UAF students make great discoveries at the University of Alaska Museum of the North.

Graduate Student Thaddaeus Buser traversed Adak Island in the Aleutians this summer in pursuit of two elusive species of sculpin necessary for his master’s degree research.

1) Does your thesis have a title yet? What is the topic? The title of my thesis is: Exploring the Evolutionary History of Internal Gamete Association (IGA) in the Sculpin Subfamily, Oligocottinae. The general topics are evolution, biology, and molecular systematics. The crux of my thesis is a well-supported hypothesis of how the different species of oligocottin sculpins are related to one another. The development of such a phylogeny then allows us to map, explore, and statistically test different  scenarios of trait evolution (such as IGA) within the group.

2) Sculpin research is relatively rare. Can you describe some of the original work you’ve done? Curator of Fish Andres Lopez and I have developed many pilot studies into sculpin biology. We documented the ability of several species to rapidly change color. We developed a project looking at the phylogeography (essentially, how the populations are structured with regard to geography) of two intertidal sculpins (Oligocottus maculosus, the tidepool sculpin, and Clinocottus acuticeps, the sharpnose sculpin) from Oregon to Kodiak Island (this project was used to mentor a RAHI student and an undergraduate in molecular-lab techniques). We described the rearrangement of genes in the mitochondrial genome of several species of oligocottin sculpins; and conducted a sampling expedition into the Aleutian Islands for the purposes of collecting intertidal sculpins and describing their habitats.

3) How does working at the museum help you in your research? Working at the museum provides me with the tools and connections I need to conduct my research. When I was planning my Aleutian trip, I was able to look up which islands intertidal sculpins had been collected from previously and I was able to look at the specimen of Sigmistes caulias already in our collection to develop a search image, as there were no pictures of this species available or perhaps even in existence before my trip.
Working at the museum has also allowed me to examine specimens on hand and request specimens from other museums  to develop a greater understanding of morphological variation. The museum also provides me with access to professors across a variety of disciplines. Brainstorming with professionals outside of my field is a great way to develop ideas outside of the “box.”
4) What kinds of questions are you still hoping to answer about sculpins? There are many basic biological questions to be answered. One big question is parental care. Most fishes provide little to no direct care for their offspring. In some species of sculpins, however, the males build nests that they guard during the breeding season. In some other species, the female builds a nest that she cares for. In still other species the female lays her eggs in the nests of larger sculpins that guard their eggs and get free daycare. Another strategy is to lay their eggs in hostile environments (such as the exposed intertidal) to lessen the likelihood of aquatic predators finding them. For the vast majority of sculpins however, the reproductive biology has yet to be described.
Another area of interest for me is looking at the unequal diversity of groups that have invaded similar habitats. For instance, there are approximately 10 species of fully-intertidal sculpins in Oligocottinae and they range from the Baja Penninsula to at least Attu Island. For a group of fishes that rarely exceed 3 inches in length, that’s a pretty astounding geographic range. Compare that with the rosylip sculpin (Ascelichthys rhodorus), which is similar in size and is also fully intertidal, but has no known close relatives and a much smaller range (SE Alaska to northern California). What factors caused the Oligocottinae to become so much more diverse? Has their diversification and success constrained species such as the rosylip sculpin or are there other forces that have led to the modern disparity?
These are the kinds of questions I would like to pursue in the future.
I attached two pictures of sculpins in tidepools taken in the Aleutians. Both sculpins pictured are calico sculpins (Clinocottus embryum). Caulias (left) is the kelp sculpin (Sigmistes caulias), Smithi (right) is the arched sculpin (Sigmistes smithi). These two are the Aleutian/Kuril-endemic species I was after. The close-up picture of the Homo sapiens was taken during my epic trek on Adak.  — Thaddaeus Buser