Sponges and Cnidarians Flashcards
Phylum Porifera have body organization that is based on a system of
Water canal and chambers
General characteristics of Porifera
- movement
- organs
- body wall
- adults are sessile and predominantly marine
- NO ORGANS, have pores on body instead for water currents to pass
- body wall contains a skeleton consisting of spicules and or spongin
Differences of water circulation for each level of sponge construction
- Asconoid: Thin choanocyte layer with large spongocoel, singular osculum
- Synconoid: thicker and smaller spongocoel, body wall folding with invaginations (incurrent canals) and evaginations (radial canals), choanocytes in chambers not atrium, singular osculum
- Leuconoid: Thickest choanocyte layer and no spongocoel, flagellated chambers, openings are prosopyles, many oscula
Why are asconoid sponges smaller in height
-thin tissues is more breakable and can’t not support larger structures
What are the advantages that the leuconoid sponges have over the syconoid sponges
Body plan provided more circulation to deliver more oxygen and nutrients per area. Body plan allows larger size
Why are the choanocytes essential to the life of the sponge
Use to capture food, sleek and generate current of seawater through and within organism
What is the function of the skeleton in a sponge
Maintains shape, scares predators and taxonomic tool to identify
What is spongin
Modified collagen protein that is horny or fibrous and found in skeleton of many sponges
Composition of spicules
Calcareous or siliceous (sclerocytes secrete spicules)
Class-Calcarea characteristics
- size
- sponge types
- small usually less than 10cm
- lack spongin but have spicules of calcium carbonate
- include sponges of asconoid, syconoid and leuconoid design
Leucosolenia sp.
- habitat
- sponge type
- where are choanocytes located
- Attached to seashore rocks
- asconoid
- in spongeocoel
Sycon sp.
- type of sponge
- what are two types of chambers
- where are choanocytes
- larvae type in body walls???
- syconoid
- incurrent and radial canals
- choanocytes in chambers, not atrium
- small, dark dots in chambers called amphiblastula
Class-Demospongiae contains what percent of all sponges?
90%
Characteristics of class-Demospongiae
- skeleton
- sponge type
- Skeleton composed of spongin and or silica spicules
- all are leuconoid
Spongia sp. (commercial bath sponge)
- composition of skeleton
- where are choanocytes
- type of sponge
- spongin
- entirely in chambers
- leuconoid
Spongilla sp.
- type of sponge
- gemmules?
- leuconoid, demospongiae
- avoid harsh environmental conditions and a means of sexual reproduction
Cliona sp.
- type of sponge
- what is it the “boring” sponge
- leuconoid
- ability to burrow into calcareous structures like clam shells
Class-Hexactinellida characteristics
- known as
- skeleton composition
- sponge type
- glass sponges
- siliceous spicules
- cylindrical or funnel shaped and are syconoid or leuconoid
Phylum Cnidarians include which species
- corals
- sea anemones
- jellyfish
General characteristics of Cnidaria
- symmetry
- body
- body wall
- body forms
- radial symmetry
- no head or segmentation
- mouth surrounded by tentacles and connects to a gastrovascular cavity
- two layer body wall: epidermis and gastrodermjs with mesoglea in between
- have Cnidae of which nematocysts are most common
- polyp and Medusa forms (polymorphism)
Subphylum-Medusozoa
2 classes of Meduosoza
All cnidarians except sea anemones and corals
Scyphozoa-true jellyfish
Hydrozoa
Characteristics of class Scyphozoa
- Medusa is dominate body form
- mesoglea is very thick and gelatinous and contains Amoeboid cells
Aurelia sp.
- what is manubrium
- purpose of gastric pouches
- meduosozoa, schphozoa
- opening of the mouth
- radial divisions of the stomach that help increase surface area
Where are rhopalia on Aurelia sp. and what is the function
-around swimming bell, contain sensory organs for balance (statocysts) and light (ocelli)
Aurelia sp. life cycle
- does planula larva result from asexual or sexual reproduction
- which body form does the scyphistoma exhibit
- how does strobilation occur
- purpose of free-swimming ephyra stage
- advantage of large numbers of ephyra
- sexual reproduction
- polyp
- asexual reproduction by transverse division of the body into segments (ephyra) which develop into separate individuals
- ephyra develop into adults but can also have adults differentiated into ephyra in unfavourable conditions
- large number of adults can be made and larger chance of survival
Cassiopea sp.
