A Survey of Life in the SeaA Survey of Life in the Sea...Reproductive Cycle of AlgaeReproductive Cycle of Algae • Alggp yae reproduce asexually. • Thallus: leafy part of algae.

A Survey of Life in the SeaA Survey of Life in the Sea

Chapter 4

ClassificationFirst, helps identify the relationship betweenClassification

Why classify?

relationship between organisms.

y y

Second classification

Third, to avoid confusion.

Second, classification requires scientists to clearly identify key h t i ti f hcharacteristics of each

organism.

Classification TaxaClassification Taxa

• Created in 1758 by Carolus Linnaeus.y• Divided organisms into taxa, which are divisions

with subdivisions.• Most specific is called species.• Most general is called kingdom.

There are 7 subdivision levels• There are 7 subdivision levels.Taxonomist: scientists who study the relationship

between and classify them.y

Various Classification MethodsVarious Classification Methods

Domains: include Archaea, Eubacteria, and Eukaryota, , y

Empires: Prokaryota and Eukaryota

5-Kindoms: Monera, Protista, Fungi, Plantae, and AnimaliaAnimalia

6-kingdoms: Archaeabacteria Monera Protista Fungi6 kingdoms: Archaeabacteria, Monera, Protista, Fungi, Plantae, and Animalia

7 Subdivision Levels Class7 Subdivision Levels

Ki d

Class

Kingdom

Species

Phylum

Genus

Phylum

Family

Order

Family

Prokaryotes• Structurally far simpler than the cells found in the

organisms of other kingdoms.• Don’t have the same complex internal membrane• Don t have the same complex internal membrane

structure.• Lack chromosomes or nucleus.• Simply have a ring of DNA or RNA.• Do not have mitochondria.• Some can accomplish photosynthesis but lack

chloroplasts.• Among the smallest organisms• Among the smallest organisms

(range from 1 to 10 microns 1 micron = 0.001mm. or 0.00003937 inches)

• Oldest type of organisms. Archaea originating 3.5 billion years ago.

ArchaeaArchaea

• One of three domains.• Best known for being extremophiles.

Halophilesp

Thermoacidophiles

MethanogensMethanogens

• Live near deep hydrothermal vents, high salinity pools, in highly acidic environments, in sulfur pools.

• Many are chemosynthesizers.

• Thought to be the first autotrophs.

• Theorized to be the oldest forms of life in existence.

Bacteria• Among the oldest life forms but not as old as

archaea.• Are extremely adaptable and capable of processes• Are extremely adaptable and capable of processes

that no other organisms can accomplish.• One important group are the cyanophytes also called

Cyanobacteria

• Also known as blue-green algae• Scientists theorize that photosynthesis evolved with

cyanophytescyanophytes.• Scientists think they created oxygen in the

atmosphere.• Responsible for nitrogen fixation.

Marine AlgaeMarine Algae

• The ocean’s counterparts of plants.p p• Account for 90% of the Earth’s primary productivity

and oxygen production. • The foundation for all marine life.

Reproductive Cycle of AlgaeReproductive Cycle of Algae

• Algae reproduce asexually.g p y• Thallus: leafy part of algae.• Specialized cells at the edge of the thallus produce

spores.• Sporophyte thallus: thallus that produces spores;

diploiddiploid.• Spores produced are haploid. Have flagella that beat

back and forth.• Spores reach ocean bottom and develop into a leafy

thallus that produces gametes; called gametophyte thallus and are haploidthallus and are haploid.

Life Cycle of Ulva (Green Algae)

• Composed of two separate stages:1. sporophyte generation2. gametophyte generation

Alternation of generations: succession of two types of generations.

DiatomsDiatoms

• Phylum Bacillariophytay p y• 5,000 to 50,000 species• Larger than prokaryotes• Reproduce asexually by budding, alternating with

sexual reproduction.Can cause HAB’s Harmful Algae Blooms• Can cause HAB’s – Harmful Algae Blooms.

• Some produce toxins and can be concentrated in fish and other species p

• Can cause poisoning when people eat contaminated animals.

