Lyretail Anthias

The lyretail anthias (Pseudanthias squamipinnis) is a small planktivorous member of the family Serranidae, subfamily Anthiinae, found across the Indo-Pacific and Red Sea from East Africa to the western Pacific. It is one of the most commonly observed anthias species on coral reefs, forming dense, colorful schools that hover above reef drop-offs and slopes. The species displays pronounced sexual dimorphism: females are uniformly orange-pink, while dominant males develop a deeper reddish-purple hue, an elongated third dorsal spine, and a distinctive lyre-shaped tail. Lyretail anthias live in haremic social groups led by a single male and are, like many anthiines, protogynous hermaphrodites capable of changing sex.

Lyretail anthias are small, brightly colored schooling reef fish.

• Color: females and juveniles are bright orange to pink; dominant males are deeper red-purple with a violet patch behind the pectoral fin.
• Fins: males have an elongated, filamentous third dorsal spine and a deeply lyre-shaped (forked with extended lobes) tail; females have a simpler, less forked tail.
• Body: slender, streamlined, and laterally compressed.
• Size: females about 8-12 cm, males up to 15 cm.
• Distinguished from other anthias species by the male's characteristic elongated dorsal spine and lyre-tail shape combined with the purple pectoral patch.

Lyretail anthias are found throughout the Red Sea, East Africa, the Indian Ocean, and the western Pacific, typically along outer reef slopes, drop-offs, and current-swept channels rich in plankton. They occur from near the surface down to roughly 35 m, most commonly between 5 and 25 m, hovering just above the reef in open water where they can feed on drifting zooplankton while remaining close enough to dive into coral crevices for shelter. The species favors reefs with strong currents that deliver a steady supply of planktonic food.

Lyretail anthias live in large, structured schools composed of a haremic social system: one dominant male oversees a group of several females, with smaller subordinate males sometimes present. They feed by picking zooplankton from the water column, often facing into currents in coordinated groups above the reef. If the dominant male is removed or dies, the largest female in the harem undergoes a sex change to become the new male, a well-documented example of protogynous hermaphroditism. Schools retreat into coral crevices for shelter when threatened by predators such as larger reef fish. As abundant planktivores, lyretail anthias form an important link between planktonic food sources and higher reef predators.