- type
- central mouth?
- why green colour?
- scyphozoan
- no central mouth but has many small oral openings leading into a complex canal system
- endosymbiotic relationship with unicellular green algae (zooxanthellae) living inside the jellyfish
Class-Hydrozoa characteristics
- body form
- mesoglea
- both polyp and Medusa forms present
- mesoglea lacks cells
Hydra sp.
- type
- solitary or colonial
- symmetry type
- in which layer are nematocysts
- hydrozoan
- solitary
- radial symmetry
- in epidermis
Hydra sp.
- are the bodies of Hydra capable of contraction?
- do the movements of the body and tentacles appear coordinated
- does it have a Medusa stage
- yes, can contract into a blob if disturbed
- coordinated
- NO MEDUSA STAGE
Gonionemus sp.
- type
- does Medusa have a velum, what does it do if it does
- hydrozoan
- yes, presence of velum causes water to be ejected from under the swimming bell through a narrower opening and thus greater velocity when the musculature contracts
Do scyphozoans have velum?
No
Obelia sp.
- type
- thecate or athecate colony?
- do memebes of colony have same function
- is the gastrovascular cavity continuous throughout colony
- what are the advantages that Obelia has over hydra
- hydrozoan
- thecate (have hydro theca around gastrozooid)
- Gastrozoids=feeding, Gonozoids=contain developing Medusa
- yes the light colony uninterrupted
- 2 polyp stages (gastrozoid and gonozoid) which is more specialized than hydra. Has Medusa and polyp and divisor of labour
Physalia sp.
- type
- commonly known as
- colony?
Hydrozoan
Portuguese man-of-war
Free floating colony consists of nightly specialized polyploid and medusoid members
Subphylum Anthozoa characteristics
- body form
- mesoglea
- polyp only
- mesoglea contains Amoeboid cells and is considered to be a true connective tissue
Anthozoa’s comprise the ______ set of cnidarian classes and are exclusively _____
Examples
Largest
Marine
Sea anemones and corals
Metridium sp.
- type
- why are mesenteries important
- function of acontia
Anthozoa (sea anemone)
- increase surface are in gastrovascular cavity for absorption of nutrients and gas exchange
- located in gastrovascular cavity, are thread-like tissues containing numerous stinging cells which serve as a defence
Metridium sp.
- which layers of the body wall form mesenteries
- what is the difference between complete and incomplete mesenteries?
- what are advantages that Metridium has over Hydra
- gastrovascular cavity (unfolding of gastroderm and mesoglea)
- primary/complete mesenteries extend from the body wall into the gastrovascular cavity to attach to the pharynx while incomplete mesenteries extend only part way into gastrovascular cavity. Free edge of incomplete mesenteries has nematocyst cells to secrete digestive enzymes and phagocytize bacteria
- more surface area for nutrient, acontia
Features of poriferans
- body is rigid, perforated bag, with flagella lining interior
- body divided into:
1. Spongocoel (internal space)
2. Choanocyte (used to capture food and sleek and generate current)
3. Mesohyl (gelatinous, non living layer containing live and mobile Amoeboid cells called archaeocytes)
4. Epidermis (pinacocyte and nucleus)
4 types of poriferans based on chemical composition of support elements
- calcarea
- desmospongiae
- Hexactinellida
- Homoscleromorpha
Where are gemmules found in sponges
Round structures scattered within the body of the sponge
Medusa body form
(Jellyfish)
- have umbrella shaped inverted mouth (facing downward)
- often thick jelly-like layer in body wall as in jellyfish
- motile by contractions of “bell”
- free-floating, pelagic planktonic
Polyp body form
-tubular body, usually sessile/ attached, mouth surrounded by tentacles
