'
'
'
FEEDING OF MARINE ANIMALS
205
much more powerful than the tube—feet, yet they soon tire,
and nally the steady pull Of the starsh conquers and the
shell begins'to gape.
As soon» as this happens the starsh
ex‘trudes its stomach through its month and forces it into the
opening (Fig. 46), where it rst probably poisons and later
certainly digests the soft body of the prey.
It is this habit
Which
makes the starsh
the greatest pest on oyster and
.
'
mussel beds.
Starsh can even attack the outwai‘dly
protected sea urchin by forcing their sto1aohs down its
throat apparentl'y quite regardless of the teeth.
.
'
Many worms are Carnivorous, seizing their food by— means
of horny jaws and usually swallowing it whole. '
Whelks and
their relatives live on caron, often dead or dying bivàlves ; '
their mouths are situated at the end of long probosces
'
-
-
Ë‘î\
'
"
‘
FIG. 46.—Dia‘gram showing how. a Star-sh
-
feeds on its prey.. (Modied after Hirsch.)
which can be extfcuded for a considerable distance, and in
_
this manner the inside of a musSel can be cleaned out, the
'
esh being 'scraped into the mouth by the radula.
Many
_
similar animals are able to attack living bivalVes by boring
through their shells either mechanically by means of the
'
radula, 'ùr else Chemically; the animal pouririg out strong
'
acid which eats through the calcareous shell: As soon as
'
the opening is” made the long proboScis with which all these
-
carniv0rous
are equipped 'is' pushed into the soft
'
esh, which is probably poisoned and then very quickly
-
consumed,
Others again open the shells of oysters by
moving on to them and “waiting until the oyster opens When,
'
'
FEEDING OF MARINE ANIMALS
205
much more powerful than the tube—feet, yet they soon tire,
and nally the steady pull Of the starsh conquers and the
shell begins'to gape.
As soon» as this happens the starsh
ex‘trudes its stomach through its month and forces it into the
opening (Fig. 46), where it rst probably poisons and later
certainly digests the soft body of the prey.
It is this habit
Which
makes the starsh
the greatest pest on oyster and
.
'
mussel beds.
Starsh can even attack the outwai‘dly
protected sea urchin by forcing their sto1aohs down its
throat apparentl'y quite regardless of the teeth.
.
'
Many worms are Carnivorous, seizing their food by— means
of horny jaws and usually swallowing it whole. '
Whelks and
their relatives live on caron, often dead or dying bivàlves ; '
their mouths are situated at the end of long probosces
'
-
-
Ë‘î\
'
"
‘
FIG. 46.—Dia‘gram showing how. a Star-sh
-
feeds on its prey.. (Modied after Hirsch.)
which can be extfcuded for a considerable distance, and in
_
this manner the inside of a musSel can be cleaned out, the
'
esh being 'scraped into the mouth by the radula.
Many
_
similar animals are able to attack living bivalVes by boring
through their shells either mechanically by means of the
'
radula, 'ùr else Chemically; the animal pouririg out strong
'
acid which eats through the calcareous shell: As soon as
'
the opening is” made the long proboScis with which all these
-
carniv0rous
are equipped 'is' pushed into the soft
'
esh, which is probably poisoned and then very quickly
-
consumed,
Others again open the shells of oysters by
moving on to them and “waiting until the oyster opens When,