Nature Blog Network

Saturday, June 30, 2007

Save the Pacific Northwest Tree Octopus!!

A commenter on Pharyngula made a suggestion to PZ Myers to check out the local fauna while he is in Seattle this week. One very important an elusive keystone species, Octopus paxarbolis, is under threat from

decimation of habitat by logging and suburban encroachment; building of roads that cut off access to the water which it needs for spawning; predation by foreign species such as house cats; and booming populations of its natural predators, including the bald eagle and sasquatch.

Please go immediately to Save the Pacific Northwest Tree Octopus Foundation to learn more about this intelligent and fragile species and learn what you can do to conserve this rarity!

Cross-Phyla Invert Double Whammy! Beetles Trade Off Between "Force" and "Fit" for Their Snail Prey

Photo credit: J. Konuma

A recent study published in American Naturalist demonstrate an interesting evolutionary trade-off between "force" and "fit" in carabid beetles (Damaster blaptoides) that feed on land snails. Force means the beetles are stout, large-head and able to crush snail shells with powerful jaws. Alternatively, they can be slender, small-headed and able to fit into the aperature of snail shells (as in the above photo).

Large headed beetles were most successful with thin-shelled snail, whereas small-headed beetles were more successful on snails with larger aperatures. It has been demonstrated that the same trade-off diversifies shell morphology in studies of freshwater snails, where elongate shells are adaptive in protecting against entry attacks and rounded shells are adaptive in protecting against crushing attacks.
Functional trade-offs are likely to affect coevolution between the prey's defensive characters and the predator's attack characters. Thus, the trade-offs between force and fit could play a significant role in character diversification through coevolution between snails and their predators.

You can read more at Science Daily: The Beetle's Dilemma

Invertebrate Rap

High school 7th grade kids rapping about invertebrates! "We ain't got no b-bone" Kind of catchy! Admittedly poor quality and can't make out what they say some of the time, but cute nonetheless. It warms my heart to see the youth of America so enthusiastic over my beloved inverts.

Seabird Diet Switched From Fish to Invertebrates, Possibly Linked to Overfishing

Seabird Diet History Revealed Through Analyisis Of Museum Samples

Using feathers from museum collections all over the world, a University of Guelph integrative biology professor has tested a new hypothesis about what led to population decline of a species of seabirds in Canada.

Prof. Ryan Norris conducted a historical analysis of museum specimens of marbled murrelets going back more than a century to examine how dietary changes may have affected the seabirds’ numbers.

The study, which will be published in the August issue of Journal of Applied Ecology, also illustrates how scientists can use museum specimens to figure out what led to a species decline and to help focus conservation efforts.

“One of the biggest unknowns for endangered or threatened species is how their populations fluctuated naturally before human disturbances,” Norris said.

“But there are millions of specimens in museums across the country, many of which were collected before habitats started to decline and that can give you really important baseline information for designing plans to conserve species.”

Norris decided to examine how marine diet over the last 100 years might have influenced the birds’ populations by analyzing the stable carbon and stable nitrogen isotopes, chemical signatures that become fixed into the marbled murrelets feathers when they’re grown.

Their isotope analysis showed that prior to 1900, the birds were feeding most on fish, but that by the 1970s, 80s and 90s, their diet consisted of marine invertebrates, which are much less energetically rich than fish.

“Murrelets have to catch around 80 to 100 marine invertebrates to get the same nutritional value as in one forage fish,” Norris said.

The researchers concluded that the seabirds’ population changes in Canada after 1950 were likely influenced by a decline in the amount of fish in their diet. It’s an important finding because it suggests that to save the species, conservation efforts should be refocused.

Thursday, June 28, 2007

New species of Bathyacmaea from the Lau Basin

This is a new species of Bathyacmaea (Mollusca, Gastropoda, Patellogastropoda, Acmaeidae) that currently under description by Takenori Sasaki at the University of Tokyo Museum in Japan. I have found hundreds of these individuals in my quantitative collections of chemoautotrophic communities at the Lau Basin hydrothermal vent fields. They reminded me of the Patella limpet I learned about in my undergrad inverts class.

Wednesday, June 27, 2007

Rock Eating Isopods

Photo credit: Yuji Okimura, emeritus professor at Hiroshima University.

What is the buzz on CRUST-L these days? How about isopods on an island off of Hiroshima in Japan that have eaten away the soft volcanic rock (called tuff) to almost sea level! In a recent news piece from MSN-Japan they document a dramatic change in the small island's stature from 1955 to the present (click on link to see and read the article in its entirety). These isopods burrow into the rock, possibly to eat at bacteria and algae and hide from predators, speeding up erosion big time. The island once stood 21.9 meters tall in 1928 and now, as the article states,
"...the highest peak has almost completely vanished, leaving only one rocky protrusion about 6 meters high. Because of this, most of the island is submerged at full tide."

Tuesday, June 26, 2007

Let us rejoice in the awe and mystery of those without spines!

It is my pleasure to start this blog on the unappreciated majority in the animal kingdom: the invertebrates! My blog will be focusing on anything and everything related to spineless curiosities. My specialty is in deep-sea marine invertebrates, so you may notice a slight bias but never fear as I am interested in all of the 95% of life we call Invertebrate!

I always welcome links and suggestions to post regarding inverts and will answer any questions about invertebrate organisms readers will post. I hope this will be an educational and informative blog as well as entertaining.