Animal Characteristics Sponges and Cnidarians Zoology

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 Acoelomates

SPONGES Digestion: NO SYSTEM filter feeders - chooanocytes Excretion: NO SYSTEM Basic diffusion; wastes exit thru osculum Circulation: NO SYSTEM- amoeboid cells Respiration: NO SYS. diffusion-obtain oxygen from water Reproduction: ASEXUAL AND SEXUAL

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

Sponge Body Structures A. Osculum: water exits-part of feeding B. Pore cells (ostia): water enters-part of feeding C. Collar cells:(choanocytes)- line interior, have flagella to filter food from water D. Amoebocytes: carry nutrients from collar cells to body of the sponge E. Spicules- support/skeleton F. Epithelial cells-”skin”-support/protection

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

Three Body Types(Forms) Asconoid- simple- pore cells open directly into sponge Syconoid- more complex- pore cells open into canals Leuconoid- most complex- pore cells open into canals that open into chamber (ex. Bath sponge)

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

Classes Calcarea- spicule made of calcium carbonate- Hexactinellida- glass sponge (spicule-silicon) Demospongia- “people’s sponge”, spicules are spongin (ex. Bath)

Class Calcarea Grantia Small Vase shape Spicules of calcium carbonate Straight or 3-4 rays

Class Hexactinellida Euplectella Spicules Siliceous 6 rays

Class Demospongiae Spongia Spicules Siliceous spongin

Fig. 12.11a

Sponge Reproduction Asexually: Fragments break off and grow into new individuals Buds form from sides of parent sponge, break offnew sponge can grow back missing parts (regeneration) Gemmules: During droughts or cold weather, some freshwater sponges produce internal buds called gemmules. A food-filled ball of amebocytes surrounded by a protective coat made of organic material and spicules

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 are the basic characteristics of Animals? What does the word Porifera mean? What type of structure? provide the skeleton of a sponge? Filter food out of the water? Allows water to exit the sponge? Class Hexactinellida has spicules made of? How do sponges survive without body systems? (Be specific)

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

Cnidarians Phylum Cnidaria: “stinging cell” Hollow gut- (coel) radial symmetry Germ Layers: 2 epidermal gastrodermal NO ORGAN SYSTEMS Segmentation: none Coelom: Acoelomate Movement: sessile or motile Have tentacles- stinging cells found on tentacles

Structures: One body opening (mouth) for food to enter and wastes to exit Gastrovascular cavity: interior cavity where food is digested & nutrients are circulated around the body Nerve net: net of nerves that allow impulses to travel around the body, senses the environment NEMATOCYSTS tentacles that contain stinging cells(cnidocysts) used to capture and poison prey Label the hydra on your notes! http://www.arkive.org/common-jellyfish/aurelia-aurita/video-10.html

Without Body Systems, how do they survive? Nervous: Cephalization absent; Nerve Net-conducts impulses Skeleton: Hydrostatic- water pressure maintains shape Respiration: Oxygen diffuses into body from water Digestion: one body opening for food & wastes Excretion: none Circulation: none Reproduction: asexual and sexual, alternation of generations

Cnidarian Reproduction Asexually: by budding Sexually: in medusa form only, sperm and eggs are released into water (fertilized egg zygotelarvaadult) Thousands of gametes are released at a time

Alternation of Generations: Video: medusa releasing from polyp

Answer the following: Explain why sponges and cnidarians release so many gametes into the water

Cnidarians: Body Forms Polyp: body with tentacles hanging upward Ex: hydra, sea anemone video polyp predation Medusa: body with tentacles hanging downward Ex: jellyfish

Structure:The Polyp and Medusa Stages Epidermis Mesoglea Gastroderm Tentacles Mouth/anus Gastrovascular cavity Mesoglea Gastrovascular cavity Mouth/anus Tentacles Medusa Polyp basal disc: sticky structure at the bottom of polyp ; sessile

Diploblastic - 2 germ layers Epidermis - outer covering (ectoderm) Mesoglea - middle non-living jelly-like layer gastrovascular cavity (endoderm)

Classes of Cnidarians Hydrozoa:fresh water and marine, polyp and medusa present ex. Hydra, man-o-war, Obelia 2. Scyphozoans: cup- large jellyfish ex. box 3. Anthozoans: flower -all marine -polyps only Ex: corals, sea anemone Riches of the sea Video jewel anenome

Class Hydrozoa Freshwater & marine. Medusa and polyp colonies which appear to be one organism-different types of polyps work together to serve the entire colony Ex: Hydra, Obelia, Gonionemus Physalia (portuguese-man-of-war) Asexual repro.-budding. Sexual repro. via gametes

Class Scyphozoa Scyph= “cup” Large- Tentacles up to 70 meters in length All marine Independent medusa forms Lack polyp stage or have for a very short time

Class Anthozoa ANTHO=“flower” All polyps-Medusa stage absent Solitary or colonial Some produce protective skeletons All Marine

Class Anthozoa Sea Anemone

Class Anthozoa Metridium Tentacles Mouth Pharynx Septum Gastrovascular cavity

Symbiosis

Class Anthozoa Corals Protective skeleton of calcium carbonate Polyp retracts when not feeding

Corals Colony of interconnected polyps

Class Anthozoa Meandrina Brain Coral

Class Anthozoa Gorgonia Sea Fan

Class Anthozoa Tubipora Pipe Organ Coral

Class Anthozoa Actinodiscus Mushroom Coral

Class Anthozoa Acropora Staghorn Coral

Coral Reefs Formed over thousands of years from successive layers of coral skeleton deposits (calcium carbonate forms underwater mountains of coral animal skeletons) The underwater equivalent of the amazon jungle- very high species diversity and biomass Reefs contain sponges, colonial hydrozoans, anemones, many varieties of coral, fish, many types of worms we’ve not discussed, not to mention bryozoans, ctenophores, protists, bacteria, etc etc..

Copyright © The McGraw-Hill Companies, Inc Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Coral Reef Ecosystem Photo © McGraw-Hill Higher Education, Barry Barker, Photographer

Coral Reefs 200 C or warmer water; large formations of calcium carbonate laid down by organisms over thousands of years

1. Fringing Reef Less than a quarter of a mile from shore

2. Barrier Reef Runs parallel to shore, has a wider and deeper lagoon

3. Atoll Reef Reef that circles a lagoon of water rather than an island

Here they are together…

Cladogram of Cnidaria Anthozoa Scyphozoa Cubozoa Medusa cuboidal Loss of medusa Hydrozoa Polyp stage reduced Septa divide gastrovascular cavity Radial symmetry, cnidocytes, planula larva

The End

Phylum Ctenophora Characteristics All marine Includes comb jellies Have eight rows of fused cilia called "comb rows" Largest animal to move by cilia Move by beating cilia Lack cnidocytes but have cells sticky cells called colloblasts that bind to prey Colloblasts located on two ribbon-like tentacles Have sensory structure called apical organ to detect direction in the water Most are hermaphrodites (make eggs & sperm) Produce light by bioluminescence

Comb jellies