Invertebrates Part 1 Phylum Porifera: Sponges April Adams Zoology

Zoology Standards SZ2. Students will explain the evolutionary history of animals over the geological history of Earth.   a. Outline the geological history of Earth and discuss the major environmental changes that have occurred over time. c. Describe the fossil record of the animals including discussing the Cambrian Explosion and major extinction events. SZ3. Students will compare form and function relationships within animal groups (clades) and across key taxa. a. Explain the similarities and differences among major body plans (e.g., asymmetry, radial and bilateral symmetry). SZ4. Students will assess how animals interact with their environment including key adaptations found within animal taxa.   a. Discuss morphological and physiological adaptations relative to ecological roles. b. Relate animal adaptations, including behaviors, to the ecological roles of animals. c. Explain various life cycles found among animals (e.g., polyp and medusa in cnidarians;

Hypothesis of Multicellularity Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Hypothesis of Multicellularity

Characteristics of Animals 1. Multicellular, eukaryotes 2. Heterotrophs 3. Cells w/out cell walls, many have specialized functions 4. Usually have a method of movement 5. Most reproduce sexually 6. Require oxygen

Describe the Body Plans of Animals 1. Symmetry: balance in body proportions a. Asymmetrical:have irregularly shaped bodies, no symmetry

b. Radial symmetry: can be divided along any plane to produce 2 halves which look alike c. Bilateral: can be divided only one way to produce mirror image halves Radial Bilateral Symmetry Posterior end Dorsal Ventral Planes of Symmetry Anterior end Planes of symmetry

2. Body arrangements: a. anterior: head region b. posterior: tail region c. dorsal: back or top d. ventral: abdomen or bottom

Sponges: Phylum Porifera (“pore bearer”) Simplest of all animals Assymetrical Sessile filter-feeders whose bodies have many pores Obtain oxygen by filtering water No nervous system or organ systems No tissue organization- 2 cell layers Blue World:Sponges Sponge Intro Video

SPONGES Digestion: filter feeders - choanocytes Excretion: Basic diffusion; wastes exit through osculum Circulation: amoeboid cells Respiration: diffusion-obtain oxygen from water Reproduction: ASEXUAL AND SEXUAL

The Anatomy of a Sponge Outer epithelial layer jellylike middle layer ( amoeboid cells and spicules) Spongocoel- inner cavity lined with choanocytes Water flow Osculum Choanocyte Central cavity Spicule Pore cell Pore Pores Epidermal cell Amoeboid cell Section 26-2

Simple Sponge Morphology Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Simple Sponge Morphology

Sponge Reproduction Asexually: Fragments break off  grow into new individuals Buds form from sides of parent sponge, break offnew sponge can grow back missing parts (regeneration) Sexually: Hermaphrodites: produce both eggs and sperm Gametes are released into water (external fertilization)larva swim to new area

Lifestyle and Importance Aquatic- mostly marine sessile as adults with free living larva Importance- As filter feeders, they clean water in ecosystem Large sponges filter 1500 liters/day

Precambrian Before 670 MYA Porifera Platyhelmithes Mollusca Arthropoda Echinodermata Hemichordata Cnidaria Nemertea Annelida Lophophores Chordata Precambrian Before 670 MYA Protozoans

How much did your brain “sponge” in? What does the word Porifera mean? Do sponges have cells? Do sponges have tissues? How do sponges survive without body systems? (Be specific) How do they asexually reproduce? How do they sexually reproduce? When did they show up in the fossil record?