Thứ Hai, 27 tháng 6, 2011

Granddad (with the spots) and a friend
Yesterday I had the delight to meet Granddad, the world's oldest fish in a public aquarium. Granddad is an Australian Lungfish who first arrived at Chicago's Shedd Aquarium in 1933! So if you only learn one thing from this article, know that Lungfish can live for quite a long time.

But if you're after two cool tidbits, know that the Australian Lungfish is essentially a living fossil. Fossilized evidence of its family members date back to the Devonian, and the Australian Lungfish itself has remained relatively unchanged for nearly 100 million years! There are five other Lungfish species still alive, and one of their closest lobe-finned relatives is the Coelacanth. Lobe-Finned fish are especially notable because it is from them that tetrapods eventually evolved!

So why are they called Lungfish anyway? Because they have lungs of course! In the case of the Australian Lungfish, only one lung is present. But if there is a lack of water it is able to surface and breathe air for a short amount of time.

Australian Lungfish reproduce through spawning, which takes place from September to December. The eggs take only three weeks to hatch, but the young fish grow very, very slowly. After eight months they may only be 6 inches long! Due to their slow growth rate, no one actually knows how old Granddad is. He was fully mature when he showed up, making him at least 80 but possibly much, much older!

Australian Lungfish are not listed by the IUCN, but they are protected by the local government and are listed in CITES Appendix 2.

IUCN Status : Not Listed
Location : Australia
Size : Length up to 5ft (1.5m)
Classification : Phylum : Chordata -- Class : Sarcopterygii -- Subclass : Dipnoi
Order : Ceratodontiformes -- Family : Ceratodontidae
Genus : Neoceratodus -- Species : N. forsteri

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