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Poriferans
OBJECTIVES
To familiarize and identify the different sponges specimens.
To classify the different sponges according to classes, body types and chemical components of spicules.
To identify the different spicules in the sponges.
Different Types of Poriferans
Class CalcareaClass HexactinellidaClass Demospongiae
Class Calcarea
Calcareous sponges (Class Calcarea) have spicules composed of calcium carbonate.
Small, usually vase shaped. Asconoid, syconoid, or leuconoid in structure.
Class Hexactinellida Glass sponges (Class Hexactinellida) are mostly
deep sea forms. Spicules are six-rayed and made of silica.
Hexactinellids lack a pinacoderm or gelatinous mesohyll.
Chambers appear to correspond to both syconoid and leuconoid types.
Class Hexactinellida Some advocate placing
hexactinellids in a subphylum separate from other sponges.
Trabecular reticulum made of a fusion of archaeocyte pseudopodia - forms the chambers opening to spongocoel. Trabecular reticulum is largest
continuous syncytial tissue known in Metazoa.
Choanoblasts are associated with flagellated chambers.
Collar bodies do not participate in phagocytosis – this is the function of the primary and secondary reticula.
Class Demospongiae
Class Demospongiae contains most of the sponge species.
Spicules are siliceous, but not six-rayed.
Spicules may be bound together by spongin, or absent.
All leuconoid, mostly marine.
Cladogram of Sponge Classes
What are the bases of classifying sponges?
Base on the shape and chemical composition of the sponges
Give the ecological importance of sponges. Filter feeders Algae are attachedContains toxins that are of medical
importance
Phylum CNIDARIA
Cnidaria (Gr knide, nettle + L. aria; like or connected with
With more than 9,000 speciesCnidocytes = which contain stinging
organelles (cnidae)Cnidae come in several types including the
common nematocystsNematocysts are used only by cnidarians
Phylum Cnidaria
OBJECTIVES
To familiarize and identify the different representatives of Cnidarians
To identify the parts of Cnidarians and know its function.
To identify the corals based on their morphological characteristics.
CNIDARIANS
BODY PLANS: Have two body forms MEDUSA & POLYPSHave Radial SymmetryKnown for Cnidocytes – contain stinging cells such as nematocystREPRODUCTION: Reproduce Sexually & Asexually
Free-swimming larva - planula
Classification of Cnidaria
Class Hydrozoa Hydra Obelia Goneonemus
Class Scyphozoa Jellyfishes
Class Anthozoa Sea anemone Stony corals
Class Cubozoa
The basis of classification is the adult forms whether polyp or medusa.
What are the bases of classifying cnidarians?
Based on the composition of the hydranths covering e.g. chitinous), accumulation of calcium carbonate and number of pinnate tentacles
Give the ecological importance of Cnidarians
Hydras as food for mollusc and flatwormsLive as commensals on shells and other
surface of host (sea anemones and certain hydroids)
Economic value of reef Reef provide substantial amounts of food for
human (fish and other animals associated with reefs
Give the ecological importance of Cnidarians
Includes:branching, plantlike hydroids
Flowerlike sea anemonesArchitects of the ocean floor- gorgonian
corals (sea whips, sea fans, etc)Stony corals –whose thousand of years
of calcareous housebuilding great reefs and coral islands.
Class Hydrozoa
Fresh water members of this class live singly, but the marine forms live singly or form polymorphic colony.
Though only polyp or medusa is found but sometimes both polyp or medusa may be found in the same animal.
Gastrovascular cavity is directly connected with mouth.
Class Hydrozoa
Alternation of generation is found in the life cycle.
Ciliated planula larva is found.No stomodeum, velum present in
medusa.Radial canals in medusa are not
branched.Gametes develop from ectoderm.
Kingdom Animalia (animals) Eumetazoa (metazoans) Phylum Cnidaria (cnidarians) Class Hydrozoa (hydralike animals, hydroids,
and hydrozoans) Order Hydroida (medusae) Suborder Hydrida Family Hydridae Genus Hydra Species Hydra utahensis
Hydra Class Hydrozoa Order Hydroida
Suborder Anthomedusae
Freshwater species
Hydranths lack a chitinous covering
With no medusa stage
Length up to 25-30 mm
Hydra
ZOOIDSMostly HYDRANTHS (Gastrozooids – feeding polyp
STALK
BASE (basal disc or pedal)
http://www.geochembio.com/biology/organisms/hydra/
Obelia
Class HydrozoaOrder Hydroida
Suborder Leptomedusae
Obelia
Obelia
Colonial or solitary
Colonial marine hydroid that forms a minute plantlike growth on rocks, pilings, and other substrates
Hydranths with chitinous covering
Obelia
DioeciousGametes are fertilized in the water and the
zygote develops into a planula larva which settles into substrate and metamorphose into colony
Kingdom: Animalia Subkingdom: Eumetazoa Phylum: Cnidaria Subphylum: Medusozoa Class: Hydrozoa Subclass: Leptolinae Order: Leptomedusae Suborder: Proboscidoidea Family: Campanulariidae Genus: Obelia
Peron and Lesueur, 1810 Species: Obelia dichotoma Obelia geniculata Obelia longissima Obelia bidentata
http://en.wikipedia.org/wiki/Obelia
Obelia
Anthozoans include corals, sea anemones, sea pens, and sea pansies.
