7. CHEMICaL COMPOSITION
207
winter in the levels of stored lipids which are then built up again after
the spring diatom increase. Consequently, it is probable that stored
lipids in this Antarctic species are used in the winter for the general
metabolism of the animal while, in the temperate species, the lipids
appear to enter the metabolism when the further burden of gonad
development is present.
Sheard (1953) states that '' it is a matter of observation that fat
storage increases as the temperature decreases, until in high latitudes
TABLE XI. LIPIDS (yo WET WEIGHT) IN SPECIES OF Thysanopoda, Nyctiphanes,
AND Thysanoessa
Species
Sea area
Average weight
yo
lipid
Date
( m s )
Thysanopoda acutvrons N. Atlantic
N. Atlantic
N. Atlantic
Thysanopoda aequalis
N. Atlantic
N. Atlantic
N. Atlantic
N. Atlantic
N. Atlantic
Thysanopoda obtusifrons N. Atlantic
Thysanopoda orientalis
N. Atlantic
N. Atlantic
Thysanopoda pectinata
N. Atlantic
Nyctiphanes couchii
N. Atlantic
N. Atlantic
Scotland
Nyctiphanes australis
S. Pacific
S . Pacific
S. Pacific
Thysanoessa inerrnis
Faroes
Faroes
Faroes
Barents Sea
Barents Sea
Scotland
Scotland
Scotland
Scotland
ThysanoBsa gregariu
N. Atlantic
Thysanoessa longicauduta N. Atlantic
N. Atlantic
Barents Sea
ThysanoZssa spinifera
N. Pacific
N. Pacific
September 1952
November 1954
April 1955
November 1955
November 1955
November 1955
November 1955
November 1955
November 1955
May 1956
June 1954
June 1954
March 1955
March 1956
April 1956
April 1956
November 1950
November 1950
November 1950
October 1954
January 1955
December 1955
December 1955
December 1955
December 1955
November 1955
November 1954
July 1955
January 1955
May 1953
April 1956
Sept.-Nov. 1955
Sept.-Nov. 1955
32
10
12
3
10
13
14
1 7
36
83
129
34
2.5
3.5
7.5
30
33
33
7.1
7.8
11
37
3.6
6.4
8.1
8.3
5.5
1.7
22
12
12
14
64
0.4
3.9
1.1
12.0
3.8
7.6
3.9
1.6
1.1
1.0
6.6
1-7
1.0
1.7
2,2
0.8
0.6
0.5
11.0
5.2
8.3
9.2
9.4
2.8
3-0
12.0
3.7
3.1
2.5
0.2
1.4
8.7
0.4