Zoology · Ch 11 — Organisms and Population
Mutualism
Mutualism
Mutualism, scored (+, +), is the interspecific interaction in which both participating species come away better off. Ecologists distinguish facultative mutualism, where each partner is still capable of surviving independently outside the relationship, from obligate mutualism, where the continued existence of one or both partners actually depends on the relationship continuing. Classic examples include the bacteria living in the caecum and intestine of herbivores, which help digest cellulose while the host in turn supplies them a favourable living environment; the cross-pollination of flowers by insects and birds seeking nectar and pollen, which is agriculturally vital; small birds that clean debris from the teeth of crocodiles, gaining an easy food source while the crocodile's mouth is kept clean; and the hermit crab that carrie …
What this figure shows. A two-part illustration of mutualistic partnerships. In the first part, a hermit crab is shown carrying a sea anemone attached to its adopted shell, with the anemone's stinging tentacles drawn extended outward, illustrating how the crab gains protection from predators through the anemone's sting while the anemone itself is carried to new feeding grounds and shares in the crab's food scraps. In the second part, a crocodile is shown with its jaws open and a small bird perched inside or near its mouth, illustrating a cleaning partnership in which the bird removes and feeds on debris from the crocodile's teeth while the crocodile benefits from having …