marine bio ch 5 and 7

marine microbes and marine invertebrates

ch 5: marine microbes

viruses

non-cellular infectious agents (particles) that have two basic characteristics: not capable of reproduction without a host cell and structure (nucleic acid core and protein coat called a capsid)

-some proteins are specific and can only exist with a certain species

retroviruses

store genetic information in the form of nucleic acid known as RNA

lysogenic viruses

reproduce by inserting their DNA into the DNA of the host cell

bacteriophages

viruses that infect bacteria

*marinephages: obligate strict agents of bacteria

viruses in the marine community

-common in marine waters

-can infect bacteria, plankton, fish, sea turtles, and marine mammals

-lysis (bursting) of viral infected cells releases large amounts of dissolved organic matter (DOM)

fibropapillomatosis

disease specific to sea turtles

-benign tumors on the surface of their biological tissue

microbes

microscopic marine organisms unseen to the naked eye (need microscope)

belongs to one of the major four groups:

1. bacteria and archaea

2. viruses-not truly (not really an organism, but still important)

3. fungi

4. protozoa

what are the two different kinds of prokaryotes that are classified in different domains?

1. archaea

2. bacteria

where do prokaryotes live?

-too cold

-too hot

-too salty

-too acidic

-too alkaline for eukaryotes to survive

ex: can live in salt pools, hydrothermal vents, acid/coal mines

autotrophs

obtain carbon atoms from carbon dioxide

heterotrophs

obtain their carbon atoms from the organic compounds present in other organisms

photoautotrophs

harness sunlight for energy and use CO2 for carbon to make glucose and sugars

chemoautotrophs

harvest energy from inorganic chemicals and use carbon from CO2 to make organic molecules (don’t need sunlight energy)

bioremediation

use microbes/plants to rid environment of toxins

-rid environment of contaminants

-have great nutritional diversity

-are quickly adaptable

-can form biofilms

archaea

can tolerate wide ranges in temperature, salinity, and desiccation

-found in extreme environments including hydrothermal vents and salt flats

where do archaea live in?

extreme environments

-have unusual proteins and other molecular adaptations that enable them to metabolize and reproduce effectively

extreme halophiles

thrive in very salty places

extreme thermophiles

thrive in very hot water

archaea: methanogens

-live in anaerobic environments

-give off methane as a waste product

-methane is a potent greenhouse gas

-found in guts of animals (cows, goats)

-deep in marine sediment and hydrothermal vents

prokaryotes: bacteria

semi-rigid cell wall

-normally microscopic, but a few are large

-wide variety of metabolic types

-very abundant worldwide

-break down dead organic matter which forms detritus, can also form marine snow

-comes in spirals, rings, spheres, rods

largest known bacterium

Thiomargarita namibiensis

cyanobacteria

-the only group of prokaryotes with plantlike, oxygen-generating photosynthesis

-some species, such as Anabaena, have specialized cells that fix nitrogen (N gas → NH4+, NO3-)

-no chloroplast, but has ch. A pigments

-filamentous strands

stromatolites

massive calcareous mounds formed by cyanobacteria, have been found that are billion years old

-layering growth, single cell photosynthesis microbes

-sheets of rock

plant-like protists

algae

-photosynthetic

-can be red, green, or brown

-diatoms

-dinoflagellates

phytoplankton

-plant like protists

-single celled

-perform nearly all photosynthesis in the oceans

-produce ½ of all atmospheric oxygen

-diatoms and dinoflagellates

frustule

shell of silica (glass)

diatoms

mostly asexual reproduction

-around half of the 12,000 known species are marine

-most are planktonic

-store excess energy as an oil which also aids in buoyancy

-tiny pores in shell used for gas/nutrient exchange

-the cell divides and each resulting cell gets one half of the frustule and must secrete the other half of the frustule (smaller piece)

oil formation

carbon gets buried in sediment, harvest oil from sediment (things like hydraulic fracturing)

domoic acid

can accumulate in the tissues of organisms that eat diatoms

-affects organisms at the top like sealions

biomagnification

-accumulation of toxins through the trophic levels of a food chain

-results in an increased concentration of the toxin in the higher organisms

bioaccumulation

occurs with toxins that are stored long term in the organism

dinoflagellates

most marine

-motile: two flagella in grooves on body

-cellulose cross-linked plates as “armor”

