218
J. Nabhitabhata
The culture conditions cause variations of the final size and the life span of S�
pharaonis in captivity (Table 12.1). Lower temperatures can extend sexual maturity,
the longevity of life span and the subsequent larger final size. Nabhitabhata and
Nilaphat (1999) reported that sexual maturity was reached at about 90 days of age
and a mean final size of 140 mm and 275 g at 210 days of age with an average life
span of 150 days at 28 °C from the open system. At similar temperatures, Anil et al.
(2005) reported later mating at 120 days after hatching but cuttlefish displayed a
larger size (168 mm) and increased weight (521 g) at 210 days after hatching. From
a closed system at 25–28 °C, further growth seems to occur. Minton et al. (2001)
reported that the sexual maturity postponed to 150–240 days after hatching and to a
mean final size of 214–230 mm, 980–1,320 g with an average life span of less than
270 days. The differences in the two studies reflect the plasticity of the strategies
of the life cycle in this species, such as the short and the long generation mode, as
adaptations to the environment.
Models of growth from hatching have been reported by Nabhitabhata and
Nilaphat (1999) and Nabhitabhata (2002). The relationship between mantle length
(ML, mm) and weight (W, g) of the pharaoh cuttlefish from hatching to 260 days
can be expressed in a single model as follows (Fig. 12.5):
W
M L
=
×
−
7 070 10
4
2591
.
.
.
(12.2)
The growth in terms of the mantle length–age (T, d) relationship (Fig. 12.6) can
also be expressed in a single model:
Fig. 12.5 Growth in terms of the relationship between mantle length (mm) and weight (g). Arrows
indicate approximate age at mating (m) and spawning (s). (After Nabhitabhata and Nilaphat 1999;
Nabhitabhata 2002)
J. Nabhitabhata
The culture conditions cause variations of the final size and the life span of S�
pharaonis in captivity (Table 12.1). Lower temperatures can extend sexual maturity,
the longevity of life span and the subsequent larger final size. Nabhitabhata and
Nilaphat (1999) reported that sexual maturity was reached at about 90 days of age
and a mean final size of 140 mm and 275 g at 210 days of age with an average life
span of 150 days at 28 °C from the open system. At similar temperatures, Anil et al.
(2005) reported later mating at 120 days after hatching but cuttlefish displayed a
larger size (168 mm) and increased weight (521 g) at 210 days after hatching. From
a closed system at 25–28 °C, further growth seems to occur. Minton et al. (2001)
reported that the sexual maturity postponed to 150–240 days after hatching and to a
mean final size of 214–230 mm, 980–1,320 g with an average life span of less than
270 days. The differences in the two studies reflect the plasticity of the strategies
of the life cycle in this species, such as the short and the long generation mode, as
adaptations to the environment.
Models of growth from hatching have been reported by Nabhitabhata and
Nilaphat (1999) and Nabhitabhata (2002). The relationship between mantle length
(ML, mm) and weight (W, g) of the pharaoh cuttlefish from hatching to 260 days
can be expressed in a single model as follows (Fig. 12.5):
W
M L
=
×
−
7 070 10
4
2591
.
.
.
(12.2)
The growth in terms of the mantle length–age (T, d) relationship (Fig. 12.6) can
also be expressed in a single model:
Fig. 12.5 Growth in terms of the relationship between mantle length (mm) and weight (g). Arrows
indicate approximate age at mating (m) and spawning (s). (After Nabhitabhata and Nilaphat 1999;
Nabhitabhata 2002)