Blue Eye Lyretail Anthias (Pseudanthias squamipinnis) - Male

Lyretail Anthias run a harem system on the reef slope, one male presiding over a group of females, and the whole arrangement is built on sequential hermaphroditism running the opposite direction from clownfish: every anthias starts life female, and when the resident male dies, the largest female in the group changes sex to take his place, often within days. The blue eye-ring only shows up in that final male phase, so what you're looking at is basically a promotion in fish form.

Care level: Moderate · Temperament: Peaceful, shoaling · Max size: ~4" · Min tank: 55 gal · Diet: Carnivore, small meaty foods, frequent feedings