288
MAKO'l'0 OM081
thought t ti& the ~igI1ifi~iiIlt,la~ greater numbers of the euphausiids and
chaetognaths iii tht. gets from tlit, net saniples may be indicative of
feeding JLfter ccy)ture.
Nergiu Zucmu feeds niciinly 011 suoh cope pods as CaZanus paci$cus
Broclsky , Clnusocalanus arcii icoruis ( I h a ) and Euchueta marina
(Prestandrea) living, roinmoidy, above 200 in depth in Suruga Bay.
However, thc gut contents w r y somewhat seasonally. The guts are
filled with the copepocls in spriiig when they are most abundant.
Eucampin woclincus Ehrenbcrg, a neritic diatom which increases in the
early spring, is found only in March. Chaetognaths and larvae of
cuphausiids and decapod crustacecms are occasionally taken in summer
and aut~umii. I~riistnles of thc diatom Coscinodiacus spp. and fine mud,
togetiiw with t~ hrgc proportion of' griLnular and fibrous debris, are
present in wiiiter; this suggests that the detritus may be an important
part of the divt of 8. Zucens especially during the cold months when the
shrimps occur near tho sea-floor (Omori, 196%). Guts of Sergestes
sirnilis cwntain, hc~sictex mixtures of thc granular and fibrous debris,
mainly ('ahit U ~ Y par.(ficm anti Melridin paci$ca Brodsky which are
most ubundant and frequently occurring calanoid species inhabiting
the uppermost 200-300 m in the Ciilifornia Current region (Judkins
ant1 F'lemingcr, 1972). These finding8 indicate that the upper mesopelagic shrimps fwd on living prey and decomposing dead material
which are most common at tho time they were caught, although small
crustac~:ttns are the maiii constituent of the food.
With the exrcption of the early larval stages, most pelagic shrimps
seem unlikely to speciciiizu in particular food items. However, the structure of their feeding appendciges suggests thiit the size range of the
food of one Hpecies differs from t hat of anothcr. Tchindonova ( 1 969)
noted a (*oridation between the form of the feeding appendages and
sixe of the food items in the guts of variow shrimps, and stated that
Sergtwtes sindis. h'et-gin jnpotiicuu and Hymenodora glacialis eat small
prey whole, wliereau Umtheogen~aema (as G'ennadas) borealis, small
speoime~is of Hymenodora glacialis and 11. frontalis grind their food.
Henfro and Peitrcy (1 966) reported that Beryestes sirnilis can utilize
food in a wide range of sizes, and swallows larger pieces, whereas thc
mouthparts of Yasiphaea paci,fica are better adapted for manipulating
relatively large prey than for capturing minute organisms, and thc
food items are chopped into many pieces. ASergestes serrhtuclus, rSergia
luc~lzs aiid S . prehensilis swallow food itcms and break them up in thc:
guts; their guts are very muscular and have an efficient gmtric mill
ensuring that large food items are properly reduced. On the other
hand, 0plopkor.m grncilirostris nnd 0. spinosua capture large prey like
MAKO'l'0 OM081
thought t ti& the ~igI1ifi~iiIlt,la~ greater numbers of the euphausiids and
chaetognaths iii tht. gets from tlit, net saniples may be indicative of
feeding JLfter ccy)ture.
Nergiu Zucmu feeds niciinly 011 suoh cope pods as CaZanus paci$cus
Broclsky , Clnusocalanus arcii icoruis ( I h a ) and Euchueta marina
(Prestandrea) living, roinmoidy, above 200 in depth in Suruga Bay.
However, thc gut contents w r y somewhat seasonally. The guts are
filled with the copepocls in spriiig when they are most abundant.
Eucampin woclincus Ehrenbcrg, a neritic diatom which increases in the
early spring, is found only in March. Chaetognaths and larvae of
cuphausiids and decapod crustacecms are occasionally taken in summer
and aut~umii. I~riistnles of thc diatom Coscinodiacus spp. and fine mud,
togetiiw with t~ hrgc proportion of' griLnular and fibrous debris, are
present in wiiiter; this suggests that the detritus may be an important
part of the divt of 8. Zucens especially during the cold months when the
shrimps occur near tho sea-floor (Omori, 196%). Guts of Sergestes
sirnilis cwntain, hc~sictex mixtures of thc granular and fibrous debris,
mainly ('ahit U ~ Y par.(ficm anti Melridin paci$ca Brodsky which are
most ubundant and frequently occurring calanoid species inhabiting
the uppermost 200-300 m in the Ciilifornia Current region (Judkins
ant1 F'lemingcr, 1972). These finding8 indicate that the upper mesopelagic shrimps fwd on living prey and decomposing dead material
which are most common at tho time they were caught, although small
crustac~:ttns are the maiii constituent of the food.
With the exrcption of the early larval stages, most pelagic shrimps
seem unlikely to speciciiizu in particular food items. However, the structure of their feeding appendciges suggests thiit the size range of the
food of one Hpecies differs from t hat of anothcr. Tchindonova ( 1 969)
noted a (*oridation between the form of the feeding appendages and
sixe of the food items in the guts of variow shrimps, and stated that
Sergtwtes sindis. h'et-gin jnpotiicuu and Hymenodora glacialis eat small
prey whole, wliereau Umtheogen~aema (as G'ennadas) borealis, small
speoime~is of Hymenodora glacialis and 11. frontalis grind their food.
Henfro and Peitrcy (1 966) reported that Beryestes sirnilis can utilize
food in a wide range of sizes, and swallows larger pieces, whereas thc
mouthparts of Yasiphaea paci,fica are better adapted for manipulating
relatively large prey than for capturing minute organisms, and thc
food items are chopped into many pieces. ASergestes serrhtuclus, rSergia
luc~lzs aiid S . prehensilis swallow food itcms and break them up in thc:
guts; their guts are very muscular and have an efficient gmtric mill
ensuring that large food items are properly reduced. On the other
hand, 0plopkor.m grncilirostris nnd 0. spinosua capture large prey like