From here on out I'll be highlighting what I find to be interesting cases of mimicry/deception employed by animals. This week we shall look at the mourning cuttlefish (
Sepia plangon). The males of this species use visual deception against there rivals in order to gain an advantage during the mating season. The male will display his courtship patterns to a receptive female on one half of his body whilst displaying female patterns on the other half in response to the presence of a rival in order to prevent disruption to his courtship, however if two females are present this deception is not used. Research by Brown, Garwood & Williams (2012, p.730) found that this tactic was employed 39% of the time that a rival male was present during courtship.
Figure 1. form Brown, Garwood & Williams (2012, p.731) shows Female (F) Male (M) and direction of rival male (A).
References:
Brown, C. Garwood, M. Williams, J 2012 "It pays to cheat: deception in a cephalopod social signalling system",
Biology Letters, vol. 8, no. 5, pp. 729-732.
The signalling system of cuttlefish is absolutely astounding and there are great videos of these males altering their visual displays depending on whether males or females are present. Do you know how these males are able to regulate their displays so closely?
ReplyDeleteHi Tasmin,
DeleteCuttlefish make use of specialized cells called chromatophores that expand and shrink in order to change the overall colour of the cuttlefish. These cells are controlled neurally with each chromatophore attached to a nerve ending and recent studies believe that not only can chromatophores expand and contract but that they can also fluoresce- helping to emit a stronger signal. This neural control means that one chromatophore may expand whilst the one next to it contracts- allowing them to produce such complex colours.
That's really interesting! Do you think the males ever make a mistake and accidentally display the wrong pattern to incoming males or do they have a way of ensuring this doesn't happen?
ReplyDeleteHi Courtney,
DeleteIn cuttlefish the main colour producing cell is the chromatophore. Each chromatophore is connected to its own nerve cell- that is each one is controlled independently! The cuttlefish has full control as to how each cell reacts and as such displaying the wrong pattern would be an unlikely scenario but if for example a male accidentally displayed some male signal to a rival then conflict for the female would ensue.