Graduate Student - Ph.D.

Neurobiology and Behavior

Cornell University (Ithaca, NY)

Carl D. Hopkins

I am interested in the origin and adaptive radiation of novel structural characteristics that effect animal communication signals, especially those related to signal diversity, mate choice and speciation.

We have recently discovered (Gallant and Hopkins, 2007, 2008, in prep) a polymorphisim in signaling behavior in the species Paramormyrops kingsleyae (shown above). This polymorphism exhibits the characteristics of the two major classes of electric organ type (anteriorly innervated with penetrating stalks and posteriorly innervated with nonpenetrating stalks) in the mormyrid fish. Most recently (Gallant and Hopkins, in prep) we have discovered that sympatrically occurring morphotypes posses electric organs that are heterogeneous for these two types. We are interested in what the molecular or developmental basis of this character may be; however molecular data on mormyrids is limited.

Recently, we have been working to develop techniques to understand the electric organ from this perspective in collaboration with David Deitcher, with the hopes of understanding the origins of the electric organ, and how it is modified to produce novel communication signals through evolution. Electric organ is closely related to skeletal muscle, and undergoes a process of transdifferentiation during the early life of the fish. This developmental process itself is rare, and involves major reorganization of muscle tissue to make electricity-transmitting tissue. We are in the process of localizing particular genes that are unique to the electric organ, and plan to look at their functional roles.