We captured an unusual-looking winter flounder (Pseudopleuronectes americanus) in the seine nets at Sandy Hook Bay in August 1990. The specimen was a juvenile, about the size of a postage stamp, which is the nickname given them by fishermen. The fish was partially ambicolored, with a large area of white on the right-eyed (pigmented) side, and portions of colored skin on the underside. "Black-bellied" flounders, those with a reversal of the usual color patterns, are reported fairly frequently in the literature as far back as the 1890's. From 1897 to 1898 one third of the flounders reported from around Providence, R.I., were "black-bellies." In later years (1900) the number was around 4 percent, which is probably more of a normal figure for this possibly genetic and apparently harmless aberration. In our area there has been a tendency to associate fish abnomalities with pollution, but since these pigment abnormalities seem to be a widespread phenomenon, it is doubtful that pollution is the cause.

Although the reason for this abnormality has yet to be deciphered, our fish didn't have any great disadvantage. It blended well with the white pebble and sand bottom where we found it, so it probably was as inconspicuous to predators as the rest of the flounders in the area. However, as it matures it will stand out more and likely become a meal for some fish-eater.

Something to think about:

• What is the cause of albinism?
• What could be some advantages to a flounder with this characteristic?
• What could be some disadvantages?
• Name other variations that might help or hinder this fish.