84
J. C. Navarro et al.
studies aiming to determine the elemental composition of O� vulgaris have been
conducted as a first approach to establish the dietary requirements in this species
(Napoleão et al. 2005a; Napoleão et al. 2005b). Thus, Villanueva and Bustamante
(2006) reported the elemental composition of the mature ovary, hatchlings, eggs at
different developmental stages, wild juvenile individuals and also paralarvae fed a
variety of experimental diets. Generally, S, Na, K, P and Mg were determined as the
most abundant elements in O� vulgaris. Compared to other cephalopods, hatchlings
from O� vulgaris contained higher levels of Ag, Cu, Mn, Ni and Zn. Compared to
subadults and adults of the common octopus (Seixas et al. 2005), the contents of
some nonessential elements, namely Ag, Al, Ba, Cd, Hg and Pb, were lower in
hatchlings and reared paralarvae, suggesting an accumulation of such elements during development. Similar accumulation of oligoelements seems to occur in cuttlefish (Lacoue-Labarthe et al. 2008a, b, 2009, 2010a, b, Lourenço et al. 2009). Certain
elements with potentially pivotal roles in the octopus and cuttlefish physiology have
been studied more extensively. Copper (Cu), a key element in the respiratory function of haemocyanin (Ghiretti 1966; D´Aniello et al. 1986), has been postulated to
be required for octopus paralarvae, as suggested by the high levels encountered in
paralarvae fed on the natural prey Maja brachydactyla zoeae in comparison with
Artemia spp. nauplii (Villanueva and Bustamante 2006). Moreover, octopuses fed
on crustacean-based diets contained increased Cu levels compared to fish-fed octopuses, and therefore hypothesized to partly account for a higher cannibalism rate in
the latter (García-García and Cerezo-Valverde 2006). The importance of Cu is also
high in S� officinalis (Decleir et al. 1978), especially during maturation of haemocyanin (Decleir and Richard 1970; Decleir et al. 1971; Wolf et al. 1980; Beuerlein
et al. 2004), and this probably extends to other cephalopods species (Taylor and
Anstiss 1999). Similar to octopus, the low content of Cu in prepared diets has been
pinpointed to provoke mortality by Castro et al. (1993).
Sulphur (S) is also regarded as an essential element for the common octopus and
cuttlefish that needs to be provided in the diet at high quantities to sustain formation
of muscular proteins (Lee 1994; Villanueva et al. 2004), vestigial shell (Napoleão
et al. 2005b) and chitinized structures such as beaks (Hunt and Nixon 1981). Other
elements such as strontium (Sr) and cobalt (Co) appear to be incorporated by the
common octopus directly from the seawater and by food intake in cuttlefish. It has
been demonstrated that Sr is critical for adequate statolith development and consequently for normal swimming and survival of newly hatched octopus, among other
cephalopods (Hanlon et al. 1989). In addition to its potential role as an integral
component of vitamin B 12 , Co has also been pointed out as important in the development of adenochrome, a pigment found in the branchial heart, and therefore with
a potential role in excretion (Miyazaki et al. 2001).
The cuttlefish S� officinalis has a cuttlebone which is made of calcium aragonite
(Hewitt 1975) and may suffer malformation resulting from malnutrition (Boletzky 1974).
Since food is the primary pathway for the accumulation of trace elements (Bustamante
et al. 2004), the inclusion of calcium in a prepared diet is implicit. In fact, the mineral
fraction of cuttlefish accounts for 22–32 % in eggs (Sykes et al. 2012) and 6 % of dry
weight at hatching (Villanueva et al. 2004), which can only be attained in such way.
J. C. Navarro et al.
studies aiming to determine the elemental composition of O� vulgaris have been
conducted as a first approach to establish the dietary requirements in this species
(Napoleão et al. 2005a; Napoleão et al. 2005b). Thus, Villanueva and Bustamante
(2006) reported the elemental composition of the mature ovary, hatchlings, eggs at
different developmental stages, wild juvenile individuals and also paralarvae fed a
variety of experimental diets. Generally, S, Na, K, P and Mg were determined as the
most abundant elements in O� vulgaris. Compared to other cephalopods, hatchlings
from O� vulgaris contained higher levels of Ag, Cu, Mn, Ni and Zn. Compared to
subadults and adults of the common octopus (Seixas et al. 2005), the contents of
some nonessential elements, namely Ag, Al, Ba, Cd, Hg and Pb, were lower in
hatchlings and reared paralarvae, suggesting an accumulation of such elements during development. Similar accumulation of oligoelements seems to occur in cuttlefish (Lacoue-Labarthe et al. 2008a, b, 2009, 2010a, b, Lourenço et al. 2009). Certain
elements with potentially pivotal roles in the octopus and cuttlefish physiology have
been studied more extensively. Copper (Cu), a key element in the respiratory function of haemocyanin (Ghiretti 1966; D´Aniello et al. 1986), has been postulated to
be required for octopus paralarvae, as suggested by the high levels encountered in
paralarvae fed on the natural prey Maja brachydactyla zoeae in comparison with
Artemia spp. nauplii (Villanueva and Bustamante 2006). Moreover, octopuses fed
on crustacean-based diets contained increased Cu levels compared to fish-fed octopuses, and therefore hypothesized to partly account for a higher cannibalism rate in
the latter (García-García and Cerezo-Valverde 2006). The importance of Cu is also
high in S� officinalis (Decleir et al. 1978), especially during maturation of haemocyanin (Decleir and Richard 1970; Decleir et al. 1971; Wolf et al. 1980; Beuerlein
et al. 2004), and this probably extends to other cephalopods species (Taylor and
Anstiss 1999). Similar to octopus, the low content of Cu in prepared diets has been
pinpointed to provoke mortality by Castro et al. (1993).
Sulphur (S) is also regarded as an essential element for the common octopus and
cuttlefish that needs to be provided in the diet at high quantities to sustain formation
of muscular proteins (Lee 1994; Villanueva et al. 2004), vestigial shell (Napoleão
et al. 2005b) and chitinized structures such as beaks (Hunt and Nixon 1981). Other
elements such as strontium (Sr) and cobalt (Co) appear to be incorporated by the
common octopus directly from the seawater and by food intake in cuttlefish. It has
been demonstrated that Sr is critical for adequate statolith development and consequently for normal swimming and survival of newly hatched octopus, among other
cephalopods (Hanlon et al. 1989). In addition to its potential role as an integral
component of vitamin B 12 , Co has also been pointed out as important in the development of adenochrome, a pigment found in the branchial heart, and therefore with
a potential role in excretion (Miyazaki et al. 2001).
The cuttlefish S� officinalis has a cuttlebone which is made of calcium aragonite
(Hewitt 1975) and may suffer malformation resulting from malnutrition (Boletzky 1974).
Since food is the primary pathway for the accumulation of trace elements (Bustamante
et al. 2004), the inclusion of calcium in a prepared diet is implicit. In fact, the mineral
fraction of cuttlefish accounts for 22–32 % in eggs (Sykes et al. 2012) and 6 % of dry
weight at hatching (Villanueva et al. 2004), which can only be attained in such way.