willow gudgeon; Gnathopogon caerulescens
A freshwater fish native to Lake Biwa and surrounding areas; also farmed and used in cuisine.
The willow gudgeon is a species endemic to Lake Biwa and can be eaten as tsukudani or tempura.
Usually written in katakana as a fish name; the kanji form 本諸子 is rare.
Kanji spelling, rarely used; the katakana form is standard.
The name ホンモロコ likely derives from 本 (true) + モロコ (a general name for small carp-like fish), distinguishing it from other similar species.