Saxitoxin, the neurotoxin responsible for ParalyticSh llfi h P i i h t f b th dShellfish Poisoning – shortness of breath, dry mouth, lack of coordination

Brevetoxin, the neurotoxin responsible for Neurotoxic Shellfish Poisoning – vomiting,

l d hnausea, slurred speech

Domoic acid, the neurotoxin responsible for pAmnesic Shellfish Poisoning – excess calcium in nerve cells causes brain degeneration.

DinoflagellatesDinoflagellates

• Phylum Dinophyta or Dinoflagellatay p y g• Can cause toxic red tide• Most are autotrophs

Ex: Noctiluca (nocturnus + lucent)Ex: Noctiluca (nocturnus + lucent)1. Capable of bioluminescence2. Have specialized structures called photophores,2. Have specialized structures called photophores,

which contain a compound called luciferin and an enzyme called luciferase.

Ex: Symbiodinium1. Live in coral polyps1. Live in coral polyps2. Provide their host with food via photosynthesis3. They get nitrogenous wastes from the coral4. Without them, coral could not exist

Green AlgaeGreen Algae

• Phlyum Chlorophytay p y• Most closely related to plants.• Many species grow attached to rocky

substrates on or near the ocean’s surface;substrates on or near the ocean’s surface; lack typical roots, stems, and leaves.

• Water passes directly into their cells from p ytheir surroundings.

• 3 types:1 Enteromorpha1. Enteromorpha2. Codium3. Acetabularia3. Acetabularia

Enteromorpha• Grows abundantly in shallow waters• Can tolerate temperatures that vary widely from

summer to winter and periods of wetness and drynessCan adapt to temporary freshwater• Can adapt to temporary freshwater environments

CodiumCodium

Spong green algae ith a branching str ct re• Spongy green algae with a branching structure.• Can grow to more than 6 meters.• Attaches itself to hard substrates like rocks andAttaches itself to hard substrates, like rocks and

shells.• When attached to mature shellfish, it affects their

survival and makes it difficult to harvest them.

AcetabulariaAcetabularia

• A very large single cell that grows to about 8cm in y g g glength.

• Shaped like a miniature umbrella.• Grows in the warm waters of the Gulf of Mexico and

off the coast of Florida.

Brown AlgaeBrown Algae

• Phylum Phaeophyta• Phylum Phaeophyta• Have a brown or green-olive color• Provide shelter or nutrients for other

organisms• Provide materials the people find valuable

3 t• 3 types:1. Sargassum2 Laminaria2. Laminaria3. Fucus

SargassumSargassum

• Floats on the water’s surface in the S Atlantic Ocean• Floats on the water s surface in the S. Atlantic Ocean and in some seas off the coasts of Asia.

• Grows in abundance in an area known as the S S (l t d i th iddl N Atl tiSargasso Sea. (located in the middle N. Atlantic Ocean)

• Fish, shellfish, and young sea turtles use it for , , y gprotection.

Laminaria

• Species of kelp• Thrives in colder waters of the temperate zones,

especially along the coasts of Maine and Californiaespecially along the coasts of Maine and California.• Attaches to rocks with a large and very sturdy holdfast.• Can reach a length of more than 60 meters. Grows to

about a third of a meter per day.• Fish, shellfish, sea urchins, sea lions, sea otters, and

sharks live in and around giant kelp forests.s a s e a d a ou d g a t e p o ests• Contains algin – a chemical used in various prepared

foods, medicines, paints, and paper products.

FucusFucus

• Also called Rockweed.• Attaches to rocks in the intertidal zones of the Atlantic,

Pacific and Gulf coastsPacific, and Gulf coasts.• Holdfast: tough, fibrous pad of tissue used for anchoring

to rocks.• Some species contain air filled bladders which help keep

it afloat and upright in water so that it can absorb more of the sun’s energy to carry out photosynthesis.

• Sea snails, small crabs, barnacles, worms, and other small creatures are found underneath it.

Red Algae• The most abundant and commercially valuable of the

marine algae.Ph l Rh d h t• Phylum Rhodophyta

• Found on rocky shores from the intertidal zone to the subtidal zones.the subtidal zones.

