'I'llE IilO1,OOY OF l'l!21dA~+l(? SIIKIMPA ZN THE OCEAN
281
C. Croiuth. neat ~crify, long~rtity and mortality
111 Spr!liu lrieem the growth o f thc young is rapid and all larval
Rt,ay;c.s awo cornplated withill a nionth ttftcr hatching. The growth
riite after t,hc pout-larviL varics, do pentling 011 the sex and age. Usually
tho rttt,e iii fimales exceeds that in males, and the young grow faster
than the adults. Growth is slowcd during the cold months, as observed
M O N T H
Yitr. 17. (Ilowt,h trends of Scrgin lurene in Suruga 13ay and AceleR juponkue 111 Ariekv
8oa and fluctuation of thoir onvilwnmental temperature.
in various specicts of pentteids. Shrimps of this species take three or
four months t o reach 20 mm in body length, and they mature sexually
at ten to tfwelvc months of age when the length attaim about 40 mm
(Fig. 17). They seem t o die within u few months after spawning. Thw
the life epcm of tho species is about fifteen monthg, but n few individuals
live for eighteen months at most under favourable conditions (Omori,
1969a; Omori el al., 1973).