▁are ▁suspect ▁to ▁min ing ▁operations ▁as ▁well ▁as ▁river ▁dam ming . ▁Either ▁of ▁these ▁projects ▁could ▁very ▁well ▁be ▁det r iment al ▁to ▁the ▁fish ▁species . ▁ ▁Life ▁history ▁The ▁fre ck le bel ly ▁d arter ▁has ▁a ▁poor ly ▁studied ▁life ▁history . ▁Sp aw ning ▁of ▁the ▁species ▁evidently ▁pe aks ▁from ▁mid - M arch ▁through ▁mid - A pril . ▁The ▁fish ▁is ▁estimated ▁to ▁live ▁about ▁three ▁years . ▁Based ▁on ▁length ▁frequency ▁data ▁this ▁species ▁is ▁re product ively ▁m ature ▁at ▁age ▁one . ▁Sp aw ning ▁occurs ▁in ▁temper atures ▁of ▁ ▁in ▁areas ▁with ▁strong ▁current ▁and ▁fine ▁gra vel . ▁Aqu arium ▁observations ▁confirm ▁that ▁this ▁species ▁bur ies ▁its ▁eggs ▁in ▁a ▁manner ▁similar ▁to ▁other ▁Per c ina ▁dar ters . ▁F ert il ized ▁eggs ▁are ▁about ▁ 2 . 5   mm ▁in ▁diameter , ▁clear , ▁dem ers al ▁and ▁slightly ▁ad hes ive . ▁ ▁At ▁ ▁eggs ▁h atch ed ▁in ▁ 1 8 – 2 5 ▁days . ▁Fem ales ▁of ▁the ▁species ▁are ▁thought ▁to ▁reach ▁sexual ▁m atur ity ▁at ▁age ▁one ▁and ▁when ▁sp aw ning , ▁lay ▁their ▁eggs ▁in ▁the ▁substr ate ▁of ▁the ▁lake ▁or ▁river ▁bed . ▁ ▁M ales ▁of ▁the ▁species ▁have ▁a ▁sem ic irc ular ▁ke el ▁on ▁the ▁ca ud al ▁ped un cle ▁that ▁appears ▁to ▁function ▁as ▁a ▁pl ough share ▁which , ▁in ▁conj unction