Dwarf seahorse

Hippocampus zosterae

Also known as Pygmy seahorse, Little seahorse, Pixie seahorse, Dwarf pygmy seahorse

SaltwaterFish

Dwarf seahorse (Hippocampus zosterae) — Will Thomas · CC BY 2.0

Care at a glance

Temperature: 68–79°F (20–26°C)
pH: 8.0–8.4
Adult size: 1.4 in (3.5 cm)
Minimum tank: 5 gal (20 L)
Temperament: Peaceful
Social behavior: Social
Swim level: Middle
Difficulty: Difficult
Breeding: Medium
Rarity: Common
Reef safe: Reef safe with caution
Origin: Native to the western Atlantic, the Gulf of Mexico and the Caribbean, living in shallow seagrass beds and floating weed.
Family: Syngnathidae

Overview

A small dedicated nano tank of around 20 to 40 litres suits a group of dwarf seahorses, with only a gentle sponge filter, since power filters suck them in, at 20 to 26 C and pH 8.0 to 8.4. Their care revolves around food: they need newly hatched live baby brine shrimp fed several times a day, which means running a brine hatchery at home. Keep them only with their own kind, as almost any tankmate outcompetes or eats them. They breed readily, and a pair will produce broods of tiny fry regularly.

In the wild

The dwarf seahorse is a tiny seahorse barely 2 to 3 cm tall that clings to blades of seagrass in the shallows off Florida and the Gulf. It comes in tan, cream, green and near-black, often with fuzzy algae growth on its body for camouflage. It is one of the smallest and slowest seahorses kept in aquariums.

Good to know

Hippocampus zosterae grows to only about 3.5 cm, making it one of the smallest seahorses in the world, and it is one of the easiest to breed at home. It is listed in the Guinness records among the slowest-moving fish. Because it is so small it must eat almost constantly, taking live baby brine shrimp throughout the day.

Did you know

Dwarf seahorses are so slow that algae and tiny animals grow right on their skin, and they are officially among the slowest-swimming fish ever recorded.