In this lesson, we will explore the external anatomy of the gizzard shad (Dorosoma cepedianum). We will also define and discuss adaptations through an evolutionary lens.
Anatomy is the study of the bodily structure of living organisms. Fish anatomy is the study of the bodily structure of fish.
Understanding anatomy allows us to better understand adaptations and how they might be beneficial to a species. We will discuss adaptations in further depth at the end of this lesson.
The gizzard shad (Dorosoma cepedianum) is a member of the herring family (Clupeidae) regularly found in the tidal Potomac and Anacostia Rivers. It is an important forage fish for a number of predatory fish species like largemouth bass, blue catfish, and striped bass, among others. Follow along as we explore its external anatomy!
The gizzard shad's unique mouth allows it to feed on plankton and detritus.
The eyes serve as the gizzard shad's sight organs.
Nares, or nostrils, allow the fish to detect various odors underwater.
The operculum, or gill plate, protects the gizzard shad's sensitive gills.
The gills allow the gizzard shad to breathe oxygen underwater.
The lateral line is a series of sensory pores that runs along the side of the fish. The lateral line helps the fish detect vibration.
The dorsal fin helps stabilize the gizzard shad while swimming.
The dorsal filament is the elongated final ray of the dorsal fin. It is found on mature fish.
The pectoral fins help the gizzard shad with lateral (side to side) movement.
The pelvic fins help stabilize and balance the gizzard shad, thus preventing it from rolling while swimming.
The anal fin provides additional stability to the gizzard shad while swimming.
The caudal fin, or tail fin, assists the gizzard shad with propulsion (forward movement).
Northern snakehead (Channa argus), pictured above
Test your adaptation knowledge by reading this article on the longnose gar (Lepisosteus osseus) from our friends at the Chesapeake Bay Program.
Once you've completed the article, brainstorm three advantageous adaptations that might help the longnose gar survive in our local waters.
Longnose gar (Lepisosteus osseus), pictured above
To learn more about the adaptations of fish found in District waters, check out our Fashion a Fish Activity on Google Jamboard!