No. 52–When is a Trout not a Trout?

Answer to the title question – when it’s a sea trout – or what we call sea trout anyway.* There are two species of marine fishes in our waters commonly referred to as sea trout with the spotted sea trout the best known and most sought after by area fishermen.

True trout are fresh water animals of the family Salmonidae. What we call sea trout are in the family Sciaenidae (drum and croaker), genus Cynoscion.

The spotted sea trout, Cynoscion nebulosis, inhabits estuarine and near shore waters from the Chesapeake to the Yucatan and is a prized game fish throughout its range. Once harvested commercially, its numbers declined steadily until the commercial harvest was banned and recreational fishing limits were imposed in the ’80s. In SC the fish must have a minimum length of 14 inches with a daily bag limit of 10 fish per person. You’ll want to take care to avoid the two very sharp canine teeth at the tip of the upper jaw when removing a hook.

A strikingly beautiful fish, the color of individual animals will vary depending where they happen to be observed. They move in a seasonal cycle from near shore the estuary and back as the water temperatures change and have the ability to change color to suit the environment as they do.

While the spots randomly scattered across the upper body length and fins are a constant, the color scheme for the rivers and creeks is a dark slate to green with blue highlights above silver sides while silver top to bottom is the rule for open water.

The weakfish (Cynocion regalis) takes it’s name from the fact that it’s mouth is soft (weak) and torn easily by fish hooks allowing the animal to often avoid capture. Also known as gray trout, summer trout locally, they range from Nova Scotia to Florida with the largest populations from Cape Cod through North Carolina.

An important fish commercially to the north of us, populations have crashed more than once due to over fishing. A high fertility rate and long breeding life, however, allow stocks to rebound relatively quickly. DNR has set a bag limit of 10 fish with a minimum length of 12 inches for state waters.

*Research for this piece revealed there is a sea trout that, through a marvelous feat of adaptation, actually is a trout. It turns out there are two sides to the brown trout known to fishermen of cold water streams a ways north of here. (I’ve chased after browns on the upper reaches of the East Fork of the Chattooga.) It turns out that while they are the same species, some populations of brown trout spend their entire lives in fresh water and others migrate to the ocean for much of their lives and return to fresh water to spawn.

Salmo trutta morpha fario remain in fresh water and Salmo trutta morpha trutta become sea trout. “Morpha” is the term used to designate variation within a species.

Another species, Oncorhynchus clarki, sharing the brown trout’s duel nature is the cutthroat trout of the Pacific Northwest. Here too we have a species with both fresh water and sea-run populations. The stay-at-homes grow to only two pounds while the seafarers can reach twenty or more. An interesting aside is that land locked populations are able to interbreed rainbow trout and produce fertile hybrids.

Next month we’ll visit other members of the Sciaenidae (drum) family in a continuation of a series on fish found in local waters.