Section outline

  • General

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  • 共生共生

    What you will learn
    ::你会学到什么

    • What is symbiosis
      ::何为共生
    • Types of symbiotic relationships
      ::共生关系类型

    A commensal shrimp sits on a sea slug, illustrating symbiotic relationships in marine life.

    Do interactions between species always result in harm?
    ::物种之间的相互作用是否总是造成伤害?

    A commensal shrimp sits on another sea organism , a sea slug. As a commensal shrimp, it neither brings a benefit nor has a negative effect on its host .
    ::一种同源虾坐在另一个海洋生物上,一种海龟。 作为同源虾,它既无好处,也无对宿主的消极影响。

    Symbiotic Relationships
    ::共生关系

    Symbiosis is a close relationship between two in which at least one species benefits. For the other species, the relationship may be positive, negative, or neutral. There are three basic types of symbiosis: mutualism , commensalism , and parasitism .
    ::共生关系是两个物种之间的一种密切关系,其中至少有一个物种受益。对其他物种而言,这种关系可能是正的、负的或中性的。 共生关系有三种基本类型:相互性、共生关系和寄生虫。

    Mutualism
    ::相互互助

    Mutualism is a symbiotic relationship in which both species benefit. An example of mutualism involves goby and shrimp (see the  Figure ). The nearly blind shrimp and the fish spend most of their time together. The shrimp maintains a burrow in the sand in which both the fish and shrimp live. When a predator comes near, the fish touches the shrimp with its tail as a warning. Then, both fish and shrimp retreat to the burrow until the predator is gone. From their relationship, the shrimp gets a warning of approaching danger. The fish gets a safe retreat and a place to lay its eggs .
    ::共生关系是两种物种都受益的共生关系。 共生关系的例子包括小犬和虾(见图 ) 。 近乎盲虾和鱼一起度过大部分时间。 虾在鱼和虾都居住的沙地上有一个洞。 当捕食者靠近虾时,鱼用尾巴抚摸虾作为警告。 然后,鱼和虾都退到洞里,直到捕食者消失。 虾从它们的关系中得到接近危险的警告。 鱼得到安全的退避和产卵的地方。

    A multicolored shrimp and green goby fish share a burrow, illustrating mutualism.
    The multicolored shrimp in the front and the green goby fish behind it have a mutualistic relationship.

    often occurs in species involved in mutualistic relationships. Many examples are provided by flowering plants and the species that pollinate them. Plants have evolved flowers with traits that promote pollination by particular species. Pollinator species, in turn, have evolved traits that help them obtain pollen or nectar from certain species of flowers. The flowering plants and the pollinators, such as a or insect, both benefit from the relationship. 
    ::许多例子来自花卉植物和授粉植物。植物进化了花卉,其特性促进了特定物种的授粉。反过来,花粉物种的进化特征有助于它们从某些花卉物种获得花粉或花蜜。花卉植物和授粉者,如昆虫或昆虫,都从这种关系中受益。

    Commensalism
    ::共社主义

    Commensalism is a symbiotic relationship in which one species benefits while the other species is not affected. One species typically uses the other for a purpose other than food . For example, mites attach themselves to larger flying to get a “free ride.” Hermit crabs use the shells of dead snails for homes. Another example of commensalism involves a whale and barnacles (see the Figure . The barnacles attach to the whale to gain greater access to food  and a secure place to live. The whale is unaffected by the relationship.  
    ::共生关系是一种共生关系,使一种物种受益,而其他物种不受影响。一种物种通常将另一种物种用于食物以外的目的。例如,老鼠用更大的飞翔来“免费搭乘 ” 。 寄居蟹用死蜗牛的炮弹作为家用。另一个共生关系的例子涉及鲸鱼和谷仓(见图 。挂在鲸鱼身上的谷仓是为了获得更多食物和安全的栖息地。鲸鱼不受这种关系的影响。

    A whale's back covered with barnacles, illustrating a commensalism relationship in nature.
    Whale and barnacles.

    Parasitism
    ::排他性

    Parasitism is a symbiotic relationship in which one species (the parasite ) benefits while the other species (the host ) is harmed. Many species of are parasites, at least during some stage of their life. Most species are also hosts to one or more parasites.
    ::寄生虫是一种共生关系,一种物种(寄生虫)受益,而另一种物种(宿主)受到伤害,许多物种是寄生虫,至少在其生命的某个阶段是如此,大多数物种也是寄生虫的宿主。

    Some parasites live on the surface of their host. Others live inside their host. They may enter the host through a break in the skin or in food or . For example, are parasites of mammals , including humans, cats, and dogs. The worms produce huge numbers of eggs, which are passed in the host’s feces to the environment. Other individuals may be infected by swallowing the eggs in contaminated food or water.
    ::有些寄生虫生活在宿主的表面,另一些寄生虫则生活在宿主内,它们可能通过皮肤破裂或食物破裂进入宿主,或者通过食物进入宿主,例如哺乳动物的寄生虫,包括人类、猫和狗。这些寄生虫产生大量的卵,这些卵在宿主的粪便中传到环境中。其他人可能通过在受污染的食物或水中吞下卵而感染。

    Some parasites kill their host, but most do not. It’s easy to see why. If a parasite kills its host, the parasite is also likely to die. Some parasites may cause relatively minor damage to their host.
    ::有些寄生虫杀死宿主,但多数虫杀不了宿主。 很容易理解原因。 如果寄生虫杀死宿主,寄生虫也有可能死亡。 有些寄生虫可能对宿主造成相对较小的损害。

    Match the symbiotic relationship with its description.
    ::将共生关系与描述相匹配

    Parasite in the Poo
    ::Poo的地铁

    Meet Tristerix aphyllus, also known as the "cactus mistletoe," a parasitic plant that obtains all its nutrients and water from its host. The "cactus mistletoe" is a parasite that penetrates the surface of cacti and grows within. A year after being sustained by the cactus' water store, their vibrant flowers erupt, ready to be pollinated.
    ::来见特里斯特利克斯·阿菲利克斯(Tristerix aphillus),又称“仙人掌寄生虫 ” ( cactus mistrenttoe), 这是一种寄生虫植物,从宿主那里获取所有养分和水。 “cactus minutetoe ” 是寄生虫,渗入仙人掌表面并在体内生长。在仙人掌的水库支撑了一年之后,它们生机勃勃的花朵爆发,准备接受授粉。

     

     

     

     

     

     

     

    Summary
    ::摘要

    • Symbiosis is a close relationship between two species in which at least one species benefits.
      ::共生关系是两个物种之间的一种密切关系,其中至少有一个物种受益。
    • Mutualism is a symbiotic relationship in which both species benefit.
      ::相互关系是一种共生关系,使两个物种都受益。
    • Commensalism is a symbiotic relationship in which one species benefits while the other species is not affected.
      ::共生关系是一种共生关系,在这种关系中,一种物种受益,而另一种物种不受影响。
    • Parasitism is a symbiotic relationship in which one species (the parasite) benefits while the other species (the host) is harmed.
      ::排他性是一种共生关系,一种物种(寄生虫)受益,而另一种物种(宿主)受到伤害。

    Review
    ::回顾

    1. Define mutualism and commensalism.
      ::界定相互主义和共产主义。
    2. Give examples of mutualism.
      ::举例说明相互性。
    3. Explain why most parasites do not kill their host. Why is it in their own best interest to keep their host alive?
      ::解释为什么大多数寄生虫不杀死宿主。 为什么让宿主活着对他们最有利?