O. javanus shows clear
sexual dimorphism, with females being distinguishable from males in both size and morphological features.
Female The female has a high, yellow-orange
cephalothorax marked with four black longitudinal bands, with the two lateral bands extending to the lateral edges. The cervical groove and radial furrow are weakly developed, while the thoracic groove is deep and vertical. The species has eight dark, circular
eyes arranged in a compact hexagonal pattern. The anterior median eyes are the smallest and positioned close together, while the anterior lateral eyes are the largest. A distinctive black line runs along the center of the cephalothorax from the anterior median eyes down to the cream-yellow
chelicerae. The chelicerae bear two promarginal teeth of unequal size and one medium-sized retromarginal tooth. The
abdomen is elongated and tapers posteriorly, brown in color with a white longitudinal band on the upper surface. Three diagonal gray bands are present on each side, and one gray band appears on the ventral portion. The entire abdomen is covered with short white bristles. The legs are long, slender, and yellowish with gray longitudinal lines on the underside of the first three pairs. They are covered with brown spines and short bristles on both sides and terminate in three tarsal claws with small teeth.
Male Males share most characteristics with females but are distinguished by their modified
pedipalps, which bear the reproductive structures. The
cymbium (the outermost part of the male palp) is 1.50 mm long with a round base and pointed tip, covered in dense brown hairs. ==Reproduction==