Dive Dry with Dr. Bill

#470: When Is a Sheepshead Not a Sheephead?

I've said many times over the years that common names for critters are often confusing and misleading. So many still call the giant sea bass the black sea bass or the giant black sea bass despite the fact that a species on the East Coast, found from Maine to NE Florida and the eastern Gulf of Mexico officially holds the name black sea bass according to the official authority, the American Fisheries Society. Scientists have no trouble distinguishing between that species (Centropristis striata) and the giant sea bass of SoCal and Mexico (Stereolepis gigas). Heck, they're not even in the same fish family! Of course scientists using Latin names still get confused, but not about these two fish!

I recently encountered another example of how common names can confuse us. I was walking the boardwalk along the yacht basin at Mom's condo development when I literally "felt" something gnawing on the wooden pilings. I slowly walked out to the end of the pier and looked down in the water to see a fish biting the barnacles attached to the piling. It was white with several black stripes making it look more like a convict perch or an albino sergeant major from warm waters. I filmed it munching away on the encrusting critters, then went back to Mom's to consult the Internet and identify this unknown species.

I quickly discovered it was commonly known as a sheepshead (Archosargus probatocephalus) but it looked nothing like our sheephead (Semicossyphus pulchra). This strange new sheepshead is a member of the porgy family of fish while our sheephead is in the wrasse family. It is also called the convict fish due to its silvery to greenish color with 5-6 black vertical bands on its sides. The bars are most distinct in young fish... which must make them juvenile delinquents! The name sheepshead may come from a card game of German and central European origin called Schafkopf (= sheep head) because it was played on the head of a wooden barrel. The body shape is deep and flattened or compressed from side to side. The snout is blunt, the pectoral fins are long and the tail or caudal fin is slightly forked.

One of the truly unique features of the sheepshead are the prominent incisor teeth at the front of the jaw. These combined with the presence of three rows of molar-like teeth in the upper jaw and two in the lower make their dentition look more like that of a human. The sheephead of southern California has sharp canine teeth making it look more like the good Dr. Bill on the night of a full moon. The stout teeth on the sheepshead are used for crushing and grinded prey with shells. In addition to barnacles, the sheepshead treats its palate with fiddler crab, blue crabs, oysters, clams, small fish and occasionally even vegetarian fare. The juveniles feed on zooplankton such as copepods, worms and insect larvae. On such a diet these fish may reach a maximum size of about 30" and 22 pounds, although most are 14-18" and just under 16 pounds. Anglers prize these fish due to their fine white flesh and mild flavor.

The sheepshead range from Nova Scotia to Florida along the western Atlantic Ocean, into the Gulf of Mexico south to the Caribbean and Brazil. One of their major population centers is in SW Florida where Mom lives. They frequent seawalls, piers, rock piles, jetties, mangroves, oyster bars (but not the ones I eat at) and tidal creeks. They are euryhaline (able to tolerate a range of salinities) generally preferring brackish water but even enter fresh water during winter. The juveniles live in seagrass meadows and over mud bottoms.

Like in all my columns, munching and mating have high priority as topics of "conversation." Sheepshead do not begin life as females, then turn into males later in life like our sheephead. They reach sexual maturity in their terrible twos! How precocious. Spawning occurs in late winter to early spring with the adults migrating offshore. Little is known of their spawning behavior (maybe humans should keep such things more secret). A single female may produce 1,000 to a quarter million eggs that hatch in little more than a day after fertilization. The larvae rely initially on the egg's yolk sac for nourishment, and settle into seagrass meadows and over muddy bottoms. At about 2" they join the adults. At least human beings make their kids wait quite a bit longer before participating in grown up activities.

© 2011 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 29, 10:00 AM weekdays and on Charter Communications Cable channel 33 at 7:30 PM on Tuesdays in the Riverside/Norco area. Please help me climb out of self-imposed poverty... buy my DVD's (see this link). Yes, take Dr. Bill home with you... we'll both be glad you did!

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East Coast version of the sheepshead munching on pilings; close-up of their human-like dentition
and our West Coast sheephead showing its canine teeth.

This document maintained by Dr. Bill Bushing.
Material and images © 2011 Star Thrower Educational Multimedia