Symbiotic Relationships Biology: Ecology Unit

Symbiosis A close, long term relationship between two organisms of different species.

Types of Relationships Predator-Prey Mutualism Parasitism Commensalism

Predator - Prey A predator is an organism that eats another organism. The prey is the organism which the predator eats.

Examples Predator and Prey relationships Animal - Animal lion and zebra bear and fish fox and rabbit Animal – Plant Bear and berries rabbit and lettuce grasshopper and leaf.

Predator – Prey Environment The prey is part of the predator's environment. The predator dies if it does not get food, so it evolves whatever is necessary in order to eat the prey: Speed Stealth Camouflage (to hide while approaching the prey) Good sense of smell, sight, or hearing (to find the prey) Immunity to the prey's poison, poison (to kill the prey)

Predator – Prey Environment The predator is part of the prey's environment. The prey dies if it is eaten by the predator, so it evolves whatever is necessary to avoid being eaten: Speed camouflage (to hide from the predator) Good sense of smell, sight, or hearing (to detect the predator) Thorns Poison (to spray when approached or bitten)

Symbiotic Relationships Three types of symbiotic relationships Mutualism Parasitism Commensalism

Mutualism Two different organisms benefit each other. + / + relationship Examples: Oxpecker (bird)/ zebra Bird gets food by eating the parasites on the zebra Zebra gets rid of the parasites on its body. Bee / flower Bees fly from flower to flower gathering nectar, which they make into food Bees get pollen on their bodies and fly from flower to flower pollinating the plant

Parasitism One organism, the parasite, lives off of another organism, the host, harming it and possibly causing death. The parasite lives on or in the body of the host. It will not kill it because it needs the host for survival. + / - relationship Examples: Tapeworms attach themselves to the insides of the intestines of animals such as cows, pigs, and humans. They get food by eating the host's partly digested food, depriving the host of nutrients. Fleas harm their hosts, such as dogs, by biting their skin, sucking their blood, and causing them to itch. The fleas, in turn, get food and a warm home. Parasitic plants can attach to other plants. Mistletoe attaches to trees, cutting off nutrients and causing it to die.

Commensalism Flowers / tree One organism is benefitted and the other organism does not benefit or is harmed. + / 0 relationship Examples: Cattle / egret (bird) Cattle walks around in pasture stirring up worms and insects for the egret to eat. Cattle is not affected by sharing the pasture with the egret. Flowers / tree Some flowers grow up high on the tree to reach the sunlight. Tree is not affected by these flowers growing up the tree.

Review A predator is an organism that eats another organism. The prey is the organism which the predator eats. Mutualism is the relationship when both organisms benefit. Parasitism is the relationship when one organism is benefitted and the other is harmed. Commensalism is the relationship where one organism benefits and the other organism is neither harmed or benefits.

Sources: http://necsi.edu/projects/evolution/co-evolution/pred- prey/co-evolution_predator.html http://necsi.edu/projects/evolution/co- evolution/mutualistic/co-evolution_mutualistic.html http://necsi.edu/projects/evolution/co- evolution/parasites/co-evolution_parasite.html Google Images