Sunday, July 26, 2009

Horseshoe Somersault

What has blue blood, feet around its mouth and 10 eyes and legs? The Horseshoe Crab - which isn't a crab at all, but an arthropod that shares a few similarities with other arthropods like spiders and crabs. They predate the dinosaurs and are most closely related to trilobites.

We didn't catch any in our seine netting on Saturday, but a walk in the mud flats at low tide revealed a few bulldozing their way through the mud in search of shelter. This area is essentially a nursery for young crabs. They molt several times in their first 2 years and by the time they get to be this size - maybe once a year - discarding the entire "shell" as they grow.
This young adult was hunkering down in a small pool of brackish water. They prefer the back bays and coves that have low wave energy. This species (of which there are 4 worldwide) is found from New Jersey south to the Gulf of Mexico. The greatest abundance of Horseshoe Crabs is in Delaware Bay where hundreds of thousands of migrating birds stop in to munch on the crab's eggs. Fortunately each female can lay up to 80,000 eggs (yet populations have been declining).
Our instructor placed it upside down to demonstrate how they can do a somersault to right themselves. Here you can see the 10 crab-like legs that surround the mouth (Like the alien in the movie Predator).
The crab is able to use its tail to roll itself over.
And flip itself to a more natural position. Not all are capable of doing so and in some Atlantic states they have instituted a "Just Flip Em" campaign to encourage beach goers to flip the harmless creatures over.
They have light sensitive organs or "eyes" on the front end as well as on their tail that allow them to see the light spectrum that we see as well as ultra violet light.
Despite what looks like a tough exterior, the exoskeleton is relatively fragile. Below - the Horseshoe Crab has burrowed into the mud. A walk in the mud flats is like walking on eggshells if you don't take care - fiddler and horseshoe crabs abound.
Technically their blood is not blue but when exposed to oxygen it turns blue. The blood has been important in medical research as scientists look at the bacteria resistant properties and develop new ways to benefit from it. Currently an extract of Horseshoe Crab blood is used in vaccines and medical devices to prevent bacterial contamination.

They look benign from the road but the mudflat tidal zone is full of a diversity of life including the acrobatic "crabs".

For more info on Horseshoe Crabs check out

Saturday, July 25, 2009

Stay-Puft Marshmallow Fish

Do you have any idea what's darting beneath the waves when you wade into the ocean? Things that blend in like aquatic ghosts. Things that sting when endangered. Things that blow up 3 times their normal size when alarmed...

I'm taking a Florida Master Naturalist course through the University of Florida extension and program and this morning we went seining on Lover's Key State Park on Fort Myers Beach. The seine is a net stretched between two posts and kept afloat at the top with small orange buoys.
Below - Chris and Jessie pull the seine through the salt water as the tide goes out, collecting whatever may be swimming, floating or crawling in the area. The diversity of critters we captured is impressive. People swim here. People play here. And fantastic animals live here.

The first species in a series of critters caught (and released) that I will post is the Puffer Fish. When alarmed, endangered and/or threatened by consumption, the Puffer will inflate itself, in turn alarming predators and suggesting that they may not make a great meal.
Below - the Puffer floats in a collection bin. It's about six inches long.
When our instructor inadvertently tickled the fish's peduncle (tail fin), it quickly inflated and remained that way for several minutes. Below - the fish bobs upside down.
When under water they fill their elastic stomach with water. When brought above the waves they can fill with air like the one pictured. You wouldn't want to eat one anyway. Some Puffer species can produce a neurotoxin that is poisonous to predators and humans.
Notice the eye? Click the photo to enlarge it. They can change the color and intensity of their eyes when necessary.
Beautiful fish under the sea - and you probably didn't know they were there.

Sunday, July 19, 2009

Ghosts of Coastlines Past

Ghosts are fast. Blink and you'll miss them. Some people have no idea they exist. Their white, ephemeral appearance helps them disappear before your eyes.
Their stalked eyes make watching you all easier. Glance at them and they dart away at up to 35 mph.
But not without a trace. Fast and cautious, the Ghost Crab retreats to a sandy burrow in a flash.

Wednesday, July 1, 2009

Python Kills Toddler

A 2-year old was strangled to death by a pet Burmese Python yesterday in Orlando, FL (story). The 12 foot exotic snake from SE Asia escaped from an aquarium and was found with the lifeless child. The boyfriend of the child's mother owned the snake and did not have the proper permit to posses a "Reptile of Concern", nor did he have the good sense to secure an obviously dangerous animal.

The Burmese Python is one of top 5 largest snakes in the world and can reach lengths greater than 18 feet in the wild. In captivity they can grow quickly and this young, former pet python that we have on display is well over 19 feet and weighs over 350 pounds. It was offered to us after the owner could no longer take care of it.

While Pythons are considered relatively docile, large snakes become difficult to handle and maintain. Many have been released into the wild in Florida by owners who were incapable of
caring for them. The US Geologic Survey released a range map in 2008 that shows where Pythons have been found to date.

Biologists estimate there are over 30,000 Burmese Pythons living in Florida. Pythons are constrictors, feeding on appropriate sized mammals including the endangered Everglades Mink and Mangrove Fox Squirrel. Females lay up to 90 eggs per clutch and are quite protective of their young - making predation by raccoons, opossums and other nest raiders tough.

In over 600 tours I have led, I have only seen 2 dead Burmese on the Tamiami Trail in the Miccosukee Reservation. Both sightings happened to be the same day but more and more Pythons are seen each year.

Not only are invasive snakes a threat to the ecosystem they now inhabit - wild Pythons could soon become a threat to nature lovers enjoying the same habitat. Various places around the Internet lit up today with comments of people terrified to visit the Everglades. While it's acceptable to be concerned about the wildlife in the place you may visit, I would suggest terror might be an over exaggerated emotion in this situation. We live among Alligators with little conflict. We can do so with Burmese Pythons if we must.

A small, light-colored 12-foot Boa Constrictor rests on top of a 19-foot Burmese Python

The difficulty will be controlling their populations. Currently there is no effective way to control let alone eliminate the giant snakes. Secluded nest sites and large clutch sizes result in high survival rates. We can assume the population will grow as long as the climate remains the same.

What is utterly unacceptable is the irresponsibility of pet owners. Large snakes such as Anacondas, Burmese Pythons and Reticulated Pythons require permits to possess such snakes but there are no doubt many who shirk this legality (including the man in this incident). These snakes should always be kept secure and under no circumstance should a child ever be left where such a snake could harm them. Sadly it has happened before and it will probably happen again. People are stupid.

Sea World may want to update their "Fun Facts".