Whales | Tohorā


The scientists have removed the rib bones from one half of the whale. It’s getting a little bit smelly!

When the scientists lifted the intestine out, I could see it was attached by a thin but very tough membrane and in the membrane were…

Not chicken pox! Those darker lumps are lymph nodes!

Lymph channels are important as part of the immune system and filter the fluid to the heart that is not returned by veins. Lymph nodes in the gut, like above, carry the fat that has been absorbed by the gut and ensure that foriegn bodies like bacteria are eliminated before reaching the heart

Above you see the tongue of the baby pygmy right whale. Whales lips aren’t flexible enough to form a suction around the mother’s nipple like human babies do.

To latch on to the mother’s nipple, a baby whale curls its tongue. A good suction is assisted by the flaps on either side of the tongue – you can see one of them above. As the baby whale gets older and is no longer suckling, the flaps will mostly disappear. Cool, huh? :-)

Drs Reidenberg and Fordyce are now actively uncovering the deeper tissues of the throat. This specimen is in an excellent state of preservation, so that delicate tissues like nerves are easy to identify.

The scientists are removing the muscle layer to reveal the pygmy right whale’s unusual bone structure.

This is Dr Sentiel Rommel’s thoughts on the rib structure:

You can see the ribs gradually changing to the unique flattened and overlapping ribs on the right. the space between the ribs allows them to move as the whale breathes and also accomodates changes in volume that occurs as the air is compressed by water pressure when the whale dives through deep water.

The flattened ribs don’t have as much space between them and overlap. The study of terrestial animals that have wide, flattened ribs (the pangolin and anteater) have shown that these ribs proably increase the stiffness of the body.

So possibly a stiffer body has advantages in the way they swim, but this is purely speculative at the moment!

Hi this is Anton on Jane’s blog. This morning we discovered that the second rib on the left side of the animal is broken. We can tell from the bloody area around the break that the animal suffered this injury prior to death. Dead animals don’t bleed. This injury probably occured at the time of the stranding but most likely did not contribute to cause of death.

I was a bit surprised to find out that whales have hair!

Cath Kemper said:

‘Most whales and dolphins are born with a few hairs on their face. Most will lose these hairs within weeks of birth but some species, such as humpbacks and maybe pygmy right whales, retain them as adults.’

It was earlier blogged that the wounds on the whale were from cookie cutter sharks.

Te Papa’s Fish collection manager, Andrew Stewart, came to have a look and this is his expert opinion:

‘Based on where the whale came ashore, the scars are probably from the cookie cutter rather than the seal shark (a larger shark species found in colder waters).

Many marine mammals carry the scars from encounters with these sharks. They have been likened to a swarm of wasps as these sharks sometimes occur in schools.

Tuna fishermen hate them as the bites can significantly reduce the market value of their fish. Fortunately for whales, a thick layer of blubber affords some protection from these unique predators!’

The dissection of the pygmy right whale is a very detailed and time consuming process!

A quick update: the skin and blubber has been removed from half of the whale as you can see above. And our pygmy right whale is a young male, probably no older than 6 months old.

The scientists will be breaking for lunch shortly and then preparing for their talks tonight at the TelstraClear centre at Te Papa at 6.30pm.

From Bruce Reidenburg:

The scientists are now exploring the layers of muscle on the sides of the whale. There is an interesting highly developed muscle that is special to the youngest baby whales. Since fetal whales are curled sideways in utero, this special adapted muscle unfolds the tail after the whale is born.

In people these muscles pull the back straight when standing. In the baby whale, this muscle is very powerful and becomes less developed as the animal ages. In humans, this is only one of a series of muscles that straighten the backwhen standing, so it is weak in baby humans and gets stronger as we learn to walk and run.

There is another interesting adaptation that is becoming visible during today’s dissection. The muscles of the abdominal wall involved in flexing ventrally are attaching to the broad non-respiratory ribs. In humans these muscles attach to the anterior part of the pelvis. In whales, these muscles are positioned to help propel the body wave during swimming. As we go deeper, we will find out what structures are tied to the whale’s small residual pelvis.

Morning!

If you’ve managed to go to the Whales|Tohorā exhibition here at Te Papa then you’ll have come across the pieces of baleen.

Some whales have teeth – others have baleen. Baleen sort of looks like bristley paintbrushes hanging down either side in a whale’s mouth. It acts like a big sieve or tea strainer. Baleen whales scoop tiny organisms like krill and copepods in mouthfuls along with sea water. They force the sea water out of their mouths through the baleen leaving the prey behind.

The whales then use a combination of their tongues, sucking action and possibly some rinsing with sea water to dislodge the prey from the baleen (its hairy on the inside and the prey gets caught) before swallowing.

The colouration of the baleen depends on the type of whale it is – the blue whale’s is almost black.

Our pygmy right whale’s baleen is creamy white on the inside, dark grey on the outside with a stripe of creamy white along the top. Its beautiful.

Well mostly because of how it’s mouth is shaped like a right whale’s but… a lot smaller. The people who named it were using a little piece of baleen and a glimpse of a live animal to give it it’s name.

Notice the curve of the upper jaw and how the lower jaw lips come up to meet the upper jaw – much like a right whale’s.

Scientists are slowly learning more about the pygmy right whale through post mortems (like this) but as they don’t wash up on beaches very often, not many have been done.

This is why this dissection over the next couple of days is so important to the scientific community. There is so much we simply do not know about this animal.

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