199
11.6.5 Growth, Survival and Sampling
Time to marketable size will greatly depend on the requested product itself. For
instance, in some Mediterranean countries, such as Portugal and Italy, undersized
cuttlefish individuals (5–25 g) are extremely appreciated and their commercial
value is higher than that of animals surpassing 100 g. Time to market will also be
dependent on culture conditions, especially temperature and food.
S� officinalis is cultured extensively in Portugal, Italy and Tunisia. By definition,
this type of culture does not involve human action at the food level, so eggs are caught
and left in earthen ponds with naturally occurring prey, where animals are grown
and collected a few months later when they reach the marketable size. According to
Palmegiano and Sequi (1981), in this type of culture, 0.15–0.30 kg of eggs will produce
800–1,200 kg of cuttlefish with a mean weight of 0.04–0.08 g. The semi-intensive
experiments performed in Italy in the 1980s obtained fast growth rates (14.2 g in 60
days, at 21–24 °C in ponds (Palmegiano and Sequi 1981); 25 g in 40 days and 80 g in
100 days, at 21–24 °C in concrete tanks (Palmegiano and Sequi 1984); 80 kg ha
−1
in
90 days, at 21–24 °C in net cages in ponds (Sequi and Palmegiano 1984)).
Similar high growth rates were obtained in 2004, in earthen ponds of a commercial company at Algarve (Portugal; unpublished data). From an initial biomass
of 600 g of cuttlefish juveniles (with mean wet weight of 1.65 ± 0.62 g), 5,000 g of
cuttlefish (30.75 ± 11.25 g) were produced in 52 days, with a mean water temperature of 21.3 ± 2.0 °C. Higher growth rates were not obtained due to problems related
to initial adaptation of cuttlefish to unfavourable conditions, such as oxygen depletion, lack of food during the fattening and bird predation observed during fishing
at the end of the experiment. These factors promoted an overall mortality of 35 %.
Summarizing and comparing data in tanks from Sykes et al. (2006a) with those
obtained in earthen ponds, it is possible to see that it takes longer (70–90 days in total)
to achieve a similar mean weight in tanks than in ponds, when cuttlefish is reared at a
similar temperature. When food is available and other identified conditions are met,
cuttlefish will grow faster outdoors than indoors, which is in accordance to the findings of Domingues et al. (2006). So depending on the weight request, it is possible
to produce cuttlefish to meet market demands within 2–3 months or even less. To
maintain a high-quality product for human consumption and enforce the best welfare
practice, cuttlefish should be killed by thermal shock in ice slurry water.
11.7 Trends in Research and Industrial Level
The bottlenecks in the cuttlefish culture identified by Sykes et al. (2006b)—reproduction, feeding and nutrition—are still under research. They need to be solved to
improve the current methodology and thereby apply to an industrial scale.
Currently, Centro de Ciências do Mar do Algarve (CCMAR) is the only research
centre performing the culture of European cuttlefish in large numbers and they are
able to supply cultured animals to research centres and public aquaria. In terms of
11 Sepia officinalis
11.6.5 Growth, Survival and Sampling
Time to marketable size will greatly depend on the requested product itself. For
instance, in some Mediterranean countries, such as Portugal and Italy, undersized
cuttlefish individuals (5–25 g) are extremely appreciated and their commercial
value is higher than that of animals surpassing 100 g. Time to market will also be
dependent on culture conditions, especially temperature and food.
S� officinalis is cultured extensively in Portugal, Italy and Tunisia. By definition,
this type of culture does not involve human action at the food level, so eggs are caught
and left in earthen ponds with naturally occurring prey, where animals are grown
and collected a few months later when they reach the marketable size. According to
Palmegiano and Sequi (1981), in this type of culture, 0.15–0.30 kg of eggs will produce
800–1,200 kg of cuttlefish with a mean weight of 0.04–0.08 g. The semi-intensive
experiments performed in Italy in the 1980s obtained fast growth rates (14.2 g in 60
days, at 21–24 °C in ponds (Palmegiano and Sequi 1981); 25 g in 40 days and 80 g in
100 days, at 21–24 °C in concrete tanks (Palmegiano and Sequi 1984); 80 kg ha
−1
in
90 days, at 21–24 °C in net cages in ponds (Sequi and Palmegiano 1984)).
Similar high growth rates were obtained in 2004, in earthen ponds of a commercial company at Algarve (Portugal; unpublished data). From an initial biomass
of 600 g of cuttlefish juveniles (with mean wet weight of 1.65 ± 0.62 g), 5,000 g of
cuttlefish (30.75 ± 11.25 g) were produced in 52 days, with a mean water temperature of 21.3 ± 2.0 °C. Higher growth rates were not obtained due to problems related
to initial adaptation of cuttlefish to unfavourable conditions, such as oxygen depletion, lack of food during the fattening and bird predation observed during fishing
at the end of the experiment. These factors promoted an overall mortality of 35 %.
Summarizing and comparing data in tanks from Sykes et al. (2006a) with those
obtained in earthen ponds, it is possible to see that it takes longer (70–90 days in total)
to achieve a similar mean weight in tanks than in ponds, when cuttlefish is reared at a
similar temperature. When food is available and other identified conditions are met,
cuttlefish will grow faster outdoors than indoors, which is in accordance to the findings of Domingues et al. (2006). So depending on the weight request, it is possible
to produce cuttlefish to meet market demands within 2–3 months or even less. To
maintain a high-quality product for human consumption and enforce the best welfare
practice, cuttlefish should be killed by thermal shock in ice slurry water.
11.7 Trends in Research and Industrial Level
The bottlenecks in the cuttlefish culture identified by Sykes et al. (2006b)—reproduction, feeding and nutrition—are still under research. They need to be solved to
improve the current methodology and thereby apply to an industrial scale.
Currently, Centro de Ciências do Mar do Algarve (CCMAR) is the only research
centre performing the culture of European cuttlefish in large numbers and they are
able to supply cultured animals to research centres and public aquaria. In terms of
11 Sepia officinalis