🐠 Square Spot Anthias (Pseudanthias pleurotaenia)
A Deep Pink-Orange Body With a Signature Square Patch • One of the Largest Anthias • A Patch That Flashes Blue in Daylight
 
📋 The Square Spot Anthias, also known as the Squareback, Pink Square, or Mirror Anthias, shows striking differences between the sexes: males have a deep pink-to-orange body marked with a bold, square-shaped purple patch on the flank, elongated fins, and a lavender belly, while females are a plainer solid yellow-to-orange with a faint blue line from nose to pectoral fin. There's a fascinating optical trick too: the male's signature purple patch appears bright blue under natural daylight, almost like a little mirror.
It ranges across the Pacific, from Indonesia to Samoa, the Ryukyu Islands, New Caledonia, and Christmas Island, and it's one of the larger anthias, reaching up to 20cm. It comes from deep, current-swept outer reef slopes and drop-offs, so it does best under low, indirect lighting, which also helps keep its colours from fading. Every Square Spot Anthias we ship is feeding well.
It's fully reef safe and does best kept as a harem of one male with several females, or singly, since two males together can lead to serious, sustained aggression. It reaches up to 20cm, so plan on at least 470L with strong water movement.
 
💡 Highlights
🎨 A Signature Square Patch: Appears bright blue in natural daylight
📏 One of the Larger Anthias: Reaching up to 20cm
🌗 Prefers Subdued Lighting: Helps preserve its vivid colours
🍽️ Ships Feeding Well: A smooth start in your tank
🌿 Fully Reef Safe: Won't harm corals or invertebrates