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22 Cards in this Set
- Front
- Back
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Temperature variation |
- affects the latitudinal range of most marine species (depends on ocean currents) |
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Homeotherms (endotherms) |
- maintain constant body temperature - have high metabolic demand (especially at low temperatures) - very energetically costly - constant cellular chemical reactions |
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Poikilotherms (ectotherms) |
- body temp varies with environment - metabolic demand decreases with low temp - low metabolic efficiency - no cost of keeping body temp up or constant - higher metabolic rate with CC heat exchange |
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Heat Regulation |
- circulation: bring blood to surface to cool - evaporation: allows heat loss - sitting in the sun when cold - light colors to reflect sun - homeotherms: insulated with blubber, fur, hair, feathers - countercurrent heat exchange |
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Cold Regulation |
- glycoproteins and glycopeptides to keep from freezing |
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How do changing temps affect marine life? |
- ranges extend towards poles - ranges extend to deeper water - effects population numbers in non migrating species |
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What marine groups are less tolerant to salinity changes? |
- echinoderms - pelagic planktonic organisms |
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Osmosis |
- movement of water across a membrane permeable to water, due to difference in solute concentration on either side |
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Diffusion |
- random movement of dissolved substances across a semi permeable membrane;tends to equalize concentrations - makes it difficult to regulate physiologicallyimportant ions |
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Osmoconformers |
- tissues and cells tolerate dilution - isotonic: internal salinity matches environment - tunicates, jellies, anenomes |
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Osmoregulators |
- maintain internal salinity despite environment - fishes, mollusks, polychaetes, some crustaceans - some only osmoregulate in certain salinities |
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Ion Regulation |
- marine fish - hypo osmotic to sea water - lose water by osmosis - gain salt thru food and water diffusion - drink seawater - concentrated pee - active salt excretion by chloride cells |
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Osmolytes |
- regulate cell volume - free amino acids (e.g., glycine, alanine, taurine) used by many invertebrates, bacteria, hagfishes - urea used by sharks and coelacanths - glycerol, mannitol, sucrose used by seaweeds,unicellular algae |
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Habitats low in oxygen |
- anoxic layer in sediments - oxygen minimum layers: where organic matter accumulates and decomposes - seasonal O2 changes: hypoxic zones (dead zones) |
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Oxygen consumption |
- increases with body mass - increases with activity - is higher for homeotherms |
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Oxygen uptake: simple diffusion |
- for small organisms with limited activity
- cnidaria, jellies |
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Oxygen uptake: gills or lungs |
- for fish - high surface area (lamella) - circulatory system brings O2 to tissue - capillaries transfer O2 to tissue - water flows against blood to maximize O2 uptake (diffusion gradient) |
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Blood pigments |
- increase blood capacity for carrying O2 - hemocyanin, hemerythrin, chlorocruorin, hemoglobin - myoglobin has a higher affinity than hemoglobin (for animals that don't hold their breath) |
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How animals reduce O2 needs in hypoxic conditions |
1. reduced activity at low tide 2. prolonged dives: peripheral vasoconstriction, reduced heart rate, reductions in energetic costs of swimming |
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Photosynthetic rate variation in photic zone |
- sometimes inhibited due to too much light - depth of greatest productivity just under 100m - generally decreases with depth |
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Accesory pigments |
- adaptation to photosynthesize at various light levels |
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Where does light availability end? |
- below the mesopelagic zone |
