Chap 31 SM 19 - Sponges, Cnidarians, Ctenophores, and Protostomes PDF

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Sponges, Cnidarians, Ctenophores, and Protostomes...

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Chapter 31: Sponges, Cnidarians, Ctenophores, and Protostomes Learning Objectives After reading the associated assignment in the textbook, attending lecture, and/ or attending the accompanying laboratory and recitation, you should be able to: 1. Describe the distinguishing features, cells, and structure of sponges [Poriferans] (remembering/understanding) 2. Name and describe three groups (classes) and the three body forms of sponges (remembering/understanding) 3. Name and describe the three types of sponge skeletons which are also used as class names (remembering/understanding) 4. Describe the distinguishing features and structure of phylum Cnidaria (remembering/understanding) 5. Describe the structure and function of a cnidocyte (remembering/understanding) 6. Name and describe the two body forms and four classes of cnidarians (remembering/understanding) Lophotrochozoans 7. Describe the general characteristics of lophotrochozoans and name the associated phyla . (remembering/understanding) See note below this cladogram in the outlines below. 8. Identify distinguishing characteristics of Phylum Platyhelminthes (flatworms) (remembering/understanding) 9. Name and give examples of the four classes of Phylum Platyhelminthes. Name, describe features and characteristics of Class Turbellaria (remembering/understanding) 10. Name, describe features and characteristics of Phylum Mollusca (remembering/understanding) 11. Name, describe features and characteristics, and give examples of the three main classes of Phylum Mollusca (remembering/understanding) [Also see slide 11 and lab materials.] 12. Identify distinguishing characteristics of annelids (Phylum Annelida) (remembering/understanding) 13. Name, describe the features and characteristics, and give examples of the three main groups (classes) of annelids (remembering/understanding) Ecdyzoans 14. Describe general characteristics of ecdyzoans and name the associated phyla (remembering/understanding)

15. Describe distinguishing characteristics of Phylum Nematoda including sexual dimorphism (remembering/understanding) 16. Name, describe, and give examples of parasitic nematodes (remembering/understanding) 17. Describe general characteristics of arthropods (remembering/understanding) 18. Name, describe the features and characteristics, and give examples of the associated subphyla and classes of arthropods (remembering/understanding)

Some New Words the rings seen on the surface of some organisms such as leeches or earthworms Auricle an ear-like flap that is involved in chemical detection and not sound reception Bivalve organisms that have two connected halves to the shell such as clams, each half is called a valve Cephalic having a head Cnidocyte a specialized cell found in cnidarians that is used in feeding and protection Medusa one of two body forms of cnidarians (jellyfish form) Nerve net a net-like formation of nerves that both conduct and Polyp one of two body forms of cnidarians Definitive host organism in which the parasite passes through sexual development, site of sexual reproduction Dioecious having separate males and females Eumetazoa animals that developed true tissues Eyesot a light sensing structure that lacks a lens so not thought to form an image Gastrovascular cavity a central cavity in which digestion occurs, it has a mouth only and no anus Hydrostatic skeleton a fluid filled compartment upon which muscles contact and produce movement in animals Intermediate host organism in which the parasite passes through the asexual stage of development, site of asexual reproduction Mantle a sheet of epithelial tissue that covers the visceral mass (internal organs) in mollusks Monoecious having both male and female reproductive structures on the same organism Platyhelminthes phylum containing the flat worms Parazoa animals that did not develop true tissues - sponges Poriferans phylum containing the sponges Amoeboid cell gives rise to all cells and the skeleton of a sponge, also transport food Choanocyte a flagellated “feeding cell” found in sponges, also called collar cell Osculum opening by which water flows out from the central cavity (spongocoel) of a sponge Mesohyl gelatin-like layer between the two surfaces of a sponge Spicule a supporting skeletal spike in sponges (may be protein, silica, or calcium carbonate) Spongocoel a centrally located cavity in a sponge (not involved in digestion) Proglottid individual body segment of cestodes, tapeworms Protonephridia one of several types of structures that function in osmoregulation, it has flame cells with cilia on the internal end where the fluid is collected from the interstitium Radula a belt of teeth (chiton) in the mouth of some mollusks, used to scrape the substrate or make a hole in a shell Scolex the anterior end of a cestode (tapeworm) on which the holdfast structures (attachment structures) used to attach to the host’s intestine are located Septum(a) a dividing “wall” such as the tissue dividing the individual segments of an earthworm Annulus(i)

a stiff hair-like structure, bristle, it can be found on the outside of the individual segments of an earthworm Syncytium (syncytial epidermis) a multinucleated cell arising from the fusion of individual cells or the specialize connection via gap junctions as seen in the heart muscle for example Visceral mass internal organs Seta(e)

