REPRODUCTIVE TIMING AND EARLY EMBRYONIC-DEVELOPMENT IN AN OLD-WORLD FRUIT BAT, OTOPTEROPUS-CARTILAGONODUS (MEGACHIROPTERA)

Otopteropus cartilagonodus (Megachiroptera, Pteropodidae) is a rare, s mall-bodied cynopterine bat endemic to Luzon Island in the Philippine Archipelago. Twenty-two female and seven male O. cartilagonodus were c ollected during March and May of 1988. Observations were made on early embryonic development and the morphology of ovaries, uteri, and teste s. All females collected during March were pregnant, and their uterine swellings occurred within a narrow size range (2-4 mm in diameter). M oreover, the embryos of all eight females captured in March and examin ed histologically were all within or just before the primitive-streak stage of development. The uterine swellings of females captured in May ranged from 15 to 20 mm in diameter, and their extrapolated birth dat es were in late May or June. The synchrony of embryologic development and the apparent lack of developmental progress during March suggests that O. cartilagonodus has a prolonged period at the primitive-streak stage of embryonic development. The morphology of the embryo, embryoni c membranes, and uterus at these stages is similar to that of two othe r cynopterine fruit bats, Cynopterus sphinx and Haplonycteris fischeri .