鯉 is one of the most commonly used Japanese kanji, and it also has a lot of special readings in addition to the standard onyomi and kunyomi readings.
ONYOMI 音読み
こい koi
KUNYOMI 訓読み
リ ri
Examples
鯉がおたまじゃくしを食べるって知ってた?Did you know that carp eat tadpoles?鯉や鱒のような魚は淡水に住んでいる。Such fishes as carp and trout live in fresh water.私は網で鯉を捕った。I caught a carp in a net.この池には鯉がうようよいる。The pond abounds with carp.少年は池のコイの群れをじっと見つめていた。The boy was gazing at a school of carp in the pond.私の祖父は晴れた日に池の色とりどりの鯉を眺めているのが好きです。My grandfather likes looking at colorful carp in the pond on a fine day.私たちの町にはきれいな川が流れていて、たくさんの鯉が泳いでいるのが見られます。A clean river flows through our town, and we can see many carp swimming in it.