"One area where we collected prickly dogfish, Chatham Rise, is known for its very productive waters and supports a very diverse collection of taxa," Finucci noted, "so prickly dogfish have no need to be picky eaters."
What's more, it's possible that the prickly dogfish's selective dining might be a trait seen in other species of rough shark.
"This specialized diet preference may be common across the Oxynotus [rough shark] genus," Finucci said. "I say 'preference' because in the case of Oxynotus centrina, a European relative of prickly dogfish, researchers found captive individuals to feed only on skate eggs. However, previous reports found wild specimens ate a diverse range of prey."
"It may be a case of when chondrichthyan [sharks, rays, skates, and chimaera] eggs are available, Oxynotus may choose to feed only on the eggs," Finucci said, "but will consume other prey items if their main food source becomes scarce or is unavailable."
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In addition to the specialized diet uncovered, the researchers also highlighted a potential problem for both the prickly dogfish and chimaera, going forward.