Marine Bio

Cyanophyta

Cyanobacteria, or blue-green “algae

Bacillariophyta

diatoms

Dinophyta

a.k.a. Pyrrhophyta, or dinoflagellates

Haptophyta

(coccolithophores

Foraminifera

Granuloreticulosa

Chlorophyta

green seaweeds

Phaeophyta

brown seaweeds

Rhodophyta

red seaweeds

Platyhelminthes

flatworms

Turbellaria

(free living flatworms

Cestoda

(tapeworms

Trematoda

(flukes

Nemertea

(ribbon worms

Nematoda

round worms

Sipuncula

peanut worms

Polyplacophora

chitons

Gastropoda

snails, slugs, nudibranchs, sea hares

Bivalvia

clams, mussels, scallops, oyster

Scaphopoda

tusk shells

Cephalopoda

octopuses, squids, cuttlefishes)

Magnoliophyta

a.k.a. Anthophyta, or flowering plants)
Includes seagrasses, cordgrasses, and mangroves

First discovered as “extremophiles”
• Many are poorly-known symbionts with other
organisms
• Include “bacteria” near hydrothermal vents
and deep-sea cold seeps
• In mid 2000s, discovered to be at least as
abundant at depths > 1,000m as bacteria
• Possible among most abundant life on planet

Archaea

a.k.a. “blue-green algae”
• Tremendously important group that
pioneered life on earth and made all
subsequently life possible (so there’s that)
• Form first known fossils (stromatolites)
• Can use (fix) atmospheric N2

Cyanobacteria

Frustules of SiO2
• Very important producers
• Reproduce both asexually and sexually

Diatoms

Cell walls of cellulose
• Some are zooxanthellae
• Many bioluminescent forms
• Cause red tides, a.k.a. “harmful algal
blooms” or HABs
• Very odd life cycles possible (eg.
Pfiesteria)

Dinoflagellates

green seaweeds
• chlorophyll a and b, carotenoids
• walls of cellulose (sometimes CaCO3)
• likely the direct ancestors of the plants
(some biologists include the green algae
in the Kingdom Plantae)

Chlorophyta

red seaweeds
• chlorophyll a, carotenoids, phycobilins
• Walls of cellulose, colloids, CaCO3
• important commercial products (colloids
uses in foods, industry, medicine like agar,
carageenan, etc...)
• Includes deepest known algae (268m)

Rhodophyta

brown seaweeds
• includes kelps
• complicated life histories
• Chlorophyll a and c, fucoxanthin (a
carotenoid)
• Cell wall of cellulose and alginates

Phaeophyta (Oligophyta)

Have true roots, stems, leaves (organs)
and vessel tissue
• Produce seeds that are enclosed in a
flower
• One of the most successful land groups,
less diverse in oceans (but marine species
extremely important in ecology of many
areas)

Magnoliophyta (flowering
plants)

Seagrasses?
• Cordgrasses?
• Mangroves?

Magnoliophyta (flowering
plants)

Actually not true grasses
• Can live completely submerged
• Are among the most productive areas in
the ocean
• Live with nitrogen-fixing symbionts

Seagrasses

Are true grasses
• Have specialized tissues for bringing
oxygen to the roots (arenchyma)
• Live with nitrogen-fixing symbionts
• Are often C4 photosynthesizers (or C3/C4
intermediate?)
• Can use seawater as a source of water,
excreting excess salts through salt glands
in the leaves

Cordgrasses

Have salt glands (like cordgrasses)
• Have nitrogen-fixing symbionts
• Get oxygen using root extensions
(pneumatophores)
• Use root hairs and lichens on prop roots to
get fresh water

Mangroves

~ 80,000 species (most in oceans)
• includes snails, slugs, nudibranchs, clams,
mussels, oysters, scallops, chitons,
octopuses, cuttlefishes, and squids.
• mantle (secretes CaCO3 shell)
• radula (chitinous tongue often scrapes)
• eucoelomate (schizocoely)

mollusks

General Life Cycle for a Mollusk

• trochophore
• veliger
• spat

Vast expanses dominated by burrowers,
deposit feeders, and suspension feeders
• Size of sediment grains influences life (eg.
Meiofauna; distribution of feeding types)
• Distributions affected by physical and
biological features (patchiness)
• Includes areas for seagrass beds

Soft sediment areas

Provide attachment surface for those
organisms who need them (kelp, oysters,
mussels, etc.)
• Often associated with high energy areas
• High diversity (complex topography,
reduced fishing)

Hard bottom areas