📸 PhotoPhoto: Kim, Hyun-tae · CC BY 4.0 · Wikimedia Commons Source
Korean crayfish
Cambaroides similis (Korean crayfish · チョウセンザリガニ)
💡 Everyday Comparisons for Size, Mass & Speed
- 💡 The median water depth of 21.4 cm at sites where many Korean crayfish were found is similar to the short side of a sheet of A4 paper (21 cm) (Comparison).
- 💡 The median current speed of 21.2 cm/s is about 0.76 km/h, or roughly one-seventh of a person's normal walking speed (taken as around 5 km/h) (Comparison).
- 💡 Because frequent droughts that dry up streams in winter and early spring can shrink populations, this organism is closely tied to water management in local streams.
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 Korean crayfish is a freshwater crayfish living on the Korean Peninsula and the Liaodong Peninsula; it can be seen in streams in Korea and is listed as Data Deficient (DD, 2010) by the IUCN.
🦴 2. Anatomy & Morphology
Specimens from China confirmed that the male reproductive legs take Form I with golden, hardened tips during the breeding season and Form II with blunt tips outside the breeding season.
🔍 3. Ecology & Behavior
It is active at night and also lives in slightly acidic water averaging around pH 6.4. It grows faster at higher water temperatures and begins mating in late autumn (September–October).
🇰🇷 4. Connection to Korea
In Korea, it is a species subject to approval for overseas export on the National List of Species of Korea, and after being confirmed at 59 sites across 12 regions in a 2023 study, it is treated as an endangered candidate species. Droughts in winter and early spring are thought to sharply reduce its populations.
📚 Sources & References
- • IUCN Red List DD (2010) — https://www.iucnredlist.org/species/153685/4531778
- • IUCN Red List category DD — latest assessment at iucnredlist.org
- • catalogueoflife.org — 7RTVD
- • iucnredlist.org — 4531778
- • 국가생물종목록(국립생물자원관) ktsn 120000048780 — https://species.nibr.go.kr/home/mainHome.do?cont_link=009&subMenu=009002&contCd=009002&ktsn=120000048780
- • wikidata.org — Q6908084
- • commons.wikimedia.org — File:Cambaroides similis.jpg
- • e-jecoenv.org — view.html
- • koreascience.kr — JAKO200911440582121.do
- • pmc.ncbi.nlm.nih.gov — PMC11659819
- • species.nibr.go.kr — general-search
Recorded dimensions are widely cited representative estimates from public literature and may vary by study or specimen.