15.31 Arthropod 增长和发展 -- -- 高级
章节大纲
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What's going on here?
::这是怎么回事?Here we see the metamorphosis of a cicada. This is the last molt, as the cicada turns into an adult insect.
::我们在这里看到一个晶体的变形。这是最后的粒子, 当该晶体变成成人的昆虫时。Growth and Development in Arthropods
::热带动物的增长和发展Some aspects of growth resemble those of , but there are several important distinctions. In this section we will examine those similarities and differences.
::增长的某些方面与......相似,但有一些重要的区别,在本节中我们将研究这些相似之处和不同之处。Growth and Molting
::增长和上市Arthropods grow by forming new segments near the tail, or posterior, end. This is similar to the growth of annelids. and arthropods both have tough chitinous exoskeletons. The mollusk exoskeleton , or shell, also contains high levels of calcium carbonate minerals , making it more rigid. Unlike mollusk shells, the exoskeleton of arthropods does not grow along with the rest of the . As the body underneath the exoskeleton grows, the animal begins to outgrow its tough exterior. In order to cope with this situation, arthropods undergo a process of shedding their exoskeleton and forming a new one periodically throughout their lifetime. This process, shown in Figure , is called molting , or ecdysis, and is regulated by special that coordinate molting events with stages of growth.
::通过在尾尾巴或后端形成新的区块来种植亚瑟罗波德。 这与肛门生长相似。 节肢动物都有坚硬的外骨质。 软体外骨质, 或外壳, 也含有高含量的碳酸钙矿物质, 使其更加僵硬 。 与软体外壳不同, 节肢动物的外骨质不会与其他部位同时生长。 随着外骨骼下体的生长, 动物开始长出其坚硬的外表。 为了应对这种情况, 节肢动物将经历一个过程, 切除外骨骼, 并在整个生命中定期形成一个新的过程。 图中显示的这一过程被称为脱落, 或摇晃, 并受特殊调节, 协调与生长阶段的摩托事件 。A crab undergoing the process of ecdysis, or molting. During molting, a new cuticle begins to form beneath the old cuticle. As this proceeds, the old cuticle detaches and eventually is completely separated from the organism. Reproduction and Development
::复制和发展Arthropods reproduce by , which involves the generation and fusion of gametes . Most arthropods are either male or female, and they undergo internal fertilization . Once the egg has been fertilized, the female usually lays the egg, and it continues developing outside of the mother’s body. During most of their , arthropods have the segmented bodies described earlier. Early on in arthropod development, however, some exist in intermediate stages that are very different from the adult form. These are called larval stages. None of the arthropod larval stages include the trochophore larva that is characteristic of mollusk and annelid . You are probably most familiar with this process in caterpillars that form a cocoon in which they undergo a drastic change in form called metamorphosis, ultimately emerging as a moth or butterfly. Development involving larval stages is called indirect development. There are also many species, such as spiders, that undergo direct development, in which the young hatch looking essentially like a smaller version of the adult. These species do not go through larval stages or metamorphosis.
::节肢动物的繁殖方式是, 其繁殖方式是产生和融合调子。 大部分节肢动物都是男性或女性, 并且接受体内授精。 一旦卵被施肥, 雌性通常产卵, 雌性在母体外继续发育。 在大部分体内, 节肢动物有上文描述的分形体。 然而, 在节肢动物发育初期, 有些处于中间阶段, 与成人形态有很大不同。 这些是被称为幼虫阶段的。 节肢动物的幼虫阶段中, 没有一个包括作为软体和内脏特征的锥体幼虫。 您可能最熟悉这种过程, 也就是在形成锥形的毛虫中。 这些物种在形态上发生了剧烈的变化, 被称为畸形, 最终成为一只毛虫或蝴蝶。 有关幼体发育阶段的发展被称为间接发展。 还有许多物种, 如蜘蛛, 正在直接发育, 其年轻的孵化器基本上与成年人一样, 处于较小的变形阶段。 这些物种不会通过变形。Summary
::摘要-
Arthropods grow by forming new segments near the tail, or posterior, end.
::通过在尾巴或尾巴尾部形成新的部分来生长阿片片类动物。 -
The exoskeleton of arthropods does not grow along with the rest of the animal.
::节肢动物的外骨骼 不与其它动物一起生长 -
Arthropods reproduce by sexual reproduction, which involves the generation and fusion of gametes.
::通过生殖性繁殖繁殖的阿赫罗波德人,这涉及生成和融合调子。
Review
::回顾-
How do arthropods usually grow in length?
::节肢动物通常如何长长? -
How is the exoskeleton of an arthropod different from the shell of a mollusk?
::节肢动物的外骨骼 与软体动物的外壳有什么不同? -
How do arthropods reproduce?
::节肢动物怎么繁殖?
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Arthropods grow by forming new segments near the tail, or posterior, end.
