Cheliped function in the porcellanid crab Petrolisthes japonicus: autotomy as an effective antipredator defence mechanism

Members of the marine bivalve family Limidae are known for their bright appearance. In this study, their colourful tissues were examined as a defence mechanism towards predators. We showed that when attacked by the peacock mantis shrimp ( Odontodactylus scyllarus ), the ‘disco’ clam, Ctenoides ales , opened wide to expose brightly coloured tissues to the predator. The predator also significantly preferred to consume the internal, non-colourful clam tissues than the external, colourful tissues. Mass spectrometry-based metabolomic analysis confirmed that colourful tissues had significantly different chemical compositions than the non-colourful ones. The internal, non-colourful tissues had metabolite profiles more similar to an outgroup bivalve than to the species' own colourful external tissues. A number of the compounds that differentiated the colourful tissues from the non-colourful tissues appeared to be peptide-like, which potentially serve as the underlying defensive compounds. This is the first study demonstrating that colourful bivalve tissues are used for chemical defence.

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Deimatism: a neglected component of antipredator defence

Biology Letters ◽

10.1098/rsbl.2016.0936 ◽

2017 ◽

Vol 13 (4) ◽

pp. 20160936 ◽

Cited By ~ 30

Author(s):

Kate D. L. Umbers ◽

Sebastiano De Bona ◽

Thomas E. White ◽

Jussi Lehtonen ◽

Johanna Mappes ◽

...

Keyword(s):

Sensory Input ◽

Sudden Change ◽

Fundamental Difference ◽

Neural Mechanisms ◽

Survival Advantage ◽

Antipredator Defence

Deimatic or ‘startle’ displays cause a receiver to recoil reflexively in response to a sudden change in sensory input. Deimatism is sometimes implicitly treated as a form of aposematism (unprofitability associated with a signal). However, the fundamental difference is, in order to provide protection, deimatism does not require a predator to have any learned or innate aversion. Instead, deimatism can confer a survival advantage by exploiting existing neural mechanisms in a way that releases a reflexive response in the predator. We discuss the differences among deimatism, aposematism, and forms of mimicry, and their ecological and evolutionary implications. We highlight outstanding questions critical to progress in understanding deimatism.

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What is the Evolutionary Advantage of Migraine?

Cephalalgia ◽

10.1046/j.1468-2982.2002.00437.x ◽

2002 ◽

Vol 22 (8) ◽

pp. 624-632 ◽

Cited By ~ 37

Author(s):

E Loder

Keyword(s):

Nervous System ◽

Natural Selection ◽

Environmental Factors ◽

Genetic Factors ◽

Evolutionary Perspective ◽

Defence Mechanism ◽

Design Constraint ◽

Trade Off ◽

Evolutionary Advantage ◽

Evolutionary Explanations

Susceptibility to migraine is determined by genetic factors and is therefore subject to the forces of natural selection. Migraine is a common and ancient disorder whose prevalence may be increasing, suggesting that a migraine-prone nervous system may be associated with reproductive or survival advantages. Five evolutionary explanations are reviewed that might account for the persistence of migraine: (i) migraine as a defence mechanism; (ii) migraine as a result of conflict with other organisms; (iii) migraine as result of novel environmental factors; (iv) migraine as a trade-off between genetic harms and benefits; and (v) migraine as a design constraint. An evolutionary perspective on migraine allows the generation of important hypotheses about the disorder and suggests rewarding possibilities for further research.

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