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
Difficulty: Easy
Breeding: No record
Rarity: Rare
Reef safe: Reef safe
Origin: Tropical Indo-Pacific, including Palau
Family: Palaemonidae

Overview

A peaceful, nearly invisible micro shrimp for nano and mature reef tanks, spending its day perched on structure and picking at whatever the current delivers. It is an undemanding omnivore that accepts fine frozen and dry foods. Keep it with nano gobies and other small commensal shrimp rather than anything that treats a 2 cm shrimp as food.

In the wild

Found across the tropical Indo-Pacific, including the reefs of Palau, living in close association with corals, anemones, and crinoids. In the aquarium it wants plenty of structure, such as branching coral, sponge, or macroalgae, and no fish large enough to eat it.

Good to know

Cuapetes is a genus of small commensal shrimp in the family Palaemonidae, most of which were classified under Periclimenes until molecular work reshuffled the group. These animals are traded at genus level because the small, glassy species are hard to pin down without a specialist, so the name is kept honest at Cuapetes sp.

Did you know

Its glassy transparency is the whole defense strategy: against coral branches the body all but disappears, and the long banded claw arms behind the common name are often the only part of the shrimp you actually spot.