THE EFFECTS OF PHYSICAL STIMULI ON THE LARVAL STAGE OF TERRANOVA DECIPIENS: III. ELECTROMAGNETIC SPECTRUM AND GALVANOTAXIS

• Published in: Canadian Journal of Zoology
• Main Author: Ronald, Keith
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1963
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Terranova
• Online Access: http://dx.doi.org/10.1139/z63-022; http://www.nrcresearchpress.com/doi/pdf/10.1139/z63-022

Various frequencies in the range of 25.9 kc to approximately 100 mmmc were used as a source of stimuli to the larval stage of the nematode Terranova decipiens. Larvae exposed to 650 kc ultrasound were killed in 4 minutes, while those exposed to 25.9 and 1000 kc were killed in 30 and 270 minutes respectively. The larvae were not affected by radiation produced either in the radio- or the micro-wave frequencies. Light radiation of less than 280 mμ had no effect on the nematode, while fish muscle insulated the larvae from the limited effects of radiations between 253.7 to 900 mμ. The larvae showed no photo tactic response. When exposed to 4 million roentgen equivalent physical, the larvae died immediately (LD 50 ); however, after a latent period of 288 hours a much lower dose (400,000 rep) will bring about death. The larvae were stimulated by low-level direct current applied intermittently, but exhibited no directional response to any level of alternating or direct current. The low resistance offered by the fish muscle habitat of the nematode excludes any application of directional stimulus.