Slide Evolutionary relationships between clades

Chapter 31: Sponges, Cnidarians, and Protostomes Objective 1: Describe the distinguishing features, cells, and structure of sponges [Poriferans] (remembering/understanding

Slide Phylum Porifera – the sponges Sponge cells and cell function Porocytes _` Choanocytes _very similar to choanoflagellates, also known as collar cells

multicellularity

Slide Amoebocytes _`

Slide Other sponge features Spongocoel __water filed central cavity Osculum _open end of the sponge Mesohyl _between external and internal surface Skeleton __` Monoecious (hermaphrodite) _`one organism produces both gametes Objective 2: Name and describe three groups (classes) and the three body forms of sponges (remembering/understanding) No slide Canal systems and body forms Asconoid Water flows through porocytes into spongocoel lined with choanocytes and out osculum Synconoid Water flows through porocytes along canals lined by choanocytes and out osculum

Leuconoid Water flows through porocytes into feeding chambers lined with choanocytes and out multiple oscula

http://www.auxbulles.com/decouverte-biologie-spongiaires.html

Objective 3: Name and describe the three types of sponge skeletons which are also used as class names (remembering/understanding) No slide Sponges have skeletons in mesophyll Calcarea calcium carbonate Hexitinellida (glass sponges) Silica Demospongia (composition varies) spongin (collagen protein) silica both neither one

Eumetazoans Radiata Objective 4: Describe the distinguishing features and structure of phylum Cnidaria (remembering/understanding) Objective 5: Describe the structure and function of a cnidocyte (knowledge/comprehension) Slide

Cnidocytes __specialized epithelial cell, cell defines phylum Cnidocyte structure Nematocyst _fluid filled, extends a thread when discharged Operculum __`cover (lid) Cnidocil __`trigger Discharge process __when stimulated by an outside force, it fires like a gun

tissues multicellularity

Slide Cnidarian tissues Epithelium __`tissue covering body surface Endothelium __`gastrodermis Diploblastic __`two tissue layer

Slide Other cnidarian features Clade radiate (radial Symmetry) __` Gastrovascular cavity _functions in digestion, single opening (mouth and anus) Mesoglea _jelly-like layer, between endoderm and ectoderm Nerve net connect sensory cells in the body wall to the contractile cells and gland cells Hydrostatic skeleton created by the epidermis and gastrodermis cells, support the body and allows movement, fluid in gastrovascular cavity

Objective 6: Name and describe the two body forms and four classes of cnidarians (remembering/understanding)

Polyp

Medusa

No slide Cnidarian classes Hydrozoa Polyps Scyphozoa Jellyfish Anthozoa Flower animals Corals, anemones Cubozoa Box jellyfish

Class Cubozoa (box jellyfish)

Protostomes Bilateria Lophotochozoa Objective 7: Describe the general characteristics of lophotrochozoans and name the associated

phyla (remembering/understanding) Slide 9

Ancestral featurs Multicellularity Tissues (three tissue layers) [ectoderm, mesoderm, endoderm] Triploblastic Bilateral symmetry Protostomic development Other features vary with class The Phyla Platyhelminthes, Mollusca, and Annelida all have these features No slide previously discussed

Objective 8: Identify distinguishing characteristics of Phylum Platyhelminthes (flatworms) (remembering/understanding)[Also see lab materials.] Slide Additional features of Phylum Platyhelminthes [Also see cladogram above and ancestral features noted below it.] Acoleomate _having no body cavity Organ level [No organs for circulation or gas exchange.] __`chemoreceptors, reproductive structures, only tubellarians have sense organs, no organs for circulation or gas exchange Simple nervous system _brain consists of two masses of nervous tissue called ganglia in the head reagion Gastrovascular cavity (digestion) _`as in cnidarians, digestion

Objective 9: Name and give examples of the four classes of platyhelminthes. Name, describe features and characteristics of class turbellaria (remembering/understanding) No slide

Four classes of platyhelminthes Free living flatworms Turbellaria (only free-living flatworms) - planarian observed in lab

Parasitic flatworms Trematoda (flukes)

Monogenea (flukes) Cestoda (tapeworms) [observed as slides in lab] NOTE: This class is referred to as the segmented flat worms.

