文档介绍：ADAPTATION OF PELAGIC LIFE
Lin Yuan-Shao (林元烧), tel: 218 9433, email: ******@xmu.
Cao Wen-Qing (曹文清), tel: 218 9433, email: ******@xmu.
Guo Dong-Hui (郭东晖), tel: 218 8471, email:******@.
Wu Li-Sheng (吴荔生), tel: 218 8455, email: ******@.
Fang Lv-Ping (方旅平), tel: 218 9433, email: ******@xmu.
Chapter 13
Adaptation of pelagic life
Significance of staying afloat
Keep buoyancy mechanism
Movement
§ Significance of staying afloat
Phytoplankton: to get enough light for photosynthesis.
Once sinking or being carried out of the photic zone by water movement, in generally, they will stop metabolism and die, unless they can somehow get back into the sunlit layer.
zooplankton: they need sunlight for their bio rhythm and their food is in the shallow water.
Staying afloat
To live in the water layers, organisms must stay in the epipelagic. All anisms face a fundamental problem——cells and tissue are denser than water.
Keep buoyancy mechanism
Organisms must avoid sinking to stay in the epipelagic. This is achieved by
Increased resistance
Increased buoyancy
The floaters
Reduced body density
Increased resistance
Surface-to-Volume Ratio
Organism’s shape
Long projections or spines
§ Increased buoyancy
The second way that anisms can stay near the surface is to have special adaptations that make them more buoyant. Unlike adaptations that help anism resist sinking, buoyancy reduces the tendency to sink.
Store lipids, such as oils or fats
Calanus with oil sac