A group of seahorses is called a family, an especially fitting term given seahorses’ unusual approach to parenting. Seahorses are one of the very few animal species where the male carries the developing young, in a specialized brood pouch, through pregnancy before giving birth to fully formed baby seahorses.

Unlike most schooling fish, seahorses are actually fairly solitary and slow-moving creatures, often found alone or in mated pairs rather than large groups. Many species are also famously monogamous, with bonded pairs performing daily greeting rituals, changing color and dancing together, to reinforce their pair bond. When seahorses are found together in numbers, it’s often a breeding population clustered around a food-rich area like a seagrass bed or coral reef rather than a true social group.

The collective noun “family” nods to both their close pair bonds and their genuinely unique reproductive partnership, making it one of the more literal collective nouns in the animal kingdom.