Some Observations On the Swimming Behaviour of the Anemone Stomphia Coccinea
1961; The Company of Biologists; Volume: 38; Issue: 2 Linguagem: Inglês
10.1242/jeb.38.2.343
ISSN1477-9145
Autores Tópico(s)Photoreceptor and optogenetics research
ResumoABSTRACT The swimming behaviour of the anemone Stomphia coccinea, previously known to be a specific response to contact with two species of starfish, is briefly described. The sphincter, isolated or intact, gives a reflex quick contraction when the tentacles are stimulated with whole Dermasterias imbricata or with extract, but not when other starfish are used. Sphincter preparations stimulated electrically give a quick facilitated contraction at frequencies above 1 in 3 sec., and slow contractions at fre quencies below 1 in 2 sec. Quick and slow contractions appear to have the same threshold, which is unaffected by the presence of starfish extract. Possible attributes of the chemosensory system are discussed. Elongation of the column is an essential preliminary to swimming, whereas detachment from the substratum, due mainly to contraction of the parieto-basilar muscles, does not always occur. Cutting experiments, and orientated recording of the swimming movements which ensue, suggest that excitation is maintained locally in the column, and that the parieto-basilar and circular muscles function synergically. Multipolar nerve cells in the column may be concerned with this activity. Various special features of the anatomy of Stomphia may be correlated with its ability to swim. Although the origin and adaptive value of the swimming response are still obscure, it is clear that it must be of distinct biological advantage to the species.
Referência(s)