4
S. von Boletzky and R. Villanueva
and some cephalopods constantly swim or hover in mid-water, whereas others stay
close to the bottom, and some bury in sandy substrata to remain immobile for large
parts of the day (thus hiding from predators along with minimizing energy expenditures). Although we view examples from different groups with various lifestyles
(including some nektonic squid species that become gregarious during juvenile
development), we are not able to cover the full breadth of adaptive features of cephalopod biology that might be exploited in culture work. However, one common feature
of all cephalopod cultures—present and future—must be emphasized, namely the
inevitably artificial character of cephalopod life in captivity.
Culture, even when achieved in very large enclosures designed to mimic a natural
environment, always introduces some artificial elements into the life of captive
cephalopods. Not the least important of these elements are the absence of potential
predators and a general loss of sensory input. Even in an advanced culture system,
cephalopod hatchlings and juveniles are thus conditioned by captivity from the outset. One should keep in mind that—no matter how small they are—newly hatched
cephalopods are already accomplished organisms equipped with complex sensory
organs, a very elaborate nervous system and powerful adult-like effectors (Nixon
and Young 2003). Disregarding body size, the similarity between newly hatched
and adult cephalopods is indeed striking. As examples, Figs. 1.1, 1.2 and 1.3 show
the generalised anatomy of adult coleoid cephalopods and Fig. 1.4 illustrates some
general morphological features of the hatchlings.
In many bottom-living inshore cephalopods, the conditioning by artificial
elements, such as confinement or illumination, may of course be exploitable for
the purposes of a culture. Some of these inshore species indeed are physiologically flexible and can adapt to artificial environments. They may live and grow on
unnatural diets, become sexually mature and reproduce even if low growth rates
can lead to a reduced adult size (Boletzky 1987). The reasons for such reduced
Fig. 1.1 Generalised anatomy of a cuttlefish. (After Boyle and Rodhouse 2005)
S. von Boletzky and R. Villanueva
and some cephalopods constantly swim or hover in mid-water, whereas others stay
close to the bottom, and some bury in sandy substrata to remain immobile for large
parts of the day (thus hiding from predators along with minimizing energy expenditures). Although we view examples from different groups with various lifestyles
(including some nektonic squid species that become gregarious during juvenile
development), we are not able to cover the full breadth of adaptive features of cephalopod biology that might be exploited in culture work. However, one common feature
of all cephalopod cultures—present and future—must be emphasized, namely the
inevitably artificial character of cephalopod life in captivity.
Culture, even when achieved in very large enclosures designed to mimic a natural
environment, always introduces some artificial elements into the life of captive
cephalopods. Not the least important of these elements are the absence of potential
predators and a general loss of sensory input. Even in an advanced culture system,
cephalopod hatchlings and juveniles are thus conditioned by captivity from the outset. One should keep in mind that—no matter how small they are—newly hatched
cephalopods are already accomplished organisms equipped with complex sensory
organs, a very elaborate nervous system and powerful adult-like effectors (Nixon
and Young 2003). Disregarding body size, the similarity between newly hatched
and adult cephalopods is indeed striking. As examples, Figs. 1.1, 1.2 and 1.3 show
the generalised anatomy of adult coleoid cephalopods and Fig. 1.4 illustrates some
general morphological features of the hatchlings.
In many bottom-living inshore cephalopods, the conditioning by artificial
elements, such as confinement or illumination, may of course be exploitable for
the purposes of a culture. Some of these inshore species indeed are physiologically flexible and can adapt to artificial environments. They may live and grow on
unnatural diets, become sexually mature and reproduce even if low growth rates
can lead to a reduced adult size (Boletzky 1987). The reasons for such reduced
Fig. 1.1 Generalised anatomy of a cuttlefish. (After Boyle and Rodhouse 2005)