HANDBOOK OF SCALING METHODS IN AQUATIC ECOLOGY MEASUREMENT, ANALYSIS, SIMULATION - PART 3

Năm 1973, Katona được miêu tả phản ứng-mate Þnding copepods xảy ra khi các copepod nam phát hiện rìa của đám mây khuếch tán của pheromone phát ra từ các phụ nữ ở một khoảng cách là 4 mm. Ở đây, quá trình khuếch tán là cần thiết để vận chuyển các phân tử tín hiệu để các cảm biến của nam giới copepod để cảnh báo ông về sự hiện diện và vị trí của một copepod phụ nữ. Tuy nhiên, bằng cách sử dụng phương trình thời gian khuếch tán đặc trưng (Dusenbery, năm 1992; t = r2/4D, coefÞcient khuyếch tán D. | 10 Signaling during Mating in the Pelagic Copepod Temora longicornis Jeannette Yen Anne C. Prusak Michael Caun Michael Doall Jason Brown and J. Rudi Strickler CONTENTS Trail Copepod Results and Scent Preferences. 151 Tracking Behavior . 154 Quantitative Analyses of Trail Structure and Odorant Levels. 155 Introduction In 1973 Katona depicted the mate-finding response of copepods as occurring when the male copepod detects the edge of the diffusing cloud of pheromone emanating from the female at a distance of 4 mm. Here the process of diffusion is needed to transport the signal molecules to the sensors of the male copepod to alert him of the presence and location of a female copepod. However using the equation for the characteristic diffusion time Dusenbery 1992 t r2 4D where the diffusivity coefficient D 10-5 cm2 s for small chemical molecules it would take approximately 45 min for the pheromone to diffuse this distance. It is unlikely the female copepod would remain in the same three-dimensional 3D position in the ocean for that length of time. Instead in 1998 we Doall et al. 1998 Weissburg et al. 1998 Yen et al. 1998 reported that male copepods detect discrete odor trails left in the wake of the swimming female copepod Figure . Within this low Reynolds number regime viscosity limits the rate of diffusion of the odor trail to molecular processes. Diffusion does not transport the pheromone to the male and instead acts to restrict odor dispersion. The scent persists as a coherent trail with little dilution of signal strength and hence remains detectable for a period that gives enough time for the male to encounter it. In the case of the copepod Temora longicornis this aquatic microcrustacean could find trails that were less than s old. Trails were followed for distances as .