Wednesday, March 25, 2009
This little two-spot octopus was only about 2 months old when the picture was taken. He (or she) would be able to fit into VERY narrow spaces, as the only hard part on its body is its beak. An adult two-spot octopus can get up to three feet in length (arm to arm), and has a beak about the size of you pinkie fingernail. This little guy was almost an inch (arm to arm), so I can't even imagine how small its beak is. But I do know that it fit into the most amazingly small spaces to enact its escapes.
This little octo is still going strong at the aquarium, and is about 6 months old at this point. We have had some success in feeding it, even though its diet constantly changes as it grows. Its about 2.5 inches from arm to arm now. Hopefully, we will be able to raise it to adulthood.
Saturday, March 21, 2009
This is a black dorid (Polycera atra) that I caught feeding on some bryozoans I collected for my thesis. I have caught at least four different species of nudibranch (sea slugs) as I am collecting their main food source, but I think this one is my favorite for its coloration. These nudibranchs tend to e a little toxic, as they concentrate the toxins from their food source in their tissues, so the beautiful patterns are used to warn off would-be predators. Some nudibranchs take a different route, and use their coloration to blend in with their food source so well, it is hard to see them even when you look very closely.
Thursday, March 19, 2009
These are grunion (Leuresthes tenuis). Found off the coast of California, these fish breed from March to July. Approximately three days after the full and new moons, these fish throw themselves on the sandy beaches of southern CA to lay their eggs. Any noise causes them to quickly flop back into the ocean.
Females bury themselves upright in the sand, while males lay on top of the sand next to the females. After the eggs are laid in the sand and fertilized, both sexes return to the ocean. The female can lay up to 3,000 eggs on a single night, and will return to the beach each time the tide is right.
Eggs take about 9 days to develop, but won't hatch until the waves from the high tides break them open, about 12 to 14 days later. Here is a picture of the developing eggs at about 6 days of age. You can already see the well-developed eyes.
If you were to look at these eggs under a microscope you can also see small red blood cells flowing through the blood vessels covering the yolk. You can also see the heart beating ( in this video, it looks like the heart is above the eyes). The tail and its associated muscles are also well developed and serve to move the small fish around in its egg.
Thursday, March 12, 2009
This is my favorite annelid. It is called a sea mouse, and from the top it is very difficult to distinguish as a worm as it is covered in seate (or chaete, depending on who you ask). It is not until you take a look at its underside, that you can see the segmentation common to worms, and the parapodia special to polychaetes.
The sea mouse can reach 6 to 8 inches (15-20 cm), and lives on the sea floor in from subtidal areas to moderately deep waters. (This particular sea mouse was caught in a benthic trawl at ~150 ft (50 m). They are active hunters and feed on other polychaete worms.
There is some interest in the optical properties of their seate. The seate projecting from the parapodia are often a copper color, but can turn a bluish-green when see from the right angle (and when not covered in mud). The crystalline formation of the seate is far more efficient in handling light than current man-made optical fibers .
Saturday, March 7, 2009
The following are pictures of (in my opinion) one of the most impressive spaces in all of the US. That is Carlsbad Cavern. The cave system is considered a national monument (like White Sands) and hosts about 110 caves. Carlsbad cavern is the name of both the park and the largest cave in the park. The entrance to the cave is atop a mountain, and the cave extends 750 ft (230 m) down. Once down you enter an amazing space...
These caves were formed by the mixing of hydrogen-sulfide rich waters seeping up from the the base of the mountain and rainwater seeping down. The mixture of these two waters created a sulfuric acid, which ate away at the limestone. You can still see pools of mineral rich waters in the caves.
This is a very unusual mode of cave formation, as most caves form by rain water only eroding the insides. The caves boast an amazing array of decorations: stalactites, stalagmites, columns, and draperies...
The formations are made in the normal way for caves. Rainwater seeping down deposits the mineral it picked up from the surface. Since the cave is now in the middle of a desert, the formations don't grow as fast as they did 10,000 years ago, when it was a woodland area. Here you can see the edge of a massive stalagmite that is still growing, with the area were the water collects and eats away at the surrounding limestone...
The cavern is a most amazing space...
Wednesday, March 4, 2009
This nautilus is a strange but beautiful member of the cephalopod family. Unlike its relatives, the squids, cuttlefish, and octopus, the nautilus has an external shell. It also possesses far more tentacles, (up to 90) that have no suckers or hooks of any sort. The hood on top of the nautilus's head is actually made from tow specialized tentacles, and acts as an operculum, or lid, for the shell.
They don't expend much energy swimming, as they relay on the gas filled chambers to keep them afloat. Because of this, they only need to feed once a month. They hunt small fishes and shrimp in the water column but scent. Although they have eyes, their vision is very poor.
Their eyes are a simple pinhole eye without a lens. The lack of a lens means light and images are not focused well on the retina, and water can actually pass into the inside of the eye!
Sunday, March 1, 2009
As dunes are completely made up of the gypsum, they have beautiful white color.
The dunes in the inner part of the field are much starker. They have few plants, and less animals. There is virtually no water in the dune field, so all animals depend ultimately on the plants for a source of water. With few to no plants present on the inner dunes, animals cannot live there.
This place is very beautiful, and so very odd looking. I highly recommend a trip there. They say that the best time to go is during the early or late parts of the day. In order to take good photos you need some shadows. Additionally, noon can be very hot. However they do have a nature center in the middle of the park, which may be a very pleasant spot to pass midday in.