Shark pup in cork-screw case: a rare find

About 12 years ago I found a Port Jackson shark egg case on 'our' beach -- here on Phillip Island -- that contained an almost fully developed baby shark attached to an egg sack. It was a rare find and we never expected to discover another.

Yesterday, however, Doug found another Port Jackson egg case which looked and felt as if it contained something. Probably sand, we reasoned, yet we brought it home and cut it open in the laundry sink. And yes, another shark pup, but this time much earlier in its development. Doug christened him Simon and preserved him in methylated spirits.

So now Samuel and Simon sit side by side in their bottles; preserved.

PS
Both shark pups were dead when we cut open their case. When the female Port Jackson shark lays her eggs, she pushes each cork-screw shaped egg case (the outer surface looks like seaweed) into a rocky crevice, there to develop and finally emerge as an independent shark pup.

Port Jackson sharks breed in Western Port Bay

One of the features of Western Port Bay flotsam is the fact that Port Jackson shark egg cases are fairly common. These screw-shaped cases, which look as if they're made of seaweed, once contained the embryo of a developing shark, attached by a cord to an egg yolk.

In my youth, we called these discarded egg cases the romantic name of mermaid's purses. Almost always they were empty of their developing shark. Sometimes though, they were full of sand.

It's been my life-long habit to pick up anything of interest along the seashore so, over the years, I've picked up hundreds of Port Jackson egg cases -- especially on Phillip Island beaches after storms.

One day, however, I found one that looked intact. Filled with excitement I carried it home where I cut it open on the kitchen bench. Miracle, miracle: inside was my very own shark pup -- Samuel! He was dead but not at all decomposed, so I preserved him in methylated spirits and have him to this day.

The egg case is tough and flexible, and screw-shaped for a reason,. The female Port Jackson shark lays her eggs and wedges each into an underwater rocky crevice, using her mouth, where it will remain stuck until hatching.

Port Jackson sharks (Heterodontus portusjacksoni) are small and do not attack people, therefore can be viewed with affection.

PS.
Tomorrow I'm booked in to have three skin cancers removed from my face, under a general anaesthetic. Consequently, I'll not be able to write my blog for a couple of days. But I will be back!