Ryukyu Fishing Spider

大狡蛛 / Ryukyu fishing spider / オオハシリグモ (Dolomedes orion)

Species information

Scientific name: Dolomedes orion
Japanese name: オオハシリグモ
Chinese name: 大狡蛛
English name: Ryukyu fishing spider
Origin: Tokara Islands, Amami Oshima, Tokunoshima, Okinawajima, Tokashikijima, Kumejima

Ecology and description

Ryukyu fishing spider is the largest hunting-type spider in Japan, and it hunts by the waterside without building a web. Ryukyu fishing spider lightly touches the water surface with its front legs to detect small fish, tadpoles, or aquatic insects for consumption.

Field photographs taken during our tours, with observation dates

During our 【Herping】 tour when visiting stream environments, we often encounter this spider species. They usually remain motionless at the water’s edge, making scenes of them catching prey very rare.

Ryukyu fishing spider (Dolomedes orion) Nov 24, 2025 Front view Kunigami
Nov 24, 2025, Kunigami, Front view
Ryukyu fishing spider (Dolomedes orion) Apr 30, 2026 Ryukyu fishing spider caught a rhinogobius fish
Apr 30, 2026, Ryukyu fishing spider caught a rhinogobius fish
Ryukyu fishing spider (Dolomedes orion) Apr 30, 2026 Another angle Ryukyu fishing spider caught a rhinogobius fish
Apr 30, 2026, Ryukyu fishing spider caught a rhinogobius fish Another angle
Ryukyu fishing spider (Dolomedes orion) Oct 31, 2025 Female carrying egg sac moving Kunigami
Oct 31, 2025, Kunigami, Female carrying egg sac moving
Ryukyu fishing spider (Dolomedes orion) Oct 31, 2025 Newly molted Ryukyu fishing spider Kunigami
Oct 31, 2025, Kunigami, Newly molted