312
MAKOTO OMORI
they were caught, although sniall crustuceans are the main constituent
of the food.
26. The membor of the pncra Rergesles, 8ergia and Acetas can
utilize food over a wide range of sizes, iind swallow larger pieces, while
Bantheogewn emn, Gmnadas, Pasiphnaa , Optophorus and Acaiithrphglra
lire adapted for tntinipulating rc:ltitivcly large prey, and the food
items are chopped and ground into smiill pieces by the mouthparts.
27. Hpipelagid and upper mcsopclagic shrimps feed chiefly on
herbivorous copepods arid euphausiids. Sergestids are potential
filter-feeders and occasionally eat phytoplankton, while bathypelagic
shrimps take mostly carnivorous copepods, ostracods, medusae and
chaetognaths.
28. Shrimps feed actively at night. However, physiological evidence
suggests that the lower meso- and bathypelagic species are able to
maintain thoir predatory activities throughout their range of migration,
by day ns well as by night.
29. The iiauplii of the penaeids and sergestids do not feed. The
larvae begin to feed by filtering suspended matter including phytoplankton at the first protozoeal stage and then tend gradually to
become omnivorous after the zoeal stage. The larvae of carids subsist
entirely on the internal yolk during their early stages and adopt the
feeding behaviour of the adult fairly quickly after metamorphosis.
30. The species of the genera Acetes and Lucifer must play a
significant role as the food of fish nnd shrimps in the coastal waters of
the tropical and subtropical regions, particularly in mangrove swamps.
The importance of pelagie shrimps in the food webs of the pelagic
community is described, and the many kinds of predators reviewed.
81. The water content of pelagic shrimps is 7,5-860/. Total carbon
content varies from 40% to 64% of dry weight, whereas nitrogen
content ranges from 6% to 120/,. There is a tendency for deep-living
apecies to have a higher carbon-nitrogen ratio. Ash content is 6 1 6 % .
Protein content varies from about 36% to 72% of dry weight. A clear
difference is found between the protein content of the shrimps occurring
in the epipelagic and upper nmopelagic zones and that in the bathypelagic zone. Lipid appears to be more variable than protein ; it ranges
from 2% to 730/6 of dry weight. Deep-living species have relatively
higher lipid contents thnn dhallow-living species. The lipid, and
especially wax esters, appear to be primarily a reserve energy store for
the developing embryos and larvae and secondarily an aid to the
buoyancy.
32. The contribution of the species of Acetes to the local fisheries is
great in the Indo-west-Pacific region. Presumably the annual catch
MAKOTO OMORI
they were caught, although sniall crustuceans are the main constituent
of the food.
26. The membor of the pncra Rergesles, 8ergia and Acetas can
utilize food over a wide range of sizes, iind swallow larger pieces, while
Bantheogewn emn, Gmnadas, Pasiphnaa , Optophorus and Acaiithrphglra
lire adapted for tntinipulating rc:ltitivcly large prey, and the food
items are chopped and ground into smiill pieces by the mouthparts.
27. Hpipelagid and upper mcsopclagic shrimps feed chiefly on
herbivorous copepods arid euphausiids. Sergestids are potential
filter-feeders and occasionally eat phytoplankton, while bathypelagic
shrimps take mostly carnivorous copepods, ostracods, medusae and
chaetognaths.
28. Shrimps feed actively at night. However, physiological evidence
suggests that the lower meso- and bathypelagic species are able to
maintain thoir predatory activities throughout their range of migration,
by day ns well as by night.
29. The iiauplii of the penaeids and sergestids do not feed. The
larvae begin to feed by filtering suspended matter including phytoplankton at the first protozoeal stage and then tend gradually to
become omnivorous after the zoeal stage. The larvae of carids subsist
entirely on the internal yolk during their early stages and adopt the
feeding behaviour of the adult fairly quickly after metamorphosis.
30. The species of the genera Acetes and Lucifer must play a
significant role as the food of fish nnd shrimps in the coastal waters of
the tropical and subtropical regions, particularly in mangrove swamps.
The importance of pelagie shrimps in the food webs of the pelagic
community is described, and the many kinds of predators reviewed.
81. The water content of pelagic shrimps is 7,5-860/. Total carbon
content varies from 40% to 64% of dry weight, whereas nitrogen
content ranges from 6% to 120/,. There is a tendency for deep-living
apecies to have a higher carbon-nitrogen ratio. Ash content is 6 1 6 % .
Protein content varies from about 36% to 72% of dry weight. A clear
difference is found between the protein content of the shrimps occurring
in the epipelagic and upper nmopelagic zones and that in the bathypelagic zone. Lipid appears to be more variable than protein ; it ranges
from 2% to 730/6 of dry weight. Deep-living species have relatively
higher lipid contents thnn dhallow-living species. The lipid, and
especially wax esters, appear to be primarily a reserve energy store for
the developing embryos and larvae and secondarily an aid to the
buoyancy.
32. The contribution of the species of Acetes to the local fisheries is
great in the Indo-west-Pacific region. Presumably the annual catch