A. randalli is a small fish which can be up to long. Its body is lengthened and cylindrical. The background coloration is white and banded with orange to yellow fine stripes. The first stripe goes around the front head passing through the eye. A multitude of small whitish dots are distributed on the white parts of the body. Other distinctive point, on the anteriordorsal fin when the latter is deployed, a black and whiteeye-spot can be seen. Eyes are round and prominent. The mouth is big and in the shape of an inverted "U".
Habitat
A. randalli can be found on soft substrates constituted of coarse and shell sand in rubblecaves at depths of from. It has been recorded in association with a species of prawn, generally Alpheus ochrostriatus.