Mating behavior and relative fecundity, egg weight, and egg volume were investigated in the banded coral shrimp Stenopus hispidus. The effect of fluctuating temperature (4-6 degrees C and 1.5-2 degrees C difference between day and night) on fecundity was also tested. The relative fecundity was 1,229 +/- 467 (mean +/- SD) eggs/brood/g of female (wet body weight, WBW); egg volume was 0.0628 +/- 0.0050 mm(3) (mean +/- SD); and dry egg weight was 35.1 +/- 2.9 mu g/egg (mean +/- SD). Linear relationship between total length of the shrimp and relative fecundity was significant (P = 0.01), and there was a significant negative relationship between egg volume and relative fecundity (P = 0.03). High temperature fluctuation (4-6 degrees C) resulted in lower dry egg weight (P = 0.0079). Mating behavior in Stenopus hispidus is described for the first time. It occurs in the following sequence: antennule contact, erection of female body, grasping, mating, and spawning. Females can mate successfully within 24 h after molting.