allti
for th(. Who[e (y1p11ut i ( ~ Iiv,er lrnd below, the alllplitude,
howcvur, derfihssil,g towards gmiltcrs depth8 (Yentech el al., 1964 ; Clarke
,,,,d ~ ~ l l ~ ,
I '~65). 111 notilth cnsra, vertical rnigratio~ls, presumably
prc?vcnt,iny thrposur(? to ~hoto-in l~ibi tiag levels, nltLJ' callcel out the die1
pattern (&liger et al., 1!)(;1), but both ryclcs were revealed distinctly in
the
of Soli (1960) :~ntl 'I'aylor et r d . (1966) on I'grodin,iuw.~ blooms.
~ f b , .
i l l cit.rc, p&odicity t\;;~s tlcmonstrated, i t seems that the major
conctern whio\l ilroso among occ~~nogrt~phera Was to ascertain whether
tile rllytllrr\
erulogenous or cxogenorrs. Backus et al. (1965) took
:~dv~tnt,c~ge of' iL soi8r O C I L ~ ) ~ ~
t,o citrry o ~ i t
what could he ~&Iled a nat11r.d
experiment; it wc~s observed that " biolan~incscent organisms [mainly
dinofli~gt~llut~c~s I ~.espondetl to tlie (dipsing Sun rnucll as they llormally
resIM,nd t,o the! settillg Srrrr ", i.e. hy a11 i~brupt increase in excitability;
the :~utliors concluded that the exogenous factor (light inhibition)
overrode any ctndogenous titning. However, further work demonstrated
that botlh irifiuences must be irivolveci (as already found from cultures;
see ttl~o Kelly i ~ u d Katona, 1066) ; papers by Kelly (1968), Seliger and
McElroy (1908) and Yentscf~ anti Li~ircl (I 968) are quite convincing in
this respect, ~)articulurfy tho last one (14'ig. t i ) .
If the ecological significance and selective advantage of stimulated
bioluminescence are not yet understood (Burkenroad, 1943; Harvey,
1952), tho question of its rhythmicity is still more perplexing. Considering that flicsl~ings niiLy hi~ve " :I survival value as a defense against
copc?po(i grazing ", i Ls dernonstrr~t,ed experimentally by Esaios and
curl (1973), ~ircl) :m uxplanst,ion xhortltl be contemplated in the context
of gruzillg rhytll ltlicitsv (and vcrticitl migrationN too), which ma,y lead
to t~ rat'her int,l.ia;tte sitjustion.
Spo~ltfLneolls emission of light is observed less cornmon]y tfian
stimulibt,f'tl lulni~icscencc! (Tett, 197 1 z~,titl rcafcrences therein). Qonyaulm
cultures hlwe ~ ~ I O W I ~
it illso to be r11pth niic!al: rt wei& emission appears
itt the enti of the (lark perioti, jt~at before cell division (Hastings llrtd
Swcf'~ley, 1959 ; liilrakitshisn i h r l t i H:~atin#~, 1962 ;
et at., 196!$ ;
Swccney, i!)(i!):t, ilnd atliers) t ~ t ~ t
cultures of Py~ocy8~is anti P?yrodiniurn
( % 4 k Y
at., 19(i9) fibiled to exhibit the " glow rhythm " and itH
occnrrellce a t scan rrrnibins to be invpstipted.
1,igIlt-inclucc~tl movcrncwta of' cliloropluats are well docurnc$nted
(for it reocnt ~*ctvic?w of sucli plic~lon~t.~iu. in i~lgue, see Hitur~t itrid fjchijnbolinl, 1970). It is thus not surprising if some marine phytoplankters
exhibit i~ dial periodicity in tht; shape imd arrangement of rhloroplasts,
but one will ~ i o t c that, in this ps~.tiauli~r ci~sc, the light ~ t ~ i m u l ~ ~ s
pre-
for th(. Who[e (y1p11ut i ( ~ Iiv,er lrnd below, the alllplitude,
howcvur, derfihssil,g towards gmiltcrs depth8 (Yentech el al., 1964 ; Clarke
,,,,d ~ ~ l l ~ ,
I '~65). 111 notilth cnsra, vertical rnigratio~ls, presumably
prc?vcnt,iny thrposur(? to ~hoto-in l~ibi tiag levels, nltLJ' callcel out the die1
pattern (&liger et al., 1!)(;1), but both ryclcs were revealed distinctly in
the
of Soli (1960) :~ntl 'I'aylor et r d . (1966) on I'grodin,iuw.~ blooms.
~ f b , .
i l l cit.rc, p&odicity t\;;~s tlcmonstrated, i t seems that the major
conctern whio\l ilroso among occ~~nogrt~phera Was to ascertain whether
tile rllytllrr\
erulogenous or cxogenorrs. Backus et al. (1965) took
:~dv~tnt,c~ge of' iL soi8r O C I L ~ ) ~ ~
t,o citrry o ~ i t
what could he ~&Iled a nat11r.d
experiment; it wc~s observed that " biolan~incscent organisms [mainly
dinofli~gt~llut~c~s I ~.espondetl to tlie (dipsing Sun rnucll as they llormally
resIM,nd t,o the! settillg Srrrr ", i.e. hy a11 i~brupt increase in excitability;
the :~utliors concluded that the exogenous factor (light inhibition)
overrode any ctndogenous titning. However, further work demonstrated
that botlh irifiuences must be irivolveci (as already found from cultures;
see ttl~o Kelly i ~ u d Katona, 1066) ; papers by Kelly (1968), Seliger and
McElroy (1908) and Yentscf~ anti Li~ircl (I 968) are quite convincing in
this respect, ~)articulurfy tho last one (14'ig. t i ) .
If the ecological significance and selective advantage of stimulated
bioluminescence are not yet understood (Burkenroad, 1943; Harvey,
1952), tho question of its rhythmicity is still more perplexing. Considering that flicsl~ings niiLy hi~ve " :I survival value as a defense against
copc?po(i grazing ", i Ls dernonstrr~t,ed experimentally by Esaios and
curl (1973), ~ircl) :m uxplanst,ion xhortltl be contemplated in the context
of gruzillg rhytll ltlicitsv (and vcrticitl migrationN too), which ma,y lead
to t~ rat'her int,l.ia;tte sitjustion.
Spo~ltfLneolls emission of light is observed less cornmon]y tfian
stimulibt,f'tl lulni~icscencc! (Tett, 197 1 z~,titl rcafcrences therein). Qonyaulm
cultures hlwe ~ ~ I O W I ~
it illso to be r11pth niic!al: rt wei& emission appears
itt the enti of the (lark perioti, jt~at before cell division (Hastings llrtd
Swcf'~ley, 1959 ; liilrakitshisn i h r l t i H:~atin#~, 1962 ;
et at., 196!$ ;
Swccney, i!)(i!):t, ilnd atliers) t ~ t ~ t
cultures of Py~ocy8~is anti P?yrodiniurn
( % 4 k Y
at., 19(i9) fibiled to exhibit the " glow rhythm " and itH
occnrrellce a t scan rrrnibins to be invpstipted.
1,igIlt-inclucc~tl movcrncwta of' cliloropluats are well docurnc$nted
(for it reocnt ~*ctvic?w of sucli plic~lon~t.~iu. in i~lgue, see Hitur~t itrid fjchijnbolinl, 1970). It is thus not surprising if some marine phytoplankters
exhibit i~ dial periodicity in tht; shape imd arrangement of rhloroplasts,
but one will ~ i o t c that, in this ps~.tiauli~r ci~sc, the light ~ t ~ i m u l ~ ~ s
pre-