Marine Life and Ecology 2. From phytoplanktons to invertebates
Virtually all primary productivity 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 Seaweeds are large marine multicellular algae. These nonvascular plants are grouped as green, red and brown Phylum Chlorophyta or Green Algae
Unicellular Marine Life Bacteria Size <5 µm Skeletal material None Habitat Benthic Producers (photosynthesizers) Blue-green algae Coccolithophores Silicoflagellates Diatoms Dinoflagellates 5 µm 3-10 µm 5-40 µm 20-80 µm 10-50 µm None CaCO 3 SiO 2 SiO 2 Cellulose or none Surface waters warm open ocean cool open ocean upwelling warm quiet waters Consumers (Oxidizers) Protozoans Radiolarians 50-500 500 µm Foraminifera 100-1000 1000 µm SiO 2 SiO 2 Surface waters and sediments
Moss
Fern
Kelp bed Marsh grass
Cell counts per 50 cm 3 of water 800 400 0 Diatoms Coccolithophores Dinoflagellates 0 800 1600 2400 Distance from shore (km)
Land plants Spermatophytae (seed bearing plants) Marine plants Spermatophytae (seed bearing plants) Pteridophytae (ferns) Bryophytae (moss) Thallophytae (algae and fungii) Thallophytae (algae and fungii)
Mangroves thrive in warm tropical waters, kelp prefers cooler waters.
Photomicrograp h of tiny marine bacteria (~1 µm) attached to the larger diatoms.
Cyanobacteria (x 3000 magnification)
Diatoms
Coccolithophores
Dinoflagellates
Marine animals Marine invertebrates Phylum 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
Characteristic size (meters) As Robert May (Scientific American, October 1992) has argued, most of the species display a predictable relation between physical size and population size: the smaller they are, the more abundant they tend to be. Implication: More species < 1 mm await discovery than ones > 1 cm. 1 mm 1 cm 1 m
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 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
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
Bizarre new jellyfish discovered 18:03 07 May 03 NewScientist.com news service 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.
Phylum Porifera Purple and Yellow Tube Sponge Orange Finger Sponge
The animals of the class hydrozoa have both a polyp and medusa stage. Siphonophores are a type of hydrozoan with a float for buoyancy. Probably the most famous of these is the species physalia, the Portugese-man-ofwar, which is a type of colonial siphonophore.
Marine worms include
Octopus
Mussels
krill
crabs
barnacles
sea urchin sea cucumber starfish