rl'(~liitlclo~~ovi~ ( I !#A!)) i ~ ~ v r s t
ig.~to(l t l i ~ w r t i(.itI distri1)11t ion of' lkw
1wl;tgic sh~.in~ps in t,h(. 1101.tIl\rrc~stc~1-11 I'r~c.ific., ilntl found that t,hc
f ) o p ~ ~ l i ~ t
lo11 I I I ~ L X ~ I ~ N
o f c.o~lgchrrc.ric- sp~(*icw trnclrd to occur at different
tlapths. I+"oxt,ol~ ( I 97 111) sl1o\v(~I i \ siniii:~~' phcno~n(~non in the vertical
tlistrih~~t io~r of 1 h c b pq)c~c%ic.s i l l t lrc. gc3nchn~ (;~trrr,r~~los. Set-!j~strs, IV~ryiu tind
~\'!/sIellrc,spix off t I I ~
( ' i ~ n ~ ~ r g
1sl1111tls tlr~~*ing t thc diiy He suggested that
soli~r ~'il(liittiOll ~ L I I ~
its ~i(~n(~tl'i~tioll into the ~ 1 ~ a
m118t he of primr
itn1)ol.t ;tnc.c i n 1~~4i~tiotl to si1(,11 j)~tticr~is of' v c ~ t
ical ciistribution. Pre1i111il1it1-y di~tjit of' 1ni11t' (O~nori. ~~ll])~~t)lish(vl) i t l ~ ~
suggestetl that the
g c x ~ ~ l ~ s
Ser!fin i n S u r ~ r g ; ~
Ili~y sliowt*ti it pritcl~~itl progrt~ssion ; by day the
~)rinc-il)i~I pitrt of' t#l~tt ~ ) o ~ ) ~ ~ l : t t i o n
o f ' 9 . l ? i r ~ n s
oc.c.nrred in 11 stratlrm of
200
111 ; S pr~hpn.silix 500 700 rn : S. jnponicus I 000- I 200 m
~.tbspc~c.tivrly. Ilowrvcr. this i~ltcrcst~ing phnnomenol~ itppcbars to be
r ~ l a t e d not o111j~ to t h ~
cwvironrnental light birt also to temperature
itrlct foot1 cwnlpctit ion, lind any interpret,et,ion remains ron jectnral
~rnt~il furt,hc.r d(btaile(1 st>~~dies arta mtulr.
'I'hc~ xl)(b(aies c-livcrsity of citrids sttnirled the meximum between
.jOO itrltl 2 000 rn tlepth in thr t,ropicaI regions of the lndian and Pacific
0ce:tns (Vinogradov, 1968). Near the ('Ianary l~litnds the t>otal number
of s1)ecit.s of all pelagic shrimps illorrased with depth and \vits greatest
s t 925 m by day, but tho number oc-curring st shallow depths increased
i1t night duca to migration and no oviderlc.e of' a grailient with depth
wiis f o ~ l ~ ~ c l
lwt \V(Y-II 100 atid fIO0 111 (1tyt 11 (Foxton. 19700).
i\'itt~ 11 f'(l\v c*s(vptio~~s cii~trt~sl \(brti(+;~l ~nigr;ttion s ( ~ r n s to ocrur
i n all c y i - ;inti rnosol~t~l~tgic. sl~r-irnl)s. t i l t l~or~gll thc 1)ehnviolrr of an
il~(iivi(l~ll~I sl)e(*i(w IIRX not so fiir 1)(~(11i stl~ditvl ill sitvh dt>tail ILS that
dcsrri1)c~tl thr cbupha~~siids by I3t,int011 (l!)fi7). Figure 4 shows the
vt3rtit:til tlistril)~ltion of c-or~~pitr;ttivc~l,y nI)rrt~dant shrimpx obsc.rvctl
~nitirily in tt*lnl)c~rate ; ~ n d ~ubtropical regions. Except for the case of
ft~c~cling rnigritt,ion. vcr.ti(>i~l migrants (lo not remitin in cc!rtain dopths
ilt tt~ly hol~r but move illvt?ssttl~tly lrpward or downwartl unlt.ss thejr
c~llcorrnter tl~cx zone whic.h is physiologically unfbvourat)le for tho
npr~cirs. It hues !)(ten observed in vctrious animals that they &pparently
begin to n~ovr. upward in the water almost as soon as they reach the
lowest point of their downwanl excursion. 'J'herefore, in the strict
.scn~c of tJl~c~ tctrrn, atnplitudes of the vertical distribution of a species
by d i ~ y itntl I)p rlight m y be continuor~e. hut in this paper the depth.rt4i~r to ttrt. Ic\.c.l at whic~li the ~)rinc.ipril part of the species pol)ulation
