Taylor,M.H.*; Callaway, S.B.: Comparative analysis of ovarian contraction in some teleost fish.

Contraction of ovaries has been demonstrated in the mummichog, Fundulus heteroclitus and several other teleosts. We have expanded this information by recording spontaneous contractions and the response to acetylcholine in ovaries of the striped killifish, Fundulus majalis, the Atlantic silverside, Menidia menidia, and the pumpkinseed, Lepomis gibbosus suspended in a smooth muscle bath containing a modified Ringer’s solution. Ovaries of all three species produced similar contractions in response to 10 ^-5 M acetylcholine. Spontaneous contractions in F. majalis, and M. menidia occurred in a series of single peaks with frequencies and amplitudes similar to the pattern previously observed in F. heteroclitus. Those seen in L. gibbosus had a lower frequency and greater amplitude, with a series of superimposed higher frequency contractions. These results suggest that ovarian contraction may be a common phenomenon in the Antherinidae and Fundulidae which share many reproductive characteristics including the occurrence of semilunar reproductive cycles. The Centrarchidae are nest-building Percoids which are taxonomically distant from the other species analyzed.