LEFT Limpets carrying tufts of Enteromorpha on their shells. This is an ideal place for the seaweeds to grow since the limpets cannot turn round to graze these epiphyte
⚫ Fig.p65
Most epiphytic species are fast growing, short-lived and filamentous, for example,丝状的红藻 Polysiphonia lanosa(多管藻)经常附生于 Ascophyllum(囊叶藻) 的叶状体上 Generally, epiphytes do not grow on rapidly growing parts of the thallus. Therefore Laminaria(it t) and Macrocystis(巨藻) stipes(叶柄) may have large standing crop of epiphytes whereas the rapidly growing fronds(HF [)or blades are largely free of epiphytes Fast-growing species such as U/va and porphyra are rarely covered with epiphytes-they simply grow too fast for the epiphytes to take hold
Most epiphytic species are fast growing, short-lived and filamentous, for example, 丝状的红藻Polysiphonia lanosa（多管藻）经常附生于Ascophyllum（囊叶藻） 的叶状体上。 Generally, epiphytes do not grow on rapidly growing parts of the thallus.Therefore Laminaria(海带) and Macrocystis(巨藻) stipes(叶柄) may have large standing crop of epiphytes whereas the rapidly growing fronds(叶面) or blades are largely free of epiphytes. Fast-growing species such as Ulva and Porphyra are rarely covered with epiphytes—they simply grow too fast for the epiphytes to take hold
●5)防止被附生植物附着 Epiphytes can harm their hosts by blocking out the light and taking up nutrients from the surrounding water Layer of epiphytes can act as effective barriers to exchange processes including gaseous exchange, reducing the hosts growth rate
⚫ 5) 防止被附生植物附着 Epiphytes can harm their hosts by blocking out the light and taking up nutrients from the surrounding water. Layer of epiphytes can act as effective barriers to exchange processes, including gaseous exchange, reducing the host’s growth rate
● Some species, including Chondrus crispus(皱波角叉 菜), Halidrys siliquosa(角长角藻), regular! y slough (i their surfaces, thereby ridding themselves of any build up of epiphytes ● Enteromopha intestinalis(肠浒苔) constantly produces new cell wall layers, while shedding outer layers of the wall, to ensure that it remains epiphyte free e Some species produce chemical deterrents to prevent epiphytes settling Phenolics(p)and halogenated lipids(卤化油脂) are thought to play such a role
⚫ Some species, including Chondrus crispus(皱波角叉 菜), Halidrys siliquosa（角长角藻）, regularly slough （脱落） their surfaces, thereby ridding themselves of any build up of epiphytes. ⚫ Enteromopha intenstinalis（肠浒苔） constantly produces new cell wall layers, while shedding outer layers of the wall, to ensure that it remains epiphyte free. ⚫ Some species produce chemical deterrents to prevent epiphytes settling. Phenolics(苯酚) and halogenated lipids（卤化油脂） are thought to play such a role
Trying not to be eaten: Adaptations in benthic algae against grazing 1)藻体形态 Algal morphology Many grazers show considerable species selectivity and this may be related to algal morphology or size Grazing difficulty increases from microalgae(diatoms blue-green algae) through filamentous(丝状体,如刚 毛藻、水云), foliose(叶状体,如石莼), corticated (带外皮的,如软骨藻), leathery form(革状种类,如 海带、墨角藻), cartilaginous form(软骨质形态,如仙 掌藻、珊瑚藻) and ultimately to crustose coralline algae(壳状、珊瑚状藻类,如石枝藻)
Trying not to be eaten: Adaptations in benthic algae against grazing ⚫ 1）藻体形态 Algal morphology Many grazers show considerable species selectivity and this may be related to algal morphology or size. Grazing difficulty increases from microalgae (diatoms, blue-green algae) through filamentous（丝状体，如刚 毛藻、水云）, foliose（叶状体，如石莼）, corticated （带外皮的，如软骨藻）, leathery form（革状种类，如 海带、墨角藻）, cartilaginous form（软骨质形态，如仙 掌藻、珊瑚藻） and ultimately to crustose coralline algae（壳状、珊瑚状藻类，如石枝藻）