These animals are either solitary or colonial polyps that live attached to a substrate (surface).
Of the 6,000 known anthozoan species, corals comprise about 2,500 species.
Class Anthozoa
Sea anemones and corals have polyps and no medusae
Corals are colonial and secrete calcium carbonate skeletons. Coral reefs are the accumulation of these skeletons.
Class Anthozoa The Class Anthozoa is further divided into three subclasses:
Octocorallia, Zoantharia, and Tabulata (extinct colonial corals).
•Subclass Octocorallia. Polyps are characterized by having eight pinnate (side- branching) tentacles. Octocorallians include gorgonian corals, sea pens, sea pansies, organ- pipe corals, and soft corals (order Alcyonacea). Most are colonial.
•Subclass Zoantharia. Polyps are characterized by having tentacles in multiples of six. Zoantharian tentacles are rarely pinnate. Black corals and reef-building corals (order Scleractinia) are members of this subclass. Reef-building corals are also known as "hard corals" or "stony corals". Zoantharians may be either solitary or colonial.
Sea Anemone
Class Anthozoa Subclass Zoantharia (Hexacorallia)
Order Actiniaria Genus Metridium
Classification:Kingdom Animalia (animals)Phylum Coelenterata (corals, jellyfish, sea anemones
hydroids)Class Anthozoa meaning "flower-like animals"
(corals and sea anemones)Order Actiniaria.
Diadumene dia
Stony Corals
Class Anthozoa Subclass Zoantharia (Hexacorallia)
Order Scleractinia Genus Meandrina (Brain coral)
Genus Astrangia (Eyed coral) Genus Fungia (Mushroom coral)
Genus Acropora (Staghorn, elkhorn, Antler coral)Genus Porites (reef coral) Genus Oculina
Class Scyphozoa
This Class contains the larger jellyfishes, with some reaching two metres across the bell and with tentacles 30 metres long.
They are mainly marine and free floating, though they can "swim" by pulsations of the bell. In this Class the polyp stage is either reduced or absent. There are around 215 species.
Aurelia (the moon jelly)
Class ScyphozoaOrder Semaeostomeae
http://www.discoverlife.org/nh/tx/Cnidaria/Jellyfish/
Aurelia(Desor, 1848) Sea nettle
http://cas.bellarmine.edu/tietjen/AnimalDiversity/Lab4%20Porifera%20and%20Cnidaria.htm
Aurelia sp. Aurelia sp. is a typical
example
The lappets come in pairs, and between them is a sense organ called a rhopalium containing a statocysts to give the animal information on its equilibrium and orientation, sensory pits, and, in some species, ocelli (simple eyes).
http://cas.bellarmine.edu/tietjen/AnimalDiversity/Lab4%20Porifera%20and%20Cnidaria.htm
Aurelia rhopallium, a multifunction sensory organ
Aurelia sp.
The oral arms capture prey.
The tentacles are armed with nematocysts (see illustration on the right), as is the entire body surface.
Aurelia sp. has relatively short tentacles, and feeds on plankton. The plankton is passed to the mouth by cilia.
http://cas.bellarmine.edu/tietjen/AnimalDiversity/Lab4%20Porifera%20and%20Cnidaria.htm
Aurelia sp. Life cycle
Sea Nettle scientific classification:
Kingdom: AnimaliaPhylum: CnidariaClass: ScyphozoaOrder: SemaeostomeaeFamily: PelagiidaeGenus: ChrysaoraSpecies: Chrysaora fuscescens
Pacific Sea Nettle (Chrysaora fuscescens), Montery BayAquariumDec 2009, Photo by Mark Leavitt
Class Cubozoa
The cubozoan body is shaped like a square bell, with the mouth suspended inside it on a tube (the manubrium) that leads upward to the stomach, which is inside the top part of the bell.
Box jellyfish have eyes that are surprisingly complex, including regions with lenses, corneas, and retinas; however, box jellyfish do not have a brain, so how the images are interpreted remains unknown.
possess stinging cells that can fire a barb and transfer venom (Waggoner and Collins 2000).
