18
J. Mather and D. Scheel
2.1 Introduction
Behaviour is one of the most simple and obvious aspects of the life of any animal. But besides being easy to see, it has logical links to the ecology of animals’
interactions with their surroundings and the physiology of their internal workings
(Drickamer et al. 1996). Generating an environment that allows a captive cephalopod to express its normal range of behaviour, such as providing shelter for cuttlefish
and octopuses, and space for squid, is important for their health and competence.
But behaviour can also be used as a cue of trouble. Unusual coloration, poor muscle
tone, change in feeding behaviour, or location in an atypical place or position can
tell the people keeping the cephalopods that something is wrong.
There are two problems with describing the behaviour of ‘the cephalopod’. The
first one is that there is a large number of species, normally inhabiting and adapted
to a wide variety of marine habitats (see Table 2.1). The abundant coleoid cephalopods are typified by cuttlefish, squid, and octopuses, many of which live in shallow water, are short-lived, semelparous, and physiologically efficient though not
necessarily active more than 25 % of the time (Mather 1988). The few nautiloids,
represented by Nautilus and Allonautilus (see Chap. 10), are long-lived iteroparous
inhabitants of the cold depths.
Some cephalopods, such as the octopuses, seem ‘preadapted’ to confinement
(Boycott 1954), occupying a sheltered ‘home’ for around 70 % of the time (Mather
et al. 1985; Mather 1988). In contrast, the jet-propelled squid in their normal pelagic
environment are typified by Sepioteuthis sepioidea, who make a startle jet escape at
an average of eight times per hour, moving a mode of 2 m distance (Mather 2010),
a difficult response in a laboratory environment.
A second problem with describing the behaviour of cephalopods is that it is
poorly known, though see Hanlon and Messenger (1996) for an excellent but somewhat dated summary. A basic ethogram (description of the common behaviour of a
species) can only be pieced together for Octopus vulgaris—see Wells’ (1978) and
Mather et al.’s (2010a) popular books—and Sepia officinalis (see Guerra 2006),
though the behaviour of the latter has not been studied in the wild. Squid and cuttlefish species often gather to mate and their agonistic and sexual behaviour is fairly
well known (Hall and Hanlon 2002; Hanlon et al. 2002; Jantzen and Havenhand
Table 2.1 Aspects of the behaviour of the three major cephalopod groups
a
Behaviour
Cuttlefish
Squid
Octopus
Habitat choice
Benthic, semi-benthic
Pelagic
Benthic
Sensory
Vision, chemical
Vision, mechanical
Vision, chemical
Locomotion
Jet
Jet
Crawl/jet
Antipredator
Camouflage, hiding, ink Jet escape, ink
Hiding, camouflage, ink
Skin displays
Camouflage, sexual
Sexual
Camouflage
Prey
Fish, crustacean
Fish
Mollusc, crustacean
Sociality
Social at reproduction
Social groups
Solitary
Care of young
None
None
Female egg brooding
a
Many minor exceptions
J. Mather and D. Scheel
2.1 Introduction
Behaviour is one of the most simple and obvious aspects of the life of any animal. But besides being easy to see, it has logical links to the ecology of animals’
interactions with their surroundings and the physiology of their internal workings
(Drickamer et al. 1996). Generating an environment that allows a captive cephalopod to express its normal range of behaviour, such as providing shelter for cuttlefish
and octopuses, and space for squid, is important for their health and competence.
But behaviour can also be used as a cue of trouble. Unusual coloration, poor muscle
tone, change in feeding behaviour, or location in an atypical place or position can
tell the people keeping the cephalopods that something is wrong.
There are two problems with describing the behaviour of ‘the cephalopod’. The
first one is that there is a large number of species, normally inhabiting and adapted
to a wide variety of marine habitats (see Table 2.1). The abundant coleoid cephalopods are typified by cuttlefish, squid, and octopuses, many of which live in shallow water, are short-lived, semelparous, and physiologically efficient though not
necessarily active more than 25 % of the time (Mather 1988). The few nautiloids,
represented by Nautilus and Allonautilus (see Chap. 10), are long-lived iteroparous
inhabitants of the cold depths.
Some cephalopods, such as the octopuses, seem ‘preadapted’ to confinement
(Boycott 1954), occupying a sheltered ‘home’ for around 70 % of the time (Mather
et al. 1985; Mather 1988). In contrast, the jet-propelled squid in their normal pelagic
environment are typified by Sepioteuthis sepioidea, who make a startle jet escape at
an average of eight times per hour, moving a mode of 2 m distance (Mather 2010),
a difficult response in a laboratory environment.
A second problem with describing the behaviour of cephalopods is that it is
poorly known, though see Hanlon and Messenger (1996) for an excellent but somewhat dated summary. A basic ethogram (description of the common behaviour of a
species) can only be pieced together for Octopus vulgaris—see Wells’ (1978) and
Mather et al.’s (2010a) popular books—and Sepia officinalis (see Guerra 2006),
though the behaviour of the latter has not been studied in the wild. Squid and cuttlefish species often gather to mate and their agonistic and sexual behaviour is fairly
well known (Hall and Hanlon 2002; Hanlon et al. 2002; Jantzen and Havenhand
Table 2.1 Aspects of the behaviour of the three major cephalopod groups
a
Behaviour
Cuttlefish
Squid
Octopus
Habitat choice
Benthic, semi-benthic
Pelagic
Benthic
Sensory
Vision, chemical
Vision, mechanical
Vision, chemical
Locomotion
Jet
Jet
Crawl/jet
Antipredator
Camouflage, hiding, ink Jet escape, ink
Hiding, camouflage, ink
Skin displays
Camouflage, sexual
Sexual
Camouflage
Prey
Fish, crustacean
Fish
Mollusc, crustacean
Sociality
Social at reproduction
Social groups
Solitary
Care of young
None
None
Female egg brooding
a
Many minor exceptions