THE FINS UNITED INITIATIVE
  • About TFUI
    • TFUI Origins >
      • About TFUI Founder Melissa
      • TFUI Officers
    • Take a Bite
    • Get Involved
    • FAQ
  • Bite Blog
  • Education
    • The Sharks >
      • Shark Anatomy
    • The Skates & Rays
    • The Chimaeras
    • Why Environments Matter
    • The Threats
    • Open Access >
      • Behind the Fins: Interview series
      • Bite into Research
      • Shark Bites: Book Recommendations
      • Sustainable Seafood Apps
  • Fins United
    • Shark Party Ideas
    • Little Fins Nursery
    • Big Fins Reef
  • Contact

Eggcase Anatomy

2/15/2017

 
PictureEgg case washed up at Long Reef. (Photo by myopixia)
If a Chondrichthyan is oviparous, then their fertilized eggs will pass out of the female body via the cloaca and vent. On contact with sea water, the shell material of the egg will harden into a tough protective coat. Here we will discuss the general anatomy of a Chondrichthyan egg and Shark Trust’s “The Great Egg Hunt” initiative.

Chondrichthyan egg cases, also known as mermaid’s purses and devil’s purses, are made out of collagen protein strands around fertilized eggs of some species of Chondrichthyans (note: all stingrays give birth to live young). The parts that make up the egg case can be seen in this diagram provided by the Shark Trust’s “Great Egg Hunt” guide.

The most distinguishable features on these egg cases are the keel and absence/presence of fibrous covering. The size and shape of these egg cases usually varies on whether it belongs to a shark, skate, or chimaera—and then it varies on the family! For example: a Port Jackson shark egg differs from a zebra shark egg which different from a catshark egg. All sharks, yet all have different egg shapes! These different egg case shapes will be looked at on the following post of this series: "Different egg cases around the world."
​
Once the pup exits the egg, they become lightweight and usually dislodged from wherever they were hidden or attached to. The ocean current takes over then, and they usually wash up on the beach by the strandline (the farthest point of the high tide). Most of these washed up egg cases are empty, though some may not be—do check before taking one home!

Shark Trust's “The Great Egg Hunt,” a UK-wide citizen science project that allows for beachgoers who find egg cases on the beach to identify the species of who the egg case belongs to, record their findings and help scientists gain knowledge about distribution and preferred habitat of these animals! You can find the latest published findings here.

have you ever seen a shark eggcase before?

glossary

  • Keel: The line along which the shell is closed.
  • Oviparous: The eggs hatch and the babies develop inside the female’s body, without a placenta to nourish the pups.
  • Pups: Baby sharks.
  • Strandline: The farthest point of the high tide.

say hello!

you may also like:

Picture
HOW SHARKS MATE
Picture
REPRODUCTION IN SHARKS
Picture
GENERAL: SKATES

Comments are closed.

    Author

    TFUI Founder Melissa C. Marquez is author of all animal bios and "Behind the Fins" segments.
    ​
    A proud #LatinainSTEM, Marquez is a marine biologist who focuses on shark habitat use and movements; she is also a science communicator (follow her on Twitter) who focuses on diverse Chondrichthyan education and who focuses on the media coverage of sharks.
    You can learn more about her on her website.

    SEE MELISSA'S TEDx TALK HERE:

    Archives

    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    April 2018
    March 2018
    February 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    March 2016
    February 2016
    January 2016

    Subscribe to The Fins United Initiative's monthly newsletter.

    SEARCH BY CATEGORIES

    Picture
    SHARKS
    Picture
    SKATES &
    ​RAYS
    Picture
    CHIMAERA

    READER FAVORITES

    Picture
    Picture
    Picture
    Picture
    Picture
    Picture
    Picture

    FOLLOW ALONG ON INSTAGRAM

    @finsunitedinitiative
    Picture
Powered by Create your own unique website with customizable templates.
  • About TFUI
    • TFUI Origins >
      • About TFUI Founder Melissa
      • TFUI Officers
    • Take a Bite
    • Get Involved
    • FAQ
  • Bite Blog
  • Education
    • The Sharks >
      • Shark Anatomy
    • The Skates & Rays
    • The Chimaeras
    • Why Environments Matter
    • The Threats
    • Open Access >
      • Behind the Fins: Interview series
      • Bite into Research
      • Shark Bites: Book Recommendations
      • Sustainable Seafood Apps
  • Fins United
    • Shark Party Ideas
    • Little Fins Nursery
    • Big Fins Reef
  • Contact