I Spy… something special!

The minute details of a developing Port Jackson shark have been revealed, from within its unhatched egg.

Do you remember AQWA’s miraculous Port Jackson pup Axyl, who ‘hatched’ prematurely – and thrived – at just 3 months old? Axyl offered AQWA’s team of marine specialists a unique view of PJ development, sans the usual protective egg case.

AQWA’s newest PJ pup has flipped the script and offered us a counterview – with a natural opening in the egg case allowing a microscopic lens a rare peek inside at the developing pup.

In this video you can spy its eye, gills, dorsal fin and curled tail and the still intact yolk sac! The substantial size of the yolk sac (at the time of recording) informed our team of aquarists that this little elasmobranch was not quite ready to pop out from its egg case, despite the small opening that has formed.

Now on display in AQWA’s Mysterious Creatures exhibit, the ideal temperature and water flow conditions of this aquarium will support the pup until full gestation – where it could surprise and delight visitors with an appearance at any moment over the next few months!

Visiting AQWA? Can you find the egg in question?

If you’re having trouble, that’s not surprising. Shark eggs are unusual in their appearance!

Rather than the stereotypical ‘hard-shelled’ oval that might come to mind, shark eggs feature a tough, leathery case. Port Jackson sharks put their own ‘spin’ on the design, producing a spiral shaped mottled brown egg case that is well camouflaged among the soft growth of seafloors and reefs.

Female’s even use the spiral shape to ‘screw’ their eggs into cervices, reefs and sea grass tendrils for safer keeping!