Sand fleas: what are they? - briefly
Sand fleas are small, marine crustaceans of the family Hippidae that resemble tiny shrimp and inhabit sandy shorelines, where they burrow just below the surface. They feed on organic detritus and are known for their powerful jumping ability when disturbed.
Sand fleas: what are they? - in detail
Sand fleas, also referred to as beach fleas or sand hoppers, belong to the order Amphipoda, family Talitridae. They are small, laterally compressed crustaceans, typically ranging from 5 to 15 mm in length. Their bodies consist of a head with two pairs of antennae, a thorax bearing seven pairs of legs, and an abdomen ending in a curled telson. The first pair of legs is modified for grasping, while the remaining legs facilitate rapid jumping across sand surfaces.
Preferred habitats include the supralittoral zone of marine beaches, dunes, and coastal marshes where moisture is sufficient to prevent desiccation. Sand fleas construct shallow burrows or seek refuge under debris, using their powerful hind legs to escape predators and to move toward food sources. Their diet consists mainly of decaying organic matter, algae, and microscopic microorganisms, which they scrape from sand particles with specialized mouthparts.
Reproduction follows a seasonal pattern in temperate regions, with mating occurring in spring and early summer. Females carry fertilized eggs in a brood pouch until hatching. Juveniles undergo several molts before reaching adulthood, a process that can span several weeks depending on temperature and humidity. Rapid development is facilitated by the high metabolic rate typical of amphipods.
Human encounters often result in minor skin irritation when sand fleas bite. The bite delivers a small amount of saliva containing anticoagulant compounds, producing a localized, itchy papule that resolves within a few days. Preventive measures include applying insect repellent containing DEET or picaridin, wearing protective footwear, and shaking out clothing after beach exposure.
Control strategies focus on habitat management rather than chemical treatment. Reducing excess organic debris on beaches, maintaining proper drainage, and limiting artificial lighting that attracts insects can lower sand flea populations. In areas where bites are a significant nuisance, targeted application of pyrethrin-based sprays may be employed, but such interventions should comply with local environmental regulations to avoid harm to non‑target species.