Biomaterial Database

Influence of water temperature on the electric organ discharge (EOD) of the weakly electric fish Marcusenius cyprinoides (Mormyridae). 1978

M J Toerring, and J Serrier

1. The influence of different water temperatures on the electric organ discharge (EOD) of a mormyrid fish Marcusenius cyprinoïdes was studied. The range of the water temperatures was fixed according to the seasonal temperature variations of the rivers in Central Africa, the natural habitat of this species. 2. The EOD activity was characterized using the following parameters: mean EOD rate, EOD pattern in the form of Interpulse Interval Histograms (IIH), IIH range, and shortest pulse interval. These parameters remained constant during control experiments at constant temperature (27 degrees C) for 4 days. 3. The mean EOD rate increases with increasing water temperatures. The lowest mean EOD rate is always found at 17 degrees C, the highest between 26 and 33 degrees C. The characteristics of the IIH are modified by stepwise temperature increases. These IIH show during high temperatures (26-33 degrees C) similar patterns to those previously observed during high level motor activity and excitement. The IIH range diminishes with stepwise temperature increases. The shortest pulse interval has a negative, linear correlation with water temperature. 4. The possible role of water temperature in the reproduction of the mormyrids is discussed. The high discharge rate of M. cyprinoïdes produced by high water temperatures during the rainy season could serve to improve the resolution of the electroreceptors during this period.

UI	MeSH Term	Description	Entries
D012098	Reproduction	The total process by which organisms produce offspring. (Stedman, 25th ed)	Human Reproductive Index,Human Reproductive Indexes,Reproductive Period,Human Reproductive Indices,Index, Human Reproductive,Indexes, Human Reproductive,Indices, Human Reproductive,Period, Reproductive,Periods, Reproductive,Reproductive Index, Human,Reproductive Indices, Human,Reproductive Periods
D004557	Electric Organ	In about 250 species of electric fishes, modified muscle fibers forming disklike multinucleate plates arranged in stacks like batteries in series and embedded in a gelatinous matrix. A large torpedo ray may have half a million plates. Muscles in different parts of the body may be modified, i.e., the trunk and tail in the electric eel, the hyobranchial apparatus in the electric ray, and extrinsic eye muscles in the stargazers. Powerful electric organs emit pulses in brief bursts several times a second. They serve to stun prey and ward off predators. A large torpedo ray can produce of shock of more than 200 volts, capable of stunning a human. (Storer et al., General Zoology, 6th ed, p672)	Electric Organs,Organ, Electric,Organs, Electric
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D005399	Fishes	A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures