▁ 2 0 1 4 , ▁Point ▁Def iance ▁Z oo ▁and ▁Aqu arium ▁lost ▁more ▁than ▁half ▁of ▁its ▁ 3 6 9 ▁sea ▁stars , ▁and ▁by ▁September ▁ 2 0 1 5 ▁they ▁number ed ▁fewer ▁than ▁ 1 0 0 . ▁The ▁aqu arium ▁treated ▁its ▁affected ▁sea ▁stars ▁with ▁ant ib iot ics ▁in ▁ 2 0 1 4 , ▁which ▁proved ▁effective . ▁Although ▁a ▁mechanism ▁is ▁still ▁unknown , ▁evidence ▁suggests ▁that ▁a ▁single ▁mut ation ▁in ▁the ▁el ong ation ▁factor ▁ 1 - alpha ▁loc us ▁in ▁P is aster ▁och race us ▁may ▁be ▁associated ▁with ▁reduced ▁mort ality . ▁ ▁Species ▁A ffect ed ▁Most ▁affected ▁( high ▁mort ality ▁rates ): ▁Sol aster ▁da w son i ▁( mor ning ▁sun ▁star ), ▁P is aster ▁bre vis pin us ▁( gi ant ▁p ink ▁star ), ▁P is aster ▁och race us ▁( och re / pur ple ▁star ), ▁Py cn op odia ▁hel ian th o ides ▁( sun flow er ▁star ), ▁Ev aster ias ▁tro sch el ii ▁( m ott led ▁star ), ▁A ffect ed ▁( some ▁mort ality ): ▁D erm aster ias ▁im br ic ata ▁( le ather ▁star ), ▁Sol aster ▁stim ps oni ▁( strip ed ▁sun ▁star ), ▁Orth aster ias ▁ko eh ler i ▁( rain bow ▁star ), ▁Hen ric ia ▁s pp . ▁( blo od ▁star ), ▁Le pt aster ias ▁s pp ▁(