ck ▁from ▁the ▁alg ae , ▁but ▁in ▁some ▁other ▁species ▁the ▁sl ugs ▁se quest er ▁and ▁use ▁within ▁their ▁own ▁t issues ▁living ▁ch lor op last s ▁from ▁the ▁alg ae ▁they ▁eat , ▁a ▁very ▁unusual ▁phenomen on ▁known ▁as ▁kle ptop last y , ▁for ▁the ▁" st olen " ▁pl ast ids . ▁This ▁ear ns ▁them ▁the ▁title ▁of ▁the ▁" sol ar - power ed ▁sea ▁sl ugs ", ▁and ▁makes ▁them ▁unique ▁among ▁met az o an ▁organ isms , ▁for ▁otherwise ▁kle ptop last y ▁is ▁known ▁only ▁among ▁single - cel led ▁prot ists . ▁ ▁The ▁Sac og loss a ▁are ▁divided ▁into ▁two ▁cl ades : ▁the ▁sh elled ▁families ▁( O x yn o ace a ) ▁and ▁the ▁shell - less ▁families ▁( P lak ob ranch ace a ). ▁ ▁There ▁are ▁four ▁families ▁of ▁sh elled ▁species : ▁C yl ind rob ull idae , ▁Vol vat ell idae , ▁Ox yn o idae ▁and ▁Juli idae , ▁the ▁b ival ved ▁g ast rop ods . ▁ ▁The ▁shell - less ▁Pla k ob ranch ace a ▁are ▁grouped ▁in ▁six ▁families , ▁divided ▁between ▁two ▁cl ades ▁(" super famil ies "), ▁the ▁Pla k ob ran cho idea ▁and ▁the ▁Lim ap ont io idea . ▁All ▁s acc og loss ans ▁are ▁distinguished ▁from ▁related ▁groups ▁by ▁the ▁presence ▁of ▁a ▁single ▁row ▁of ▁teeth ▁on ▁the ▁rad ula . ▁The ▁teeth