Transcript Skate Dissection

Skate Dissection
Phylum Chordata
Class Chondrichthyes
Order Rajiformes
Family Rajidae
More about our specimen:
While it may not seem like it, sharks and rays
(the skate is in a subgroup of rays) are very
closely related. They both fall into the class
chondrichthyes.
External anatomy differs greatly, but internally and
developmentally, sharks and ray are almost
identical.
Inexpensive and easy to cook
We can try
to say that
they’re cute,
but that’s a
stretch.
Only label the
circled terms.
Note the fins,
they all exist on a
ray just like they
do on normal fish,
only they’ve been
adapted for the
rays unique
lifestyle.
Sketch 1
If it is a male
Sketch 2
If it is a male
See if you can
spot the
ampullae of
Lorenzini.
When you find
them, label
them also.
(They are not
pictured here)
Sketch 3
Carefully open the gut below
the gill openings on the ventral
side of the skate.
First, note the large liver with
reproductive organs on either
side (if a male).
Draw a picture of the
liver/gonads and then remove
them to reveal the digestive
organs underneath.
Heart
Sketch 4
Next, remove the liver to reveal the 2
stomachs (pyloric on the left, cardiac
on the right). Draw a quick sketch of
these organs.
Lifting the cardiac stomach will reveal
the spleen (dark sac on stomach) and
the kidney (brown organ on the right)
Also, note the intestine
running to the anus.
And the uterus/ovary
if female….
If male, parts (testis)
will looks smaller
Sketch 5
Using scissors,
cut open the
head region
between the
eyes to reveal
the brain.
Just like with
the bony fish,
be careful and
try not to
destroy the
brain while
opening the
head.
You’re all done with sketches……
• If you have any other areas you want to explore, feel
free.
• Dissecting scopes are on the front table if you want to
view anything at a high magnification.