Invertebrates 1 Sponges

Home , Acoela, Acorn worm, Ecdysozoa, Lophophore, Loricifera, Rotifer

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Figure 25.10

Cnidarians

• Diversity of invertebrates Echinoderms – fossil record Chordates

• Lophotrochozoa Molluscs – Annelids Arthropods – Molluscs PROTEROZOIC PALEOZOIC Ediacaran Cambrian 635 605 575 545 515 485 0 Feb 20, 2013 Time (millions of years ago)

Figure 33.3a Figure 33.3b Porifera (5,500 species) Placozoa (1 species) Platyhelminthes Ectoprocta Rotifera Brachiopoda (20,000 species) (4,500 species) (1,800 species) (335 species) 0.5 mm

A brachiopod

A sponge 0.1mm A marine flatworm Ectoprocts A rotifer (LM) Cnidaria (10,000 species) Acanthocephala Nemertea Cycliophora Annelida (16,500 species) A placozoan (LM) (1,100 species) (900 species) (1 species) Curved Ctenophora (100 species) hooks

A jelly 100 µm Acoela (400 species) An acanthocephalan (LM) A cycliophoran (colorized SEM) A marine annelid Mollusca A ribbon worm (93,000 species)

1.5 mm Acoel flatworms (LM) A ctenophore, or comb jelly An octopus Lophotrochozoa

Figure 33.3c Figure 33.3d Loricifera (10 species) Priapula (16 species) Onychophora (110 species) Hemichordata Chordata (85 species) (52,000 species) 50 µm

A tunicate A loriciferan (LM) A priapulan An onychophoran Echinodermata (7,000 species) Nematoda Tardigrada Arthropoda (25,000 species) (800 species) (1,000,000 species)

100 µm An acorn worm

A roundworm (colored SEM)

Tardigrades Ecdysozoa A scorpion (an arachnid) Deuterostomia (colorized SEM) A sea urchin

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Fig. 32-11 “Porifera” Silicea Metazoa

Calcarea ANCESTRAL

COLONIAL Ctenophora FLAGELLATE Eumetazoa For common invertebrates (eg. Cnidaria jellyfish, spider, sea urchin, etc) you Acoela

Deuterostomia Echinodermata should know which phylum it is in and Bilateria Chordata how that fits in the general

Platyhelminthes

Lophotrochozoa Rotifera phylogenetic classification of animals. • Ectoprocta Why is “porifera” in Brachiopoda quotation marks? Mollusca Annelida Ecdysozoa Nematoda

Arthropoda

Figure 33.4b

For each major group, you Choanocyte should know:

• What is the basic body plan?

• What are the life stages or Pore developmental stages? Spicules

Epidermis • How does it eat? Water flow • How does it move? Amoebocytes

Figure 33.4c Figure 33.UN02

Porifera Eumetazoa Eumetazoa Food particles Cnidaria in mucus Flagellum Lophotrochozoa Choanocyte Collar Ecdysozoa Deuterostomia

Phagocytosis of food particles Amoebocyte

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Figure 33.5 Figure 33.6

Mouth/anus Tentacle Tentacle Cuticle of prey Gastrovascular cavity Thread Gastrodermis

Mesoglea Nematocyst Body “Trigger” stalk Epidermis

Tentacle Thread Mouth/anus discharges Polyp Medusa

Thread (coiled) Cnidocyte

Figure 33.8-3 Figure 33.UN03

Porifera

Feeding Cnidaria polyp Bilateria Lophotrochozoa MEIOSIS Ecdysozoa Medusa Egg Sperm Deuterostomia SEXUAL ASEXUAL REPRODUCTION Portion REPRODUCTION of a (BUDDING) colony FERTILIZATION of polyps Zygote Planula (larva)

Key Haploid (n) 1mm Diploid (2n)

Figure 33.10 Figure 33.14a

Gastrovascular cavity

Mouth

Eyespots Lophophore Ventral nerve cords

Ganglia (a) Ectoprocts, colonial lophophorates

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Figure 33.17 Figure 33.15

Nephridium Heart Visceral mass Digestive tract Coelom Intestine Gonads Mantle

Mantle Stomach cavity Shell Mouth Radula Anus (a) A land snail Gill

Mouth Radula Foot Nerve Esophagus (b) A sea slug (nudibranch) cords

Figure 33.20 Figure 33.24 Cuticle Coelom Coelom Epidermis Hinge area Mantle Gut Heart Adductor muscle (one or two) Metanephridium Digestive gland Anus Anus Mouth Chaetae Excurrent Intestine siphon Skin

Fused nerve cords

Clitellum

Crop Shell Intestine Giant Australian earthworm Palp Water flow Gizzard Foot Cerebral Mantle Incurrent ganglia Ventral nerve cords Gonad Gill siphon cavity Mouth Circulatory with segmental ganglia system vessels

Figure 33.UN06a