Japanese Night Shrimp

The Japanese Night Shrimp (Hayashidonus japonicus) is an invertebrate and a peaceful species that is considered reef-safe with caution, admired for its tiny size, nocturnal behavior, and unique “dancing” response when exposed to light.

Males typically display a slender body with slightly longer antennae, while females/juveniles are more rounded in body shape and may appear slightly larger when carrying eggs.

They reach about 1 inch (2.5 cm) in adulthood and should be housed in aquariums of at least 10 gallons (though larger systems are preferable for stability). Provide a fine sandbed, rubble zones, and plenty of live rock with hiding spots, along with stable water parameters (salinity ~1.020–1.025, temp ~72–79°F, pH ~8.1–8.4). A secure lid is recommended since many small shrimp species can escape.

Diet should consist of planktonic foods, finely crushed meaty items (such as mysis or enriched brine shrimp), copepods, and microalgae. With proper care, this shrimp makes a fascinating and unusual addition to specialized aquariums, though it remains rare in captivity due to its nocturnal habits and delicate nature.

International Aquatics Quarantine & Guarantee: All fish are checked by marine vets, given a formalin bath, and held for 14 days in copper-treated systems. We feed Selcon-soaked food with Kanaplex and Metroplex during quarantine. Unless marked, all livestock comes with our 15-Day Guarantee. You will receive a video of your fish eating before shipment. On request, we also send photos/videos after arrival at IA. Some species are import-to-order (3-10 business days). Many common species are already cleared or near the end of QT.

Several species will be import-to-order and may take anywhere from 3-10 business days to secure. Once your fish is secured, you will be notified, and the quarantine process will then begin.