This journal is brought to you by…
On this beautiful day, Michelle, Rachel and Roxanne are holding flags of your flags while waiting for the helicopter to pick us up. Photo credit: Alex Eilers
- Mrs. Kristi’s 3rd grade class at Lakewood Elementary
- Mrs. Pullen’s 2nd PLUS class at St. Francis of Assisi Catholic School
- Margaret Blount and her 1st grade class at Riverwood Elementary
What does a Weddell seal eat? Let’s take a look at the menu!
What would you choose if you had to select from one of these tasty items on the menu?
The seal’s breath smells mighty fishy – and rightly so – because one of their favorite foods is ICE FISH. Photo credit: Kurt Guttensohn
Let’s take a look at some of these tasty treats!
The Antarctic Silverfish (Pleuragramma antarcticum)
This fish gets a ‘five star ranking’ from the Weddell seal. They are among the most common fish the Weddell seal eats. Although, I’m not quite sure if it’s because the seals prefer the silverfish – or because they’re very common in the Ross Sea. It’s most likely number one; seals perfer silver fish. As you can see in the picture, these fish live up to their name – they’re silver! But, they also have a pinkish tint. I was surprised to learn that while the fish is alive it looks pinkish (with silver highlights). However, after the fish dies it turns completely silver. These fish are less than a foot long (about 6-10 inches), and can be swallowed whole. A seal could chow down on over 100 silver fish in one dive.
Here’s a fun fact: Ice fish, like the silverfish, also have a unique adaptation for living in such an extremely cold environment: they have an antifreeze protein in their blood which protects them from in the icy cold waters.
Antarctic Silverfish. Photo credit: Philippe Koubbi, Commonwealth of Australia 2011 - antarctica.gov.au
The Bald notothen (Pagothenia borchgrevinki)
The Bald notothen or ‘Borch’ – pronounced ‘bork’– is another tasty treat for a Weddell seal. These ice fish are less than a foot long and are yellowish in color with dark spots.
Borch, under sea ice in McMurdo Sound. Photo credit: R.W. Davis
Weddell seals are crafty creatures. Scientists have observed them ‘capturing their prey’ by blowing air bubbles into ice holes to scare fish out. When the fish come out of their hiding places, the seal quickly gobbles them up. Borchs are often captured this way because they feed on animals under the ice.
Antarctic Cod
This is a fish that finds itself in a seal’s belly a little less often, probably because of its large size. Antarctic Cod can weigh over 150 pounds but most weigh less than that – about 70 pounds!
Antarctic Cod in the aquarium at Crary Lab - McMurdo Station. Photo credit: Peter M. Amati, Jr
Tentacles or Crustaceans, anyone?
Other bite-sized morsels that can be swallowed whole are small squid, shrimp and krill. Weddell seals can gobble these guys up like popcorn.
Krill Pool. Photo Credit: Kyle Hoppe, National Science Foundation
You’ve heard the saying, ‘You are what you eat!’
Well, that’s actually true! Scientists are using that idea to study the diet of Weddell seals. They collect whiskers and blood samples from seals, so they can find out what the seal has been eating. What are they looking for, you ask? Good question! Each time a seal eats, chemical compounds from the digested food are left in various parts of their bodies like their whiskers. Scientists are able to study those compounds that get stored in the seal’s body and match them to the particular prey these compounds originated from. Then, knowing the rate that the seal’s whisker grows, scientists are able to estimate the seal’s long term eating patterns by analyzing the chemical compounds in the whiskers. Very interesting!
You try it!
Create your own Weddell seal menu and share it with me on the 'Ask the Team' section of my web page here.
Comments