Author:
Mindy Boland
Subject:
Applied Science, Life Science, Biology
Material Type:
Module
Level:
Community College / Lower Division, College / Upper Division
Provider:
Rice University
Provider Set:
OpenStax College
Tags:
  • Ambulacral System
  • Annelid
  • Annelid Anatomy
  • Annelid Morphology
  • Annelida
  • Anthozoa
  • Archenteron
  • Arthropod
  • Arthropod Morphology
  • Arthropoda
  • Biramous Appendage
  • C. Elegans
  • Captacula
  • Cephalothorax
  • Chaetae
  • Chelicerata
  • Clitellum
  • Cnidaria
  • Cnidarian
  • Cnidocyte
  • Coelenteron
  • Coelom
  • Coelomate
  • Conspiral
  • Crustacea
  • Ctenidia
  • Cubozoa
  • Cypris
  • Echinoderm
  • Echinoderm Anatomy
  • Echinoderm Excretory System
  • Echinoderm Morphology
  • Echinoderm Nervous System
  • Echinoderm Reproduction
  • Echinodermata
  • Enterocoelous Coelom
  • Eucoelomate
  • Gemmule
  • Hemocoel
  • Hermaphrodite
  • Hexapoda
  • Hydrozoa
  • Invertebrata
  • Invertebrate
  • Lophotrochozoa
  • Madreporite
  • Mantle
  • Medusa
  • Mesoglea
  • Mesohyl
  • Metamerism
  • Mollusca
  • Myriapoda
  • Nacre
  • Nauplius
  • Nematocyst
  • Nematoda
  • Nematode
  • Nematode Excretory System
  • Nematode Morphology
  • Nematode Nervous System
  • Nematode Reproduction
  • Nemertea
  • Nemertea Digestive System
  • Nemertea Morphology
  • Nemertea Nervous System
  • Nemertea Reproduction
  • Osculum
  • Ostia
  • Oviger
  • Pedipalp
  • Phylum Annelida
  • Phylum Arthropoda
  • Phylum Cnidaria
  • Phylum Echinodermata
  • Phylum Mollusca
  • Phylum Nematoda
  • Phylum Nemertea
  • Phylum Porifera
  • Pilidium
  • Planospiral
  • Planuliform
  • Polyp
  • Porifera
  • Pseudocoelomate
  • Radula
  • Rhynchocoel
  • Schizocoelous Coelom
  • Sclerocyte
  • Scyphozoa
  • Sponge
  • Sponge Locomotion
  • Sponge Metabolism
  • Sponge Morphology
  • Sponge Reproduction
  • Spongocoel
  • Superphylum Lophotrochozoa
  • Trocophore
  • Uniramous Appendage
  • Veliger
  • Zoea
  • License:
    Creative Commons Attribution Non-Commercial
    Language:
    English

    Introduction

    Introduction

    The photo shows a purple and orange starfish on a sandy flat beach.
    Nearly 97 percent of animal species are invertebrates, including this sea star (Astropecten articulates) common to the eastern and southern coasts of the United States (credit: modification of work by Mark Walz)

    A brief look at any magazine pertaining to our natural world, such as National Geographic, would show a rich variety of vertebrates, especially mammals and birds. To most people, these are the animals that attract our attention. Concentrating on vertebrates, however, gives us a rather biased and limited view of biodiversity, because it ignores nearly 97 percent of the animal kingdom, namely the invertebrates. Invertebrate animals are those without a cranium and defined vertebral column or spine. In addition to lacking a spine, most invertebrates also lack an endoskeleton. A large number of invertebrates are aquatic animals, and scientific research suggests that many of the world’s species are aquatic invertebrates that have not yet been documented.