What 蠌 means
It names an aquatic creature, though the exact animal is unclear.
The Erya, an old Chinese word glossary, pairs 蠌 with 螖 and explains the pair through 蟧. Later dictionaries give different descriptions: some say a water creature or snail-like kind, while the Kangxi Dictionary links 蠌 with 螖 and 蟛螖, described as a small crab-like creature. These records preserve the animal name without settling on one species.
Classical zoological vocabulary; it reads like a dictionary gloss, not ordinary conversation.
Alone, it does not identify one exact animal.
Questions people ask
1Why does 蠌 show as a box on some devices?
Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.
How to type 蠌
蠌\880CCodes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.