Invert Zoology 02 Protozoans

Ch 3 Protozoa

start

Protista:

Unicellular eukaryotes

what was the “first animal”?

Protozoans

Protozoans

• Heterotrophic - non photosynthetic

• Lack: collagen, chitinous cell walls’

• not animals: no blastula (single celled)

Animals evolved from ?

flagellated protozoa

protozoans have major roles in:

• primary production

• decomposition

• food source

• diseases

• model specimens

many are small, about ?

5-250 micron meters

protozoans need moist conditions:

freshwater, marine, soil

Single cell =

complete organism

types of Locomotion:

• Cilia

• Flagella

• Pseudopodia

Cilia:

• Microtubule arrangement

• Numerous

Cilia Movement:

power stroke, recovery stroke

Cilia speed:

2 mm/sec (2000 micron m/sec

protoslow →

slows them down to look at under microscope

Flagella:

• Structurally, like cilia

• Mastigonemes

• Longer and fewer than cilia

Flagella Movement:

several waves in single flagellum, from tip; propeller like

Flagella speed:

200 micron m/sec

Pseudopodia:

• Cytoplasmic streaming

• Mechanism - uncertain

Cytoplasmic streaming:

• lobopodia

• filopodia

• reticulopodia

• axopodia

lobopodia:

have broad rounded tip with cap that aids in movement and feeding.

filopodia:

filament, thin, extends out, may branch, no cap and is often used for sensory functions.

reticulopodia:

reticulated, thin filaments that branch in particular ways, net-like for catching food and aiding in movement.

axopodia:

axis/axel, radiates outward on spines and serve primarily for capturing prey and providing structural support.

Pseudopodia Movement:

forms on any part

is protoslow needed on Pseudopodia?

no

pseudopodia speed:

300 micron m/minute

Asexual Reproduction:

• Fission

  • Regeneration

Asexual Fission-

binary, multiple, Budding, plasmotomy

Asexual Regeneration-

Encystment → cyst → excystment

Encystment

can lose distinctive features; some can stay there for years

excystment

comes out of that stage, goes back to normal

Sexual reproduction-

by group

Intracellular feeding:

single celled, absorb, digest with cell components

Food Vacuole feeding-

small cavity in the cytoplasm of a protist that temporarily stores food, causes pH change

Coloniality:

• In many, typ. similar to single celled ones

• Ancestral to multicellarity?

• some become more dependent than others causing daughter cells

Kingdom Chromista

Alveolata (SAR clade)

Alveolata:

in the SAR clade, possess membrane bound sacs (alveoli)

Phylum Ciliophora:

• “cilia bearing”

• Monophyletic

• Advanced from primitive protozoans

• Alveoli

• Pellicle, trichocysts

• Cystome, cytoproct

Pellicle:

outer covering, can be rigid or flexible

Trichocysts:

defensive features, can be triggered by mechanical or chemical change in the water

Cystome =

cell mouth

Cytoproct =

cell anus

Ciliation:

• in some life stage - whole, reduced

• Infraciliature - Kinetodesmos; metachronal beating

• Modifications: undulating membrane, membranelle, cirrus

Kinetodesmos:

the way it extends out of the cilia to the adjacent cell

Undulating membrane:

flattened sheet of cilia, moves as one unit

Membranelle:

some cilia in adjacent rows, creates a tooth-like action

Cirrus:

where they’re all bundled together creating a tip

Phylum Ciliophora Reproduction:

• primarily asexual, through binary fission, but can also reproduce sexually by conjugation

• 2 nuclei - dimorphic = heterokaryotic

• Plasmotomy

• Autogamy

Heterokaryotic =

different kernel

Conjugation:

how genetic material is exchanged, complicated

does macro stay or go away during conjugation?

goes away

does micro stay or go away during conjugation?

stays

Autogamy -

form of self fertilization

what kind of movement do Ciliaphora have?

motile and sessile and use cilia for locomotion.

