Gulf killifish

Fundulus grandis has a unique coloration that separates it from other Fundulus species. First, the base color is a dull greenish above shading to lemon-yellow below. Furthermore, the differences in coloration between males show much more vivid colors with silver flecking and noticeable striping; and females, which can appear olive to dull olive below if they grow big enough. Additionally, stripes, spots, and different colors occur along the body structure. In the predorsal region are predorsal stripes, which may be present, but generally fade as the fish ages and occasionally predorsal spots. Also, small pearly spots are found along the side of the fish. The anal and lower half of the caudal region may be yellow or the anal, dorsal, and caudal regions may be darker in color with white splotches at the base. Additionally, the coloration of the male fish changes when they are breeding. In all, these males are deep blue dorsally, and have blue median fins with light blue spots and yellow-orange margins. However, in general, the Gulf killifish is characterized by its yellowish or pale belly, and darker back with many pale spots, mottling, and inconspicuous bars.