ig.~to(l t l i ~ w r t i(.itI distri1)11t ion of' lkw
1wl;tgic sh~.in~ps in t,h(. 1101.tIl\rrc~stc~1-11 I'r~c.ific., ilntl found that t,hc
f ) o p ~ ~ l i ~ t
lo11 I I I ~ L X ~ I ~ N
o f c.o~lgchrrc.ric- sp~(*icw trnclrd to occur at different
tlapths. I+"oxt,ol~ ( I 97 111) sl1o\v(~I i \ siniii:~~' phcno~n(~non in the vertical
tlistrih~~t io~r of 1 h c b pq)c~c%ic.s i l l t lrc. gc3nchn~ (;~trrr,r~~los. Set-!j~strs, IV~ryiu tind
~\'!/sIellrc,spix off t I I ~
( ' i ~ n ~ ~ r g
1sl1111tls tlr~~*ing t thc diiy He suggested that
soli~r ~'il(liittiOll ~ L I I ~
its ~i(~n(~tl'i~tioll into the ~ 1 ~ a
m118t he of primr
itn1)ol.t ;tnc.c i n 1~~4i~tiotl to si1(,11 j)~tticr~is of' v c ~ t
ical ciistribution. Pre1i111il1it1-y di~tjit of' 1ni11t' (O~nori. ~~ll])~~t)lish(vl) i t l ~ ~
suggestetl that the
g c x ~ ~ l ~ s
Ser!fin i n S u r ~ r g ; ~
Ili~y sliowt*ti it pritcl~~itl progrt~ssion ; by day the
~)rinc-il)i~I pitrt of' t#l~tt ~ ) o ~ ) ~ ~ l : t t i o n
o f ' 9 . l ? i r ~ n s
oc.c.nrred in 11 stratlrm of
200
111 ; S pr~hpn.silix 500 700 rn : S. jnponicus I 000- I 200 m
~.tbspc~c.tivrly. Ilowrvcr. this i~ltcrcst~ing phnnomenol~ itppcbars to be
r ~ l a t e d not o111j~ to t h ~
cwvironrnental light birt also to temperature
itrlct foot1 cwnlpctit ion, lind any interpret,et,ion remains ron jectnral
~rnt~il furt,hc.r d(btaile(1 st>~~dies arta mtulr.
'I'hc~ xl)(b(aies c-livcrsity of citrids sttnirled the meximum between
.jOO itrltl 2 000 rn tlepth in thr t,ropicaI regions of the lndian and Pacific
0ce:tns (Vinogradov, 1968). Near the ('Ianary l~litnds the t>otal number
of s1)ecit.s of all pelagic shrimps illorrased with depth and \vits greatest
s t 925 m by day, but tho number oc-curring st shallow depths increased
i1t night duca to migration and no oviderlc.e of' a grailient with depth
wiis f o ~ l ~ ~ c l
lwt \V(Y-II 100 atid fIO0 111 (1tyt 11 (Foxton. 19700).
i\'itt~ 11 f'(l\v c*s(vptio~~s cii~trt~sl \(brti(+;~l ~nigr;ttion s ( ~ r n s to ocrur
i n all c y i - ;inti rnosol~t~l~tgic. sl~r-irnl)s. t i l t l~or~gll thc 1)ehnviolrr of an
il~(iivi(l~ll~I sl)e(*i(w IIRX not so fiir 1)(~(11i stl~ditvl ill sitvh dt>tail ILS that
dcsrri1)c~tl thr cbupha~~siids by I3t,int011 (l!)fi7). Figure 4 shows the
vt3rtit:til tlistril)~ltion of c-or~~pitr;ttivc~l,y nI)rrt~dant shrimpx obsc.rvctl
~nitirily in tt*lnl)c~rate ; ~ n d ~ubtropical regions. Except for the case of
ft~c~cling rnigritt,ion. vcr.ti(>i~l migrants (lo not remitin in cc!rtain dopths
ilt tt~ly hol~r but move illvt?ssttl~tly lrpward or downwartl unlt.ss thejr
c~llcorrnter tl~cx zone whic.h is physiologically unfbvourat)le for tho
npr~cirs. It hues !)(ten observed in vctrious animals that they &pparently
begin to n~ovr. upward in the water almost as soon as they reach the
lowest point of their downwanl excursion. 'J'herefore, in the strict
.scn~c of tJl~c~ tctrrn, atnplitudes of the vertical distribution of a species
by d i ~ y itntl I)p rlight m y be continuor~e. hut in this paper the depth.rt4i~r to ttrt. Ic\.c.l at whic~li the ~)rinc.ipril part of the species pol)ulation