Publication Date:
2021-06-23
Description:
The effect of maturation on relative growth of somatic tissues was investigated by measuring and comparing monthly changes in dry weight of somatic tissues and reproductive organs. In both sexes, reproductive tissues grew in relation to total body mass; at maturity female reproductive tissue was 16% of total dry body mass, whereas male reproductive tissue was 2.6%. In females, the relative mass of the mantle and head decreased during maturation, whereas the relative mass of the viscera increased. In males, the mass of the viscera increased with maturation, but no decreases occurred. The percentage composition of protein in the mantle and head of females for each maturity stage did not differ significantly. Far bath sexes, the digestive gland mass remained relatively constant throughout the different maturity stages and seasons, and analysis of stomach fullness indicated that feeding increased in the final maturity stages. All observations support the hypothesis that energy and nutrients for maturation are supplied mainly by diet rather than by stored resources,but that during maturation there is a shift of emphasis from somatic growth to gonadal development and vitellogenesis. Sepia pharaonis, which appears to be an intermittent multiple spawner, does not use protein from muscle tissue for developing and growing its reproduction tissues.
Type:
Article
,
PeerReviewed
Format:
text
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