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The Protozoans

The Protozoans. Ciliates Amoeboid Protozoans Flagellated Protozoans. Protists. Defining Characteristics All are unicellular eukaryotes What is a prokaryote ? Many species are both heterotrophic and autotrophic at the same time or at different stages of the lifecycle

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The Protozoans

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  1. The Protozoans Ciliates Amoeboid Protozoans Flagellated Protozoans Kingdom Protozoa

  2. Protists • Defining Characteristics • All are unicellular eukaryotes • What is a prokaryote? • Many species are both heterotrophic and autotrophic at the same time or at different stages of the lifecycle • Move independently (Ocean, fresh water, crawl in soil (some water) ) Kingdom Protozoa

  3. Eukaryote Cell

  4. Prokaryote Cell

  5. Adaptability • Protozoans are ecologically important primary producers, consumers and as vital links in the food chain • Eyespot – localized region of pigment that detects light variations in the environment • Cyst – a hardened external covering that stops all metabolic activity when organism is outside of host to survive in harsh environments • e.g. nutrient deficient, drought, decrease oxygen, or pH/temp changes Kingdom Protozoa

  6. Reproduction • Asexually • binary fission – produce one identical organisms • multiple fission – produce several identical organisms • Sexually – conjugation Kingdom Protozoa

  7. Asexual Reproduction Amoeba Flagellate Ciliate Kingdom Protozoa

  8. Binary fission

  9. Multiple fission

  10. Conjugation • Paramecia pair up • Macronuclei disntegrate & micronuclei undergo meiosis • All but one micronuclei disintegrates. It undergoes mitosis. • Each paramecium exchange 1 micronuclei • Micronuclei fuse • Paramecia separate and marconucleus re-form

  11. Classification Alveolate Protozoans (Having a honeycombed surface) Phylum Ciliophora Phylum Dinozoa Phylum Apicomplexa Amoeboid Protozoans The Rhizaria Phylum Foraminifera Phylum Radiozoa Kingdom Protozoa

  12. Paramecium feces Phylum Ciliophora • Defining characteristics • Body externally ciliated in at least some lifecycle stages • Have the highest degree of subcellular specialization and are considered advanced protozoans Kingdom Protozoa

  13. Cilia • Cilia • Hair-like structures by which the organism moves, collects food and senses their surroundings • Fastest of all the protozoans Kingdom Protozoa

  14. Ciliate Biology • Oral groove • Cytostome • Cytoproct • Contractile vacuole Paramecium

  15. Ciliate Lifestyles • 65% of all ciliate species are free-living and mobile • Some ciliates form colonial aggregations and have sessile habits • Other ciliates have symbiotic relationships in invertebrates and vertebrates Vorticella Kingdom Protozoa

  16. The most dominant planktonic ciliates in the Egyptian waters • Vorticella • Vorticella are sessile organisms. However, young Vorticella are free-swimming. Adult forms attach to substrates with contractile stalks. This stalk is a filamentous organelle called the spasmoneme. Adults can also be free-swimming if these stalks are cut. They can also detach themselves if food supplies are scarce and they need to find a new location. Vorticellaare heterotrophic organisms. They prey on bacteria. Vorticella use their cilia to create a current of water (vortex) to direct food towards its mouth. Vorticella are aquatic organisms, most commonly found in freshwater habitats. They attach themselves to plant detritus, rocks, algae, or animals (particularly crustaceans). Typically, Vorticella reproduce via binary fission.

  17. WHAT IS A TINTINNID CILIATE? • tintinnids are ciliate protists of the class Spirotrichea,order Tintinnida. • It is a shelled cell. There are other groups of shelled organisms in the plankton, such as foraminifera and pteropods, but very few are as diverse as the tintinnids.  • Although tintinnids ciliates are characteristic of the marine plankton, there are a few species found in freshwaters. • Besides the lorica, there are some cytological characteristics that distinguish tintinnids The oral ciliature includes structures called tentaculoids, which appear to be related to prey capture. The posterior end of the cell is a contractile, stalk-like, peduncle which connects the cell to its lorica. The tintinnid cell surface has a distinct field of rows of short somatic cilia

