September 2012

While conducting September's survey of Chesapeake Bay and its Virginia tributaries, the VIMS Trawl Survey scientists identified specimens of several species not commonly known to residents of Virginia's portion of Chesapeake Bay: star drum, pinfish, and sharksucker.  Star drum (Stellifer lanceolatus) is a lesser known member of the family Sciaenidae (Drums) to which red drum, black drum and Atlantic croaker also belong.  Though commonly thought to only occur as far north as the mouth of Chesapeake Bay, this year specimens of star drum were taken far to the north and well inland of that locality. Star drum are nondescript, diminutive silver fish resembling silver perch with a slightly more rounded snout and a more pointed caudal fin (tail). Habits of this fish within Virginia waters are little known as we are thought to be at the northern edge of its range and local densities of this fish are thought to be quite low. While still not an abundant species, pinfish (Lagodon rhomboides) are more common than star drum but due to their very close resemblance to scup (Stenotomus chryops) they are often misidentified.  An easy way to distinguish between pinfish and scup is by inspecting their teeth.  Scup, a common and abundant species from spring through autumn, has pointed conical teeth, while pinfish, an occasional summer visitor, has incisor-like teeth resembling very small horse teeth.  As mentioned above, scientists aboard the R/V Fish Hawk captured a sharksucker (Echineis naucrates), one of four remora species known to inhabit local waters. Unlike other remoras, sharksuckers are known to be free swimming and are common in some inshore waters.  They have been known to attach themselves to ship hulls and unsuspecting swimmers in addition to their normal hosts of sharks and other large fishes.  You may recall from the last installment of Net Notes that survey personnel had recently captured the other species of sharksucker, the whitefin sharksucker (Echeneis neucratoides).  Members of this family (Echeneidae) are easily recognized by the large sucking disk, used to attach itself to its host, located on the dorsal portion (top) of the head.  As noted in that same version of Net Notes, there is some debate among ichthyologists as to whether or not these two species of sharksucker are in fact a single species as they are extremely similar. The morphometric counts and measurements used to distinguish between the two species are known to overlap.