Kingdom:AnimaliaPhylum:CnidariaClass:CubozoaWerner, 1975Order:CubomedusaeHaeckel 1877
Activity: ½ x.w. paper
Draw the flowchart taxonomic classification of the classes of Cnidarians
Acoelomate Bilateral Animals
The term worm is loosely employed in biology and is applied to very different animals including the segmented worms (Annelids), roundworms (pseudocolomates and a variety of acoelomate bilateral animals.
Acoelomate Bilateral Animals
There are three phyla of acoelomate bilateral animals:Platyhelminthes: flatwormsNemertea: ribbon wormsGnathostomulida: jawed worms
Acoelomate Bilateral Animals
By far the most important in diversity and economic importance is the phylum Platyhelminthes, which includes a variety of parasitic forms such as the flukes and tapeworms.
Phylum Platyhelminthes
Members of the Platyhelminthes typically have dorsoventrally flattened bodies that are usually slender and leaflike or ribbonlike.
There are four classes in the Platyhelminthes. The Turbellaria are free living whereas as members of the Monogenea, Trematoda and Cestoda are parasitic.
Classification of Platyhelminthes
There are four classes in the Platyhelminthes:Class Turbellaria: free-living flatworms.Class Turbellaria: endoparasitic flukesClass Monogenea: parasitic flukes that are
mainly ectoparasitesClass Cestoda: tapeworms
Class Turbellaria
Class Turbellaria contains about 3000 species. There is considerable debate about the classification of the class and it is likely that the class is not monophyletic.
Most species are marine and benthic. However, some are also found in fresh water as well as in moist temperate and tropical terrestrial habitats.
8.2
Figure 14.10
Marine turbellarian
Dugesia tigrina, a freshwater turbellarian
© Mauricio A. Muñoz
Class Turbellaria
Most Turbellarians are predators of invertebrates smaller than themselves. Other species are herbivores or scavengers.
Turbellarians move by swimming, creeping or crawling. They combine muscular contractions with ciliary movement to move.
Class Trematoda
There are about 9000 species of trematodes all of which are parasitic. Most parasitize vertebrates.
Adaptations for parasitism include suckers and hooks for attachment, glands to produce cyst material and increased reproductive capacity.
Sheep liver fluke
Class Trematoda
Structurally trematodes are similar to turbellarians having a well developed digestive system and similar nervous, excretory, and reproductive systems. However, a major difference is the tegument.
Digenean Trematodes
There are three subclasses of Trematodes, but two are small, poorly studied groups.
The third group, the Digenea, however is a large group of major medical and economic importance.
Digenean trematodes
The flukes have a complex life cycle in which a snail is the first (or intermediate) host and a vertebrate the final (or definitive host).
The definitive host is one in which the fluke reproduces sexually.
Digenean trematodes
In some species there may be 2 or 3 intermediate hosts before the definitive host is reached.
Trematodes inhabit a variety of sites in their hosts including the digestive tract, respiratory tract, circulatory system, urinary tract, and reproductive tract.
Digenean trematodes
Digenean life cycles are very complex and the fluke passes through numerous stages.
Clonorchis liver fluke
Clonorchis is the most important liver fluke to infect humans. Common in much of Asia (including China, Japan and southern Asia).
Adult flukes live in the bile passages and shelled miricidia pass out in feces. The miricidia enter snails eventually leave the snails as cercariae and find a fish where they encyst.
If fish is eaten raw or poorly cooked the person becomes infected
8.8
Figure 14.12
Schistosomiasis
Schsitosomiasis is an infection with blood flukes and is one of the most important major infectious diseases on the planet.
More then 200 million people are infected worldwide with these flukes which they acquire swimming or walking in water in which the intermediate snail host lives
Schistosome life cycle.
Schistosomiasis
When a schistosome cercaria swims it takes care to avoid UV light which can damage it, but is very sensitive to the scent of humans.
When it senses molecules from human skin it swims rapidly and jerks around looking for the person. When it makes contact it releases chemicals that soften the skin and burrows in shedding its tail at the same time.
8.9a and b
Figure 14.13
Class Monogenea
The monogenetic flukes were previously classified as on order of the Trematoda, but recent work suggests they are more closely related to cestodes (tapeworms).
Monogeneans are typically external parasites of fish that clamp onto the gills using a hooked organ called an opisthaptor. Some also parasitize frogs and turtles.
8.11
Figure 14.16
Class Monogenea
Unlike the trematodes Monogeneans have only a single host.
The egg hatches into a ciliated larva which seeks out its host in the water.
Class Cestoda (tapeworms)
Tapeworms are parasites of the vertebrate digestive tract and about 4000 species of are known.
Almost all tapeworms require at least two hosts with the definitive host being a vertebrate although intermediate hosts can be invertebrates.
Class Cestoda
Members of the Class Cestoda (tapeworms) are quite different in appearance from the other members of the Platyhelminthes.
