📸 PhotoPhoto: RYO SATO from Hamamatsu, Shizuoka, Japan · CC BY-SA 2.0 · Wikimedia Commons Source
Japanese sleeper ray
Narke japonica (Japanese sleeper ray · シビレエイ)
💡 Everyday Comparisons for Size, Mass & Speed
- 💡 Its maximum body length of 40 cm is about 10 cm longer than the long side of an A4 sheet of paper (29.7 cm) (Comparison).
- 💡 Its body length of 40 cm is slightly shorter than the width of a standard keyboard (about 44 cm) (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 sleeper ray is a small electric ray living in the northwestern Pacific from southern Japan to the South China Sea. It is assessed as Vulnerable (VU, 2021) on the IUCN Red List.
🦴 2. Anatomy & Morphology
It grows up to 40 cm, and males reach maturity at around 25 cm.
🔍 3. Ecology & Behavior
Living on sandy bottoms, it is ovoviviparous and gives birth to 4–6 young (up to 5 in some records) at a time.
🇰🇷 4. Connection to Korea
It is listed as 'Jeongigaori' (Korean name) on the National List of Species of Korea.
📚 Sources & References
- • IUCN Red List VU (2021) — https://www.iucnredlist.org/species/201629258/201629674
- • IUCN Red List category VU — latest assessment at iucnredlist.org
- • catalogueoflife.org — 45PVP
- • iucnredlist.org — 201629674
- • 국가생물종목록(국립생물자원관) ktsn 120000057339 — https://species.nibr.go.kr/home/mainHome.do?cont_link=009&subMenu=009002&contCd=009002&ktsn=120000057339
- • wikidata.org — Q4668667
- • commons.wikimedia.org — File:Narke japonica.jpg
- • fishbase.se — Narke-japonica.html
- • species.nibr.go.kr — mainHome.do
- • Silhouette: PhyloPic — Tree of Life App · CC0 1.0 (Related taxon silhouette — Narkidae)
Recorded dimensions are widely cited representative estimates from public literature and may vary by study or specimen.