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Objective 10: Name, describe features and characteristics of Phylum Mollusca (remembering/understanding) No slide General molluscan features [body plan] A. Soft body with visceral mass B. Head [gastropods and cephalopods] C. Foot [solid in bivalves and gastropods; tentacles in cephalopods] D. Mantle [sheet of epithelial tissue; very visible in bivalves E. Coelom - coelomates F. Circulation

a. Open [bivalves and gastropods] b. Closed [cephalopods] G. Radula [tongue-like structure with chitinous teeth; has poisonous barbs in cone snails] H. Respiration 1. Pulmonate Having lungs [land dwelling snails] 2. Gills Fresh water and marine snails, bivalves, and cephalopods I. Movement 1. Muscular foot Bivalves and snails 2. Modified foot Tentacles in some cephalopods – the octopus 2. Water expelled through siphon Cephalopods and some bivalves J.Digestive system Complete Objective 11: Name, describe features and characteristics, and give examples of the three main classes of Phylum Mollusca (remembering/understanding) [Also see slide 11 and lab materials.] The three classes in Phylum Mollusca: Gastropoda, Bivalvia, Cephalopoda Phylum Mollusca Slide Class Gastropoda Examples snails, slugs, conchs, sea slugs, and their relatives Habitat _most inhabit marine waters. Some in brackish or freshwater or on land Shell structure __`spirally coiled, flattened, or absent Body Torsion A twisting of the visceral mass Head [cephalic] _well-developed head with tentacles Two eyes __located on stalks

Slide Radula [belt of chitinous teeth] -[tongue-like structure

Animal examples Many snails and other mollusks including cephalopods Specialized adaptation _`cone snail, radula equipped with poisonous barba Respiration [epithelial tissue] Pulmonate _`mantle functions as lungs (pneumostome) Gills _`aquatic

Slide Class Bivalvia Examples Clams, oysteres, mussels, scallops and their relatives Habitat _`freshwater and marine Shell structure __`hinges dorsally and open ventrally, bibalve Body Lateral compression _`side-to-side Acephalic _`lacking a head Solid muscular foot Respiration Siphons __`take water through an extension of the mantle called the incurrent siphon Gills _`water passes over the gills and traps food particles from the stream of water

Slide Class Cephalopoda Examples Octopus, squid, nautilus, cuttlefish Habitat _`marine

Shell structure __octopus have no shell and squid have shells located inside the body are greatly reduced Body Head [cephalic] _well developed eyes, structurally similar to vertebrate eyes and function much the same way Foot __`tentacles surrounding mouth

Slide Radula and beak _mouth has two strong horny beaks used to kill prey and tear is to bits Respiration _`gills in mantle cavity Movement _`funnel-like siphon, also draw water into mantle cavity for respiration

Slide Protection Chromatophores _cells in the skin that contain pigment granules Iridophores __`reflector cells, brightness Ink _produces a thick, black liquid the animal released in a dark cloud when alarmed

Objective 12: Identify distinguishing characteristics of annelids (phylum Annelida) (remembering/understanding) Phylum Annelida (ringed) (segmented roundworms) (lab) No slide I. General features A. Segmentation Segmented round worms B. Septa Internal membranous partitions C. Annuli Surface rings indicating where the septa are located

Leeches have only surface annuli and not septa D. Setae External bristles of epithelial origin Not found in leeches. E. Nervous system F. Circulatory system Closed system G. Digestive system Complete H. Respiration Across body surface I. Excretory system J. Reproduction Monoecious – both male and female reproductive structures on same organism K. Coelomates

Objective 13: Name, describe the features and characteristics, and give examples of the three main groups (classes) of annelids (remembering/understanding) Three classes of Phylum Annelida are Polychaeta, Oligochaete and Hirudinida Phylum Annelida Class Polychaeta Slide Habitat __mobile marine worms that swim freely in the sea Body Cephalic __`jaws, eyes and anatenna, sensory tentacle and palps Parapodia __each body segment typically bears a pair of paddle-shaped appendages, locomotion/ gas exchange (diffusion), multiple setae (bristles) Class Oligochaeta (earthworms) (Also see lab materials.) Slide Habitat __fresh water and in moist terrestrial habitats Body Acephalic __`no defiend head Clitellum

_`produces mucous Segmented round worms Both polychaetes and oligochaetes

Slide Protection Cuticle _protects the body from drying by a thin transparent cuticel Mucus _ secreted by gland cells of the epidermis and forms an additional protective layer Sensory structures Setae __`surface bristles Statocyst _`gravitational orientation

