Monday, June 9, 2008

This end up

Frog Egg Mass
Photo credit: Pete Pattavina, U.S. Fish and Wildlife Service

My new friend Steven, over at Tropical Biodiversity, recently blogged about his rare pajurá de Óbidos (Pouteria speciosa) seed. He was concerned when the seed didn’t germinate – until he found out that he’d planted it upside down! Happily, when he turned the seed over, nature took its course and the seed is now a seedling.

Seeds aren’t the only “babies” with a top and a bottom. Recently, I watched a Discovery Channel show with a similar theme. A mama crocodile had laid her eggs too close to humans. Someone wanted both the crocodile and the eggs moved because every time anyone came near the nest, the mother croc would hiss at them. But moving crocodile eggs is a delicate business. If you turn the eggs the wrong way after a certain point of development, the little incubating baby crocodiles will drown. Australia’s Billabong Sanctuary discusses this on their Conservation & Breeding Projects page. Happily, most of the eggs in the story I was watching survived to hatch safely inside an animal sanctuary.

Frog eggs are a little more resilient. Soon after they are fertilized, frog eggs are known to align with the gravity vector (in other words, they have an up and a down). It was once believed that this rotation was crucial to their development, but recent studies of frog egg development in outer space have shown that this may not the case.

[Sidenote: If you’d like to learn more about animal studies in space, be sure to drop by NASA’s Astrobiology page. You can always Ask an Astrobiologist your questions! Also, Space Today Online has an interesting timeline of animals that have gone into outer space – an impressive list that includes not only frogs, but dogs, monkeys, rats, mice, and worms (among other critters).]

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