Invertebrates

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10

Slide 90

Insect diversity

Slide 91

Crustaceans

While arachnids and insects thrive on land, crustaceans, for the most part, have remained in marine and freshwater environments.

Crustaceans, subphylum Crustacea, typically have branched appendages that are extensively specialized for feeding and locomotion.

Most crustaceans have separate males and females.

Slide 92

Isopods include terrestrial, freshwater, and marine species

Pill bugs are a well known group of terrestrial isopods

Decapods are all relatively large crustaceans and include lobsters, crabs, crayfish, and shrimp.

Slide 93

Crustaceans

(a) Ghost crab

(b) Krill

(c) Barnacles

Slide 94

Planktonic crustaceans include many species of copepods. These are among the most numerous of all animals

Krill

Slide 95

Barnacles are a group of mostly sessile crustaceans. They have a cuticle that is hardened into a shell.

Barnacles

Slide 96

Concept 33.5: Echinoderms and chordates are deuterostomes

Sea stars and other echinoderms, phylum Echinodermata, may seem to have little in common with phylum Chordata, which includes the vertebrates

Shared characteristics define deuterostomes (Chordates and Echinoderms)

Radial cleavage

Formation of the mouth at the end of the embryo opposite the blastopore.

Slide 97

Fig. 33-UN5

Calcarea and Silicea

Cnidaria

Lophotrochozoa

Ecdysozoa

Deuterostomia

Slide 98

Echinoderms

Sea stars and most other echinoderms are slow-moving or sessile marine animals.

A thin epidermis covers an endoskeleton of hard calcareous plates.

Echinoderms have a unique water vascular system, a network of hydraulic canals branching into tube feet that function in locomotion, feeding, and gas exchange.

Males and females are usually separate, and sexual reproduction is external.

Slide 99

Anatomy of a sea star, an echinoderm

Anus

Stomach

Spine

Gills

Madreporite

Radial

nerve

Gonads

Ampulla

Podium

Tube

feet