科: Palaemonidae
青虾为长臂虾科（Palaemonidae）淡水虾，是中国经典的原生缸与食用种类。成体约 6–9 cm，属机会主义捕食者，只能与体型相近的鱼混养，适宜水温 18–28 °C。
Macrobrachium nipponense is a Palaemonidae freshwater prawn, China's classic food and native-tank species. In the aquarium it is an opportunistic predator — peaceful only with similar-sized tankmates. Plan on 6–9 cm of adult prawn at 18–28 °C, and never combine it with small fish or shrimp.
饲养难度：中等。Opportunistic predator — peaceful only with equals。
水温控制在 18–28 °C，重点是稳定。Stable 18–28 °C; tolerates seasonal cool。
成体约 6–9 cm；最小缸体 60 L，并留出活动空间。
Omnivore-scavenger; will actively catch small fish and shrimp。建议人工饲料搭配冷冻或活饵，保证多样性。
Opportunistic predator — peaceful only with equals；Solitary or a pair; territorial perches。理想混养对象：Medium-to-large robust community fish — Too large to be prey, Large snails — Armored tankmates survive。需避开Small fish and small shrimp — Will be hunted, especially at night, Slow fish with long fins — Claws nip fins。
分布于East Asia — China, Japan, Korea; widely farmed：Warm rivers, lakes and ponds with vegetation and shelter，Still to gentle current。
确认会跳：请使用密闭缸盖，并适当降低水位。
人工环境下：Larvae require brackish water; difficult in home aquaria。Males have extremely long second claws; females heavier-bodied。