In sexual selection and thermoregulation, bigger is better, at least for fiddler crabs

Sexual dimorphism in fiddler crabs. Female (A) and male (B) Uca panacea. Scale bars indicate 1 cm. From Darnell and Munguia 2011

Imagine yourself a fiddler crab. For this exercise, imagine yourself a male fiddler crab. Are you with me? Great. Check out your right claw, it’s a sleek, slender machine, perfect for picking through the sand as you sift out bacteria and other microorganisms for food. It also makes a handy shovel for digging nice deep burrows to protect you from harsh conditions. Now check out your left claw. Wow! This thing is massive. If you possess a particularly vivid mind and have place your ego within the carapace of Uca panacea, your giant claw is more than a quarter of your body weight. This comically mis-proportioned appendage is why those pesky bipeds call you and your cousins “Fiddler Crabs”.

See that female fiddler crab at the perimeter of your territory? Yes, she is checking you out. That giant claw of yours is primarily used to attract mates, signalling to interested parties that your are fit and fecund. You even have a special dance, unique to each fiddler crab species, to announce your vitality. And if some other, lesser-clawed, male tries to move in to your territory, why, you’re equipped with a serious piece of hardware to drive off that interloper.

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Saving Coral Reefs, today at 3 EDT

ScienceLIVE will be featured noted marine biologists Dr. John Bruno and Dr. Mark Eakin who will be discussing the state and future of coral reefs. From the website:

Coral reefs from Australia to the Gulf of Mexico are some of the planet’s most vibrant ecosystems. They’re also among the most threatened habitats in oceans today. Over recent decades, a strong community of researchers and concerned citizens alike has dedicated themselves to investigating the dangers facing reefs and to developing solutions for their ongoing survival. From rising ocean temperatures to overfishing, what are the biggest dangers facing coral reefs today? What can scientists and the public do to protect these rich habitats? And how can we restore lost diversity to reefs around the world?


Tune in this afternoon. You can leave questions in the comment box over at Science live before the show.

Climbing Mount Chernobyl

Chernobyl Reactor 4, after the explosion

In the last century, humans have made dramatic changes to both local and global ecosystems. Some of these changes have been subtle and remained unnoticed until very recently, while others were so visible and so destructive that their names are indelibly etched into our collective consciousness. Despite a legacy of desolation, many of these places, unsafe and long-abandoned, have made dramatic recoveries. Standing tall, but not alone, among these environmental catastrophes is the melt-down of reactor 4 at the Chernobyl Nuclear Power Plant.

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Tagging Bull Sharks in the Neuse River

Meagan Dunphy-Daly is a graduate student at the Duke University Marine Lab studying the effectiveness of marine reserves in protecting apex predators. She also has ongoing research examining bullshark/dolphin interactions in the Neuse River, NC, where she recently caught an 8 foot bullshark.

Well, it’s Shark Week and instead of heading up to the Neuse River to try to track bull sharks, I’m sitting in front of my computer staring at the marine forecast. Right now, we’re under a small craft advisory until tomorrow night and we’re all keeping our eyes on what Tropical Storm Emily is going to do over the weekend. Such is the ever-exciting life of a field biologist. Although there are a fair number of days spent in an office in front of a computer (be it checking the weather, entering data, or hoping that a manuscript will write itself), the days in the field are what make this job so sweet. I’m a graduate student in Dr. Andy Read’s Lab at Duke University and, in addition to my dissertation interest in the effectiveness of marine reserves for apex predators (think sharks, tuna, and billfish), I have the chance to carry out and participate in many other research projects in North Carolina and elsewhere (check out Reny Tyson’s previous posts on our trip to Antarctica). This summer, I’m studying bull shark habitat use in the Neuse River. Andrew joined us for a day of fieldwork last week and, although we didn’t catch a shark on this trip, we caught a big bull shark on the first day of our season the week before.

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New Scaly-Foot Gastropod found in Indian Ocean

Megumi Shimizu is a second year PhD student at the Duke University Marine Lab. Since the news has so far only been reported in Japanese, we asked her to provide a short write-up of the discovery.

Image courtesy JAMSTEC -

The first scaly-foot gastropod, Crysomallon squamiferum, was found in the Indian Ocean ten years ago (Van Dover et al 2001), and  continues to attract deep-sea fan with its black appearance and iron-fortified shell and operculum. Last December a team from JAMSTEC (Japan Agency for Marine-Earth Science and Technology) reported the discovery of a white scaly-foot gastropod in the Indian Ocean. The exciting news was announced in Japan soon after the conclusion of the research cruise.

Here is the press release.

Except for its color, the shape and characteristics are the same as the black scaly-foot gastropod. Unlike the mysterious black one, the white one gives me different impression: pretty and innocent looking.

They found white scaly-foot gastropod during an investigation of habitats at newly found hydrothermal vents in November 2010. Several aggregations of white scaly-foot gastropods were found at the sites. Although scaly-foot gastropods are usually covered by iron sulfide shell and scales, the white scaly-foot gastropod does not assimilate iron sulfide.

The physiological details have not yet been revealed.

Many questions come to mind from this discovery: Are they same species? How did they evolved? Why do black scaly-foots need iron scales?

I am definitely looking forward to reading the final publication.

The Global Extinction Crisis – species area relationships, habitat loss, and population dynamics

We are in the midst of a global extinction crisis. Biodiversity is in decline as species after species disappear. Some estimates predict that up to 50% of species will be committed to extinction by 2050. Other estimates claim the current rate of extinction may be 10,000 times the background rate. Many ecologists and conservationists have declared the current species decline the sixth great mass extinction.

A recent paper published in the journal Nature argues that our current estimates of species loss are based on a flawed model and tend to overestimate the magnitude of species decline. The paper has received plenty of attention, and has been heavily criticized by ecologists and conservation biologists. The paper is wrong, but it is wrong for the right reasons, and the criticisms it has garnered point to a gaping hole in our  understanding of population dynamics.

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The Outer Banks Ablaze

Early hours of the wildfire in Dare Country. Image NCFWS

In Beaufort, the first sign that something was amiss occurred on Sunday night. The air became thick with haze and smelled like of burning mulch. At first we thought it was just an overzealous barbecue somewhere down the road, but as we drove over the Morehead City highrise bridge, we discovered that the smoke was everywhere. This wasn’t an isolated grilling accident, trash burn, or house on fire, some thing was burning, something big. It could only be a forest fire, and, judging by the direction of the wind, it was blowing in from somewhere near the Outer Banks.

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Biodiversity Wednesday: Yellowstone Geysers

Yellowstone National Park was established to preserve the American West, largely held up as the iconic American landscape. Picturesque Yellowstone houses the hopes and dreams of the frontier, the wilderness that is a large part of American heritage, and the final refuge for North American wildlife. Despite such a colorful and large part of American history, Yellowstone should perhaps be famous not for its astounding trees and bouncing elk, but instead for the ecosystems that depend on Yellowstone’s geysers. They are the unsung heroes of modern biotechnology and place Yellowstone’s wilderness leaps and bounds above other temperate forests in terms of biodiversity.

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