First-ever deep-sea alligator food fall

First-ever deep-sea alligator food fall


This is an alligator sitting on the bottom of the Gulf of Mexico right now over 1 mile deep. It’s being eaten by giant deep-sea isopods. Studying this alligator is helping us learn more about the invertebrates of ancient oceans and how carbon from land makes it into the deep ocean. The alligators in this study were donated to science by the state of Louisiana. They were humanely euthanized as part
of an intense management program that has helped the American alligator bounce
back from nearly going extinct. Most of the earth is covered by oceans so deep that no sunlight reaches them. These places are dark and cold
but full of life. The deep ocean is a food desert
sprinkled with food oases. Some of these oases are vents in the ocean floor where chemicals come out
or food falling from the ocean’s surface. Most food fall research so far has focused on marine mammals like whales and sea lions, large fish like tuna, sometimes sharks and rays, and even wood. Putting an alligator on the seafloor, just like the woodfall work we’ve done, helps us see what happens when rivers transport food to the deep ocean. Alligator falls may be common. Alligator carcasses are regularly found
on beaches and coastlines and after big storms or hurricanes, alligators have been seen alive 18 miles offshore. Alligator falls are also a way for us to peek into the past. Alligators are one of the closest ways
we can study the food falls of long-extinct, large marine reptiles like ichthyosaurs. Indeed, alligators and crocodile food falls may be the last remaining refuge of specialized invertebrates that were also in ancient oceans. This alligator is tens of miles off the coast of Louisiana and a mile and a quarter down on the seafloor. After 24 hours at the bottom
it looked like this. These animals are giant deep-sea isopods. They’re related to the roly polies or pill bugs we have on land but they’re about as big as a football. They’re scavengers who eat dead animals. This footage was taken less than 24 hours after the alligator was placed on the seafloor. I was surprised that there was already
giant isopods all over it. I thought it would take a while for them to get the chemical cues that would allow them to sort of locate a food fall like an alligator. I was also impressed at the work
that they were able to do. I thought that the alligator hide would be something hard for them to get through but obviously their pinching and crushing mandibles made easy work of the hide. You can see where the hide has actually been ripped away and the ribs are exposed. There’s actually 2 inside there. They’re hard to see, but 2 of them have just started going at the alligator from the interior of the body cavity. So it’s actually interesting and quite
funny to see that giant isopod do a nosedive into the bottom because we’ve
seen that in other scavengers, where they’ll eat so much that they basically become immobile or stupefied in their actions, and so that may just be the fact that they’ve gorged themselves so much in an effort to get this rare resource
that they’ve actually, you know, inhibited themselves from from proper locomotion. And this is the whole strategy of a giant isopod. We think that one of the reasons
why they’re so giant compared to the roly polies or pill bugs that we know of is that
a lot of the interior of a giant isopod is just lipid and fat, so
they have this amazing ability to gorge themselves, store that energy, and then basically not have another meal for months to years afterwards. Giant isopods that have been kept in aquaria including the Okinawa aquarium have not fed for over 2 years. When we return two months after
this video is made, I suspect we’ll see about half the animal-
the alligator carcass removed. I think it’ll be interesting to see what new scavengers show up within the 2 months that we’ve been there, if any. Don’t you think maybe, there might be some brittle stars or some other… Brittle stars in the sediments around,
rattails, we’ll probably see some more scavenging fish, maybe amphipods… Yeah, as the flesh gets harder to get by the large guys, that will probably open up the room for smaller animals to get in there and just kind of, go at it, bit by bit. And we’re hoping when we return, one of
those ribs or another bone will be easily collected by- can be easily
collected by the remote operated vehicle so that we can see if there’s hints of
bone-eating worms or Osedax on this. Osedax have never been described from the Gulf of Mexico and obviously never from an alligator fall since this is the first one, and so we may be discovering a new species of bone-eating worm
from these experiments.

Roly Polies Came From the Sea to Conquer the Earth | Deep Look

Roly Polies Came From the Sea to Conquer the Earth | Deep Look


Pill bugs…… roly polies….. potato bugs… whatever you want to call them, somehow there’s something less creepy about these guys than other insects. More loveable, or something. Maybe it’s because they’re not insects
at all. Pill bugs are actually crustaceans. They’re more closely related to shrimp and
lobsters than crickets or beetles. Pill bugs even taste like shellfish, if you
cook them right. Some adventurous foragers call them wood shrimp. As early as 300 million years ago, some intrepid
ancestor crawled out of the ocean, sensing there might be more to eat, or less competition,
on dry land.” But unlike lobsters, pillbugs can roll up
into a perfect little ball for protection. If you look closely you can see the evidence
of where these guys came from. Like their ocean-dwelling cousins, pill bugs
still use gills to breathe. True insects — like this cricket — use a
totally different system. See those tiny holes on this cricket’s abdomen? They’re called spiracles. They lead to a series of tubes that bring
fresh air directly to the insect’s cells. But pill bugs don’t have any of that. To survive on land, they had to adapt. Their gills, called pleopods, are modified
to work in air. Folds in the pleopod gills developed into
hollow branched structures, almost like tiny lungs. In a way, the pillbug is only halfway to becoming
a true land animal. Because… they’re still gills. They need to be kept moist in order to work. Which is why you usually find pill bugs in
moist places, like under damp, rotting logs. They can’t venture too far away. Sure, pill bugs look like the most ordinary
of bugs. But they’re much more than that: evidence
that over evolutionary time, species make big, life-changing leaps. And those stories are written on their bodies. Hey, while we’re on the subject of oddball
crustaceans… check out this episode about mantis shrimp. Their eyes see colors we can’t even
comprehend. Their punch is faster than Muhammad Ali’s. And while we have you: Subscribe. OK? Thank you! And see you next time.