Stenorhynchus sp.

Datasheet

General Description

The Decorator Arrow Crab, also known as the Spider Crab, is characterized by its lengthy legs and distinctive shape resembling an arrow. It can reach sizes of up to 10 inches, although females may be considerably smaller. This crab has a unique camouflage behavior where it adorns itself with algae, rocks, and even coral fragments. Different species of Arrow Crabs originate from various regions around the world, with the most common being the Stenorhynchus seticornis from the Caribbean.

Aquarium Suitability

The Decorator Arrow Crab is considered easy to care for and is a hardy and long-lived invertebrate suitable for reef aquariums. However, caution is advised when housing them with other crustaceans like Banded Coral Shrimp, as they may exhibit semi-aggressive behavior and pose a threat to slow-moving fish.

Demands

As a carnivorous species, the Decorator Arrow Crab should be provided with a varied diet consisting of meaty, flake, and tablet foods. It may also help control populations of smaller Bristle Worms, seen as pests by some aquarists. Regular supplementation with calcium, magnesium, iodine, and trace elements is recommended to maintain optimal health.

Care and Hardiness

This species is known for its ease of care and relative hardiness in the aquarium environment. It is capable of adapting to various water conditions within the acceptable ranges of pH (8.1-8.4), alkalinity (8-12 dKH), and specific gravity (1.020-1.025).

Reef Suitability

While the Decorator Arrow Crab can be reef-compatible, it should be closely monitored, especially in mixed invertebrate setups. Their semi-aggressive temperament and tendency to scavenge for food may lead to interactions that can disrupt coral or harm other tank inhabitants.

Aquarium Setup

A suitable aquarium setup for the Decorator Arrow Crab should include hiding places like small caves or crevices resembling their natural habitat. Providing ample space and appropriate decor for camouflage can help simulate their natural environment and reduce stress levels within the tank.

Behaviour

These crabs may exhibit territorial behavior and might display aggression towards tankmates. Their scavenging nature means they will actively forage for food, sometimes picking at mushrooms or polyps if their dietary needs are not fully met.

Feeding and Diet

To ensure proper nourishment, a varied diet of meaty, flake, and tablet foods should be provided to the Decorator Arrow Crab. Additionally, they may assist in pest control by preying on smaller Bristle Worms within the aquarium.

Habitat and Distribution

The Decorator Arrow Crab is commonly found in reef environments, typically residing in portions of the reef associated with caves or crevices for shelter. While the most prevalent species originate from the Caribbean, other variations can be sourced from regions like the Indo-Pacific, eastern Africa, and California. In the wild, they serve as valuable members of the reef ecosystem due to their feeding habits and role in the food chain.