Porifera And cnidaria Flashcards
Heterotrophic
Eating other organic molecules
What is necessary to be considered an animal?
Multicellular, eukaryotic, heterotrophic, lacks rigid cell walls.
Metazoans
Multi cellular animals
What is the advantage of being multicellular
Can reach a greater size
What is the advantage of a greater size
Cheaper to move and maintain homeostasis
Cellular specialization
Each cell takes on its own job
Interdependence
Cells must depend on each other for survival.
What is the danger of interdependence
If one kind of specialized cell dies off the organism may not be able to survive.
Parazoa
Includes only phylum Porifera and placozoa
Eumetazoa
All other animals, the ones we typically think of.
Mesozoa
20-30 celled creatures, cells arranged in two layers. Parasitic, work like animals.
Characteristics of mesozoa
Minute, ciliated, wormlike. Very small, all are parasitic in marine animals.
Rhombozoa
Live in the kidney of octopi and cuttlefish
Orthonectids
Parasite of invertebrates like sea stars. Have sexual and asexual stages.
Plasmodium
Part of the asexual reproduction of the orthonectids. Multi nucleated mass which divides to create makes and females.
Why are mesozoans important in the phylogeny of other animals?
They’re considered to be the missing link between unicellular and multicellular animals.
Placozoa
Contains a single species, trichoplax adhaerens.
Describe the trichoplax adhaerens
Plate like body, no symmetry, no organs or systems. Have dorsal epithelium of cover cells and shiny spheres. Ventral epithelium has monociliated cells and nonciliated gland cells.
Trichoplax adhaerens feeding behavior
1) glide over prey
2) shoot digestive enzyme on prey
3) absorb
Porifera
Sponges, pore bearing
What is the evolutionary advantage of sponges?
Extreme multicellularity, so they can get really big.
Symmetry of sponges
Asymmetrical, some radial
Habitat of sponges
All aquatic, the majority marine
Locomotion of sponges
Sessile, some can swim
What are sponges lacking?
Organs, tissues, systems.
Spongocoel
Hollow body of the sponge. Surrounded by cells and spicules in a jellylike layer.
Mesoglea of sponges
Jelly like layer that cells and spicules live in, also has collagen.
Spicules
Needle like, make up sponges skeleton.
What are spicules made of?
Calcium carbonate, silica, collagen
Spongin
Made of collagen, gives support
Oscula
Large pores that let water out
Ostia
Tiny pores that let water in. Connected by canals and chambers in mesoglea.
Why are Ostia smaller than oscula?
Many small holes mean better surface area to volume of water ratio.
Pinacocytes
Flat, epithelial like cells that cover the outside and some interior surfaces.
Choanocytes/collar cells
Have flagella, aid in filter feeding and absorption of food
Archaeocytes
Ameboid cells that move in the mesoglea. Break down particles and build new structural elements like spicules and spongin.
Asconoid
Simples organization, water comes in dermal pores and into the Spongocoel lined with choanocytes. Usually part of a branched colony.
Syconoids
Tubular body, thick walls, have radial canals with choanocytes. Have epithelial cells in the spongocoel. Don’t make branched colonies. Found in classes hexactinellida and calcarea.
Leuconoids
Allows largest size, most complex. Form large masses with many oscula. Don’t have ostia, have kill rooms.
Sponge feeding behavior
Filter feeders. Suck water through tubes/canals, absorb all food substances. Shoot water back out.
Where does digestion of sponges take place?
Directly inside cells. (Intercellular)
How does sponge respiration and excretion take place?
Through diffusion
Sponge buds
Asexual reproduction, outgrowth of sponge that breaks off and becomes a new sponge.
Sponge gemmule
Seed like baby that survives harsh environments. Archaeocytes fill mesoglea and spongin and spicules make a tough coating around it.
Sponge regeneration
Sponges can regrow broken or missing parts
Sexual reproduction in sponges
Eggs and sperm are produced, sperm released in water, enter another sponge, amoebocyte takes it to egg. Creates a larvae that swims away.
Class Calcarea
Small size, shallow water, calcium carbonate spicules. 3/4 rayed spicules. All marine, have all three types of canal systems represented.
Class Hexactinellida
Glass sponges, silicone spicules, deep water dwelling. 6 rayed spicules. All marine, syconoid or leuconoid. Radially symmetrical.
