- · Grid units represent actual meters (m); human and animals are drawn to the exact same scale with original silhouette aspect ratios preserved.
- · When a size range is recorded (e.g. 1–1.6m), the lower bound is used for scale comparison.
- · Kalseori freshwater side swimmer silhouette: PhyloPic — Prespa Research Group and Kurtis Wothe · CC0 1.0 (Gammarus fossarum)
- · Human silhouette: PhyloPic — NASA · Public Domain Mark 1.0
Kalseori freshwater side swimmer
Gammarus zeongogensis (Kalseori freshwater side swimmer · Kalseori freshwater side swimmer)
🇰🇷 Class II endangered wildlife (Korea)
💡 Everyday Comparisons for Size, Mass & Speed
- 💡 Its body length of 12 mm is nearly half the diameter of a Korean 500-won coin (26.5 mm) (Comparison).
- 💡 Because it is an indicator species that signals water quality in freshwater ecosystems, mountain streams where this amphipod lives have clean water.
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 Kalseori freshwater side swimmer is a freshwater amphipod endemic to Korea that lives in clear mountain streams around Yeoncheon in Gyeonggi-do.
🦴 2. Anatomy & Morphology
Its body is laterally compressed and pale brown, and the flagellar segments of its 2nd antennae bear disc-shaped sensory organs called calceoli.
🔍 3. Ecology & Behavior
It chews on submerged decaying leaves. It mates from March to June; the male holds onto the female until she molts, and the eggs are fertilized after molting.
🇰🇷 4. Connection to Korea
A Korean endemic species and a Class II endangered wildlife (Korea), it is distributed domestically in Yeoncheon-gun, Gyeonggi-do. Its type locality in Jeongok was destroyed by development, and the IUCN assessed it as Near Threatened (NT, 2023).
📚 Sources & References
- • IUCN Red List NT (2023) — https://www.iucnredlist.org/species/199350626/200406532
- • 멸종위기 야생생물 Ⅱ급 — 국가생물종목록(국립생물자원관) ktsn 120000047485 — https://species.nibr.go.kr/home/mainHome.do?cont_link=009&subMenu=009002&contCd=009002&ktsn=120000047485
- • IUCN Red List category NT — latest assessment at iucnredlist.org
- • Korean protection status: Class II endangered wildlife (Korea)
- • catalogueoflife.org — 3F8N9
- • iucnredlist.org — 200406532
- • 국가생물종목록(국립생물자원관) ktsn 120000047485 — https://species.nibr.go.kr/home/mainHome.do?cont_link=009&subMenu=009002&contCd=009002&ktsn=120000047485
- • wikidata.org — Q13639664
- • nie.re.kr — view.do
- • species.nibr.go.kr — general-search
- • Silhouette: PhyloPic — Prespa Research Group and Kurtis Wothe · CC0 1.0 (Congeneric silhouette — Gammarus fossarum)
Recorded dimensions are widely cited representative estimates from public literature and may vary by study or specimen.