Planaria

We did an awesome lab with planaria! We got to see them with microscopes and with our bare eyes. Then we gave them egg yolk to eat and got to see them eat. The planaria senses the food with chemoreceptor cells.The planaria eats by wrapping its body around the prey, sliming it, and then sticking out its mouth tube and sucking on the prey. The planaria does not have eyeballs but eyespots that can only see light and dark. What do you know about planaria? (by Mika A)

Cross-Eyed Creature

In class, we are doing a unit when we look under a microscope at a series of living organisms and do labs on those organisms. One of those organisms that I am going to be focused on most is the planaria. The planaria has a rather odd appearance. It has a spear shaped head and has two eyespots that aren’t like our eyes at all. The planaria’s eyespots just can detect the change of dark to light. Also, it’s eyespots appear to be crossed. The planaria’s color changes with what type of food it eats, but most commonly it is brown. The way a planaria eats its food is really odd. The planaria’s mouth is in the middle of the underside of the planaria’s body and whenever they want to eat, they have to latch on to their prey, cover it in slime, and then they pump out their mouthtube from their body and start to eat. Look at the picture and tell me your favorite feature or fact about the planaria. (by Owen A.)

Bears in Maine

During the election this past week, one of the topics you could vote about was bear baiting. Bear baiting is a way of luring bears with food and an attempt to reduce or even out the bear population. Some people think that bear baiting is a cruel way to reduce the population, but it does help keep bears under control. All of the other states have successfully controlled bears, so maybe Maine doesn’t need bear baiting. If the bear population goes up then, the salmon and the tree squirrel population would decrease because they are prey of the bear. If the bear population decreased then the salmon, tree squirrel and many other populations would increase. This connects to our science class because we have been talking about food webs. The reason people try to control the bear population is because otherwise like we learned in class it will change the whole food web. If you could vote what would you vote on bear baiting? (by Ben A)

Why Northern Shrimp are in Trouble

  In our last quarter, we talked about food webs, food chains, and population fluctuations. It reminded me that this past summer in Georgetown, I heard that there was a ban on shrimping in Maine because the population of the organism was too low. Apparently fishermen over fished over the last several years so the shrimp population plummeted. The northern shrimp feeds upon phytoplankton whose population has also gone down due to warmer waters. It also feeds upon small ocean invertebrates. The natural predators of northern shrimp are larger fish and seabirds. The natural predators are not the problem. The problem is that the natural predators of the shrimp have been overtaken by the human fishermen, who have overfished and depleted Maine’s shrimp population. The good news is that a regulatory agency has banned shrimping so that the little crustaceans can reproduce and bring their population back up to acceptable levels. Here is a link to a site that helped me learn more about the northern shrimp: http://www.asmfc.org/species/northern-shrimp        (by Joey A-M)