jawless

简明释义

英[ˈdʒɔːləs]美[ˈdʒɔləs]

无颚的

英英释义

单词用法

同义词

反义词

例句

1.Any of various primitive elongated freshwater or anadromous fishes of the family Petromyzontidae, characteristically having a jawless sucking mouth with rasping teeth.

七鳃鳗，八目鳗一种七鳃鳗科的原始细长淡水或溯河产卵鱼，特点是长有无。

2.Any of various primitive elongated freshwater or anadromous fishes of the family Petromyzontidae, characteristically having a jawless sucking mouth with rasping teeth.

七鳃鳗，八目鳗一种七鳃鳗科的原始细长淡水或溯河产卵鱼，特点是长有无。

3.The jawless 无颚的 anatomy of these fish is quite different from that of jawed fish.

这些鱼类的无颚解剖结构与有颚鱼类截然不同。

4.Scientists are studying jawless 无颚的 organisms to understand early vertebrate evolution.

科学家们正在研究无颚的生物，以了解早期脊椎动物的进化。

5.The jawless 无颚的 design of certain ancient fish allows them to survive in various environments.

某些古代鱼类的无颚设计使它们能够在各种环境中生存。

6.The jawless 无颚的 fish species, such as lampreys, have unique feeding habits.

无颚的鱼类，如七鳃鳗，具有独特的摄食习性。

7.Some jawless 无颚的 creatures can regenerate their bodies, making them fascinating subjects for research.

一些无颚的生物能够再生它们的身体，使它们成为研究的迷人对象。

作文

In the vast expanse of the animal kingdom, there exists a fascinating group of creatures known as jawless animals. These animals, which include species such as lampreys and hagfish, have evolved without the presence of jaws, setting them apart from the majority of vertebrates. The term jawless (无颌的) refers to their unique anatomical structure, which lacks the complex jaw systems that are common in most fish and other vertebrates. This absence of jaws has led to a variety of adaptations that allow these creatures to thrive in their environments.The evolutionary history of jawless animals is intriguing. They are considered some of the most primitive vertebrates, with fossil records dating back hundreds of millions of years. Their jawless (无颌的) condition is believed to be a result of early vertebrate evolution, where the development of jaws provided certain species with advantages in feeding and survival. However, those that remained jawless adapted to their ecological niches in unique ways.For instance, lampreys are known for their parasitic lifestyle, where they attach themselves to other fish and feed on their blood. Their jawless (无颌的) mouths are equipped with rows of sharp teeth, allowing them to grasp onto their hosts effectively. This method of feeding may seem brutal, but it has allowed lampreys to survive and flourish in various aquatic environments.On the other hand, hagfish are scavengers, feeding on dead or dying marine animals. Their jawless (无颌的) mouths are designed for rasping and tearing flesh, enabling them to consume organic matter efficiently. Interestingly, hagfish also possess a unique defense mechanism; when threatened, they can produce large amounts of slime that can suffocate predators. This remarkable adaptation highlights the resilience of jawless animals in the face of danger.Despite their lack of jaws, jawless (无颌的) animals play crucial roles in their ecosystems. They contribute to the balance of marine life by participating in nutrient cycling and serving as prey for larger predators. Furthermore, their evolutionary significance provides valuable insights into the history of vertebrate development. Studying jawless (无颌的) species helps scientists understand how vertebrates have adapted over time and the various pathways that evolution can take.In conclusion, jawless animals represent a unique and ancient branch of the vertebrate family tree. Their adaptations and ecological roles demonstrate the diversity of life on Earth. As we continue to explore the natural world, it is essential to appreciate the jawless (无颌的) creatures that have survived through millennia, reminding us of the intricate tapestry of evolution that has shaped all living beings. Understanding these remarkable animals not only enriches our knowledge of biology but also fosters a deeper appreciation for the complexity of life itself.

在动物王国的广阔领域中，存在着一群迷人的生物，被称为jawless动物。这些动物，包括七鳃鳗和盲鳗等物种，已经进化得没有下颌，这使它们与大多数脊椎动物区分开来。术语jawless（无颌的）指的是它们独特的解剖结构，缺乏大多数鱼类和其他脊椎动物常见的复杂下颌系统。这种下颌的缺失导致了各种适应，使这些生物能够在其环境中生存。jawless动物的进化历史令人着迷。它们被认为是最原始的脊椎动物之一，化石记录可追溯到数亿年前。它们的jawless（无颌的）状态被认为是早期脊椎动物进化的结果，在这一过程中，下颌的发展为某些物种提供了在觅食和生存方面的优势。然而，那些保持jawless（无颌的）状态的物种以独特的方式适应了它们的生态位。例如，七鳃鳗以寄生生活方式而闻名，它们附着在其他鱼类身上并吸食血液。它们的jawless（无颌的）嘴部配备了一排锋利的牙齿，使它们能够有效地抓住宿主。这种觅食方法似乎很残忍，但它使七鳃鳗能够在各种水域中生存和繁衍。另一方面，盲鳗是 scavengers，以死去或濒临死亡的海洋动物为食。它们的jawless（无颌的）嘴部设计用于刮削和撕扯肉类，使它们能够高效地消耗有机物。有趣的是，盲鳗还具有独特的防御机制；当受到威胁时，它们可以产生大量的粘液，窒息掠食者。这种显著的适应性突显了jawless动物在面对危险时的韧性。尽管缺乏下颌，jawless（无颌的）动物在其生态系统中发挥着至关重要的作用。它们通过参与营养循环并作为大型掠食者的猎物来维持海洋生物的平衡。此外，它们的进化重要性为我们提供了对脊椎动物发展的历史的宝贵见解。研究jawless（无颌的）物种帮助科学家理解脊椎动物如何随着时间的推移而适应，以及进化可能采取的多种途径。总之，jawless动物代表了脊椎动物家族树的一个独特而古老的分支。它们的适应和生态角色展示了地球生命的多样性。当我们继续探索自然世界时，欣赏那些经历了千年仍然生存的jawless（无颌的）生物是至关重要的，这提醒我们进化的复杂织锦塑造了所有生物。理解这些非凡的动物不仅丰富了我们对生物学的知识，也培养了我们对生命复杂性的更深层次的欣赏。