Lamine Diakite
Mr. Meek
AP Biology
October 7, 2012/MHSIS
By: Lamine Diakite, and Rahim
ROLY-POLIES
Figure 1: The left image show the shape of pillbugs when threatened and the right image show the shape of pillbugs while in movement.
Abstract
If pillbugs are allowed to move freely for ten minutes when equally placed on both sides of sand/rock choice chamber, then most will be found on a rock side. For the first experiment the rock was placed on one side of a choice chamber and sand on the other. Then seven pillbugs was equally placed in each choice chamber. After looking for their favorable habitat; pillbugs moved to the rocky environment instead of the sandy one. This shows that pillbugs prefer a rocky environment which favored them to escape from the choice chamber. In the second experiment the same procedure was replicated expect that the amounts of rocks was reduced to minimize the chance of pillbugs to escape. In the wet/dry experiment, the pillbugs preferred the moist environment rather than the dry one because they breathe through gills.
Introduction
Pillbugs range in size from ¼ to ½ inch long and are dark to slate gray (2). Their oval, segmented bodies are convex above but flat or concave underneath (1-2). They possess seven pairs of legs and two pairs of antennae (only one pair of antennae is readily visible) (1-3). The pillbugs are known as roly-polies, because of their ability to roll into a ball when threatened and for protection against predators such as spiders, ants, birds, and amphibians (3). They also have glands that make defensive chemicals. Their nocturnal habitat probably helps them avoid some predators too (3). The pillbugs live in wet locations. They are found under damp object or in inorganic garbage. If pillbugs enter a building, they will often dry out and die. This is because pillbugs breathe through gills (1). Pillbugs use gill-like structures to exchange gases (1). They require moist environments to breathe, but cannot survive being submerged in water. The way pillbugs communicate is so amazing. They have poor vision, and probably communicate chemically (3). (Next page)-
Pillbug’s mother carries their eggs in a pouch (1-3). Like crabs and other crustaceans, pillbugs tote their eggs around with them. Overlapping thoracic plates form a special pouch, called a marsupium, on the pillbugs underside (1). Upon hatching, the tiny juvenile pillbugs remain in the pouch for several days before leaving to explore the world on their own. Pillbugs grow by molting a hard exoskeleton (1-3). First the back half of its exoskeleton splits away and slides off. A few days later, the pillbugs sheds the front section. Pill bugs mostly eat rotting vegetation like vegetables and they graze on algae, fungus, moss, bark, and all kinds of decaying plant and animal material (2-3). Pillbugs also eat their own poop because each time they poop they lose a little copper, an essential element it needs to live (1). In order to recycle this precious resource, the pillbug will consume its own poop, a practice known as coprophagy (1). Pillbugs drink water through their rear ends (1). They have an amazing ability to tolerate ammonia gas, which they can pass directly through their exoskeleton. So, there is no need for pillbugs to urinate (1).
Like other animals, pillbugs can contract viral infections. If you find a pillbug that looks bright blue or purple, it’s a sign of an iridovirus (1). Even though pillbugs get sick; they do not spread diseases or contaminate food (1-2). To prevent pillbugs from living in your home and the area around your home, you must keep your home clean and dry (1-2). A pillbug’s blood is blue (1) .Many crustaceans, pillbugs included, have hemocyanin in their blood. Unlike hemoglobin, which contains iron, hemocyanin contains copper ions. When oxygenated, pillbug blood appears blue (1). Do pillbugs mainly prefer a rocky or sandy environment? If pillbugs are allowed to move about freely for