Demospongiae
Mostly made of spongin, silicone spicules. Deep and shallow water. 95% of sponge species. All marine except 1 family. All leuconoid.
Schlerospongiae
Hard, spicules of silicone and calcium carbonate, found in deep waters.
Phylum Cnidaria
Stinging creatures with tentacles
What symmetry do cnidarians have
Radial
What are the key evolutionary advancements of cnidarians
Symmetry, tissues
Habitat of cnidarians
Water, mostly marine, few fresh water. Some live singularly some live in colonies.
What germ layers are present in ALL species of cnidarians.
Ectoderm and endoderm
What germ layer is present in sea anemones
Mesoderm
Locomotion of cnidarians
Mostly sessile
Polyp
Mainly sessile, tube body, basal disk on aboral end. May be alone or in colonies.
What kind of morphism is present in cnidarians?
Polymorphism (more than two form),
Dimorphism (2 forms)
Basal disk
Whole bunch of adhesive glands that help polyp stick to stuff
Tetramerous radial symmetry
Body parts arranged in fours
Oral
Region with the mouth
Aboral
Region without the mouth
Cnidarians epidermis
Forms from ectoderm, has epithelial muscular cells, interstitial, glands, cnidocyte, and sensory nerve cells.
Epitheliomuscular cells
Cover, protect, but can also contract for movement. Found only in cnidarians.
Interstitial cells
Produce all cells except epithiliuscular cells
Gland cells
Secrete adhesives for attachment and gas bubbles for detachment
Gastrodermis
Inner layer formed by endoderm
Gastrodermal gland cell
Secrete digestive enzyme that partly breaks down prey
Lining cells
Absorb partially digested foods.
What kind of digestion do cnidarians have?
Extracellular
Cnidarian mesoglea
Distinct layer between the epidermis. Jellylike material that separates the two tissue layers.
Cnidocyte
Stinging cell
Nematocysts
The hard capsule with thread inside. Inside the cnidocyte. This is the part that shoots out.
Cnidocil
Trigger for the cnidocyte. Triggered by touch. Allows water to enter the cell, increase osmotic pressure, shoots out nematocyst.
Osmotic pressure
Pressure that builds up and shoots out the nematocyst. Caused by water.
Paralysis occurs when…
The poisons are pumped from the nematocyst capsule and string into the victim’s cells
Glutathione
Hormone released by damaged cells that trigger feeding response.
Gastrovascular cavity
Cavity that acts as a stomach for cnidarians. They shove food straight in there.
Why is Extracellular digestion an advantage?
Can digest prey larger than a single cell.
What are cnidarians lacking?
Organs and systems.
Nerve net
Nerves of the cnidarian. Two way system, can send and receive signals both ways.
Cnidarians budding
Outgrowth of epidermis and gastrodermis which goes tentacles and pops off.
Regeneration
Regrows missing parts
Class Hydrozoa
Hydra and physalia (Portuguese man of war)
Hydrozoa habitat
Marine and freshwater. Some live in colonies, others solitary.
Pneumatophore
Expanded, gas filled sac that help man of war keep afloat
Class Anthozoa
Flower animals, like coral and sea anemone
Anthozoa habitat
Marine water, solitary or colony life
What stage does Anthozoa lack?
Medusa. All polyps.
What is special about anthozoas germ layers?
Has mesoderm
What does mesoderm do?
Develop into muscles
How are coral ecologically important?
Indicator animals, if they die something is bad in the environment.
Marginal/fringing reef
Runs along beach, not usually larger than a mile.
Barrier reef
, largest we know of.
Atoll
Coral reef donut, surrounds a lagoon
Septa
Separating walls in the mesoglea, help absorb more food.
Pharynx
Like a throat, leads into gastrovascular cavity. Found in sea anemones.
Class Scyphozoa
Sea nettles and jellyfish, mostly medusa, polyp is just part of the reproductive cycle. Large jellyfish
Scyphozoa habitat
Mostly marine
Statocyst
Detects gravity
Ocelli
Detects light
Manubrium
Large tube that is an extension of the mouth. Forms frilly arms.
Planula larva
What the zygote develops into, becomes a polyp
Strobillation
Repeated lateral budding. Forms ephyrae.
Ephyrae
Become medusa after breaking off polyp
Class Cubazoa
Cube jellyfish, aka dangerous ones. Polyps directly become medusa.
