Marine Biology 278

Apr. 2, 2008 REVIEW OUTLINE FOR EXAM II

NOTE: you might want to review topics from EXAM I / REVIEW OUTLINE I that apply to the current material. E.g.: temperature and life; wave action; light colors & UV

BENTHIC BIOLOGY

OVERVIEW of BENTHIC ADAPTATIONS: Why Movement Factors favor the evolution of sluggish, sessile animals using COST-BENEFIT idea. Thus marine animals are sometimes plantlike! Note how the following adaptations are often analogous to land plant adaptations:

3. BIOTIC interactions --OFFENSES

BEHAVIORAL

Carnivore Behaviors: hunt&chase (raptorial); ambush; creeping; sedentary/opportunistic

ANATOMICAL & PHYSIOLOGICAL/BIOCHEMICAL:

a) Crushing/smashing device - -i) crab claws; ii) fish jaws; iii) mantis shrimp! Know how each work. BIOMIMETICS why the interest in mantis shrimp claws?

b) Ambush weapons: harpooning/paralyzing/stunning/poisoning/suckering….

i) Cnidaria nematocysts; ii) cone snail harpoon; iii) snapping shrimp claw jet burst ; iv) octopods -- suckers know how each works!!! BIOPRODUCTS: why interest in cone-snail toxins?

4. ABIOTOIC--CURRENTS/WAVES –resisting/avoiding:

GLUES, other gripping mechanisms ! How MUSSEL byssal threads may work (more later).

5. LIFE-CYCLE Adaptations: r- vs K-selected (or strategies): apply cost-benefit idea!

Modes: a. Asexual (clonal) growth: mutual protection from predation, waves, etc.; rapid colonization

b. Planktonic Larval Stage: r-strategy: know this lifecycle, outcome, how larvae settle

--sluggish/sedentary spp need means of DISPERSAL

--and ways to RECOLONIZE habitats after destruction of adults

c. Direct Development: K-strategy; or mixed r- and K: many fishes, crabs, mammals

--mobile adults care for eggs, or put more energy into them as yolk, etc.

--young and old both usually mobile enough to disperse readily

ALSO: Sex-Reversal in some animals, e.g., clownfish: why useful; magic number in READING

LECTURES 15-16: OVERVIEW of BENTHIC ANIMALS: PHYLA as follows:

a. PORIFERA--filterers: pores (and exit osculum) and flagellated cells

b. CNIDARIA--carnivores: nematocysts, tentacles!! Polyp forms: Hydrozoa (simple,) Anthozoa (complex)

d. Platyhelminthes--carnivores: protrusible pharynx, hard tip stylet

e Pseudocoelomates: rotifers, gastrotrichs, etc.—MEOIFAUNA! (know definition)

f. Brachiopoda--filterer (spiral lophophore); clam-like 2-piece shell but has pedicle stalk & hole!

g. Bryozoa--filterer (tentacled /ciliated lophophore, horseshoe shape); zooids more advanced than polyps

h. MOLLUSCA—ARCHETYPE has head/foot; radula, shell. Features, feeding of classes:

i) Cl. Polyplacophora--8-plate shell; herbivores

ii) Cl. Gastropoda--1-piece shell; gone in slugs/nudibranchs; many feeding types

iii) Cl. Bivalvia--most filterers using gills; 2-piece hinged shell

iv) Cl. Cephalopoda--radula + beak: carnivores; shelled or reduced or lost shell (octopods)

i. Sipunculida--deposit feeder; sticky tentacles

j. Echiuroidea--filterers; proboscis, U-tube

k. Nemertina—ribbon worms, protusible sticky proboscis wraps prey

l. ANNELIDA; Cl. POLYCHAETA--segments/parapodia, chaetes; many feeding types

n. NEMATODA--many types of feeding; jaws; meiofaunal

o. ARTHROPODA subphylum CRUSTACEA; 2 pair antenna at front

i) Cl. Cirripedia--filterers (limbs); head grows into mantle=carapace/cement glands

iii) Cl. Malacostraca-- lobster, crab, hermit crab, many shrimp; isopods, amphipods

--SubPHYLUM CHELICERATA: Cl Pycnogonida: seaspiders

p. ECHINODERMATA--features of 5x-fold symmetry; skeleton; spines; tube feet

i) Cl. Asteroidea--carnivores (stomach evert) ii) Cl. Echinoidea--sand dollar, sea urchin types; Aristotle’s lantern; many feeding types; iii) Cl. Ophiuroidea--deposit feeders

iv) Cl. Holothuroidea--deposit, filter feeders; v) Cl. Crinoidea--sea lilies; mostly filter-feed

q. CHORDATA subphylum UROCHORDATA--2-siphon filtering system: Cl. Ascidea--tunicate form

r, CHORDATA subphylum VERTEBRATA: many feeding types: I) Agnatha;

ii) Cl. Chondrichthyes iii) Cl. Osteichthyes v) Cl. Reptilia vi) Cl. Aves vii) Cl. Mammalia

