—
"
416
EFFECT or LINES ON INVERTEBRATES.
—Ë
which crowd, throughout the greater part of the year, the:
_
region over the bottom, and ascend to the surface.
Swa1ms
of
pelagic forms, such as Spirialis, which, smallthough=
it be, is often eaten by ducks at the surface, and more
dantly by many young shes near the bottom, are m1ngled—
with these and the larval nudibranchs, and occasionally evenwith 0Zionè.
The latter does not attain the bulk of the
'
examples, but is by .no means infrequent at certain seasons_
Finally, the proximity of a mussel-bed, or the presence ofan:
extensive coating of small mussels ou the rocks, lls the water:
(J une and July) with myriads of pelagic mussels, which
and—by adhere to— everything affordihg a surface, and form a£
favourite food of young shes, and even of some of the£
Irrèspective of its direct relation to sh—food, thisunceas1n:
wealth of pelagic life has a close connection with the susten—=
'
ance of the bottom-fauna.
Every invertebrate group, mentioned:
in the foregoing paragraphe., feeds on the pelagic fauna or its
débris ; for, even the highest—via, the cuttle-shes—frequently’
devour the pelagic shes. The whole system forms awond€rful—
cycle, and is far more important, from a sheries’ point of View,
than at rst sight appears.
‘
_
In returnirig the contents of the trawl to the water, many’
forms are doubtless devoured by shes in their descent to the
“bottom, just as the.gulls which follow the herring—boats'in
western lochs,‘ or the wake of a trawler on the eastern coasts,
swoop on the offal thrown overboard, or On the inj ureol shes
which escape from the net at—the surface when hauling. The
“
same, remark applies to the ivertebrates thrown oVerb0&ïd by
b EfectsoftheooksoftheLmers on” the same Ground
—In censermgtheeffect of the mm ou
.
ammals
"
416
EFFECT or LINES ON INVERTEBRATES.
—Ë
which crowd, throughout the greater part of the year, the:
_
region over the bottom, and ascend to the surface.
Swa1ms
of
pelagic forms, such as Spirialis, which, smallthough=
it be, is often eaten by ducks at the surface, and more
dantly by many young shes near the bottom, are m1ngled—
with these and the larval nudibranchs, and occasionally evenwith 0Zionè.
The latter does not attain the bulk of the
'
examples, but is by .no means infrequent at certain seasons_
Finally, the proximity of a mussel-bed, or the presence ofan:
extensive coating of small mussels ou the rocks, lls the water:
(J une and July) with myriads of pelagic mussels, which
and—by adhere to— everything affordihg a surface, and form a£
favourite food of young shes, and even of some of the£
Irrèspective of its direct relation to sh—food, thisunceas1n:
wealth of pelagic life has a close connection with the susten—=
'
ance of the bottom-fauna.
Every invertebrate group, mentioned:
in the foregoing paragraphe., feeds on the pelagic fauna or its
débris ; for, even the highest—via, the cuttle-shes—frequently’
devour the pelagic shes. The whole system forms awond€rful—
cycle, and is far more important, from a sheries’ point of View,
than at rst sight appears.
‘
_
In returnirig the contents of the trawl to the water, many’
forms are doubtless devoured by shes in their descent to the
“bottom, just as the.gulls which follow the herring—boats'in
western lochs,‘ or the wake of a trawler on the eastern coasts,
swoop on the offal thrown overboard, or On the inj ureol shes
which escape from the net at—the surface when hauling. The
“
same, remark applies to the ivertebrates thrown oVerb0&ïd by
b EfectsoftheooksoftheLmers on” the same Ground
—In censermgtheeffect of the mm ou
.
ammals