(Revised 3 March 2008)
I. Ecology
B. Organisms on earth (life forms)
2. To maintain life, cells must cellularly respire
carbon dioxide + water = food + oxygen (w/ chlorophyll, light) ii. Animals (consumers, heterotrophs) eat to get food
- carnivores eat animals - omnivores eat both plants and animals
- uses up oxygen and produces carbon dioxide
- produces oxygen for their use and extra for animal use 3. Biggest ecosystem = Earth
b. next step = herbivorous animals (consumers) c. top step = carnivorous animals (consumers)
b. microscopic based (phytoplankton, in all waters - shorelines and open ocean)
B. Intertidal rocky shore zones of California are a result of physical and biological factors
ii. Wet 1/4 day, dry 3/4 day iii. Indicator species = periwinkle snails, fingernail limpets, and buckshot barnacles
ii. Wet 1/2 day, dry 1/2 day iii. Indicator species = balanus barnacles, gooseneck barnacles, and mussels (mussels would cover Zones 2, 3, 4, and subtidal to 20 feet except for starfish)
ii. Wet 3/4 day, dry 1/4 day iii. Indicator species = aggregating anemones
- hold shell/rock pieces on sides (protection, shade) - clones fight along edges to leave anemone free zones - acrorhagi deflated and kept hidden until touching an anemone with different genes - acrorhagi used only to fight between members of this species not from same parent, or starburst/sunburst anemones
ii. Usually always wet iii. Everything and anything could be found here but surfgrass, starburst anemones and starfish are used as indicator species
- starburst anemones have acrorhagi and fight with each other - or any other anemones - starburst anemones usually nicely spaced starting about 0 tide level 3. Physical factors usually determine how high an organism can live in intertidal - primarily desiccation 4. Biological factors usually determine lower limit of organisms range in zones
b. Predation - larger predators can't dry out so stay in zone 4 and only venture up at hi tides. c. Starfish are considered a "keystone species" because their presence has a profound effect on the diversity of the rocky intertidal
b. Fingernail Limpets - herbivores with radula, shell made to match home scar c. Buckshot Barnacles - filter feeders with legs, hard shell can close d. Balanus Barnacles - filter feeders with legs, hard shell can close, crowds out buckshots e. Gooseneck Barnacles - filter feeders with legs, hard shell plates can close, MPL searches for members of its own species so they usually live in crowded clumps f. Mussels - filter feeders with mucus on gills, attached with strong threads, can crowd out all species if left unchecked by predator g. Aggregating Anemones - omnivore with tentacles, clone, clone wars with acrorhagi h. Starfish (= sea stars) - carnivores on shellfish, suckers hold and open shellfish, evert stomach into open shellfish, digest i. Starburst/Sunburst Anemones - omnivores with tentacles, no clones, acrorhagi keep them spaced, green color from symbiotic algae j. Surfgrass - photosynthetic, great hiding place, sunny days oxygen bubbles seen in tidepools
b. cracks, overhangs, cervices remain moist so zones elevated c. water pools (but may get very hot in the sun) d. north vs. south facing rocks - south facing rocks get more winter sun so dry out faster in northern hemisphere e. seasons f. sand movement III. Plankton
b. pelagic (water dwelling)
ii. planktonic (floaters or feeble swimmers)
ii. Zooplankton = animal plankton (eat)
ii. Meroplankton = plankters spending only part of life in plankton
- hypotheca = bottom of frustule with more pores - side view is square (or rectangular) like a hat box - top view and bottom view is circular - when conditions are bad diatoms die, sink, the cell decomposes and the frustule breaks mixes with sand and mud. This is diatomaceous earth and is mined by man for its filtering properties and the frustule pieces used as grit c. Reproduction
- sexually with eggs or sperm formed by the diatoms that are too small to divide any more
* after fertilization, original female (now a zygote) sheds tiny frustule, swells to largest size and secretes new frustule
- variations include centric (round), oval and fan shapes, colonies - one species makes domoic acid (toxic to vertebrates in high concentrations) - important oxygen producers in ecosystems (first step in food chain) - holoplanktonic
ii. hypocone is bottom with two points iii. few forms "naked", w/o this shape iv. 2 flagellae - one in groove around middle other one trailing
ii. some also eat, some are both photosynthetic and 'eaters'
ii. sexual reproduction occurs but is not understood
ii. many have flotation mechanisms (spines, colonies, oil) iii. holoplanktonic
b. meroplankton
2. Holoplanktonic forms are primarily copepods
-feed on phytoplankton (2nd step in food chain) -most common zooplankter
2. Spring - hi light levels, hi nutrients; hi phyto, hi zoo (big bloom)* 3. Summer - hi light levels, thermocline so low nutrients and nutrients used up by spring bloom; lo phyto (nutrient limited), lo zoo (food limited) 4. Fall - declining light, no thermocline so nutrients available, second smaller bloom trailing off as winter comes; hi phyto, hi zoo (small bloom) * * red tide, shellfish poisoning, bioluminescence, and domoic acid events common during blooms (This is generally May 1 through October 31 in California.) IV. Tides produce the intertidal zonation (semi-diurnal mixed tides cover most of Earth)
2. Equal bulge on opposite side of Earth (centrifugal force) 3. Earth rotates about once per day relative to moon so a point on the surface of Earth experiences two high and two low water levels (tides) per day 4. High and Low tides of one day are usually of unequal height because Earth's axis is tilted relative to the moon
2. At first and third quarter moon when earth, moon and sun are at right angles, the tides are less amplified = neap tides (lower highs and higher lows) 3. Alternate monthly between one week amplified spring tides, one week less amplified neap tides, one week amplified spring tides, and one week less amplified neap tides, etc.
