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The Effects Of Photoperiod On The Prolactin Cells Of Notropis Cornutus (Mitchell), Matthew Kevin Hettinger

Masters Theses

Three groups of the common shiner (Notropis cornutus, Mitchell) were adapted to three different photoperiods. These photoperiods were 16L:8D (summer), 12L:12D (controls), and 8L:16D (winter). The prolactin cells were studied histologically and morphologically with respect to staining characteristics, cell and nuclear morphology, nuclear size, and cellular density. The prolactin cells of those fish under the long photoperiod exhibited greater cellular activity than the controls as evidenced by an increase in nuclear size, cellular density, and by becoming more circular. The prolactin cells of those fish under the short photoperiod exhibited the same characteristics as those in the long photoperiod. The …