Thread by @ZSLScience

Cetacean strandings team from @ZSLScience here- join us tomorrow morning when we'll be taking over the channel and live tweeting updates during the examination of a dead stranded pygmy sperm whale recovered from Ginst Point in Carmarthenshire earlier today #CSIoftheSea

The CSIP team are taking over shortly, please be aware the nature of the work is graphic in content #CSIoftheSea

Hi, this is the team from CSIP! We’re taking over @ZSLScience this morning and providing live updates during our investigation of this Pygmy sperm whale #CSIoftheSea

Every year, around 700 cetaceans (whales, dolphins and porpoises) are found stranded around the UK coast. The CSIP is contracted to investigate these strandings to learn more about the threats they face in UK waters.

This whale was found dead stranded on Tuesday 11th June at Ginst Point in Carmarthenshire. Recovered by the team in Wales and transported to our lab here in London #CSIoftheSea

The is the sole Pygmy sperm whale recorded starended in the UK this year and is only the 14th we’ve recorded since the project began in 1990. Also the third to be found stranded in Wales, so this is a relatively unusual species for the UK #CSIoftheSea

Thought to have a wide distribution in primarily offshore waters/near the continental shelf edges and at a depth of 400-1000m. They feed predominantly on squid and the population size is unknown #CSIoftheSea

This species is relatively poorly understood because it’s difficult to study in the wild. Most of the information we know is derived from examination of strandings like this one #CSIoftheSea

This male measures 2.48m meaning it’s likely to be an adult #CSIoftheSea

External peck marks and the loss of eyes is consistent with post-mortem scavenger action from birds #CSIoftheSea

We take samples of blubber to measure the thickness and often find parasites in the blubber #CSIoftheSea

Samples of blubber are taken from below the dorsal fin for analysis to check for man-made contaminants (e.g. PCBs) #CSIoftheSea

Incisions are made along the blubber to flense the blubber from the ribs #CSIoftheSea

We can now see the ball and socket joint of the whale’s ‘shoulder’ - where the pectoral fin joins to the body #CSIoftheSea

We take the ribs off to expose the underlying viscera. Cutting through the rib cage takes a lot of strength - and a lot of crunching! #CSIoftheSea

Now the left side of the rib cage has been removed, we can see the whale’s internal organs - listen to Rob pointing them out! #CSIoftheSea

We take swabs and samples of the lung, liver, kidney and spleen to send to bacteriology and virology for testing #CSIoftheSea

Small samples of blubber are taken to send to histopathology to look at the pathology at the cellular level #CSIoftheSea

As you can see here, the Pygmy sperm whale has lots of sharp teeth on its lower jaw - if you look closely you can even see sucker marks (little circles) from the squid it has eaten!

The sack you can see here (bottom right) is full of an ink-like fluid which the whale uses as a defensive response - kind of like a squid. The sack is located at the end of the digestive tract and the whale releases the ink from its anus #CSIoftheSea

This is just one drop of the ink - you can see how it spreads in the water #CSIoftheSea

Now we’re looking at the liver! In cetaceans livers have two lobes. We are taking samples to check for naturally occurring trace metals that have made their way up the food chain #CSIoftheSea

This photo shows the whale’s spine is quite prominent - the team wonder if this whale was nutritionally compromised #CSIoftheSea

These are the whale’s kidneys. In cetaceans, the kidneys are reniculated #CSIoftheSea

This is the left eye. We are collecting this for a collaboration with a project that works on investigating vision in deep diving animals #CSIoftheSea

This synovial fluid is found within skeletal joints to keep them lubricated #CSIoftheSea

Nematode parasites are frequently found around the head - this cool paper describes detailed anatomical investigation of the habitat use of the parasite in this species int-res.com/abstracts/dao/…

More parasites! This time found in the oesophagus, likely from the stomach #CSIoftheSea

Everyone is excited about finding more parasites! #CSIoftheSea

The penis of the Pygmy sperm whale #CSIoftheSea

These are the lungs. The part that Rob is holding is the larynx fits into the entrance to the blow hole from below, the trachea then split into the lungs. We found a large volume persistent froth in the trachea, but this isn’t necessarily diagnostic #CSIoftheSea

This is the whale’s heart - see the scale bar beneath for scale #CSIoftheSea

Now we’re looking inside the whale’s stomach which has three separate chambers - we have found a lot of hair-like parasites and multiple squid beaks (which are persistent in the stomach), but no evidence of recent feeding #CSIoftheSea

We are just off to recharge - we will be back online shortly! #CSIoftheSea

We’re back! But we’re a reduced size team now, so we’ll give a series of final updates in a bit- bear with us... #CSIoftheSea had a cuppa and back on it

Ok back again let’s pick up where we left off... Nematode parasites in two of three stomachs and lots of squid beaks- latter collected for dietary studies. No evidence of recent feeding and no marine debris/plastics found #CSIoftheSea

This is a cross section through the soft tissue of the head, showing melon and spermaceti organ- toothed cetaceans primary sense is auditory and this is all part of the echolocation process #CSIoftheSea

We then removed the brain using an oscillating saw to remove the back of the skull #CSIoftheSea

The brain appeared to be grossly normal #CSIoftheSea

We collected teeth to help age the animal- cetacean teeth have growth layer groups within them, a bit like the rings in a tree trunk. This species is thought to live to around 25 years #CSIoftheSea

We also removed and examined the various parts of the ear (or tympanic bullae) #CSIoftheSea

Finally we examined the intestinal tract, including the modified colon which forms the sac filled with dark viscous fluid we mentioned earlier. Bile staining in first part of the intestine consistent with lack of recent feeding #CSIoftheSea

Summary of where we are with this one at the moment- awaiting follow up tests now before the teams vet will allocate a final cause of death #CSIoftheSea

OK- that's it from us for today, hope you've found all this of some interest. If you want to learn more about our #CSIoftheSea work, this dissection focussing on #bycatch is still available.
See you on the beaches soon...