Reproductive Ecology of the Tidewater Silverside, Menidia peninsulae (Pisces: Atherinidae) from Santa Rosa Island, Florida

Abstract

The reproductive ecology of the tidewater silverside, Menidia peninsulae, was studied during 1982-83 along the shoreline of Santa Rosa Island, Florida. Adult Menidia were observed at low tide spawning on a red alga, Ceramium byssoideum. Pinfish, Lagodon rhomboides, were noted preying upon newly spawned Menidia eggs. The annual reproductive cycle of M. peninsulae extended from Feb.-July with the highest spawning activity during March-June at water temperatures of 16.7-30.8 C. Several statistical analyses of tidal stages and gonadal indices failed to reveal significant differences between spring and neap tides and reproductive activity. However, on four occasions peaks in the percentage occurrence of mature eggs within ovaries coincided with the time that the moon was positioned over the equator. Moreover, analysis of young-of-the-year Menidia (6-28 mm SL) revealed distinct length classes, suggesting that spawning and subsequent hatching of larvae may have occurred in periodic pulses throughout the spring and early summer.