,
MIGRATION …®F. FISHES»
49
of the ocean
they all,:st far—‘aswe yet know, migrate
’
tOwards the shallower waters" in order to spaWn. - In British
and northern waters, as well as in—-A1heri€an waters, ;the
commonest form _isjthe Mackerel. As is
théMackerel
coasts in the summer _m0nths in
'
immense
or
Spawning over, they also go"
in pursuit Of the Herring, and—in winter retireÿinto_rdeep
water.
.
:
_
Ç
'
»
This same tendency to mrgrate from deeper to shallower
waters ih='=order to spawn, is also shown by the Clupeids,
Herring—, 'Menhaden,_Pilchàrd,Anchovy, etc. As;in the
case of"the Tunny long migrations used to be credited
Herring, as far as the Greenland ice, for example;»‘but
'—
”recent inŸestigations make :it doubtful whetherthe migra—
Îj
tions are of any great extent ;; the Herring frequent the
-deeper waters—- off the 'co_asts and forgathér toWards
shalloWèr— waters when the impulsë'
comes upon
_
them
,
as mentioned in the previous chapter, the
wanderings along the coasts maybe Very extensive.
»
_A
aboùt,the Herring, not kndwn£in any
""':Ï:other'SpeéièS,iSits ability'to Spawn 'at‘allseasons of the year
'
and'Ïj‘in' fresh as
thus under the most"
tof; temperature and: SaliDity.
'
.
ŸafîaË'i-litÿ"ÿfîn=thisiçf6‘spëèvsilêggests that fmm_ the—jbegipingr
—
it has been a shallowêwater orbraclqsh-waterform ,1t can
'
readin adapt itself to any
fathoms. ;There are Winter 'Herrings Whichgspawn in:—the
_
“
’
Firth of Forth and in the west; spring Herring in Norway,
_
_
‘
in the Schley, and north of Scotland ; summer Herringo‘“
'
the north—east coast ; autumn Herring spaWning in the
southern” N.0rthîêea, and so
But the Herring keeps to
'
the
;
the tropical and subtropiealregibn$…
'
the Variability has changed itinto other species. ‘
;
—
»_
-.
'
interesting problem in distributioni$ furnished
_
bÿiitsjt61ative, the
”This—is
’
“
its main spaWning" placé$1ntheMed1terranean ".
_
_fand
-' 'à,djàçeñf ”Waters; _- ,Yet a;;ôh€tii
'
"
regulayçyear ïbYî.‘yeargd
':