Abstract
Mating habits of the viviparous surfperch, Ditrema temmincki, were observed underwater with the help of SCUBA on the northern coast of Kyushu, Japan, during the period from 1977 to 1979.The mating season of the fish lasted from early September to early December.During the season, the fish moved into depths of 0.5-5.0 m, and large males over 1 year in age set up territories of 5-10 m in diameter.Females of nearly the same body length as males visited territories everyday.When females appeared in a territory, the male displayed by marked body color change and head-lowering posture.The territorial behavior and color change in small males under 1 year in age were not conspicuous in comparison with large males.After a repeated pre-copulatory behavior, copulation was accomplished between the sexes of nearly the same body length by contacting anal regions for a short time.Although courtship display of males and pre-copulatory behavior were seen frequently, copulation was seen only infrequently.The relationship between the mating season and occurrence of spermatozoa in ovaries is discussed.
