Fish families

Petromyzontidae are a family of lampreys native to the Northern Hemisphere, comprising the vast majority of living lampreys. Petromyzontids have the highest number of chromosomes (164–174) among vertebrates.

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The Telmatherinidae, the sail-fin silversides are a family of atheriniform fish, inhabiting fresh and brackish water. All but the species Kalyptatherina helodes are restricted to the Indonesian island of Sulawesi, and most are found solely in the Malili Lake system, consisting of Matano and Towuti, and the small Lontoa (Wawantoa), Mahalona and Masapi. They were formerly treated as a subfamily of the Melanotaeniidae.