Laboratory Studies for Animal Diversity

Coral reefs are among the most diverse ecosystems on the planet; the reefs of the Raja Ampat Islands in Indonesia have over 500 coral species and 1300 fish species. The integrity of this complex ecosystem often depends on a balance of organisms. Damselfishes are one of the largest groups of reef fishes, both in number of species and total individuals. This group, which includes the orange-and-white anemonefishes, includes many attractive species that are popular among aquarium keepers. Many damselfishes are tightly linked to reef ecosystems, requiring live coral for food or shelter. Some damselfishes, like the blue-green damselfish (Chromis viridis) shown on the cover, consume zooplankton. Many are herbivorous, grazing on algae. Herbivorous damselfishes create dense patches of algae by killing the polyps of coral, which encourages mats of algae to grow on the coral skeletons. These "gardens" of algae, which provide habitat for many small invertebrates, are maintained and vigorously defended by the damselfises. One species is known to "weed" its gardens, selectively removing less desirable algae. Normally, herbivorous damselfishes do little harm to reefs, because their populations are kept in check by larger, predatory fishes. Unfortunately, the predators are highly prized by anglers; predatory fishes have severely declined in many locations from overfishing. Decline of predatory fishes subsequendy allowed populations of "gardening" damselfishes to increase, jeopardizing the health of coral reefs. Scientists and the public continue to be fascinated by the complex behaviors of damselfishes, many of which are still being discovered.

PART ONE
ACTIVITY OF LIFE

EXERCISE 1
Ecological Relationships of Animals 2

EXERCISE 2
Introduction to Animal Classification 7

PART TWO
THE DIVERSITY OF ANIMAL LIFE

EXERCISE 3
The Microscope 20

EXERCISE 4
Protozoan Groups 28

EXERCISE 5
The Sponges 54

EXERCISE 6
The Radiate Animals 63

EXERCISE 7
The Flatworms 79

EXERCISE 8
Nematodes and Four Small Protostome Phyla 96

EXERCISE 9
The Molluscs 108

EXERCISE 10
The Annelids 123

EXERCISE 11
The Chelicerate Arthropods 138

EXERCISE 12
The Crustacean Arthropods 145

EXERCISE 13
The Arthropods 157

EXERCISE 14
The Echinoderms 177

EXERCISE 15
Phylum Chordata 193

EXERCISE 16
The Fishes 202

EXERCISE 17
Class Amphibia 221

EXERCISE 18
The Nonavian Reptiles 238

EXERCISE 19
The Birds 243

EXERCISE 20
The Mammals 246