📸 PhotoPhoto: opencage · CC BY-SA 2.5 · Wikimedia Commons Source
Japanese feather star
Anneissia japonica (Japanese feather star · Japanese feather star)
Not Evaluated (NE) on the IUCN Red List yet.
💡 Everyday Comparisons for Size, Mass & Speed
- 💡 Its maximum arm length of 13.5 cm is almost equal to a ballpoint pen (about 14 cm) (Comparison).
- 💡 A cirrus length of 27 mm is almost equal to the diameter of a Korean 500-won coin (about 26.5 mm) (Comparison).
Reference standards: coach bus ~12 m, mid-size car ~4.9 m, compact car ~1 t, basketball hoop 3.05 m, credit card 8.56 cm.
📖 1. Overview
The Japanese feather star is a feather star with feathery arms that some studies regard as endemic to Japan.
🦴 2. Anatomy & Morphology
It has 38 arms up to 135 mm long, and the hemispherical central mass (centrodorsal) is about 10 mm wide. On the underside are 57–69 cirri that grow up to 27 mm long.
🔍 3. Ecology & Behavior
Hiding under rock overhangs or among corals, it spreads its arms in multiple layers; the arms are dark brown with orange to white tips. Feather stars wave their arms to catch tiny food particles and pass them along food grooves to the mouth.
🇰🇷 4. Connection to Korea
Although it is listed as 'Ilbongit-gaetgosari' (Korean name) in the National List of Species of Korea, a 2020 Japanese paper noted that the specimen recorded from the South Sea appeared to be a juvenile, making species identification difficult.
📚 Sources & References
- • IUCN Red List: not evaluated (NE) — cross-checked with the Wikidata conservation-status entry
- • marinespecies.org — aphia.php
- • 국가생물종목록(국립생물자원관) ktsn 120000212383 — https://species.nibr.go.kr/home/mainHome.do?cont_link=009&subMenu=009002&contCd=009002&ktsn=120000212383
- • wikidata.org — Q61469693
- • commons.wikimedia.org — File:Oxycomanthus japonicus 1.jpg
- • tb.plazi.org — BB0087C5FF921D5A7996FD82FA8A0E04
- • australian.museum — orange-feather-star
Recorded dimensions are widely cited representative estimates from public literature and may vary by study or specimen.