Motile:

mobile

Sessile:

ones that are stuck in one place

do Ciliaphora have a test?

they may or may not (shell/lorica)

Ciliaphora have the ability to become ?

“larval”

“larval”:

go back to primitive state, reverse direction

how many Ciliates are symbiotic?

1/3

what type of feeding do Ciliates have?

free-living, and suspension feeding

free-living:

non parasitic, just grab things

suspension feeding:

create currents to feed, filter feeding

what kind of habitat do Ciliates live in?

all habitats, you can find them everywhere

Phylum Apicomplexa (apical complex):

• cluster of micro tubules, organelles

• Endoparasites: host, vectors

“Endo”, parasites

inside parasites

Diffinitive host:

adult stage

Intermediate host:

various different life stagesthat support development of the parasite before reaching the definitive host

Vectors:

transmits diseases until it gets to final host

important spp in Phylum Apicomplexa:

Plasmodium (spores found inside red blood cells)

Plasmodium causes what disease?

malaria, its a malarial parasite

what transmits malaria?

It is transmitted by the bite of infected female Anopheles mosquitoes, which are the primary vectors for Plasmodium.

how long does malaria live in the gametophyte stage?

2 weeksbefore developing into sporozoites.

K. Chromista. Rhizaria (SAR clade)

Slender pseudopodia (not monophyletic), various complexities

subPhylum Foraminifera

• Benthic, marine , few planktonic

• Sm. multichambered test (shell)

• Reticulopodia

• Feed, no parasites

• Origins - Cambrian

• Economic importance

Reticulopodia

A type of pseudopodia used by certain protists, characterized by a net-like structure that helps in feeding and movement.

Foraminifera economic importance:

where they’re found is an indication of oil preserve, test is made of calcium carbonate (CaCO3), huge threat of ocean acidification bc of CaCO3

subPhylum Radiozoa =

Radiolarians, Acantharians

what type of water do Radiozoa live in?

marine, planktonic (they float)

Radiozoa Endoskeleton:

intra- extracapsular zone

intra- capsular zone (inside):

nucleus are there

“extra”capsular zone (outside)

eat there

what is the Endoskeleton made of?

Silica (silacious) - glass

Axopodia

Long, thin pseudopods, and flexible projections used for feeding and locomotion in Radiozoa

what do Radiozoa feed on?

algae, microscopic prey

Radiozoa have only ? exanct spp (still around)

100

Radiozoa have ? fossil spp

7,700

K. Protozoa

Excavata (clade)

Phylum Euglenozoa

• flagellated

• FW, marine, soil, terrestrial (moist)

• Some photosynthetic (in light), horozoic (in dark), some autotrophic

• has photosensitive organelle

• Euglena, Chlamydomonas

Trypanosomes:

• endoparasitic found in the bloodstream but outside the red blood cells

• Kinetoplast

• causes and transmits diseases

• Evades immune systemssuch as sleeping sickness and Chagas disease.

Kinetoplast:

dark stain disk inside mitochondria

Leishmania:

• Parasite

• Causes leishmaniasis (aka “black fever” or “white leprosy”

Giardia:

• Parasite

• Human affliction

• in intestines, causes nausea & diarrhea

• get it by drinking contaminated water

• Lack mitochondria

Related to Euglenozoa…

Naegleria (fowleri)

Naegleria (fowleri):

• Brain eating amoeba

• flagellated organism

• 98.5% fatality

• kills host in 1 week

• shows up as flu, once you realize you have it, it’s too late

• Transitional characteristics

• more common in warm

Naegleria Transitional characteristics:

Cyst stage → Flagella stage → Amoeba stage

Phylum Metamonda:

• Internal “gut parasites”

• loss of flagella

• termites, wood roaches, cockroaches (can break down cellulose)

• can hold and become 1/3 Biomass of a termite

Unikonta (clade

Phylum Amoebozoa:

• FW, marine, soil, internal. Mosses

• Amorphic to structured

• Feed - POM, DOM

POM =

Particulate Organic Matter

DOM =

Dissolved Organic Matter