July 2012

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     The Ocellated Flounder collected by the survey on June 6, 2012. This specimen is 123 mm long.  
  • _whitefinsharksucker.jpg
     The Whitefin Sharksucker captured on July 23rd measured 333 mm total length.  
  • _whitefinsharksuckerdisk.jpg
     Sharksuckers use the sucking disk on the dorsal surface of the head to attach to other vertebrates. However, these fish can also be free-swimming.  
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Over the past two months, the Virginia Institute of Marine Science’s (VIMS) Juvenile Fish and Blue Crab Trawl Survey encountered two fish species that stand out among the many that were identified, measured and returned to the Bay. The first of these fish, an Ocellated Flounder (Ancylopsetta ommata), is the survey’s first record for this species within Chesapeake Bay.  Ocellated Flounder are generally recorded from North Carolina southward, along both coasts of Florida and the Gulf of Mexico.  Ocellated Flounder are diminutive flounder, attaining a maximum size of only 10 inches (25cm), characterized by having a distinct pattern of four ocellated (ringed) spots on the eyed side of the fish. Three of the spots are in a triangular pattern on the aft half of the fish while the fourth is far forward above both the pectoral fin and the arch in the lateral line. The ecology of these fish within Chesapeake Bay is little known as they are so uncommon in our area.  An additional specimen of this species was also identified by another group of VIMS scientists working in the lower Chesapeake Bay several days later.  Every specimen helps add to our knowledge of these fish.  The second species, equally rare for the Trawl Survey to encounter, was captured during the Survey’s July sampling.  A Whitefin Sharksucker (Echeneis neucratoides) was among the fish in a trawl off the mouth of Occohannock Creek near the Eastern Shore.  The Whitefin Sharksucker is one of four species of the remora family (Echineidae) known from Chesapeake Bay, none of which are common. Remoras are easily recognized by the large sucking disk, used to attach itself to its host, located on the dorsal portion (top) of the head.  Little is known about the habits of this species in our area other than it has been seen as far north as the York River and is known to attach to sharks and sturgeons.  There is some debate among ichthyologists as to whether or not this species and another very closely related species, the Sharksucker (Echeneis naucrates), are in fact a single species as they are extremely similar. The counts and measurements used to distinguish between the two species are known to overlap.

In July, large numbers of Blue Catfish and Striped Bass were captured in the upper Rappahannock River in the vicinity of Cat Point Creek.  The catfish ranged in size from about a half of a pound on up to fish in the 5lb. range while the Striped Bass were all in the 24 inch and up range.  While known to commonly occur in the same areas, it is a bit unusual for the survey to encounter both species together in such large numbers and is the greatest number of large Striped Bass anyone related to the survey could recall ever capturing in a single tow.