Paperinarua

Paperinarua is a small, benthic crustacean belonging to the order Amphipoda. It is commonly referred to as the paper shrimp due to its translucent carapace and delicate, paper‑like appendages. The genus was first described by marine biologist Dr. Lila Thompson in 1984, based on specimens collected from shallow coastal mudflats in the Gulf of Mexico. The species name *paperinarua* derives from the Latin words for "paper" (papyrus) and "in rang" (in a line), reflecting its flattened body shape.

Morphologically, *Paperinarua* measures between 3.5 and 5 mm in length and displays a translucent, soft body that lacks a hard exoskeleton. Its head bears two small eyes and a pair of antennae, while the thorax is protected by a thin dorsal plate. Legs are short and adapted for burrowing into fine sediment. The species exhibits sexual dimorphism; males possess longer second antennae and a reduced gnathopod.

The distribution of *Paperinarua* is restricted to temperate coastal regions of the western Atlantic, from North Carolina to Veracruz. It typically inhabits intertidal mudflats and estuarine environments, where it feeds on detritus and microalgae. Reproduction is direct, with brooding females carrying eggs attached to the ventral surface of the abdomen.

Ecologically, *Paperinarua* plays a role in sediment turnover and nutrient cycling within its habitat. It is a prey species for small fish and larger crustaceans. Because of its sensitivity to pollution and habitat disturbance, the genus has become an indicator species for the health of estuarine ecosystems. Dedicated monitoring of *Paperinarua* populations has helped assess the impacts of coastal development and eutrophication.