They have long, flat, tape-like bodies composed of a scolex for attaching to their host and a chain of many reproductive units or proglottids called a strobila. New proglottids form behind the scolex and the strobila may become extremely long.
8.12
Figure 14.18
Tapeworm scolex
The scolex is equipped with a combination of The scolex is equipped with a combination of suckers and hooks that enable it to grip onto its suckers and hooks that enable it to grip onto its host’s intestines.host’s intestines.
Hooks
Suckers
8.14
Figure 14.20
Human tapeworms
Humans are definitive hosts to several tapeworms including the beef tapeworm Taenia saginata, pork tapeworm T. solium, and fish tapeworm Diphyllobothrium latum.
8.15
Figure 14.19
8.16
Figure 14.21
Cysticerci in human brain
Nematoda
Phylum Nematoda
From the Greek Nema for Thread and Eidos for form.
only about 80 000 species have been described
Nematodes live in a vast variety of habitats, ecologically they can be divided into free
living forms and parasitic forms.
Characteristics of Nematoda
1)Bilaterally symmetrical, and vermiform. 2)Body has more than two cell layers, tissues and organs.
3)Body cavity is a pseudocoel, body fluid under high pressure. 4)Body possesses a through gut with a subterminal anus. 5)Body covered in a complex cuticle. 6)Has a nervous system with pharyngeal nerve ring. 7)Has no circulatory system (no blood system) 8)Reproduction normally sexual and gonochoristic. 9)Feed on just about everything. 10)Live just about everywhere, many species are endoparasites.
Trichuris trichura (Whipworm) Kingdom: Animalia Phylum: Nematoda Class: Adenophorea Order: Trichocepalida Family: Trichuridae Genus: Trichuris Species: trichiura Scientific name:
Trichuris trichura
Trichuris trichura
Trichuris trichura
Enterobius vermicularis (Pinworm/ Threadworm)
Kingdom: Animalia Phylum: Nematoda Class: Secernentea Subclass: Spiruria Order: Oxyurida Family: Oxyuridae Genus: Enterobius Species: vermicularis Scientific name:
Enterobius vermicularis
Mouth
Esophagus
Spicules
Testes
Intestine
Enterobius vermicularis
Trichinella spiralis (Pork worm) Kingdom: Animalia Phylum: Nematoda Class: Adenophorea Order: Trichocephalida Family Trichinellidae Genus: Trichinella Species: spiralis Scientific name:
Trichinella spiralis
Ascaris lumbricoides (Giant roundworm)
Kingdom: Animalia Phylum: Nematoda Class: Secernentea Order: Ascaridida Family: Ascarididae Genus: Ascaris Species: lumbricoides Scientific name:
Ascaris lumbricoides
Ancylostoma caninum (Dog Hookworm)
Kingdom: Animalia Phylum: Nematoda Class: Secernentea Order: Strongylida Family: Ancylostomatidae Genus: ancylostoma Species: caninum Scientific name:
Ancylostoma caninum
Phylum Annelida
Phylum Annelida(L. annelleus = little ring)
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Phylum Annelida
This phylum is divided into three classes:Oligochaeta: Earthworms - Most earthworms and their equals are inhabitants of damp soil and fresh waters.Hirudinea: Leeches - The leeches are found mainly in fresh water or on moist ground.Polychaeta: Bristle-worms - The marine worms are found chiefly in close vicinity of the shore.
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Class of Annelida
OLIGOCHAETA = EarthwormsHIRUDINEA = LeechesPOLYCHAETA = Bristle-worms
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The first body segment is called the peristomium.
The peristomium contains the mouth.
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a sensory device
a tongue-like lobe above the mouth
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Adult (sexually mature) earthworms have a distinct swelling called a clitellum.
• located about one-third of the way down the earthworm
• often white or orange in colour
• It produces most of the material secreted to form earthworm cocoons.
• Forms a band that can be
flared, non-flared, saddle-shaped, or annular. It is generally found between segments 26 and 33.
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The shorter region to one side of the clitellum is the anterior or head-end of the animal
This end of the worm is usually more pointed than the posterior end of the animal. posterior
or tail end
anterioror head-end
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The periproct is the last segment of an earthworm.
The periproct is the last segment of an earthworm.
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The number and arrangement of setae are important clues to the identification of earthworms.
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Setae
• Each segment, except the first and last, have tiny bristle-like structures called setae.
These structures help the earthworm to move and act to sense the environment.
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The epidermis is the name for the skin of an earthworm. It is the outer layer of worm and it secretes a mucous.
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GP
SR
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A traverse section through a polychaeta at the level of its intestine showing the presence of a pair of parapodia.
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Different types of setae and parapodia.
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Reference:
Hickman Jr. C.P. and et al., 2007. Animal Diversity 4th edition. Boston: McGrawHill
http://www.naturewatch.ca/english/wormwatch/resources/anatomy.html
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