360
THE BIOLOGY OF EUPHAUSIIDS
in the same year confirmed this finding for herring brought into Wick.
They also noticed that the abundance of M . norvegica in the stomachs
of herring caught by boats from Stornoway was greatest in April and
less in May and June. Stomachs of herring brought into Girvan, in the
Firth of Clyde, in February contained many M . norvegica but in May
the numbers were small. I n Loch Fyne, euphausiids were not abundant
among the stomach contents of herring caught in the late spring, summer
and early autumn and Scott (1888) confirmed the greater importance of
copepods in the diet a t these seasons of the year. I n the same year,
however, Brook and Hoyle (1888) mention M . norvegica and Thysanoessa rmchii as the food of the herring in the Clyde and Murray (1 888)
describes Loch Fyne herring with their guts packed with these two
species and, moreover, observed the herring concentrating on swarms
of the euphausiids on the surface. Similar variations in the food of the
herring were subsequently observed in other areas where it was fished.
Thus, Kardy’s (1924) data, in his study of the Shields herring fishery,
showed euphausiids as relatively unimportant components of the diet
in the overall survey but there were times, for example, in September
1923, when Meganyctiphanes norvegica was predominant in the
stomachs; similar variations for this fishery are reported by Savage
(1931, 1937). Frost (1932) states that Nyctiphanes couchii, Meganyctiphanes norvegica, and Thysanoessa inermis are important food of herring
off the southern coast of Ireland while Scott (1 924) records euphausiids
in the stomachs of Manx herring during the period June to September.
Another sea area in which euphausiids, and especially Meganyctiphanes
norvegica, are eaten extensively is the Skagerrak (Kramp, 1913). Both
Lissner (1919-23) and Ehrenbaum (1919-23) confirmed this observation
and further observed that the herring appear to seek out the euphausiids by following them into the deeper water. Poulsen (1926)
demonstrated, with impressive data, the predominance of M . norvegica
in the food of Skagerrak herring and Hjort and Ruud (1929) went so
far as to say that the species was constantly to be found in the stomachs
of fish from this area. Hjort (1927) pointed out that the spent herring
leave the Norwegian coastal banks or the North Sea Bank and feed on
the immense shoals of euphausiids, M . norvegica and Thysanoessa
inermis, living along the continental slopes and he gives examples of
successful fisheries developed in such areas. On the Blnden Ground,
however, in the North Sea (V. Hansen, 1955) and in the northwestern
North Sea (Ogilvie, 1934) euphausiids did not constitute a large part
of the diet of the herring. On the other hand, farther north Boldovsky
(1941) found that euphausiids were the predominant food organisms of
many of the herring shoals near the Murman coast.
THE BIOLOGY OF EUPHAUSIIDS
in the same year confirmed this finding for herring brought into Wick.
They also noticed that the abundance of M . norvegica in the stomachs
of herring caught by boats from Stornoway was greatest in April and
less in May and June. Stomachs of herring brought into Girvan, in the
Firth of Clyde, in February contained many M . norvegica but in May
the numbers were small. I n Loch Fyne, euphausiids were not abundant
among the stomach contents of herring caught in the late spring, summer
and early autumn and Scott (1888) confirmed the greater importance of
copepods in the diet a t these seasons of the year. I n the same year,
however, Brook and Hoyle (1888) mention M . norvegica and Thysanoessa rmchii as the food of the herring in the Clyde and Murray (1 888)
describes Loch Fyne herring with their guts packed with these two
species and, moreover, observed the herring concentrating on swarms
of the euphausiids on the surface. Similar variations in the food of the
herring were subsequently observed in other areas where it was fished.
Thus, Kardy’s (1924) data, in his study of the Shields herring fishery,
showed euphausiids as relatively unimportant components of the diet
in the overall survey but there were times, for example, in September
1923, when Meganyctiphanes norvegica was predominant in the
stomachs; similar variations for this fishery are reported by Savage
(1931, 1937). Frost (1932) states that Nyctiphanes couchii, Meganyctiphanes norvegica, and Thysanoessa inermis are important food of herring
off the southern coast of Ireland while Scott (1 924) records euphausiids
in the stomachs of Manx herring during the period June to September.
Another sea area in which euphausiids, and especially Meganyctiphanes
norvegica, are eaten extensively is the Skagerrak (Kramp, 1913). Both
Lissner (1919-23) and Ehrenbaum (1919-23) confirmed this observation
and further observed that the herring appear to seek out the euphausiids by following them into the deeper water. Poulsen (1926)
demonstrated, with impressive data, the predominance of M . norvegica
in the food of Skagerrak herring and Hjort and Ruud (1929) went so
far as to say that the species was constantly to be found in the stomachs
of fish from this area. Hjort (1927) pointed out that the spent herring
leave the Norwegian coastal banks or the North Sea Bank and feed on
the immense shoals of euphausiids, M . norvegica and Thysanoessa
inermis, living along the continental slopes and he gives examples of
successful fisheries developed in such areas. On the Blnden Ground,
however, in the North Sea (V. Hansen, 1955) and in the northwestern
North Sea (Ogilvie, 1934) euphausiids did not constitute a large part
of the diet of the herring. On the other hand, farther north Boldovsky
(1941) found that euphausiids were the predominant food organisms of
many of the herring shoals near the Murman coast.