A. INTERTIDAL Zone

TECTONICS, Surface, Movements:: Basics of Rocky, Sandy, Muddy habitats and wave energy

TECTONICS: Active vs Passive margins -- differences and why

TIDES: SOLAR Tides create neap, spring tides: how

ROCKY SHORE COMMUNITY: Highest wave energy

ADAPTATIONS to Tide/Wave factors:

1. Wave Shock--pounding physically by waves, altered by tide level

a) Anatomical: shells ; streamlining ; elastic dissipation; Flexible polysaccharides in Macroalgae!

b) Physiological/biochemical:. GLUES & anchorages: --mussel byssal threads-- READING!!

c) Behavioral Avoidance—crevices; “boring” clams

d) Life-cycle: i) colonies give mutual protection; ii) planktonic larvae to recolonize destroyed area

2. Water availability/loss (evaporation problem):

a) Anatomical: shell, other waterproof coverings

b) Physiological/biochemical: "Tolerance"--algae dry up 60-90%; some chitons 30-70%; unknown how survive,

c) Behavioral Avoidance--crevices/under algae

d) Life-cycle: i) colonies give mutual protection; ii) planktonic larvae to recolonize destroyed area

3. Oxygen: gills don't work in air

a) Anatomical: Lungs—Littorina periwinkle! Isopod scavengers -- both live in upper intertidal

b) Physiological Tolerance: Dormancy & enhanced Anaerobic metabolism:

i) non-acid endproducts (cf. lactic); or ii) branch to modified Krebs-cycle path; yield more GTPs/ATPs

4. Temperature -- Pattern: rapid ∆T in sun exposed limpets, barnacles, etc.

a) Anatomical: Reflect/radiate: light-colored and/or sculpted shells; darker to absorb in polar

b) Physiological Tolerance: temperature-insensitive dormancy; how stress or heat-shock proteins might protect upper intertidal organisms

c) Behavioral Avoidance--crevices/under algae

d) Life-cycle: planktonic larvae to recolonize

5. Salinity--drastic changes possible in air: osmosis damage

a) Anatomical--waterproof coverings

b) Physiological: most exposed spp. killed by major changes, e.g. severe rainstorms

--BUT If changes within the range of 150/200-1500 mOsm:

i) Osmoregulation --tidepool fish: gills regulate blood by NaCl transport, reversible!

Or ii) Osmoconforming with Compatible Osmolytes: example of DMSP in algae!

c) Behavioral Avoidance--crevices/under algae

d) Life-cycle: planktonic larvae to recolonize; crucial since major storms can kill off adults.

6. Nutrients for producers: none when tide out; macroalgae cannot absorb from rocks

b) Physiological/biochemical: cyanobacteria & lichens symbiosis: PO₄ from rocks, and

--N2 fixation by cyanobacteria --reason for success in splash/upper zones!

7. Light Intensity: No canopy can develop due to waves

a) Anatomical--symmetrical blades

b) Physiol/Biochemical--UV absorbing pigments: READING on mycosporin amino acids=MAAs

BIOTIC: 8. Food/prey availability--none when tide out , so go dormant

Exceptions: animals with lungs! 1) Littorina; 2) Isopods; 3) BIRDS: Surf bird’s adaptation from the video

9. Predator exposure--more intense in LOWER zones

a) Anatomical-- shells; spines; CAMOUFLAGE: e.g., chiton with algae on it

b) Physiological/biochemical: toxins, noxious compounds

Phaeophytes--vacuoles w/H2SO4, etc.

c) Behavioral--avoidance

d) LifeCycle: as before

10. Competition: b) Physiol/Biochem: anti-competitor compounds

c) Behavioral: Territoriality--Anemone clone wars -- acrorhagia battles

ii) Farmer LIMPET patrols territory, removes competitors, slams carnivores!

c) LifeCycle strategy--colonize rapidly w/larvae and grow fast

ECOLOGY: Factors/Adaptations lead to ZONATION: be able to draw and explain zones and KITE diagrams of key factors; typical organisms

--Refuge and harsh-environment hypotheses; how this shows that variable abiotic stresses are <