Anteaeolidiella decorus S.-Q. Zhang & S.-P. Zhang, 2023

アンテアエオリディエラ・デコルス Anteaeolidiella decorus

Location: Sirato kaisuiyokuzyou, Amakusa, Kumamoto, Japan
Date: 2025/03/27
Length: 20mm
Depth: 3.0m
Water temperature: 13.0℃

Description

A small aeolid nudibranch reaching about 25 mm in length. The body is elongate, translucent white as a background, with bright orange to pink pigment spreading across the dorsum. A U-shaped orange marking runs across the head from the base of one rhinophore through to the base of the other oral tentacle, and the lateral edges of the head are bordered in pink. The rhinophores are relatively long and stout, with the basal half translucent orange and the distal half opaque white. The oral tentacles are slightly longer than the rhinophores, with a translucent white base and opaque white tip. A white midline runs from behind the rhinophores to the heart region, where a white oval patch is encircled by orange-pink. The cerata are arranged in 25–28 rows with up to seven cerata per row; they are dusted with grey, orange and pink pigment, with a white subapical band and a white tip.

Distribution

Originally described from the intertidal of Port Nantun, Qingdao, Shandong Province, China (Yellow Sea–Bohai Sea). Subsequent molecular data have confirmed that the species also occurs around Japan.

Etymology

The specific epithet decorus is Latin for "beautiful" or "elegant", in reference to the vivid colour pattern of the species.

Remarks

Feeds on sea anemones of the genus Aiptasia. The egg mass is a simple three-turn spiral. Japanese specimens previously identified as Anteaeolidiella cacaotica are now referred here on the basis of molecular data. The closest known relative is the Australian A. cacaotica, from which it differs by about 7.6–7.8% in COI distance.