182
found within the literature. For instance, Domingues et al. (2001b) tested the effects
of feeding either Artemia sp. or Paramysis nouvelli during the first 20 days after
hatching (DAH), followed by a diet of P� varians until 70 DAH and frozen Carcinus
maenas for the remaining life cycle with similar results of fecundity (Table 11.1).
Domingues et al. (2002) used P� nouvelli for the first 20 DAH and afterwards live
grass shrimp to close the cycle, achieving narrow increased results in individual
fecundity but lower fertility (Table 11.1) when compared with the 2001 F1 generation. The effects of using either live or frozen grass shrimp, after being fed during
the first 15 DAH, were tested by Domingues et al. (2003b) attaining increased individual fecundity and fertility when using the frozen diet (Table 11.1). A mixture of
live P� varians, C� maenas and fish used by Correia et al. (2005) attained one of the
highest individual fecundity ever in 250 L tanks (834 eggs per female, Table 11.1).
We believe that this result is related more to temperature, densities and sex ratio
than type of food, but further studies are needed.
Sykes et al. (2006a) studied five consecutive generations of cuttlefish in captivity
using a diet of live P� varians in 250 L tanks and obtained a maximum individual
fecundity of 478 eggs per female and fertility of 67.5 % at the F5 generation
(Table 11.1). On the other hand, Sykes et al. (2009) confirmed an increased fecundity in a F2 generation (787 eggs per female; Table 11.1), being fed on live grass
shrimp for the first 20–30 DAH and frozen grass shrimp onwards (in accordance
with the methods described by Sykes et al. 2006b). However, the sex ratio was
completely inversed when compared with that obtained by Correia et al. (2005).
Recently, Sykes et al. (2013b) obtained the best values of individual and overall
fecundity (1,383 and 16,593 eggs, respectively) and an acceptable individual fertility (72 %, Table 11.1) following a similar feed methodology but increasing the
bottom area of the tanks.
Based on these results, it seems that the diet per se will not have a direct effect on
egg number and quality. However, we do not discard the fact that the use of frozen
grass shrimp may be influencing the higher individual and overall fecundity and
fertility by promoting lower energy expenditure associated with feeding.
11.4 Spawning Process
11.4.1 Female Conditions
S� officinalis attains sexual maturity at very different sizes/weight (Sykes et al.
2006a) and has an estimated potential fecundity of a maximum of 8,000 eggs in
nature (Laptikhovsky et al. 2003). The species displays a very typical behaviour
of courtship, mating and agonistic male-to-male interaction, briefly described by
Boletzky (1983) and Hanlon and Messenger (1996), where males mature earlier
than females. Females receive the spermatophores in the paired seminal receptacles,
under the buccal mass, where it may remain and used for as much as 2–5 months
A. V. Sykes et al.
found within the literature. For instance, Domingues et al. (2001b) tested the effects
of feeding either Artemia sp. or Paramysis nouvelli during the first 20 days after
hatching (DAH), followed by a diet of P� varians until 70 DAH and frozen Carcinus
maenas for the remaining life cycle with similar results of fecundity (Table 11.1).
Domingues et al. (2002) used P� nouvelli for the first 20 DAH and afterwards live
grass shrimp to close the cycle, achieving narrow increased results in individual
fecundity but lower fertility (Table 11.1) when compared with the 2001 F1 generation. The effects of using either live or frozen grass shrimp, after being fed during
the first 15 DAH, were tested by Domingues et al. (2003b) attaining increased individual fecundity and fertility when using the frozen diet (Table 11.1). A mixture of
live P� varians, C� maenas and fish used by Correia et al. (2005) attained one of the
highest individual fecundity ever in 250 L tanks (834 eggs per female, Table 11.1).
We believe that this result is related more to temperature, densities and sex ratio
than type of food, but further studies are needed.
Sykes et al. (2006a) studied five consecutive generations of cuttlefish in captivity
using a diet of live P� varians in 250 L tanks and obtained a maximum individual
fecundity of 478 eggs per female and fertility of 67.5 % at the F5 generation
(Table 11.1). On the other hand, Sykes et al. (2009) confirmed an increased fecundity in a F2 generation (787 eggs per female; Table 11.1), being fed on live grass
shrimp for the first 20–30 DAH and frozen grass shrimp onwards (in accordance
with the methods described by Sykes et al. 2006b). However, the sex ratio was
completely inversed when compared with that obtained by Correia et al. (2005).
Recently, Sykes et al. (2013b) obtained the best values of individual and overall
fecundity (1,383 and 16,593 eggs, respectively) and an acceptable individual fertility (72 %, Table 11.1) following a similar feed methodology but increasing the
bottom area of the tanks.
Based on these results, it seems that the diet per se will not have a direct effect on
egg number and quality. However, we do not discard the fact that the use of frozen
grass shrimp may be influencing the higher individual and overall fecundity and
fertility by promoting lower energy expenditure associated with feeding.
11.4 Spawning Process
11.4.1 Female Conditions
S� officinalis attains sexual maturity at very different sizes/weight (Sykes et al.
2006a) and has an estimated potential fecundity of a maximum of 8,000 eggs in
nature (Laptikhovsky et al. 2003). The species displays a very typical behaviour
of courtship, mating and agonistic male-to-male interaction, briefly described by
Boletzky (1983) and Hanlon and Messenger (1996), where males mature earlier
than females. Females receive the spermatophores in the paired seminal receptacles,
under the buccal mass, where it may remain and used for as much as 2–5 months
A. V. Sykes et al.