‘FILE lIlOLO(IY OF I’LLAUIC SHRIMPS IN THE OCEAN
291
that the lwey W ~ R
brought into the centre of it strong vortex caused
by the body iilld widely opcm long nriterinal flagella. The prey was
theti easily hcld by the sec>olid mitxillipcds. According to Zimmerman
(1 973), ft*eding of Lucifer chrrcei wits often initiated only after a prey
swtbrn rlowc to the vontrd anterior iir(ttt of the Lucifer’s body. A few
titncs, liowcvcbr, it lunged II fctw millirnctres to catch thc prey.
C:encrdly shrimps feod actively at night. The guts of Sergia Zucens
are tilled with much more food at night t h m in daytime. This and the
trend to wtird Icsa advanced digestion in night samples snggest that the
fectding uotivit,y becomes highcst in the period from sunset to 3-4 hours
twforci siinriw (Omori, 196!h). A similar result has beeii reported for
Serg~stes siwiilix (Jndkine und Vleniinger, 1972). Apparently an
individud i w i i r n i L 1 does riot fcetl 24 hour8 it day but has resting periods.
It is not m in usual that 30 60%, of the guts of meso- and bathypelagic shrinii)s itre empty or almost rmpty. Seryestes similis and
Acrtw jnyonicirrs dso have, occtisionully, many of the guts empty (60%
or more). Although we lark knowledge of the digestive rate, the
shrimp n ~ y
bt- iibk to live for long times without food in the deep
Isyors w Iierc prq‘ is scarce.
A rehtioiiship between the feeding activity and the diurnal migration probably exists, but we have little data on feeding patterns in the
spccius living below 500 m. Respiration of epipelagic euphausiids
mid NerrJrsIrs . s k i ilia tends to he independent of hydrostatic pressure,
but clccroc~scs greatly with depth because of decreasing temperatures
(‘real and (hrcy, 1!307; PetLrc*y and Small, 1908). On the contrary,
rtwpiratioii of’ thr lower mesopelngic s p e h s such as &rgia 8pZpnden.r
(ns S. crns8us), Oplophorus t+pinosuN, ilcanthephyra purpuren and
8y~teEla;upi~r dPhilis tq)pears to remain conatant throughout their depth
rtingca ( N a p m , 1964 ; Teal, 197 1 ) (Fig. 19). In these species the decrease
in rcrsl)irution wused by lower ternperaturca at depth is off-set by an
iiicrrase due to higher Imssure. These contrasting results suggest that
it, is to the itdviintsge of the lower meso- and bathypelagic shrimps to
be uble to muiritnin their predatory activities throughout their range
of’ migration, by day as well as night (Teal, 1971).
Crirstacetin larvae are freqriently filter feeders, adolescents omnivores, while thc. adults may be more strictly carnivorous. The nauplius
of Seryin Zmw. and probably of all penaeids and sergostide, does not
feed but’ obtains its nourishment from the remainder of the yolk
present in t h c body. The antennae and mandibles have no ventral
setae for filteririp food from the water. The fist protozoeal stage has
functional moiithparts I I ~
feeds by filtering suspended matter including phytoplariktm from the surrounding water. During the breeding
291
that the lwey W ~ R
brought into the centre of it strong vortex caused
by the body iilld widely opcm long nriterinal flagella. The prey was
theti easily hcld by the sec>olid mitxillipcds. According to Zimmerman
(1 973), ft*eding of Lucifer chrrcei wits often initiated only after a prey
swtbrn rlowc to the vontrd anterior iir(ttt of the Lucifer’s body. A few
titncs, liowcvcbr, it lunged II fctw millirnctres to catch thc prey.
C:encrdly shrimps feod actively at night. The guts of Sergia Zucens
are tilled with much more food at night t h m in daytime. This and the
trend to wtird Icsa advanced digestion in night samples snggest that the
fectding uotivit,y becomes highcst in the period from sunset to 3-4 hours
twforci siinriw (Omori, 196!h). A similar result has beeii reported for
Serg~stes siwiilix (Jndkine und Vleniinger, 1972). Apparently an
individud i w i i r n i L 1 does riot fcetl 24 hour8 it day but has resting periods.
It is not m in usual that 30 60%, of the guts of meso- and bathypelagic shrinii)s itre empty or almost rmpty. Seryestes similis and
Acrtw jnyonicirrs dso have, occtisionully, many of the guts empty (60%
or more). Although we lark knowledge of the digestive rate, the
shrimp n ~ y
bt- iibk to live for long times without food in the deep
Isyors w Iierc prq‘ is scarce.
A rehtioiiship between the feeding activity and the diurnal migration probably exists, but we have little data on feeding patterns in the
spccius living below 500 m. Respiration of epipelagic euphausiids
mid NerrJrsIrs . s k i ilia tends to he independent of hydrostatic pressure,
but clccroc~scs greatly with depth because of decreasing temperatures
(‘real and (hrcy, 1!307; PetLrc*y and Small, 1908). On the contrary,
rtwpiratioii of’ thr lower mesopelngic s p e h s such as &rgia 8pZpnden.r
(ns S. crns8us), Oplophorus t+pinosuN, ilcanthephyra purpuren and
8y~teEla;upi~r dPhilis tq)pears to remain conatant throughout their depth
rtingca ( N a p m , 1964 ; Teal, 197 1 ) (Fig. 19). In these species the decrease
in rcrsl)irution wused by lower ternperaturca at depth is off-set by an
iiicrrase due to higher Imssure. These contrasting results suggest that
it, is to the itdviintsge of the lower meso- and bathypelagic shrimps to
be uble to muiritnin their predatory activities throughout their range
of’ migration, by day as well as night (Teal, 1971).
Crirstacetin larvae are freqriently filter feeders, adolescents omnivores, while thc. adults may be more strictly carnivorous. The nauplius
of Seryin Zmw. and probably of all penaeids and sergostide, does not
feed but’ obtains its nourishment from the remainder of the yolk
present in t h c body. The antennae and mandibles have no ventral
setae for filteririp food from the water. The fist protozoeal stage has
functional moiithparts I I ~
feeds by filtering suspended matter including phytoplariktm from the surrounding water. During the breeding