MIMICRY IN JUVENILE DEEP-SEA SQUID
Cephalopods are common inhabitants of the deep ocean's mesopelagic zones worldwide, yet very little is known about their behaviour due to the inaccessibility of this environment. This is the first case of siphonophore mimicry by a cephalopod Juveniles of the mesopelagic squid Chiroteuthis calyx were observed orienting and coloring their tail and body to closely match the common mesopelagic siphophore Nanomia.
This mimicry is not consistent across life stages; as juveniles progress into the subadult life stage, they lose their tail, and therefore the ability to resemble Nanomia. It is likely that the smaller and more vulnerable juvenile Chiroteuthis avoid predation as a result of mimicking Nanomia’s appearance and behavior and simply hiding in plain sight.
Behavioural and morphological differences between the two life stages support the hypothesis that juvenile C. calyx mimic the abundant siphonophore Nanomia bijuga, in order to deter predation.
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Reference: Burford et al. 2014. Behaviour and mimicry in the juvenile and subadult life stages of the mesopelagic squid Chiroteuthis calyx. Journal of the Marine Biological Association of the United Kingdom.