Marine LifeMarine Lifeand Ecologyand Ecology2.2. From From phytoplanktonsphytoplanktons

to to invertebatesinvertebates

Virtually all primaryproductivity on land comes from large

… seaweeds such as these do exist, but they need shallow water where Sunlight is available and firm substrate for anchorage

by their holdfasts.

… whereas microscopic unicellular plants (diatoms, dinoflagellates) and algae account

for most of the ocean’s primary productivity.

Phylum Phaeophyta or Brown Algae

Phylum Rhodophyta or Red Algae

Phylum Chlorophyta or

Green Algae

Seaweeds are large marine multicellular algae. These non-vascular plants are grouped as green, red and brown

l

SizeBacteriaBacteria

Producers Producers (photosynthesizers)(photosynthesizers)

BlueBlue--green algaegreen algaeCoccolithophoresCoccolithophoresSilicoflagellatesSilicoflagellatesDiatomsDiatomsDinoflagellatesDinoflagellates

Consumers (Oxidizers)Consumers (Oxidizers)ProtozoansProtozoans

RadiolariansRadiolariansForaminiferaForaminifera

<5 <5 µµmm

5 5 µµmm33--10 10 µµmm55--40 40 µµmm

2020--80 80 µµmm1010--50 50 µµmm

5050--500 500 µµmm100100--1000 1000 µµmm

NoneNone

NoneNoneCaCOCaCO33SiOSiO22SiOSiO22

Cellulose Cellulose or noneor none

SiOSiO22SiOSiO22

BenthicBenthic

Surface watersSurface waterswarm open oceanwarm open oceancool open oceancool open ocean

upwellingupwellingwarm quiet waterswarm quiet waters

Surface waters and Surface waters and sedimentssediments

Skeletalmaterial Habitat

Unicellular Unicellular Marine LifeMarine Life

Moss

Fern

Marsh grass

Kelp bed

0 24001600800

800

400

0

Distance from shore (km)Distance from shore (km)

Cel

l cou

nts

per 5

0 cm

Cel

l cou

nts

per 5

0 cm

33of

wat

erof

wat

er

DiatomsDiatoms

DinoflagellatesDinoflagellates

CoccolithophoresCoccolithophores

Marine plantsLand plants

SpermatophytaeSpermatophytae(seed bearing plants)

Pteridophytae(ferns)

Bryophytae(moss)

Thallophytae(algae and fungii)

SpermatophytaeSpermatophytae(seed bearing plants)

Thallophytae(algae and fungii)

Mangroves thrive in warm tropical waters, kelp prefers cooler waters.

Photomicrograph of tiny marine bacteria (~1 µm) attached to the larger diatoms.

Cyanobacteria(x 3000 magnification)

Diatoms

CoccolithophoresCoccolithophoresCoccolithophoresCoccolithophores

DinoflagellatesDinoflagellates

Marine invertebratesPhylum Porifera (Sponges)Phylum Cnidaria (Corals, Portugese Man-of-War, Jellyfish)Phylum Mollusca (Clams, Snails, Octopi)Phylum Anthropoda (Crabs, Shrimp, Lobsters, Copepods)Phylum Echinodermata (Sea Stars, Brittle Stars)Marine worms (Polychaeta, Vestimentifera)

Marine vertebrates

Marine animals

As Robert May (Scientific American, October 1992) has argued, most of the species display a predictable

relation between physical size and populationsize: the smaller they are, the more

abundant they tend to be.

Characteristic size (meters)

1 mm 1 cm 1 m

Implication: More species< 1 mm await discovery

than ones > 1 cm.

Jellyfish are cnidarians which lack the polyp stage of the life cycle. Therefore, they are always in the medusae stage. They are considered plankton because they cannot swim on their own--they are dependent upon the current to take them places. They are normally found in the epipelagic layer of the ocean.

The deep scattering layerThe deep scattering layer

Zooplankton concentration shows two peaks in the very productive summertime subarctic or cold temperate waters: • some are feeding at the surface,

while• others are resting, or metabolizing

what they have consumed, just below the photic zone.

In contrast, in the tropics, the zooplankton concentration is on the photic surface waters.

Yellow sponges on a reef. Sponges

are filter feeders - they filter their food particles from

water that passes

through them

An anemone is a cnidarian, a simple animal consisting of an open gut surrounded by tentacles - stinging cells in these tentacles help paralyze small prey that the tentacles then help bring into the gut.

Jellyfish, a cnidarian, consuming a fish that it has captured

A bizarre new species of jellyfish has been discovered in the deep waters off the Californian coast. The bell-shaped creature spans a meter in diameter and has been nicknamed "big red", because of its unusual deep red color. The US and Japanese teams that discovered it say the species deserves its own subfamily.

Tiburonia granrojo was discovered using video cameras on deep-diving remotely operated vehicles (ROVs). Its color and shape set it apart from its other gelatinous relatives, but it has another unusual characteristic —a complete lack of tentacles.

Bizarre new jellyfish discovered18:03 07 May 03NewScientist.com news service

Phylum Porifera

Orange Finger SpongePurple and Yellow Tube Sponge

The animals of the class hydrozoa

have both a polyp and medusa

stage.Siphonophores

are a type ofhydrozoan with a

float for buoyancy.

Probably the most famous of these is

the speciesphysalia, the

Portugese-man-of-war, which is a type of colonialsiphonophore.

Marine worms include

Octopus

Mussels

krill

crabs

barnacles

sea urchin

starfish

sea cucumber