species possesses a protruding mouth and a concave snout profile. The caudal peduncle spine has a narrow posterior connection to the body, and the caudal fin is truncate. The body exhibits a grey coloration with approximately 8 dark grey vertical bars, each containing 2 to 3 orange or yellow vertical lines that fragment into spots towards the lower body and the anal fin. Two dark brown bars adorn the head, with one bar passing through the eye. A dense pattern of small, light yellow spots covers the head and body, along with similar spot arrangements on the dorsal fin. The caudal fin is adorned with pale blue spots. Juveniles display slender grey and yellow body bars and 2 black head bars.

Geographical Distribution

Zebrasoma desjardinii inhabits the 🌊 Indian Ocean, with locations extending off the eastern coast of Africa, as far south as Sodwana Bay, 🇿🇦 South Africa, and throughout the Middle East, including the coasts of 🇮🇱 Israel, 🇸🇦 Saudi Arabia, and 🇾🇪 Yemen. The species is also distributed across various 🌊 Indian Ocean islands, including 🇱🇰 Sri Lanka, islands in the Andaman Sea, Sumatra (🇮🇩 Indonesia), Java, the Cocos (Keeling) Islands, and Christmas Island. An isolated observation in 1999 recorded a pair off the coast of Florida in the Atlantic Ocean, likely from aquarium release.

Habitat and Ecology

This species is found at depths ranging from 1 to 30 m (3 ft 3 in to 98 ft 5 in) in lagoon and seaward reefs, with juveniles typically occupying more sheltered reef areas.

Behavior and Diet

Adults are generally observed in pairs, whereas juveniles are solitary. The diet primarily consists of filamentous algae, macroalgae, and plankton. In the 🌊 Red Sea, individuals have been noted feeding on jellyfish (Scyphozoa) and comb jellies (Ctenophora). Algal feeding may occur in aggregations, during which the predatory slingjaw wrasse may mimic the tangs' coloration and feeding behavior to hunt prey.

Reproduction

Zebrasoma desjardinii exhibits pair spawning, a trait common within its genus, although group spawning is more prevalent at the family level.