10. GROWTH, MATURITY AND MORTALITY
305
AND BREEDING OF EUPHAUSIIDS
Breeding seasota
Area
Authority
-
May
Oc tober-November
November-April
Varies with latitude ;
Spring-summer
March-June
May-August
May-August
March-June
April-May
April-Ma y
MayJune
MayJuly
June-September
MayJuly
-
-
N. Atlantic
N. Pacific
Antarctic
Antarctic
N. Atlantic,
Mediterranean
S. and S.W. Iceland,
Southern areas
N. and E. Iceland,
Norwegian Sea
West Greenland
S. and S.W. Iceland,
Southern areas
Hardanger Fjord,
S kagerrak
N. and E. Iceland,
Norwegian Sea,
S.E. Aleutians
West Greenland
N.E. Aleutians
N. Atlantic
N.E. Aleutians
S.E. Aleutians
S.E. Kamchatka
Einarsson (1 945)
Nemoto (1957)
Baker (1959)
Bargmann (1945), Nemoto
Einarsson (1945),
Mauchline (1960),
Mauchline and Fisher (1967)
Einarsson (1945),
Mauchliie (1966a)
Einarsson (1945)
Einarsson (1945)
Einarsson (1945)
(1959)
Einarsson (1945),
Wiborg (1966)
Einarsson (1945)
Nemoto (1957)
Einarsson (1945)
Nemoto (1957)
Einarsson (1945)
Nemoto (1957)
Nemoto (1967)
Nemoto (1957)
length relationship, the second by recourse to Fig. 110. The resulting
annual increments are rather different, those using Nemoto’s data being
higher than those using the data in Fig. 110, which is to be expected
because the upper part of the regression line does not fit the data very
well and so underestimates the weight of the largest animals. The
0-group comprises animals which have not yet matured sexually and
bred; immediately they breed, they become the I-group or animals
which have bred once and the following year, if they breed again, they
become known as the 11-group, animals which have bred twice.
Specified periods, corresponding to the periods of increased rate of
growth in the spring and summer, are examined for both the 0-, I-, and
11-group animals. The average daily increments of weight are calculated
for each year of growth and also over the larger part of the animal’s life.