Ogasawara Spiny Lobster

Panulirus brunneiflagellum is a typical spiny lobster. Adults vary in carapace length in the range 90–120 millimetres (3.5–4.7 in). The chief distinction between P. brunneiflagellum and related species of spiny lobster is in the colouration of the antennules (first antennae). In P. brunneiflagellum, the bases of the antennules are blackish purple, with white spots around the joints. The flagella are brownish, with no bands of colour. P. longipes bispinosus has paler antennules, and the flagella have four white bands across them.

The Ogasawara Group, or Bonin Islands, are an outlying archipelago of Japan in the western Pacific Ocean, on the Izu–Bonin–Mariana Arc. They lie around 1,000 kilometres (620 mi) south of Tokyo, and 1,500 km (930 mi) north of Saipan in the Mariana Islands. P. brunneiflagellum is the dominant Panulirus species around the southern islands in the group, but has also been recorded from Hachijo Island, at the north end of the Izu Ridge, 300 km (190 mi) from the Japanese mainland.

Panulirus brunneiflagellum lives in clear, tropical waters at depths of up to 90 metres (300 ft), where temperatures are in the range 19–29 °C (66–84 °F). It lives in open caves, sometimes in association with P. longipes bispinosus, but usually near the entrance, whereas P. l. bispinosus shelters in the depths of the caves.