195
varians with success. DeRusha et al. (1989); Domingues et al. (2004) and Almansa
et al. (2006) tested the effect of exclusively using fish and reported lower growth
than when using grass shrimp.
Despite all this effort, it is not economically viable to produce cuttlefish in large
numbers with a growout based on any of those foods. Not only is the amount of
food biomass too high but also the availability of these food resources is scarce.
Therefore, further research has been performed with the objective of developing
alternative diets to cephalopods. Several works regarding trials on artificial diets
were performed first by Lee et al. (1991), Castro and colleagues (Castro 1991;
Castro et al. 1993; Castro and Lee 1994) and, more recently, by Domingues et al.
(2005, 2008) and Ferreira et al. (2010). However, all these attempts to feed cuttlefish on a prepared diet failed to achieve proper growth and survival (for details, see
Table 11.5). Fish pellets have also been tried and accepted by juvenile cuttlefish.
However, after only 2 days, individuals started to reject this food and cannibalism
was observed.
The lack of proper knowledge regarding the physiology and metabolism of the
species, at different geographical locations, has hampered the existence of a successful design. Only by having a well-designed, inexpensive and storable artificial
diet, cuttlefish aquaculture will reach its maturity and industrial stage (Sykes et al.
2006b). In this way, Domingues et al. (2009) tested the effects of thermal treatment
of food given to cuttlefish and obtained interesting growth and survival data that
suggest this process affects diet quality, by provoking protein denaturation, washing
of proteins and amino acids and lipid oxidation. Current research in Portugal is
focused on developing new diets based on the most recent knowledge regarding
cuttlefish physiology, metabolism and raw materials. Up to now, similar results to
those obtained by Hanlon et al. (1991) and Lee et al. (1991) were registered. Nonetheless, the lack of knowledge regarding cuttlefish physiology and metabolism still
remains as the bottleneck to overcome.
11.6.4 Cleaning Techniques
In ponds, periodical cleaning is only performed at the inlet and outlet filters but
several cleaning routines should be performed in tanks.
According to Forsythe et al. (1994), no substratum is needed for normal growth and
survival, even in cultures performed at high densities. This practice not only facilitates
cleaning itself but also prevents pathologies and promotes good welfare under culture
conditions (Sykes et al. 2012). Tanks should be siphoned daily with a hose and purged
(total time spent will depend on the water quality and volume of the tank). On a weekly
basis, airlifts, air stones and water outlet filters should be cleaned with a scrubber with
tap water. Afterwards, these elements should be kept for 24 h in Atlantol 914 (Atlantol,
Belgium), rinsed with tap water and then placed in VirkonS (DuPont Animal Health
Solutions, Europe) for 15 min. Finally, all these materials should once again be abundantly rinsed with tap water. The nets or any material used for animals handling should
follow a similar procedure to avoid contaminations, pathologies and spread of diseases.
11 Sepia officinalis
varians with success. DeRusha et al. (1989); Domingues et al. (2004) and Almansa
et al. (2006) tested the effect of exclusively using fish and reported lower growth
than when using grass shrimp.
Despite all this effort, it is not economically viable to produce cuttlefish in large
numbers with a growout based on any of those foods. Not only is the amount of
food biomass too high but also the availability of these food resources is scarce.
Therefore, further research has been performed with the objective of developing
alternative diets to cephalopods. Several works regarding trials on artificial diets
were performed first by Lee et al. (1991), Castro and colleagues (Castro 1991;
Castro et al. 1993; Castro and Lee 1994) and, more recently, by Domingues et al.
(2005, 2008) and Ferreira et al. (2010). However, all these attempts to feed cuttlefish on a prepared diet failed to achieve proper growth and survival (for details, see
Table 11.5). Fish pellets have also been tried and accepted by juvenile cuttlefish.
However, after only 2 days, individuals started to reject this food and cannibalism
was observed.
The lack of proper knowledge regarding the physiology and metabolism of the
species, at different geographical locations, has hampered the existence of a successful design. Only by having a well-designed, inexpensive and storable artificial
diet, cuttlefish aquaculture will reach its maturity and industrial stage (Sykes et al.
2006b). In this way, Domingues et al. (2009) tested the effects of thermal treatment
of food given to cuttlefish and obtained interesting growth and survival data that
suggest this process affects diet quality, by provoking protein denaturation, washing
of proteins and amino acids and lipid oxidation. Current research in Portugal is
focused on developing new diets based on the most recent knowledge regarding
cuttlefish physiology, metabolism and raw materials. Up to now, similar results to
those obtained by Hanlon et al. (1991) and Lee et al. (1991) were registered. Nonetheless, the lack of knowledge regarding cuttlefish physiology and metabolism still
remains as the bottleneck to overcome.
11.6.4 Cleaning Techniques
In ponds, periodical cleaning is only performed at the inlet and outlet filters but
several cleaning routines should be performed in tanks.
According to Forsythe et al. (1994), no substratum is needed for normal growth and
survival, even in cultures performed at high densities. This practice not only facilitates
cleaning itself but also prevents pathologies and promotes good welfare under culture
conditions (Sykes et al. 2012). Tanks should be siphoned daily with a hose and purged
(total time spent will depend on the water quality and volume of the tank). On a weekly
basis, airlifts, air stones and water outlet filters should be cleaned with a scrubber with
tap water. Afterwards, these elements should be kept for 24 h in Atlantol 914 (Atlantol,
Belgium), rinsed with tap water and then placed in VirkonS (DuPont Animal Health
Solutions, Europe) for 15 min. Finally, all these materials should once again be abundantly rinsed with tap water. The nets or any material used for animals handling should
follow a similar procedure to avoid contaminations, pathologies and spread of diseases.
11 Sepia officinalis