Athanas is a genus of shrimp of the family Alpheidae. These are small shrimp measuring 2 cm in length. They can be blue, red or transparent in colour. The rostrum is well-developed and straight, projecting beyond the first segment of the first antenna. Two anterior projections of the carapace partially cover the eyes, hence the common name hooded shrimp. The first pair of walking legs is enlarged, symmetrical in females and asymmetrical in males. Females have smaller chelae than males .