394
M. SAKTHNEL:
Limacina inflata is abundant in the northern latitudes (between 9 and 120 S) almost
throughout the year (Fig. 9b). The area of abundance extends spatially up to 20
0
S
between August and November in 1962 and May to August in 1963. The central latitudes
between 15
0
and 26 0 S show less abundance and southern latitudes in general between
26
0
and 32
0
S are poor. This follows the results on the latitudinal variation of biomass
well (TRANTER, 1969). The absence of Limacina inflata in many collections in the southern
latitudes and periodical occurrence in certain months might be due to the scarcity of this
Fig. 10. Latitudinal variation in the mean number of Limacina inf/ata with % of occurrence
species in an area where water conditions are stable. The central latitudes in general show
less abundance but in the period of summer divergence, as reported by ROCHFORD (1969),
Limacina inflata undergoes a significant increase, as in northern latitudes. As a whole this
species is in maximum abundance during August, following the peak period of chlorophyll, reported as maximum during June to August (HUMPHREY and KERR, 1969). The
maximum abundance of Limacina inflata in the northern latitudes might be due to the
upwelling during the SE monsoon as described by WYRTKI (1962) followed by high
biological productivity. The absence of this species in 4 of the collections in the northern
latitudes during September - October 1962 might be due to the different type of gear used.
Out of 18 night tows using the Clarke-Bumpus Sampler (CBS) during September and
November Limacina inflata was present in only 8 samples, whereas this species was
M. SAKTHNEL:
Limacina inflata is abundant in the northern latitudes (between 9 and 120 S) almost
throughout the year (Fig. 9b). The area of abundance extends spatially up to 20
0
S
between August and November in 1962 and May to August in 1963. The central latitudes
between 15
0
and 26 0 S show less abundance and southern latitudes in general between
26
0
and 32
0
S are poor. This follows the results on the latitudinal variation of biomass
well (TRANTER, 1969). The absence of Limacina inflata in many collections in the southern
latitudes and periodical occurrence in certain months might be due to the scarcity of this
Fig. 10. Latitudinal variation in the mean number of Limacina inf/ata with % of occurrence
species in an area where water conditions are stable. The central latitudes in general show
less abundance but in the period of summer divergence, as reported by ROCHFORD (1969),
Limacina inflata undergoes a significant increase, as in northern latitudes. As a whole this
species is in maximum abundance during August, following the peak period of chlorophyll, reported as maximum during June to August (HUMPHREY and KERR, 1969). The
maximum abundance of Limacina inflata in the northern latitudes might be due to the
upwelling during the SE monsoon as described by WYRTKI (1962) followed by high
biological productivity. The absence of this species in 4 of the collections in the northern
latitudes during September - October 1962 might be due to the different type of gear used.
Out of 18 night tows using the Clarke-Bumpus Sampler (CBS) during September and
November Limacina inflata was present in only 8 samples, whereas this species was