T. Kotani, A. Hagiwara, T.W. Snell
Abstract:
Recent studies on sexual isolation among euryhaline Brachionus species suggest that differences in the molecular structure of a mate recognition pheromone (MRP) are important in maintaining reproductive isolation. It has not been clarified whether MRP structure can be affected by the environment . The objective of this study was to examine the effect of temperature on mate recognition of the rotifer B. plicatilis. Three strains (Russian, German, and Tokyo strains) of B. plicatilis were cultured on Nannochloropsis oculata and a series of intrastrain matings were made using rotifers reared at three temperatures (15, 20, and 25 C). Thus the matings were conducted for nine combinations of treatments (3 strains x 3 temperatures). Temperature affected the attempted matings (frequency of circling behavior per male/female contact) differently among strains and sexes. Culture temperature of females affected the frequency of mating attempts than that of males. Male recognition of females occurred best at 20 C for the Russian strain. German strain males only recognized females when they were reared at 20 C. For Tokyo strain, however, rearing temperatures did not affect mate recognition. The degree of binding of anti-MRP antibody from Russian females will be compared to binding females of all three strains. Antibody binding will be discussed in relation to the above mating results.
(Graduate School of Marine Science & Engineering, Nagasaki University, Bunkyo, Nagasaki, Japan)
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