. ▁vol can ii ▁occurs ▁a sex ually ▁by ▁binary ▁f ission . ▁This ▁practice ▁is ▁similar ▁to ▁that ▁of ▁other ▁Arch ae a ▁and , ▁indeed , ▁that ▁of ▁b acter ia . ▁ ▁H . ▁vol can ii ▁cells ▁have ▁no ▁cell ▁wall ▁and , ▁like ▁many ▁arch ae a , ▁therefore ▁use ▁their ▁exterior ▁S - layer ▁for ▁structure . ▁An ▁individual ▁H . ▁vol can ii ▁arch ae on ▁can ▁vary ▁from ▁ 1 - 3 ▁mic rom eters ▁in ▁diameter . ▁They ▁are ▁typically ▁recogn is able ▁by ▁their ▁' d ished ▁cr isp ' ▁shape , ▁but ▁are ▁somewhat ▁ple i omorphic ▁so ▁may ▁be ▁seen ▁in ▁other ▁shapes ▁including ▁c oc co id . ▁ ▁The ▁memb ran es ▁of ▁this ▁organ ism ▁are ▁made ▁of ▁the ▁typical ▁ ether ▁linked ▁memb rane ▁lip ids ▁found ▁sole ly ▁in ▁arch ae a ▁and ▁also ▁contain ▁a ▁high ▁level ▁of ▁car oten oid s ▁including ▁ly cop ene , ▁which ▁gives ▁them ▁their ▁distinct ive ▁red ▁colour . ▁ ▁H . ▁vol can ii ▁use ▁a ▁salt ▁in ▁method ▁to ▁maintain ▁os most asis , ▁rather ▁than ▁the ▁typical ▁compatible ▁sol utes ▁method ▁seen ▁in ▁b acter ia . ▁This ▁method ▁involves ▁the ▁maintenance ▁of ▁a ▁high ▁degree ▁of ▁pot ass ium ▁ ions ▁in ▁the ▁cell ▁to ▁balance ▁the ▁sod ium ▁ ions ▁outside . ▁ ▁For ▁this ▁reason ▁H . ▁vol can ii ▁has ▁a ▁complex ▁ion ▁reg ulation ▁system ▁and ▁is ▁chem o aut