457
24 Octopus vulgaris: Ongrowing
24.4 Feeding
24.4.1 Ongrowing with Natural Diets
Both growth and food conversion rates vary widely as a function of the food supplied. The best growth (18–20 g day
−1
; 1.8 % BW day
−1
) and survival rates were
obtained using a diet composed entirely of crustaceans or when crustaceans made
up an important part of mixed diets (Cagnetta and Sublimi 2000; Tuñón et al. 2001;
Aguado Giménez and García García 2002; García García and Cerezo Valverde
2004). García García and Cerezo Valverde (2006) obtained similar results with a
diet based solely on crustaceans ( C� mediterraneus) and another one in which they
were partially replaced by fish (2 days Boops boops and 1 day C� mediterraneus).
This pattern was subsequently applied successfully to ongrowing in the open sea
(García García et al. 2009). Similarly, the partial replacement of crustaceans by
Diplodus vulgaris provided excellent results (Prato et al. 2010). Growth rates similar to those obtained using crustaceans, and even higher than those obtained with
mixed diets including crustaceans, were obtained with diets based on B� boops with
a medium–high lipid content (7–17 % lipids wet weight; Prato et al. 2010; Biandolino et al. 2010; Estefanell et al. 2011, 2012b). García García and Aguado-Giménez
(2002) also tested the influence of the lipid content, obtaining better growth and
conversion index in octopus fed B� boops (6 % lipids; 1.14 % BW day
−1
) than with
Sardina pilchardus (20 % lipids; 0.84 % BW day
−1
). Petza et al. (2006) obtained
poorer growth rates including in the smallest specimens (0.43–0.95 % BW day
−1
)
the use of anchovy, Engralius encrasicolus. Other natural diets low in lipids (< 2 %
lipids) such as squid ( Loligo gahi or Illex coindetii) or hake have also been seen to
generate good growth (1.7–1.9 % BW day
−1
) and show good feed efficiency (Cagnetta and Sublimi 2000; Domingues et al. 2009a). Poorer results were obtained
with mussel (0.3–0.9 % BW day
−1
) and crayfish (1.1 % BW day
−1
), attributable in
the first case to low acceptability (López et al. 2009; Prato et al. 2010) and in the
second case to a poor conversion index (Domingues et al. 2009a). In general, diets
based on fish or squid, or mixed diets have been notable for their high feed efficiencies (40–64 %) compared with monodiets of crustaceans (25–40 % in all studies).
Estefanell et al. (2013) attributed the better feed efficiency of fish and its protein
to the efficient use of lipids, while other studies have demonstrated the capacity of
the octopus to mobilise its reserves of triglycerides in the digestive gland, involving
up to 30 % of its total energy costs during starvation (García-Garrido et al. 2010b;
Morillo-Velarde et al. 2012a).
24.4.2 Ongrowing with Formulated Diets
From the beginning of the 1990s until 2008, much effort in cephalopod culture was
invested in preparing formulated diets, especially in cultures of Sepia officinalis and
O� maya (Lee et al. 1991; Castro 1991; Castro et al. 1993; Castro and Lee 1994;
24 Octopus vulgaris: Ongrowing
24.4 Feeding
24.4.1 Ongrowing with Natural Diets
Both growth and food conversion rates vary widely as a function of the food supplied. The best growth (18–20 g day
−1
; 1.8 % BW day
−1
) and survival rates were
obtained using a diet composed entirely of crustaceans or when crustaceans made
up an important part of mixed diets (Cagnetta and Sublimi 2000; Tuñón et al. 2001;
Aguado Giménez and García García 2002; García García and Cerezo Valverde
2004). García García and Cerezo Valverde (2006) obtained similar results with a
diet based solely on crustaceans ( C� mediterraneus) and another one in which they
were partially replaced by fish (2 days Boops boops and 1 day C� mediterraneus).
This pattern was subsequently applied successfully to ongrowing in the open sea
(García García et al. 2009). Similarly, the partial replacement of crustaceans by
Diplodus vulgaris provided excellent results (Prato et al. 2010). Growth rates similar to those obtained using crustaceans, and even higher than those obtained with
mixed diets including crustaceans, were obtained with diets based on B� boops with
a medium–high lipid content (7–17 % lipids wet weight; Prato et al. 2010; Biandolino et al. 2010; Estefanell et al. 2011, 2012b). García García and Aguado-Giménez
(2002) also tested the influence of the lipid content, obtaining better growth and
conversion index in octopus fed B� boops (6 % lipids; 1.14 % BW day
−1
) than with
Sardina pilchardus (20 % lipids; 0.84 % BW day
−1
). Petza et al. (2006) obtained
poorer growth rates including in the smallest specimens (0.43–0.95 % BW day
−1
)
the use of anchovy, Engralius encrasicolus. Other natural diets low in lipids (< 2 %
lipids) such as squid ( Loligo gahi or Illex coindetii) or hake have also been seen to
generate good growth (1.7–1.9 % BW day
−1
) and show good feed efficiency (Cagnetta and Sublimi 2000; Domingues et al. 2009a). Poorer results were obtained
with mussel (0.3–0.9 % BW day
−1
) and crayfish (1.1 % BW day
−1
), attributable in
the first case to low acceptability (López et al. 2009; Prato et al. 2010) and in the
second case to a poor conversion index (Domingues et al. 2009a). In general, diets
based on fish or squid, or mixed diets have been notable for their high feed efficiencies (40–64 %) compared with monodiets of crustaceans (25–40 % in all studies).
Estefanell et al. (2013) attributed the better feed efficiency of fish and its protein
to the efficient use of lipids, while other studies have demonstrated the capacity of
the octopus to mobilise its reserves of triglycerides in the digestive gland, involving
up to 30 % of its total energy costs during starvation (García-Garrido et al. 2010b;
Morillo-Velarde et al. 2012a).
24.4.2 Ongrowing with Formulated Diets
From the beginning of the 1990s until 2008, much effort in cephalopod culture was
invested in preparing formulated diets, especially in cultures of Sepia officinalis and
O� maya (Lee et al. 1991; Castro 1991; Castro et al. 1993; Castro and Lee 1994;