Turning loss into opportunity: the key deletion of an escape circuit in decapod crustaceans.
نویسنده
چکیده
Decapod crustacean escape responses are adaptive behaviors whose neural bases are well understood. The escape circuit is composed of giant neurons. Lateral giant interneurons (LGs) respond to posterior stimuli by generating a somersaulting tailflip; medial giant interneurons (MGs) respond to anterior stimuli with a backwards tailflip. Both sets of interneurons connect to giant fast flexor motor neurons (MoGs). Most features of the escape circuit are thought to result from strong selective pressure to respond to stimuli in the shortest possible time. Despite the apparent advantages of the escape circuit, it has been lost in multiple taxa independently. Some losses of the escape circuit may be rare cases of disaptation, where organisms are less well adapted than related species (i.e., those with the escape circuit). The losses of the escape circuit might be key deletions that promoted the radiation of decapod crustaceans by increasing selection pressure for species to evolve new anti-predator strategies and removing constraints against change.
منابع مشابه
Motor neurons in the escape response circuit of white shrimp (Litopenaeus setiferus)
Many decapod crustaceans perform escape tailflips with a neural circuit involving giant interneurons, a specialized fast flexor motor giant (MoG) neuron, populations of larger, less specialized fast flexor motor neurons, and fast extensor motor neurons. These escape-related neurons are well described in crayfish (Reptantia), but not in more basal decapod groups. To clarify the evolution of the ...
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The present study was carried out to determine the Decapod Crustaceans fauna in association with Sarcotragus muscarum Schmidt, 1864 from the Levantine Sea coasts of Turkey studied between 13 September 2005 and 07 October 2005. As a result of the present study, a total of 711 specimens belonging to 12 decapod species were identified. Among the species determined, Synalpheus gambaroloides (Nardo,...
متن کاملDecapod Crustaceans associated with the sponge Sarcotragus muscarum Schmidt, 1864 (Porifera: Demospongiae) from the Levantine coasts of Turkey
The present study was carried out to determine the Decapod Crustaceans fauna in association with Sarcotragus muscarum Schmidt, 1864 from the Levantine Sea coasts of Turkey studied between 13 September 2005 and 07 October 2005. As a result of the present study, a total of 711 specimens belonging to 12 decapod species were identified. Among the species determined, Synalpheus gambaroloides (Nardo,...
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عنوان ژورنال:
- Brain, behavior and evolution
دوره 72 4 شماره
صفحات -
تاریخ انتشار 2008