Bryozoan larva (aka moss animal)
Saturday, July 26, 2008
Thursday, July 24, 2008
This is a leaf barnacle, most likely Pollicipes polymerus. Like most intertidal animals, they are subject to solar radiation, extreme salinity fluctuations, and heat (among other things), and have no way to regulate their body temperature internally. So how do these guys stay cool?
First, you get a good placement. The leaf barnacles live in the crevices of mussel beds [1,2]. The mussel beds, because of the closeness of the animals can retain a bit of cool water to help combat the heat. Living in shady cervices also helps. Additionally, most intertidal animals (especially barnacles) have special proteins that can help protect other proteins from unfolding and becoming useless in the heat. Some barnacles can function in 34 degrees C for several hours, without their proteins degrading (That's 93 degrees F for you Americans) . But leaf barnacles have a third way of keeping cool. They can lose up to 40% of their body water from their fleshy stalk . This evaporation process helps keep their body temperature slightly cooler than to ambient temperature.
Saturday, July 19, 2008
This was a tough one to pick, as I have TONS of pictures of creatures that most people don't know what they are. I also have pictures of larval forms of a variety of creatures. I decided to go with an animal that people can recognize, but I like this photo for the shock value. Who would pay $15,000 dollars for a butterfly? Well, the reason why this butterfly costs so much is: it's a gynandromorph. That's not the name of the butterfly species, but rather the condition of having both male and female characteristics. The males of this butterfly species have a green back, yellow abdomen, and some green on their wings. The females have brown on their wings.
Thursday, July 17, 2008
Superclass: Agnatha (jawless fish)
This pacific hagfish (Eptatretus stoutii) was caught offshore from a depth of 600m. Although once thought to be parasitic, these guys are now known to scavenge off dead carcasses. They don't possess jaws, so they tend to rasp the flesh off their meals with their tongue, and tie themselves into knots, to tear chunks off (for an example check out the end of Blue planet's the Deep episode).
They only have a partial cranium and lack vertebrae, which has often led scientists to reclassify hagfish outside of the vertebrata (who all are characterized by a complete skull around their brains). However, developmental processes regulating cranial and vertebral patterns are similar for hagfish and other vertebrates, which lends weight to the idea that hagfish do belong within the vertebrates .
The hagfish is also known by the name slime eels. These guys produce a slime which contains fibrous threads, allowing for major cohesion of the slime wad. Best guess is the slime is a defense mechanism used to clog the gills of the would-be predator. Love puts it best: "Hagfish produce truly gargantuan amounts of slime. We are talking major league quantities here. Your average hagfish can take a bucket full of water and solidify it with slime in a few minutes." Says it all, really.
Thursday, July 10, 2008
Class: Insecta (Hexapoda)
Family: Saturniidae (silk moths)
This is a caterpillar of Samia cynthia, the cynthia moth. It is originally from Asia, but was introduced to the eastern US, when they wanted to start silk farms. It is only one of the moths used to produce silk, and not considered as 'domesticated' as some of the other members of the saturniidae family. I am particularly proud of this picture, because I raised this cynthia from eggs deposited in my classroom (the adults had been bought for the students to look at). It was a super fun experience, as my summer class got to see them grow from little black fuzzy caterpillars to these great honkers about the size of my middle finger. I got to spend a lot of time taking leaves off of the various trees on campus and from my 'garden' to see what they would eat. (When we got the adult cocoons they were labeled with the wrong species name, so I could not just look up their diet on the web) They spun a cocoon during class in the fall, and many of my students would periodically check up on them during class (not bad for a non-majors course!).
Saturday, July 5, 2008
What is more pointy than a sea urchin? In addition to the spines that most people see, sea urchins have small pinchers in between their spines called pedicillaria. The pedicillaria are used to pinch off any creature which tries to settle on them (like barnacles or algae) for a free ride. They can also be used as a defense against predators who aren't deterred by the spines, like sea stars. The urchin will fold down their spines and use the pedicillaria to pinch the sea star's tube feet and stomach.
They also have super pointy teeth. There are five teeth that continuously grow and are held in a structure called Aristotle's lantern. They use these teeth to scrape algae off of rocks, and to form little pockets in the rock where they live. Sea urchins kept in aquariums can cause lots of damage to the acrylic by chewing it up, and if they are kept in a concrete and fiberglass touch tank, they can chew right through it.
Thursday, July 3, 2008
This is some species of christmas tree worm, Spirobranchus sp., found in a coral head in Australia. These worms have a hard calcareous tube, which they can retract into to escape from predators. They can see light and dark, and may retract if a shadow passes over them. The two christmas tree-like plumes are made up of ciliated tentacles which they use to filter out plankton. The cilia sort them by size and the worms only ingest plankton of the correct size. The larvae of these worms preferentially settles on certain species of coral. There are different coral preferences for different Spirobranchus species. A really good online article on them can be found here.