  18. THE LORICA AS THE DEFINING CHARACTERISTIC OF TINTINNID CILIATES • tintinnids are also the only ciliates of the plankton with loricae. • Although there are cytological characteristics that distinguish tintinnids, the defining one is its lorica or shell  , which are mostly protein but may incorporate minute pieces of minerals. • The lorica, although of various shapes ranging from tubular to vase- or bowl-shaped, is always open at one end, the oral end, and closed at the opposite, or bottom end.  •  Within the lorica the tintinnid cell is attached near the bottom end by a contractile portion of the ciliate cell, a pedicle or peduncle  • tintinnids traditionally have been divided into two groups corresponding to easily distinguished lorica types: one with agglutinated (or agglomerated) loricae composed of particles and another, those with hyaline, generally transparent, loricae. The two lorica types very approximately correspond to different habitats : coastal and open waters

  19. Mineral particles are used in the “agglutinated” loricae of species in the genera  Tintinnopsis, Stenosemella, Tintinnidium, and Leprotintinnus. These forms are generally restricted to coastal waters. In some genera there are species that incorporate the hard parts of some microalgae like diatoms Some tintinnid species with agglutinated loricae: Tintinnopsis radix (a), T. campanula (b), T. dadayi (c), T. spiralis (d), Codonellaelongata covered with coccoliths (e), Tintinnidium sp. (f), Stenosemellaventricosa (g), Leprotintinnuspellucidus (h), and Codonellopsisschabi (i). Species names are attributed based on lorica morphology.

  20. “Hyaline loricae” groups tintinnids of a very large variety of shapes, sizes, and architectures whose sole common characteristic is a lack of unnecessary particles in the lorica.  Although some hyaline lorica species are found in coastal waters (e.g. species of Helicostomella, Favella) typically they are the dominant forms in open-water tintinnid assemblages. Examples of tintinnid species with hyaline loricae: Amphoridesquadrilineata (a), Amplectellacollaria (b), Climacocylisscalaria (c), Acanthostomellaconicoides (d), Protorhabdonella simplex (e), Epiplocylisblanda(f), Xystonellopsisparadoxa (g), Ormosellatrachelium (h), Proplectellaelipisoida (i), Dadayiellaganymedes (j), Dictyocystalepida (k), Metacylismediterranea (l), Parafavellaparumdentata (m), Parundellamessinensis (n),Ascampbelliatortulata (o), Eutintinnusstramentus (p), Undellahyalina (q), Helicostomellasubulata (r), Salpingellaacuminata (s), Rhabdonellaspiralis (t), and Cyttarocylis cassis (u). 

  21. Planktonic foraminifera • Planktonic foraminifera are unicellular organisms with a complex cell (Eukaryotes), and genetic material within a cell nucleus and belong to kingdom Protists or Protista. Kingdom Protozoa

  22. Foraminifera pseudopodia shell made of CaCO3 • foramen= hole • ferre= to bear • found in ocean and freshwater • porous shell known as tests • form the sedimentary rocks • symbiotic algae

  23. Planktic (planktonic) foraminifera can permanently float or drift in the water column. They are very abundant in inner to outer neritic sediments They are widespread and have had rapidly evolving ancestries

  24. Planktonic foraminifera live floating in the surface waters of the open ocean, and secrete a calcium-carbonate shell. These shells fall to the sea floor after the organisms reproduce.  • Many of the foraminiferans have symbiotic algae living within their protoplasm. During the day time, they let these algae outside the shell, so that they algae will photosynthesize, and the foraminifera can take up their waste products. At night they haul them in again. • All foraminifera, including the ones with symbionts, also eat, all creatures smaller than they themselves. Some foraminifera appear to prefer algae, other microscopic animals. • Foraminifera have sticky pseudopods (long, thin streamers of protoplasm), with which they grab food and place it in contact with their protoplasm, which engulfs their prey and digests it. Kingdom Protozoa

  25. Phylum Actinopoda (radiolarians) • Have shells (external skeletons) made of silica (glass) • Pseudopods needle-like • Marine group. Part of plankton (microscopic floating marine organisms) • Valuable fossils for geological record. Pseudopods Beautiful radiolarian shell

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