▁of ▁marine ▁organ isms ▁belonging ▁to ▁the ▁ph yl um ▁C n id aria . ▁According ▁to ▁the ▁World ▁Register ▁of ▁Marine ▁Species , ▁the ▁order ▁contains ▁ 1 7 5 ▁species . ▁ ▁Although ▁a ▁si phon oph ore ▁may ▁appear ▁to ▁be ▁an ▁individual ▁organ ism , ▁each ▁spec imen ▁is ▁in ▁fact ▁a ▁colonial ▁organ ism ▁composed ▁of ▁med us oid ▁and ▁poly po id ▁zo oid s ▁that ▁are ▁morph olog ically ▁and ▁function ally ▁special ized . ▁Zo oid s ▁are ▁mult ic ell ular ▁units ▁that ▁develop ▁from ▁a ▁single ▁fert il ized ▁egg ▁and ▁combine ▁to ▁create ▁functional ▁colon ies ▁able ▁to ▁reproduce , ▁dig est , ▁float , ▁maintain ▁body ▁position ing , ▁and ▁use ▁jet ▁prop ulsion ▁to ▁move . ▁Most ▁colon ies ▁are ▁long , ▁thin , ▁transparent ▁float ers ▁living ▁in ▁the ▁pel ag ic ▁zone . ▁▁ ▁Like ▁other ▁hydro zo ans , ▁some ▁si phon op hor es ▁emit ▁light ▁to ▁attract ▁and ▁attack ▁pre y . ▁While ▁many ▁sea ▁animals ▁produce ▁blue ▁and ▁green ▁bi ol um ines c ence , ▁the ▁si phon oph ore ▁was ▁only ▁the ▁second ▁life ▁form ▁found ▁to ▁produce ▁a ▁red ▁light ▁( the ▁first ▁one ▁being ▁the ▁scale less ▁drag on fish ▁Ch iro st om ias ▁p li opter us ). ▁ ▁An atom y ▁and ▁morph ology ▁ ▁Col ony ▁characteristics ▁▁ ▁Si phon op hor es ▁are ▁colonial ▁hydro zo ans ▁that ▁reproduce ▁a sex ually ▁through ▁a ▁bud