Slide Class Hirudinida Hirudin is secreted anticoagulant Leeches Habitat _most live in fresh water Parasites _`blood-suckin parasires Medicinal use _have been used since ancient times for drawing blood from areas swollen by poisonous stings and bites, removes accumulated fluid and blood Body Annuli __`none Setae __`none Appendages _`none Suckers __`muscular structures at both ends

Ecdysozoa Objective 14: Describe general characteristics of ecdyzoans and name the associated phyla (remembering/understanding)

Ancestral features Phylum Nematoda and Arthropoda have these features Multicellularity Tissues (three tissue layers) Triploblastic Bilateral symmetry Protostomic development Group molts surface covering [new for all ecdysozoans] Arthropods are segmented and have joined appendages Other features vary with phylum and class

Ecdysozoa Polyphyletic group Nematoda and Arthropoda

Objective 15: Describe distinguishing characteristics of Phylum Nematoda including sexual dimorphism (remembering/understanding) Phylum Nematoda [elongated round worms] (Also see lab materials.) Additional features other than with cladogram above.

Slide Phylum Nematoda Habitat _can be found in soil in marine and freshwater sediment Body Shape _`elongated and round Pseudocoelomate __`also no internal septa Surface covering _`membrane bound cuticle, smooth, no setae

Slide Skeleton __`fluid, hydrostatic Eutely _`fixed number of cells Reproduction Dioecious __`separate sexes Sexually dimorphic __`males physically different from females Other systems muscles, digestive tract (complete)

Objective 16: Name, describe, and give examples of parasitic nematodes

(remembering/understanding) No slide Ascaris (lab) common intestinal parasite Hookworms intestinal parasite, sucks blood Pinworms commonly found in children Trichina worm internal parasite of animals; humans infected by eating undercooked, infected meat

Objective 17: Describe general characteristics of arthropods (remembering/understanding) Phylum Arthropoda (Also see lab materials.) Additional features other than with cladogram above. Slide Phylum Arthropoda __`most successful group, 80% of known animals- includes the insectss Habitat __`freshwater, marine, terrestrial Body Coelomate Segmented _` repetition of body parts, allows specialization of body parts seen in annelids, arthropods and chordates Exoskeleton __composed of chitin and proteins, covers entire body and appendages

Slide Appendages __serves as swimming paddles, walking legs, mouth parts for capturing and manipulation food, sensory structure, or organs for transplating sperm Senses __hearing and antennas, compound eyes Respiration Gills

__`truly aquatic arthropods Tracheal tubes __internal branching air tubes, terrestrial form Book lungs __`platelike, some terrestrial forms No slide E. Other systems 1. Circulatory – open with hemolymph 2. Digestive - complete [similar to earthworms] 3. Reproductive - sexual, some hermophroditic

Objective 18: Name, describe the features and characteristics, and give examples of the associated subphyla and classes of arthropods (remembering/understanding)

No slide

Slide Subphylum Chelicerata Mandibles or maxillae __no chewing mandibles

Appendages Chelicerae _located immediately anterior to the mouth, fanglike feeding appendages Pedipalps _modified to perform different functions in various groups including manipulation of food, locomotion, defense and copulation Antennae _only arthropods without any

Slide Body __`cephalothorax and abdomen Classes within subphylum Merostoma __`only one living group- horseshoe cran Arachnida _includes spiders, scorpions, ticks, harvestmen and mites Appendages _most have 6 pairs of jointed appendages Food source _`most carnivores Ticks a group of arachnids parasites transmit bacteria causing Rocky Mountain spotted fever and Lyme disease

Slide Subphylum Crustacea Members Crayfish, lobsters, crabs, shrimp, barnacles Mandibles and maxillae _mandibles are used for biting and grinding food, maxillae are used to manipulate and hold food Appendage structure Uniramous _`not branched- antennae Biramous

__`branched- antennules, swimmerets Antennae Antennae _serve as a sensory organ for touch and taste Antennules ___`smaller Slide Body Cephalothorax and abdomen

Reproduction Dioecious Sexually dimorphic Senses Compound eyes Statocysts Excretion (antennal glands) __`regulate salt balance

Slide Subphylum Hexapoda Class Insecta Body Regions _head, thorax and abdomon Thorax Prothorax, mesothorax, metathorax __`three tedions with a led attached Uniramous appendages _`three pairs of legs extended from thorax Wings _`many have one of two pairs of winds Antennae _`one pair

Slide

Eyes simple __`ocelli compound Mouthparts Mandible and maxilla _`chewing, piercing, lapping Labial palps...