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.
We’re experiencing network connection problems in the room where our whale bloggers are. We are trying to fix it as fast as we can in order to resume blogging.
Sorry about the inconvenience.
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.
A blog from Bruce Reidenberg
Pygmy right whale mouth and chin
The pygmy right whale – chin on. You can see first incisions.
Dr. Joy Reidenberg has examined larynges (voice boxes) of many aquatic and terrestrial mammals. There are unique adaptations of whales to life in the water. One of these adaptations is the use of sound. Whales tend to make two types of sound: a high frequency sonar to examine their environment and a low frequency series of sounds that are used to communicate between individuals and groups. Very little is known about pygmy right whales’ sound production.
Since Dr. Joy Reidenberg has examined larynges of many species of whales whose sound production is well described, evaluating the anatomy of pygmy right whales may show similarities or differences with species that are better known. From this anatomical relationships, the types of sound made by pygmy right whales may be estimated. Then other scientists listening to whale recordings may be able to validate the guesses over time.
In addition to guessing the types of sound that pygmy right whales might make, Dr. Joy Reidenberg is looking forward to working with Prof. Fordyce, Drs Kemper and Rommel to compare the anatomy we observe over the next few days with fossil whales. From these comparisons, we expect new insights into understanding how whales have evolved from a land-based ancestor.
Hi this is Anton blogging in on Emma’s blog. At the moment we are taking lots and lots of photos. Documenting animals in this way allows us to have landmarks on the outside of the animal that we can link to internal structures. So that we can build up a picture of how the insides relate to the outside. We also do this to be able to make comparisons with future animals. For instance if we were to get a larger animal of this species we could show how things change (or don’t change) relative to size.
Good morning!
Everybody has gathered, its a little bit like an operating theatre (except cold!) with all the instruments on the table beside the dissection table. Knives are being sharpened:
Anton has sharpened 9 so far.
Measurements have been taken:
From tip of upper jaw to the deepest part of the fluke notch – 2.31 metres
Girth – 1.2 metres
Dorsal fin is situated far back along the body – 1.5m from its snout
Dorsal fin height – 7cm
Span of fluke – 60cm
He’s a male.
They’ve found 12 bite marks so far, these are assumed to be from a cookie-cutter shark (isistius braziliensis). These won’t have been cause of death.
That got your attention! I’ve been learning some dissection terms. Autopsy is generally used in relation to humans and looks at cause of death.
A necropsy usually refers to animals. It looks at how the animal’s body
works as well as the possible cause of death.
Here’s a picture of the pygmy right whale fresh out of the freezer on Saturday, ready for the necropsy. The white stuff you can see is ice!
The scientific team are all here and have spent today planning how it’s all going to go. External measurements first – guess how much it weighs!
We’ll be blogging from about 9am tomorrow. See you then.