• Contain the red pigment phycoerythrin and the blue pigment phycocyanin that enable red algae to use th li it d li ht th t t t th d tthe limited light that penetrates the deep waters where they can be found.

• 3 types:3 types:1. Porphyra2. Irish moss3. Coralline algae

PorphyraPorphyra

• Also called nori.• Grows attached to rocks in the lower

intertidal zone, from the Carolinas northward.,• A tasty seaweed that is cultivated in Japan.

Irish moss

• Short bushy seaweed found in the lower intertidal• Short, bushy seaweed found in the lower intertidal and subtidal zones.

• Carpets rocks with a dense, spongy growth.• Harvested for use as a food item.• Contains a chemical carrageenan which is used as a

binding agent in ice cream p ddings andbinding agent in ice cream, puddings, and toothpaste.

• Other soft red algae supply a chemical called agarg pp y gwhich is used to make foods and medicinal products, and as a medium for growing bacteria.

Coralline algaeCoralline algae

• Have calcium carbonate in their cell walls, the chalky substance found in shells and coralssubstance found in shells and corals.

• Can be found attached to rocks in the lower intertidal zone from Canada to Long Island.g

• Hard and brittle.

Beach PlantsBeach Plants• Upper Beach: area where beach plants are found.• Winds move the sand into small hills called dunesWinds move the sand into small hills called dunes.• Dunes are held in place by the roots of the plants.• Resembles the conditions of a desert.• Some common plants found in dune areas:

Prickly pear cactus

Seaside goldenrod

M i GMarine Grasses

Marsh GrassesMarsh Grasses

• Grow along sandy beaches of calm bays.Grow along sandy beaches of calm bays.• 3 examples:

1 reed grass1. reed grass2. cordgrass3 glasswort3. glasswort

Reed GrassReed Grass

• Also known as Phragmites.Also known as Phragmites.• Can be easily identified by its fluffy brown

tassels

Cordgrass• Can be found along the water’s edge, in the intertidal

zone.H i l d t ti th t h l th i i• Have special adaptations that help them survive in salty environments.

• Special glands in the leaves are able to excreteSpecial glands in the leaves are able to excrete excess salt.

• Decaying cordgrass supply nutrients to plankton.• 2 common species:

Spartina alterniflora Spartina patens

GlasswortGlasswort

• Also called pickle weed.p• A salt-tolerant marsh grass.• Grows in the upper intertidal zone, from

Massachusetts to the Gulf Coast.• Their thick waxy stems store the freshwater that they

need to surviveneed to survive.

Salicornia

Sea GrassesSea Grasses

• Found in the shallow subtidal zones alongFound in the shallow subtidal zones along many shores.

• 2 examples:p1. Eel grass2. Turtle grass2. Turtle grass

Eel Grass (Zostera marina)• Found in the cooler waters along the Atlantic and

Pacific coasts.• Lived in the protected bays and inlets of the subtidal• Lived in the protected bays and inlets of the subtidal

zone.• Their tufts grow close together, forming beds that

provide hiding places for mollusks, arthropods, and fish.

Turtle Grass (Thalassia)• Found in the bays and inlets of warmer waters, along

the coasts of Florida and the Gulf of Mexico.• Have underground stems, rhizomes, which forms an

interlocking mat that helps stabilize the sandy seafloor.seafloor.

• Home to fish and invertebrates; an important food source for sea turtles.

Mangrove Trees• Able to grow in salt water.• Grow close together forming a thick jungle of

vegetation.• Called mangrove swamp or community.• Prop roots: anchor the trees into the muddy

sand.• The tangle of the roots acts as a net to trap• The tangle of the roots acts as a net to trap

organic debris brought in by the tides.• Seedpods, resembling like small pencils and 10-Seedpods, resembling like small pencils and 10

12cm in length, fall into the water when ripe. They float vertically and are carried by ocean currents to the locations where they grow into mangrove seedlings.

• Bacteria plankton and decaying remains of• Bacteria, plankton, and decaying remains of marine organisms are trapped by mangrove roots and provide nutrients for the community.

• Mangroves provide food and hiding places for many animals.

• Mangrove swamps are called the “nurseries” of the sea.

Red mangrove White mangrove

Black mangrove