Lewis looked at what the lab has called the “couch potato effect,” to see how time in captivity affects the physiology of skates. 

“We're essentially looking at whether the animals we've had in captivity have become lazy, or gotten out of shape because they've been here so long,” said Lewis. “We're comparing the metabolic rates of skates that we've had for many months with skates we've just recently captured.” 

Lewis hypothesized that skates held in captivity will have lower metabolic rates than wild skates. She is currently analyzing her data to determine if holding time impacts metabolism in skates. 

Crawford looked at two factors on metabolic rates: body size and the sex of the skates. He said that with respect to metabolic rates across other species, females tend to have higher metabolic rates, so he wanted to see if that trend was the same for skates. 

For body size, Crawford explained, “We want to know if smaller animals are going to have a higher mass specific metabolic rate than bigger animals. We're trying to see if that trend is the same for Clearnose skates.” 

Christensen looked at the digestion of the Clearnose skates. He explained that they fed the skates right before testing their metabolic rates which gave them a sense of how much energy they use in digestion. More specifically, he looked at how different diets affect the skates’ metabolism. 

“Different prey items vary in the amount of macronutrients they have,” said Christensen. “We'll feed them shrimp which is very high in protein and then we’ll feed them sardines which is very high in fat and that should hopefully show a difference in the amount of energy they need to use to digest it.” 

Clifford looked at how the diel cycle affects the skates and hopes to find evidence of a circadian rhythm—a pattern of behavior that occurs every 24 hours such as a sleep cycle.

“I was interested to see if they were more active at night or more active during the day,” said Clifford. “We do this using respirometry data where we seal the skates in a giant tank, watch their oxygen consumption rates, and we equate that to energy use. If they're consuming more oxygen, we believe they're more active or using a lot more energy, and if they're lower, they're less active or using less energy.”

Throughout the summer, the four students bonded through their shared research experience, especially since much of what they studied hadn’t been thoroughly researched before. 

“There's not a lot of research on skates and respirometry so we were kind of learning how to do it ourselves. We eventually figured out the system but when we started, there were a lot of different problems we had to work through,” said Lewis. “We grew to figure out ways to do each experiment and how to better work on everybody's experiment and that's just an incredible amount of knowledge we gained.” 

In addition, they pointed out that they had help from Carlisle and graduate students in Carlisle’s lab. Getting a chance to interact with those students helped them to realize that they had made the right choice when it came to an area to study in school.  

“The grad students and all the other people who've helped us along the way have been so great. It’s been amazing to have these people that we can rely on, this backbone that we have because I don't think we could have done this without the people in our lab,” said Lewis. “Seeing them and interacting with them, I'm looking forward to going to grad school because I see all that they do and I'm just like, ‘This is the path I know that I want to be on.’ It ensures that I'm going in the right direction.” 

Christensen agreed with those sentiments, adding, “We couldn’t have accomplished as much in the summer if it weren't for the grad students. They have been very hands-on and helped us so much.” 

Tess Avery, one of the graduate students in Carlisle’s lab who helped with the students’ projects, said they have all been incredible to work with. 

“It's been so much fun for me to work with them,” said Avery. “I also am not someone that has worked with respirometry before, so I learned a lot of it along with them, which has been an interesting experience for me as they're learning. They're doing an amazing job doing their work independently. They’re curious about it and it's been really great.” 

Having come to UD from outside institutions, both Crawford and Lewis said they were a little nervous at first, but those nerves dissipated almost the instant they got to UD. 

“Once I got here, everyone was very accepting of you and just there to help you anytime you needed it,” said Crawford. “They were always there to give you a new experience to learn so you could learn new skills and make you a better marine science student. It’s been a really good experience the entire summer.” 

Crawford said in addition to all the research, the students were also able to learn a lot about animal husbandry, something he hadn’t had much experience with before this summer. 

“I never really knew how to take care of wild animals,” said Crawford. “Being able to feed them and do water changes, and water quality tests, just how to take care of the animals and keep them alive was a good skill to learn.”