TankBud

Long arm shrimp

Cuapetes sp.

Also known as Commensal Shrimp

SaltwaterShrimp

Long arm shrimp (Cuapetes sp.)
Biota · Used with permission

Care at a glance

Temperature
75–82°F
24–28°C
pH
8.1–8.4
Adult size
0.8 in
2 cm
Minimum tank
5 gal
20 L
Temperament
Peaceful
Social behavior
Social
Swim level
Bottom
Diet
Omnivore
Difficulty
Easy
Breeding
No record
Rarity
Rare
Reef safe
Reef safe
Family
Palaemonidae
Origin
Tropical Indo-Pacific, including Palau

Overview

The long arm shrimp is a peaceful, nearly invisible micro shrimp for nano and mature reef tanks. It is easy to keep.

Did you know

The long arm shrimp's glassy transparency is its whole defense. Against coral branches its body all but disappears. The long, banded claw arms behind its common name are often the only part you actually spot.

Caring for the long arm shrimp

Give the long arm shrimp a tank of 5 gal (20 L) or more with plenty of structure, such as branching coral, sponge or macroalgae. It spends its day perched on that structure, picking at whatever the current delivers.

Keep the water at 75 to 82°F (24 to 28°C) with a pH of 8.1 to 8.4. It is an undemanding omnivore that accepts fine frozen and dry foods.

The long arm shrimp is peaceful, reef safe and fine alone or in a group. Keep it with nano gobies and other small commensal shrimp. Leave out any fish large enough to eat it.

Good to know

The long arm shrimp belongs to Cuapetes, a genus of small commensal shrimp in the family Palaemonidae. Most of its species were classified under Periclimenes until molecular work reshuffled the group. These shrimp are traded at genus level, because the small, glassy species are hard to pin down without a specialist. That keeps the name honest at Cuapetes sp.

In the wild

The long arm shrimp is found across the tropical Indo-Pacific, including the reefs of Palau. It lives in close association with corals, anemones and crinoids.

Weekly picks

Tank mates

The long arm shrimp is a peaceful, social species that keeps to the bottom. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a long arm shrimp need?

A long arm shrimp needs at least 5 gal (20 L). It spends most of its time in the bottom.

What temperature and pH does a long arm shrimp need?

A long arm shrimp is comfortable at 75–82°F (24–28°C) with a pH of 8.1–8.4.

What does a long arm shrimp eat?

A long arm shrimp is an undemanding omnivore that accepts fine frozen and dry foods. While perched on structure, it also picks at whatever the current delivers.

How big does a long arm shrimp get?

An adult long arm shrimp reaches about 0.8 in (2 cm).

Related species