Tactile and chemical perception in earthworms-II responses to acid pH solutions

Tactile and chemical perception in earthworms-II responses to acid pH solutions

1961

E00334

(l) An attempt to explain the distribution of earthworms on the basis of the sensitivity to pH is described.(2) A. Zanga will not burrow into soil having a pH below 4.5; L. terrestris will not enter soil of pH 4-1 while L. rubellus will tolerate soils below either of these limits. (3) Experiments involving dipping earthworms into buffer solutions confirm these observations since rejection of pH 4.4 by A.Zanga, pH 4-2 by L. terrestris and pH 3.8 by L. rubellus is very swift. (4) Recordings from the nervous system, taken from intact or pared segmental nerves show that acid-sensitive fibres are present universally over the earthworm body surface. There is no indication that the prostomium is more sensitive than the rest of the body surface. (5) The threshold values at which these organs respond are pH 4,6-4'4 for A. Zanga; pH 4, 3-4-1.for L. terrestris and pH 3 -8 for L. rubellus. They are specific to acid- stimuli, not reacting to sodiwn chloride, quinine or sucrose. (6) The different threshold responses reflect the different field distributions of these three species.

v.2:22-34, COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY, B: COMPARATIVE BIOCHEMISTRY

Research > Published Articles