The Development Of A Ctenometer: A Device To Count Luminescent Animals

The description of a device to count mnemiopsis is contained in this report. The construction of the device arose out of a requirement by several researchers at the Graduate School of Oceanography, University of Rhode Island (URI), who wished to count ctenophores in Narragansett Bay by a remote method. Previously they had towed nets and counted by hand. Disturbing the animals generally causes them to flash, the flash is detected by the ctenometer circuit and recorded on a strip chart recorder. A unit designed by Clark, et. al. (1956) at Woods Hole Oceanographic Institution was chosen because of its portability, high sensitivity and proven workability. Several modifications, however, were made in the URI model. All modification and fabrication of the mnemiometer circuit described in this report was carried out by the Ocean Engineering Department at URI.