▁travel ▁over ▁relatively ▁large ▁distances , ▁including ▁one ▁c ray fish ▁moving ▁over ▁ 7 0 0 ▁m ▁in ▁a ▁single ▁night . ▁ ▁Ju ven iles ▁are ▁sus pected ▁to ▁migr ate ▁to ▁season al ▁cre eks ▁or ▁shall ow ▁faster - flow ing ▁waters ▁known ▁as ▁r iff le ▁zones ▁where ▁they ▁are ▁at ▁less ▁risk ▁from ▁pred ators ▁including ▁other ▁c ray fish , ▁fish , ▁plat yp us ▁and ▁ra k ali . ▁Lar ger ▁sub - ad ult s ▁( < ▁car ap ace ▁length ) ▁will ▁move ▁to ▁deeper - flow ing ▁straight ▁sections ▁of ▁the ▁catch ment . ▁Ad ult s ▁have ▁no ▁natural ▁pred ators ▁and ▁will ▁take ▁refuge ▁in ▁shelter ed ▁deep ▁po ols ▁and ▁appear ▁to ▁toler ate ▁each ▁other ▁despite ▁being ▁ag gress ive ▁elsewhere . ▁M ales ▁are ▁territorial ▁and ▁maintain ▁a ▁ha rem ▁of ▁up ▁to ▁several ▁females . ▁ ▁Re production ▁Tas man ian ▁giant ▁fresh water ▁c ray fish ▁have ▁extremely ▁slow ▁m atur ation ▁rates , ▁with ▁females ▁reaching ▁sexual ▁m atur ity ▁at ▁approximately ▁ 1 4 ▁years ▁of ▁age , ▁a ▁weight ▁of ▁ ▁and ▁a ▁car ap ace ▁length ▁of ▁. ▁M ales ▁are ▁thought ▁to ▁reach ▁m atur ity ▁more ▁quickly ▁at ▁around ▁ 9 ▁years , ▁ ▁and ▁ ▁car ap ace ▁length . ▁ ▁Fem ales ▁mate ▁and ▁spawn ▁once ▁every ▁two ▁years ▁in ▁aut umn ▁after ▁a ▁summer ▁mou lt , ▁producing ▁ 2 2 4 – 1 3 0