Cephalopholis igarashiensis, commonly known as the igarashi grouper, is a marine fish found in coral reefs of the Indo-Pacific region. It features a robust body, vivid coloration with patterns that blend into its environment, and is known for its solitary and territorial nature.

Cephalopholis igarashiensis, commonly known as the Igarashi's grouper, is native to the Western Pacific Ocean. Its geographical distribution includes regions such as the Ryukyu Islands of Japan, Taiwan, and the northern part of the Philippines.

The Igarashi's grouper typically inhabits coral reef environments. These regions are characterized by warm tropical waters, with temperatures ranging from 24°C to 28°C. The water is generally clear, allowing sunlight to penetrate and sustain coral and other marine life.

Cephalopholis igarashiensis occupies a predatory niche within the reef ecosystem. It often resides in deeper parts of the reef, usually at depths ranging from 20 to 60 meters. It preys on smaller fish and invertebrates, contributing to the regulation of these populations within its habitat. The species is adapted to living in complex reef structures, which provide both hunting grounds and protection from larger predators.