Relationships in Nature

BIO108

Symbiosis

• Living together• A partnership• Two different species• Both partners benefit

– mutual benefit

Animal Kingdom

• Nile crocodile & crocodile bird

• Hermit crab & sea anemone

• Buffalo & oxpecker

• Shark & remora fish

Crocodile & Bird

• Nile crocodile– Usually eats animals– Allows bird to walk around its mouth

• Crocodile bird– Cleans parasites in croc’s teeth– Removes and eats scraps of food– Eats harmful leeches and parasites

Hermit Crab & Sea Anemone

• Hermit crab– protects the crab

• Sea anemone– Gets leftover food

http://www.ms-starship.com/sciencenew/symbiosis.htm

Buffalo & Oxpecker

• Buffalo– Lets the bird eat

• Oxpecker– Eats ticks and other parasites off skin– Warns buffalo of danger

http://www.pbs.org/wnet/nature/enemies/partners.html

Shark and Remora Fish

• Shark– Lets the fish eat

• Remora Fish– Eats parasites– Gets the shark’s leftovers

Lichen

• Slow growing plants

• Partnership: fungi & algae

• Neither could live alone

Relationships

• Phoresis• Commensalism• Mutualism• Parasitism

Phoresis

• Loose association

• One organism is smaller than other

• Larger organism used for transport

• Dung beetles and cow dung

Commensalism

• “eating together at the same table”• Only one member benefits

– sharing space, defense, shelter, food

• Neither will die if relationship is ended

• Shrimp & sea cucumber

http://www.ms-starship.com/sciencenew/symbiosis.htm

Mutualism

• Both organisms derive mutual benefit• Intimate and obligatory• Neither can survive without the other• Example – host and parasite

• Tickbirds and rhinos• Clownfish & sea anemone

Parasitism

• Not symbiotic• Causes harm to host