-can form chains, some are bioluminescent

-flagellar motor (one is for turning, one is for propulsion)

diel vertical migration

-migrate for nutrients at night at depth

-migrate to sunlight in the morning

-mostly by dinoflagellates

-some even known to go into the sediment

zooxanthellae

a dinoflagellate that lives in a symbiotic relationship with corals, sea anemones, and other organisms

-coral provides the algae with a protected environment, compounds they need for photosynthesis

-the algae provides coral with oxygen, remove wastes, supply coral with sugars, glycerol, and amino acids

-zooxanthellae head: made up of thousands of polyps

zooxanthellae coloring

when corals become physically stressed, the polyps expel their algal cells, and the colony takes on a stark white appearance commonly known as coral bleaching

-doesn’t have the partner to make sugars

the paradox of coral reefs

-algal cells need light for photosynthesis

-therefore corals require clear water (low turbidity=low productivity)

-they are generally found only in waters with small amounts of suspended material

algal blooms

diatoms and dinoflagellates can go through periods of rapid growth

-resulting in high levels of nutrients in the water

red tides

some dinoflagellates can reproduce in larger numbers and produce red tides

-Pfiesteria is a dinoflagellate that produces serious toxins that can cause massive fish kills and impair nervous system in humans

-not always harmful, but not always red

bioluminescence (type of chemiluminescence)

-bio=life, is chemiluminescence that takes place inside a living organism

-luciferase (enzymes end in -ase) interacts with luciferin (substrate) and produces light

-enzyme-substrate specific

-bacteria, jellies, and urchins light up

-counter color illumination

silicoflagellates

star shaped internal skeleton of silica

-two flagella of varying lengths

coccolithophores

elaborate shells of calcite (calcium carbonate)

-thrive in water with a low pH created by greatly raising concentrations of CO2

protozoa

-only found in marine community

-found on sandy or rocky bottoms

-shells of calcium carbonate

-can be important contributors of calcareous material on coral reefs or sandy beaches

ciliates

used for locomotion

-may live on hard substrate

-most live as solitary cells

fungi

-eukaryotic and mostly multicellular

-most of 1500 species of marine fungi are microscopic

-many fungus break down dead organic matter into detritus

-some live in symbiosis with cyanobacteria (lichens)

-lichens live in wave splashed areas of rocky shorelines and other hard substrate (algae on surface, fungi on bottom)

microbial loop

refers to the small microscopic organisms in the ocean – viruses, bacteria, the small phytoplankton and microzooplankton – and the relationships between them

ch 7: marine invertebrates

general animal characteristics

-eukaryotic

-multicellular

-heterotrophic

-uses some type of reproduction method (sexual, asexual, both)

-cells lack cell walls

animal reproduction

zygote divides by mitosis to form a hollow ball of cells called a blastula

tissue layers

-endoderm (think inside or internal): forms a lining of the future digestive tract

-ectoderm (think outer or outside): forms an outer layer that will give rise to the skin and nervous system

-mesoderm (m for middle): forms a middle layer that will give rise to muscles and most internal organs

larva

immature individual that looks different from the adult animal

-goes through metamorphosis and becomes a mature adult

vertebrates

animals with a backbone

what percentage of animals are invertebrates, or animals without a backbone?

around 97%

protostome

first mouth in greek, future mouth

deuterostome

second mouth in greek, aka the future anus (like humans)

radial symmetry

round: equal parts radiate out from a central point (ex: sea star)

bilateral symmetry

organism can be divided down the middle into right and left halves that are more or less equal (ex: marine mammals, humans)

assymetry

having no symmetry (ex: sponge)

dorsal side

top side

ventral side

belly side

suspension feeding

feeding on particulate organic matter suspended in the water

filter feeding

suspension feeding but water is actively pumped or filtering structures are swept through the water

passive suspension feeding

no active pumping of water, but use of cilia and mucus to move particles to mouth

deposit feeding

feeding on particulate organic matter that settles on the bottom

sponges (phylum porifera)

