Effect of bilateral eyestalk ablation on the heart rate of the crab Chasmagnathus granulata Dana, 1851 (Crustacea - Decapoda).
1. We have studied the effect of bilateral eyestalk ablation on the heart rate (HR) of a crab. Recordings of the heart rate of normal and eyestalkless Chasmagnathus granulata, a meso-supralittoral crab from southern Brazil, were obtained starting 1 h after electrode implantation for 44 and 144 h, respectively. 2. The time required for HR stabilization was 24 h for normal animals and 7 h for eyestalkless animals. The effect of electrode implantation varied significantly with wet body weight (P less than 0.05). Smaller animals were more affected by the procedure (higher initial HR), although they recovered more rapidly. 3. Stabilized HR values (means +/- SD) were significantly higher (P less than 0.001) in eyestalkless animals (95.8 +/- 36.8 beats/min vs 69.5 +/- 32.8 beats/min for normal animals). 4. These data demonstrate that bilateral eyestalk ablation causes an increase in HR. The mechanism of the effect, i.e., hormonal and/or neural, is not known.
Silva-Nery
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Departamento de Ciências Fisiológicas, Fundação Universidade do Rio Grande, Brasil.
Santos
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EA
D000818:Animals; D003386:Brachyura / Q000502:physiology*; D004567:Electrodes, Implanted; D004594:Electrophysiology; D006339:Heart Rate / Q000502:physiology*; D008297:Male; D013508:Ophthalmologic Surgical Procedures