[7] Siganus canaliculatus has a moderately slender, laterally compressed body, the standard length being 2.3 to 2.8 times its depth.

The caudal fin is nearly emarginate in smaller individuals of less than 10 cm (3.9 in) standard length becoming forked in larger fish.

It can be greenish grey to yellow brown and is marked with 100-200 perlescent blue to whitish spots on the nape and anterior part of the body, these are similar in size to a match-head on the lower flanks.

[8] Siganus canaliculatus has a wide Indo-Pacific distribution, ranging from the Persian Gulf to the Philippines and New Guinea, north to the Ryukyu Islands and south to northern Australia.

[3] Siganus canaliculatus is said to be able to tolerate more turbid waters than the closely related S. fuscescens and may be found near river mouths, particularly where there are beds of sea grass.

The juveniles form very large schools, which reduce in size as the fishes mature; adults occur in groups of around 20 individuals.

The Teochews of Singapore and Malaysia are particularly fond of this fish, which they refer to as pek tor her (Chinese: 白肚鱼; pinyin: báitùyú; lit.

The white-spotted spinefoot is particularly popular during Chinese New Year, when the fish is heavy with milt and roe and its consumption is considered auspicious.

[10] The white-spotted spinefoot has been used for mariculture in some areas in which it occurs because it has herbivorous habits, grows rapidly and is economically valuable.