220
J. Nabhitabhata
of decrease in the final size after consecutive-generation cultures due to inbreeding,
and the fertility in cultured batches is much lower than in wild stocks (Nabhitabhata
and Nilaphat 1999; Minton et al. 2001). From the aquaculture point of view, it
means that seed production cannot rely solely on cultured broodstocks and has to
depend, at least, partially on captured spawners. However, the small size at yielding
is an advantage, whereas a weight of 100–400 g is optimum and required by the
seafood industry for frozen food product processing and packaging. It takes only
150 days to produce the cuttlefish of the mentioned size. The short rearing period
facilitates a higher production and a more reliable supply (through higher survival)
and a lower cost of production.
Live cuttlefish products can be distributed to the ornamental aquaculture trade
for which there is a rapidly growing demand. Live cuttlefish of this size are suitable
for the small volumes of home aquaria. Their benthic habits and high tolerance to
different culture conditions are undeniable advantages.
An increased rearing period of more than the suggested 150 days, obtained at
high-temperature conditions, is feasible and will postpone the maturity of the cuttlefish. The high temperature that accelerates the growth of S� pharaonis and shortens
the life span through the early maturity is unavoidable in flow-through open systems (operated at a lower cost compared to closed systems) used in tropical countries. A possible solution to this problem may involve decreasing sexual stimuli and
activities by separation of males and females, hence the mono-sex culture.
The main focus of future research should be devoted to developing feeds for
large-scale culture, both live and artificial. Live feed is required in the nursing
phase, since the young innately feed on a certain prey. The development of mass
culture of mysids as well as any other crustaceans is necessary. The use of commercially produced penaeid shrimp larvae is reliable, but their own commercial
value discourages production. Another trend of research on the live food area is the
enrichment of Artemia sp. as a supplementary and substitute feed for young cuttlefish in the nursing phase, following studies in S� officinalis (Koueta et al. 2002)
and Sepiella inermis (Muthuwan et al. 1993; see also Chap. 13 of this volume).
The innate feeding on live feed is really the bottleneck of the nursing phase. The
artificial feed is feasible through behaviour-approached research on the acceptable
form of the food pellets. The making of artificial feed for the ongrowing phase is
feasible in the short term, because of the higher probability of acceptance of an
artificial diet by juveniles than hatchlings since their ability to learn and their lower
degree of food preference are known. The acceptable form of feed is the first step to
be studied through behavioural approaches (Nabhitabhata et al. 2001b). The form
has to mimic the appearance (shape, colour, brightness, locomotion) and characters
(texture, “odour”) of natural feed. It will be of great benefit to consider some details,
i.e. the acceptable form, from the studies previously held on S� officinalis (Castro
1991; Castro et al. 1993).
The difference in growth rate among different morpho-types and molecular
types, thus inter-populations and intra-populations, could be very interesting in
view of maximising the aquaculture production. The S� pharaonis is probably a
complex species (Reid et al. 2005) of three morphological types (Norman 2000) and
J. Nabhitabhata
of decrease in the final size after consecutive-generation cultures due to inbreeding,
and the fertility in cultured batches is much lower than in wild stocks (Nabhitabhata
and Nilaphat 1999; Minton et al. 2001). From the aquaculture point of view, it
means that seed production cannot rely solely on cultured broodstocks and has to
depend, at least, partially on captured spawners. However, the small size at yielding
is an advantage, whereas a weight of 100–400 g is optimum and required by the
seafood industry for frozen food product processing and packaging. It takes only
150 days to produce the cuttlefish of the mentioned size. The short rearing period
facilitates a higher production and a more reliable supply (through higher survival)
and a lower cost of production.
Live cuttlefish products can be distributed to the ornamental aquaculture trade
for which there is a rapidly growing demand. Live cuttlefish of this size are suitable
for the small volumes of home aquaria. Their benthic habits and high tolerance to
different culture conditions are undeniable advantages.
An increased rearing period of more than the suggested 150 days, obtained at
high-temperature conditions, is feasible and will postpone the maturity of the cuttlefish. The high temperature that accelerates the growth of S� pharaonis and shortens
the life span through the early maturity is unavoidable in flow-through open systems (operated at a lower cost compared to closed systems) used in tropical countries. A possible solution to this problem may involve decreasing sexual stimuli and
activities by separation of males and females, hence the mono-sex culture.
The main focus of future research should be devoted to developing feeds for
large-scale culture, both live and artificial. Live feed is required in the nursing
phase, since the young innately feed on a certain prey. The development of mass
culture of mysids as well as any other crustaceans is necessary. The use of commercially produced penaeid shrimp larvae is reliable, but their own commercial
value discourages production. Another trend of research on the live food area is the
enrichment of Artemia sp. as a supplementary and substitute feed for young cuttlefish in the nursing phase, following studies in S� officinalis (Koueta et al. 2002)
and Sepiella inermis (Muthuwan et al. 1993; see also Chap. 13 of this volume).
The innate feeding on live feed is really the bottleneck of the nursing phase. The
artificial feed is feasible through behaviour-approached research on the acceptable
form of the food pellets. The making of artificial feed for the ongrowing phase is
feasible in the short term, because of the higher probability of acceptance of an
artificial diet by juveniles than hatchlings since their ability to learn and their lower
degree of food preference are known. The acceptable form of feed is the first step to
be studied through behavioural approaches (Nabhitabhata et al. 2001b). The form
has to mimic the appearance (shape, colour, brightness, locomotion) and characters
(texture, “odour”) of natural feed. It will be of great benefit to consider some details,
i.e. the acceptable form, from the studies previously held on S� officinalis (Castro
1991; Castro et al. 1993).
The difference in growth rate among different morpho-types and molecular
types, thus inter-populations and intra-populations, could be very interesting in
view of maximising the aquaculture production. The S� pharaonis is probably a
complex species (Reid et al. 2005) of three morphological types (Norman 2000) and