Feeding Habits Analysis: Tasty Menhaden Morsels
This week I finally got to start diving into my dogfish stomach contents, and the results so far have been nice and gory. The post up at Southern Fried Science about the Menhaden of History really brought home the importance of these humble oily fish in the diets of just about everything bigger than them. As the quote from G. Brown Goode states, “their mission is unmistakably to be eaten.”
If the mission of menhaden (of which the Atlantic species has the deceptively badass Latin name Brevoortia tyrannus) is to be eaten, then the mission of the spiny dogfish is unmistakably to do the eating. Though I’ve only scratched the surface of my samples so far, the gut contents I’ve analyzed have overwhelmingly included menhaden, either whole or in pieces. Photographic evidence of the carnage the jaws and teeth of Squalus acanthias can create can be found below the jump.
Since I misplaced my camera this week (don’t worry, I found it), this gory scene was captured on Dan Z’s cell phone. Apologies for all the pixels.
Dogfish put their sharp teeth to good use, carving up menhaden that when intact must have been nearly a third as long as the sharks themselves. While traditionally fishes are thought of as swallowing each other, sharp cutting teeth are a great way of overcoming gape limitation by turning one large prey item into manageable pieces. Sharks are far from the only fishes using cutting teeth this effectively, piranha and bluefish are also well known for their ability to take large prey apart (I’m still waiting for SyFy to do a movie about man-eating bluefish
This sort of scene must be pretty awe inspiring to witness, like the sardine runs off of South Africa but with larger prey and smaller predators. Yes, the study of predator/prey interactions provides interesting data and can be very important for conservation and management, but let’s not kid ourselves: we find predators interesting because predation is awesome.