Acorheaded worm

Balanoglossus misakiensis (scientific name: Balanoglossus misakiensis) is an enterobranchial animal distributed in coastal areas of Japan and China, but in very small numbers. It is distributed along the coasts from the Yellow Sea to the South China Sea in my country. It belongs to the genus Acornicea in the family Aconidae.

Misaki Acornworm has a strong regenerative ability. The front segment of the insect body with snout, collar and gill area can regenerate the rear organs to restore a complete individual. Misaki acornworm mainly lives in fine sandy beaches and muddy beaches in the mid-tide and low-tide areas of the coast.

Acornworms are more common in China than in any other country in the world. Because it is a coastal intertidal species, it is easily affected by human production, sewage discharge, and tourism, and is damaged. For example, the tidal flats of Cangkou, Nvgukou, and Huangdao in Jiaozhou Bay, Biao Island, have always had a lot of acornworms. However, due to pollution, it has been difficult to find traces of them in recent years.

The snout is subconical, orange-yellow, with a deep longitudinal groove in the center of the back. The collar is cylindrical, with many longitudinal pleats and obvious horizontal band lines. The collar groove is light yellow, and there is a dark orange-red horizontal band at the rear. The reproductive wings are well developed, gray-brown in females and egg-yellow in males. The trunk has obvious ring patterns. The liver capsule is arranged in 2 rows. There are 2 longitudinal epidermal stripes on the back of the tail area.

Domestically distributed in Shandong and Guangxi. Distributed abroad in Japan. It inhabits intertidal zones and lurks on sandy or muddy bottoms.