Description:

Dorsal spines: 0; Dorsal rays: 9; Strong spine on middle of dorsal ridge. Anal spines: 0; Anal rays: 9.

A small boxfish. The back is somewhat convex, the flanks are concave and the belly rounded with lateral ridges, giving the fish its angular body shape. It has a pair of 
prominent forward projecting spines situated in fron of the eyes. Another pair of spines projects posteriorly below the caudal fin from the lower "corners of the box" 
(i.e.the rear of the ventro-lateral ridges). A single large anterodorsally curved spine situated in the middle of the back. Small terminal mouth with protruding lips. 
Caudal peduncle is relatively long and slender, the caudal fin is fan shaped. 

Colour. Greenish to yellow or brown with blue spots and dashes. Colour is variable and can change with surroundings.

Size:

Maturity: Unknown. Max length : 23.0 cm TL. Commonly to 15cm TL.

Habitat and Ecology:

Inhabit clear outer lagoon and seaward reefs, over rubble and sand (depth 5-132m, usually 6-30m). Feeds on benthic invertebrates, often exposed by jets of water from the 
mouth blowing away sand, and picked up by suction from the sea bed. Usually solitary. Males are territorial in the breeding season.
 

Fishery Status:

This species is not protected or subject to fishery regulations. The fish is considered poisonous/inedible but occasionaly retained for drying as an ornament.

Notes:

Photos (c) 2021 and courtesy Dr Olaf Jakobsen. Photos taken at shark rock, south west of la Digue, at approx 15m depth. 

References:

Bray, D.J. (2020). Lactoria fornasini in Fishes of Australia. https://fishesofaustralia.net.au/home/species/839 (04/11/21).
Froese, R. & D. Pauly. Eds. (2021). FishBase. Lactoria fornasini (Bianconi, 1846), Thornback cowfish. https://www.fishbase.se/summary/7837 (04/11/21)
iNaturalist.ca (2021). Thornback Cowfish, Lactoria fornasini. https://inaturalist.ca/taxa/199600-Lactoria-fornasini (04/11/21). 
McGrouther, M. (2019). Thornback Cowfish, Lactoria fornasini (Bianconi, 1846). Australian Museum. https://australian.museum/learn/animals/fishes/thornback-cowfish-lactoria-fornasini-bianconi-1846/ (04/11/21). 

Citation:

Nevill, J.E.G. & Jakobsen, O. (2021). Lactoria fornasini, Thornback cowfish. Seychelles Seatizens. www.seatizens.sc. https://seatizens.sc/species/lactoria-fornasini-bianconi-1846/