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ADAPTATION
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269
bilities of the Other creatures of the deep. Many other
shes, for example, the Blennies_and Cottids, have loose
aps of skin above their heads, but they are not known to
use them as a lure.
Possibly they are rendered less conspicuous among the seaweed wherethéy live, so that the
unsuspecting prey approaches them and are, then ‘capturedby a short but quick effort.
‘
_
’
_
Noteworthy examples of_ the 1
of various
structures to one and the same end are given by the shes
_
Which attach themselves ito solid objects for some reason
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or
another.
In. the…rapid streams of the
the
Anabantoids usetheir m0vablespines to anchor themselves
but the Loricariid'æ of Central and South America, '
.
which have no spines, uset—heir mOut—h as a -sucker and keep
such rm hold they cannot be pulled off without difculty.
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It is by this means that they manage to reach up to great
heights, over 11,000 feet, among the Andes. Still mor-e
remarkable is the behaviour of the Globe—sh.(Tetrodo_n)
of East India.
It is a voracious andpredatory sh inspite
of its diminutive size (ab0ut3 inches), and is able to inate
its body
a-VÇOid…beig‘ carried away _by’thè ,
_
openingsbétWee stones,
ora. behind;
’snails Which
has. piled up, and
1
sweljls ont
body,, like
_
"
between the stones,
just
Without effort(Thilo)
Another form of attachment is*the adhesive’disc
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belly of the sh, andithis would
be the most natural
apparatus for; the purpose,
a Current.
And if
’
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structures ,arose and developedon aCcount of their utility
Wer.ËhÔuld expect to nd it in the freshwater forms, but
it
is0nly’Ê'found in marine forms. The nearest appr0a0h to
the condition in,Ïfrésh Water is Gastromyzon of North-‘Borneo
,
in WlChih6Wh016_ ve‘ntral surface of the
.
pe0torals at the sides :in
-_
front and the} ,ventrals-béhind,
forms a large sucker ”and is used by the sh
adhf3ÿ€}t0
stones in
the _.mountain…
.
lives inïî‘ÇhÇ
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