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  • Jaejeong & Jaeah Kim

Skate Dissection|| A Mermaid's Purse

What’s the difference between skates and rays? Find out as you learn how to dissect a skate in this video, which also covers its external and internal anatomy and physiology. In this simple dissection of a skate, you’ll learn various parts of its anatomy, what exactly a ‘mermaid purse’ is, and why a skate’s liver floats in water.

Skates are one of the most underrated animals among the cartilaginous fishes, often overshadowed by their flashier cousins– rays and sharks. However, did you know that skates have many unique features neither rays nor sharks possess, such as their distinctive method of laying eggs within rectangular leathery sacs? In this video, you’ll learn general information about skates, which will be tied into their anatomical structures and physiological importance.

This dissection lab is for anyone who is curious about skate anatomy, wants to cover skate anatomy for a zoology course, missed the skate dissection during biology class, or just wondered, “How are skates different from rays?”. The video will teach you how to dissect a skate step by step, and review the external and internal anatomy of the skate.

In these videos, we’ll cover the following structures:

Eyes Liver

Spiracles Gallbladder

Gill slits Cardiac stomach

Mouth Pyloric stomach

Teeth Intestine

Nostrils Pyloric valve

Rostrum (snout) Spiral valve

Skin Rectum

Denticles Spleen

Pectoral fins Pancreas

Pelvic fins Rectal gland

Tail Rugae

Spike Ovary

Cloaca Fallopian tube

Claspers [mentioned] Uterus

Heart Egg sac

Gills Kidneys

Gill filaments Cerebral hemispheres

Gill rakers Olfactory nerves

Sinus venosus Optic lobe

Conus arteriosus Cerebellum


Part 1: External Anatomy & Thoracic Cavity

Part 2: Abdominal Cavity & Cranial Cavity

If you want to learn more about skate anatomy, here’s a link to a website with more detailed information, as well as diagrams:

If you have any questions regarding skate anatomy, dissection methodology, or general biology, feel free to leave a comment. We'll try our best to reply.


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