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Hagfish. You love them. I love them. The owner of this sedan has no choice but to love them:
2017 was a big year for hagfish science.
Big Ideas (the ecologic paradigms that hagfish shifted)
Heincke’s law is one of those ecologic principles that more often acts as a foil for rejecting the null hypothesis than as a consistent pattern in ecology. It’s most basic summary is: The further from shore and the deeper dwelling a fish is, the bigger it grows. Heincke’s law does not appear to be true for hagfish, whose size appear to have no relation to the depth at which they occur. On the other hand, phylogenetic relationships do seem to play some role in regulating body size in hagfish.
- Schumacher and friends (2017) No support for Heincke’s law in hagfish (Myxinidae): lack of an association between body size and the depth of species occurrence. DOI: 10.1111/jfb.13361.
Defense and Behavior (how hagfish do the things that they do)
Hagfish are master escape artists, capable of squeezing in and out of tight spaces barely half the width of their body. This great for getting in an out of rotting whale carcasses on the sea floor, creeping into crevices, and avoiding predators. But how do they accomplish this incredible feat? Hagfish have a flaccid sinus under their skin which allows them to control the distribution of venous blood and alter their body width as they wriggle through narrow passages. Freedman and Fudge identified 9 distinct behaviors which take advantage of this adaptation, including anchoring, forming tight loops to push the body through an opening, and bending the hagfish head 90 degrees to force it through a slit. And there are videos!
- Freedman and Fudge (2017) Hagfish Houdinis: biomechanics and behavior of squeezing through small openings. DOI: 10.1242/jeb.151233.
The Fudge lab has been busy this year, cranking out some of the most noteworthy work on the incredible behavior of hagfish. In addition to examining hagfish motility, Boggett and friends looked into how those flaccid sinuses aid predator avoidance. The team build wee little guillotines loaded with shark teeth to see how hagfish skin protects the animal from vicious bites. In a year when a truckload of hagfish spectacularly crushed a car, the fact that this research was the biggest breakout sensation in hagfish pop culture says everything you need to know about the compelling results of this study. You can read more about this study at The Verge, Futurity, Popular Science, and plenty of other outlets.
- Boggett and friends (2017) Flaccid skin protects hagfishes from shark bites. DOI: 10.1098/rsif.2017.0765.