hor es , ▁particularly ▁in ▁Nan om ia ▁bij uga ▁conf ers ▁evolution ary ▁advantages . ▁A ▁large ▁amount ▁of ▁concentr ated ▁individuals ▁allows ▁for ▁redund ancy . ▁This ▁means ▁that ▁even ▁if ▁some ▁individual ▁si phon op hor es ▁become ▁function ally ▁comprom ised , ▁the ▁col ony ▁as ▁a ▁whole ▁is ▁not ▁neg atively ▁affected . ▁ ▁Tax onomy ▁▁ ▁Organ isms ▁in ▁the ▁order ▁of ▁Si phon op hor ae ▁have ▁been ▁class ified ▁into ▁the ▁ph yl um ▁C n id aria ▁and ▁the ▁class ▁H ydro zo a . ▁The ▁ph y log en etic ▁relationships ▁of ▁si phon op hor es ▁have ▁been ▁of ▁great ▁interest ▁due ▁to ▁the ▁high ▁vari ability ▁of ▁the ▁organization ▁of ▁their ▁pol yp ▁colon ies ▁and ▁med us ae . ▁Once ▁believed ▁to ▁be ▁a ▁highly ▁distinct ▁group , ▁lar val ▁similar ities ▁and ▁morph ological ▁features ▁have ▁led ▁research ers ▁to ▁believe ▁that ▁si phon op hor es ▁had ▁evol ved ▁from ▁simpler ▁colonial ▁hydro zo ans ▁similar ▁to ▁those ▁in ▁the ▁orders ▁Anth o at he c ata ▁and ▁Le pt othe c ata . ▁Con sequently , ▁they ▁are ▁now ▁un ited ▁with ▁these ▁in ▁the ▁subclass ▁H yd roid ol ina . ▁ ▁Early ▁analysis ▁divided ▁si phon op hor es ▁into ▁ 3 ▁main ▁sub groups ▁based ▁on ▁the ▁presence ▁or ▁the ▁absence ▁of ▁ 2 ▁different ▁tra its : ▁sw imming ▁b ells ▁( nect op hor es ) ▁and ▁flo ats ▁( p neum