This large-toothed flounder is found throughout the Indo-West Pacific region, in Australia it occurs in the coastal waters of all states except Victoria and Tasmania.
Pseudorhombus arsius occurs in shallow waters and estuaries, on muddy and sandy bottoms down to a depth of 200 meters, sometimes juvenile animals in particular occur in brackish water, in winter they migrate to deeper waters.
When these flatfish spawn, they can be found in shallow water on sandbanks and near the coast.
The spawning season lasts 3 to 4 months, from April to July, and reaches its peak in April and May, during which time the animals move to the sandy shoals near the coast.
The spawn is deposited in a single batch.
With a total length of between 16 and 17 cm, the flounders reach sexual maturity.
The flounder has an oval-shaped body, the caudal fin is separated from the dorsal and anal fins, both eyes are on the left side of the body.
The upper side is yellowish brown, mottled and spotted with darker brown, and shows a large blackish spot at the transition of the curved and straight part of the lateral line, in the middle of the straight part on the back half of the body there is one blackish spot and several indistinct dark spots above and below the lateral line;
all patches contain small scattered bright orange-yellow patches, the fins are lighter than those on the eye side of the body.
The species varies in colour and adapts exactly to the substrate on which it rests.
Pseudorhombus arsius is commercially fished in West Bengal in the mouth of the Hooghly River on a small scale, otherwise it is a flatfish that is often caught by sport fishermen and is often used for human consumption.
Attention: The large-toothed flounder has an impressive set of teeth in the front of its jaw, it has 6 to 13 large, strong teeth on the lower jaw of the blind side,
Anglers should be careful when removing the hook from the mouth of this species.