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     David Sheriff Board Administrator Username: admin Post Number: 319 Registered: 01-2004 |
Notice on the urchin photos you can also see the tube feet as long as the spines. More visible on the darker urchin. I read that the red color in sea hare disturbance discharges is concentrated in a special gland from the red algae they eat. If you only feed them green algae, the discharge isn't red. They produce other secretions derived from their algae diet that are poisonous. Apparently that is how they survive without an external shell. Some point out that the "ink" can't play the same role as it does in the octopus because the hare is so slow. If the capability has been retained, then it must serve a function. If defence related, it could be a warning or it might make the water taste bad, again as a warning. | ||
| Mark Howe Moderator Username: unclemark Post Number: 449 Registered: 08-2003 |
I couldn't resist putting together a script to go with David's slideshow. Stoned urchin. Coralline algae in the upper right and lower left corners, little specks of green sea lettuce lower right. Two wait on the tide Ocher stars and eelgrass. Rock weed and mussels to the right but I don't see any gooseneck barnacles. Small kelp plants may be juvenile sea palm or feather boa with Agar weed and miscellaneous other algae to the right Red seed pod. Coralline algae to the left, agar weeds upper right, juvenile feather boa lower right and bottom. Sand. Sandcastle worms. If you see these when the tide is in, each little pore has the lavender blue tentacles of a feather duster worm hanging out, filtering the water for food. Sanded. Anemone. The large green ones have chlorophyll bearing critters coexisting inside their bodies. Since this one is white, it either has been in the shade for a while or it's a different kind of Anemone. Red branches. Lots of different kinds of red algae with bits of sea lettuce mixed in. Beautiful photo. Young tidepool sculpin. Very well camouflaged. If you can pick out the V-shaped white marking on the back, it is pointing towards the head. Purple urchins. Green Anemone to the right with all of its chlorophyll bearing critters. A fragment of a red Gorgonian coral whip washed in with the waves. Mussels waiting. Yes they are, and so are the barnacles at the top. A Barnicle is a kind of shrimp like creature that begins life by cementing its head to a rock, building a protective shell, and then spending the rest of its life kicking the food into its mouth with its legs. It's fascinating to watch barnacles when the waves come in as their lightning fast legs sweep out for food. Little predator feet. Ocher star even though it's more of a wine color. It's predator feet are tubular hydraulic jacks that can exert tremendous forces on the shells of the critters they are trying to open. Once there is an opening, his stomache comes out of his body and into the prey to digest him on the spot. Upper left is a colonial Anemone protecting itself from the low tide with little bits of shell and sand. There are two others in the picture; can you spot them? The carnivorous snail lower left is probably attacking some poor Barnicle or shellfish. Nicked limpet. Owl limpet is the big one with smaller limpets and periwinkle snails in the crevice. The little limpets may be baby owls or other species. Young sea hare. Grazing. He squirts purple when tickled between the flaps covering the gills on his back. These guys grow from the size of the head of a pin to a small football in one year, then lay masses of eggs in chains and then die. They wash up on the beach looking like huge black hunks of tar. But they don't smell like tar. They copulate in daisy chains. :-) Giant keyhole limpet. The black covering around the edges is the mantle that secretes the shell. It's not always black and sometimes can't be a blotchy brown. The foot is bright orange in various shades. It comes under the category of "good to eat but not very". In other words you would have to be pretty hungry, but they are meaty. Eelgrass. Yes. And coralline algae. Colored coat. The coralline algae are constructed of a lime or calcium carbonate based substance. The red lavender encrustation on the rock is also an algae called an encrusting algae and is hardened with the lime. The deep red encrusting algae is soft and does not contain the lime. Anemone with stone. Tentacles with stinging cells are waiting for prey. Not only does the chlorophyll produce food, captured prey helps as well. Beautiful colors from the encrusting algae are sometimes enhanced with red sponge or colonial tunicates upper right. My stock is showing. Colonial Anemone. At low tide colonies of these guys will cover themselves with bits of shell and sand for protection. They are hard to see because of the, camouflage, but if you poke them with your finger they will squirt you. The water is held inside the body to keep them from drying out during a low tide. Note the coralline algae lower right showing frost damage. Wetter bolt. And a sea lettuce patch. Please clean this bolt. Very hard to see; 3c. | ||
| David Sheriff Board Administrator Username: admin Post Number: 316 Registered: 01-2004 |
This link will take you to the photos I made on our trip February 8. I have photos of four bolts, which is all I remember finding. However, you will have to rely on your memory or notes to figure out which bolt is which. I could figure out the sequence in which they were taken if I had to. If the bolts are hard to find in the photos, they are in the exact center of the shot. picassa tidepool 90208 photos | ||
| Mark Howe Moderator Username: unclemark Post Number: 357 Registered: 08-2003 |
Phylogeny; primarily for intertidal Read the sections in the Marine Biology book. Particularly pg. 150 Porifera – primitive, undifferentiated cells spongy, colorful, primitive, smelly Cnidaria – stinging cells medusae vs polyp Siphonophore Jellyfish, anemone, hydroid Mollusca gastropod, ; snails and slugs, seahare pelecypod, ; clams, mussels cephalopod Echinodermata – spiny skin starfish, urchins, cucumbers Annelida – segmented worms Polychaetes "worms with many hairs" Arthropoda – jointed, exoskeleton Crustaceans barnacles, shrimp, crabs plankton: copepods, amphipods, Urochordata [chordates] Tunicates Bryozoa – moss animals | ||
| Mark Howe Moderator Username: unclemark Post Number: 346 Registered: 08-2003 |
Low tides for Feb: Wed 2/6 1500 -1.1 Pres. Weekend Sun 2/17 1320 -1.2 Mon 2/18 1400 -1.3 *Best opportunity Tues 2/19 1430 -1.3 I recommend we plan for Mon 2/18; meet at the Ocean Institute at 1300. Next opportunities are March: Wed 3/5 1400 -.8 Sun 3/16 1300 -.7 Mon 3/17 1400 -.8 These dates will work for individual investigations but not so well for a class meeting. |
