The first record of an alien freshwater shrimp, Caridina logemanni from Ara River System, eastern Japan

Abstract

Caridina logemanni is a landlocked freshwater shrimp native to Hong Kong. Between May 2018 and May 2021, 31 individuals were collected from a small stream of the Ara River System on the Kanto Plain, Japan. During the sampling period, four ovigerous females and one juvenile were among the individuals collected, suggesting that this species has established and is reproducing at the survey site. This shrimp species is commonly kept for ornamental purposes, and the morphological charact- eristics of individuals sold in an aquarium shop near the survey site match those of the sampled specimens. Therefore, the origin of the C. logemanni population at the survey site is thought to be the abandonment of ornamental shrimp into the stream. A standard Japanese name is proposed for this species.