B. Marine life has great diversity in the Kingdom Animalia (9 common phyla will be covered in this class, see syllabus for lecture dates. Up to this exam only the first four phyla are required.)
2. Cnidaria (stinging animals) 3. Platyhelminthes (flatworms) 4. Annelida (segmented worms) 5. Bryozoa (bryozoa) 6. Mollusca (snails, bivalves, octopus) 7. Arthropoda (crabs, lobster, shrimp) 8. Echinodermata (seastars, urchins) 9. Chordata (squirts, fish, sharks, rays, whales, seals, etc.)
2. incurrent pores (ostia) microscopic 3. filter chambers lined with collar cells (choanocytes) 4. epidermal cells cover outside 5. general cells make up bulk of body 6. spicules of calcium or glass secreted by general cells act as protection and support
2. Water turbulence brings plankton by sticky collar and it gets stuck 3. Plankton is injested by collar cell 4. Food shared with all cells
b. regeneration c. fragmentation d. budding e. gemmules
b. eggs and sperm shed into water thru filter chamber and sperm washed out (eggs usually kept in filter chamber) c. egg and sperm from same species may come together in the water and fertilization of the egg occurs. d. The fertilized egg is called a zygote and develops into a parenchymella larvae (circular with cilia = MPL) usually in filter chamber e. parenchymella larvae are released into ocean from filter chamber through osculum and they sink and swim in the plankton (= MPL) f. planktonic parenchymella sinks and then settles, when it is competent, if conditions are right and metamorphoses to a mini benthic sponge attached to a solid substrate
2. Boring sponge is common on shells (can dissolve calcium) leaves pin holes 3. Glass sponge used as symbol of marriage in some Asian cultures because of small crustaceans that get trapped inside as planktonic larvae and can not get out. This deep water sponge has fused spicules leaving a skeletal outline when it decomposes.
2. One rare species (from mudflats) can give human skin a rash and kill other marine animals if put in a closed container for a few hours
2. Radially symmetrical 3. Internal space for digestion (no anus) 4. Nematocysts concentrated on tentacles but may be anywhere
2. Digestion in internal space, undigested material spit out mouth 3. Nematocysts are key for feeding (also for defense)
b. Cell has 'inside out' stinger c. Cell has trigger d. Firing when trigger is stimulated by touch or chemicals
ii. Water pushes stinger out and turns it right side out (quickly) iii. stinger remains attached to nematocyst cell iv. after firing, nematocyst cell is discarded (but new ones take its place) v. only a few nematocysts are fired with each stimulus (so they reserve 'fire power')
ii. sticky iii. entangling
ii. gonozoids on colony bud off medusae (very small) iii. separate sexed medusae shed eggs and sperm into water, fertilization usually in water iv. zygote grows into planula larva (oval with cilia) (planktonic) v. planula larva sinks and swims till it is competent and then settles to form a polyp vi. polyp divides by asexual reproduction to form colony of polyps covered with external continuous skeleton of chitin (fingernail-like material) = hydroid
ii. sperm shed, eggs shed (or brooded on oral arms) iii. fertilization external iv. zygote develops to planula larva v. planula larva is planktonic and sinks and swims vi. planula settles and grows to scyphistoma (polyp) vii. scyphistoma strobilates to form strobila and bud off tiny ephyrae (medusoid) viii. ephyrae (mini adults) released into plankton and grow to adults
ii. sperm and eggs generally shed into water iii. fertilization external iv. zygote develops to planula larvae v. planula larvae sinks and swims in plankton vi. planula settles to form a polyp
b. a few colonial hydrozoans are pelagic/planktonic (not benthic)
ii. Portuguese man-of-war, = Physalia (not in CA.) iii. "sea snot"
now put in own class (Class Cubozoa)
b. Corals
- corals are solitary or colonial (colonial forms from asexual reproduction of original polyp, corallites cemented together)
- 8 pennately branched tentacles on each polyp - generally secrete common covering with holes for polyps (no radiating septa) - often bioluminescent for defense
2. Before touching any cnidarian one should be sure that its nematocysts cannot sting you VIII. Phylum Platyhelminthes (marine forms called flatworms)
2. mouth (with short eversible pharynx) usually underside in middle 3. gut with three lobes (no anus) 4. May have eyespots - seek dark areas but can't see images C. Reproduction Asexual(excellent regeneration) and Sexual (no MPL, crawl away young) D. Atypical forms (variations) - nothing special E. Poisoning - none
2. complete digestive tract (mouth - gut - anus) 3. pair of parapodia on each segment 4. setae (bristles from parapodia) 5. varied heads and feeding - those with jaws are usually carnivores or herbivores, those with feather dusters are filter feeders, those with plain mouth may be deposit feeder 6. tubes present in some species (sand, mucus, paper-like material) C. Reproduction varied with both asexual and sexual (trochophore MPL common) D. Atypical forms (variations) - too many to mention E. Poisoning - jaws and/or setae in some species |
| © 2000 Genny Anderson (Revised 3 March 2008) |
|