-asymmetrical

-lack true tissues

-sessile (not motile, lives attached to substrate)

-filter feeders

Reproduction: asexually (fragmentation) or sexually (hermaphrodites: male and female parts)

osculum

open cavity which is responsible for water flowing out of the sponge

spongin (support protein)

exoskeleton of sponges. supports soft tissues of body and holds up the cells to give the sponge its shape

spicules

support structures made of silica or calcium carbonate

movement of water through the sponge:

through the pores by the flagella of choanocytes (specialized cells that have a single flagellum)

choanocytes (collar cells)

flagella to propel water throughout the body and food into the body

porocytes

control flow of water through pores in the sponge body

amoebocytes

transport of nutrients within the sponge

pinacocytes

flattened cells cover the exterior of the body

sponge reproduction:

-asexual budding: fragmentation of a cluster of cells from an original sponge

jellies, corals, sea anemones (phylum cnidaria)

characteristics of phylum cnidaria

-radial body symmetry

-2 tissue layers: outer epidermis and gastrodermis to line internal body cavity, used for digestion

-2 body forms: polyp and medusa

polyp

cylindrical, attached stage of cnidarians (sea anemone). mouth and tentacles are oriented upward

medusa

upside down polyp (mouth and tentacles are oriented downward) so that sea jellies can swim through water

nematocysts

stinging structure of cnidarians

cnidocytes

cell that contains a nematocyst

nerve net

throughout body, able to coordinate movements

reproduction of cnidarians

sexual: eggs and sperm released to medusa’s epidermis

asexual: polyp budding (does the settling on a substrate, starts developing into a mature colony)

phylum cnidaria, class scyphozoa

-all marine

-medusa body form

-mobile (drifts in currents) and can’t swim against current

-uses cnidocytes to capture prey and ward off predators

phylum cnidaria, class cubozoa

box jellies: small medusae with tentacles. most deadliest venom in the world. could almost cause death

phylum cnidaria, class anthozoa

corals, anemones, sea fans/whips, sea pansy

-single or colonial polyp body form

-no medusa

-mostly sessile

-uses stinging cells to capture prey

corals

-secrete calcium carbonate shells

-possess symbiotic algae within body tissues called zooxanthellae

phylum ctenophora

comb jellies, aka also known as sea walnut

-8 rows of thick cilia that beat continuously (looks like rainbows). captures light in water column

-no nematocysts, only colloblasts

-bilateral symmetry

colloblasts

sticky but not venomous

cnidaria vs ctenophora

-colloblasts in ctenophores, nematocysts in cnidarians

-cnidarians can either be sessile or mobile (but ctenophores are always mobile)

-cnidaria: radial symmetry

-ctenophores: bilateral symmetry

flatworms (phylum platyhelminthes)

-bilateral symmetry

-three tissue layers (triploblasts)

-first brain: clusters of nervous tissues in head

-incomplete digestive tract: gut without anus

-circulatory system

-live individually ex: on sediment floor

cilia is mainly used for…

locomotion

flatworms can either be…

parasitic or free living

coelomates

organism with fluid body cavity

acelomates

organism lacking a fluid filled body cavity

types of flatworms:

planarians (turbellaria), flukes (trematoda) and tapeworms (cestoda)

planarians

free-living

flukes

all parasitic

-have sucks to attach to inside of blood vessels near intestines host

-vertebrates are the host of the adult fluke

-larval stages may be harbored in shellfish or fish

tapeworms

parasitic flatworm

-suckers and hooks for attachment in host’s intestines

-no digestive system of their own

-adult tapeworms live in vertebrates, larvae are found in invertebrate and vertebrate species

phylum nemertea (ribbon worms)

-prefers shallow, coastal waters

-complete digestive system (mouth and anus)

-proboscis, long fleshy tube to used to entangle prey

phylum nematoda (round worms)

-parasitic or free living

-bilateral symmetry

-complete digestive system

-some species are important decomposers on the sea floor

-larval stages often seen in fish- which can be passed on to humans via consumption of raw meat