ambulacral foot

简明释义

管足;

英英释义

例句

1.During our marine biology class, we observed how the ambulacral foot functions in echinoderms.

在我们的海洋生物学课上，我们观察了足部在棘皮动物中的功能。

2.Each ambulacral foot is equipped with tube feet that help in locomotion.

每个足部都配有助于运动的管足。

3.The starfish uses its ambulacral foot to move along the ocean floor.

海星利用它的足部在海底移动。

4.Scientists study the ambulacral foot to understand the locomotion of sea stars.

科学家研究足部以了解海星的运动方式。

5.The ambulacral foot plays a crucial role in feeding for many sea creatures.

足部在许多海洋生物的进食中起着关键作用。

作文

The ocean is home to a diverse range of creatures, many of which exhibit fascinating adaptations that allow them to thrive in their unique environments. One such creature is the sea star, or starfish, which belongs to the class Asteroidea. These marine animals are known for their radial symmetry and remarkable regenerative abilities. A key feature of sea stars is their ambulacral foot, an essential component of their anatomy that plays a vital role in locomotion and feeding.The term ambulacral foot refers to the tube feet that are part of the water vascular system in echinoderms like sea stars. These tube feet are not only responsible for movement but also serve various functions, such as capturing prey and facilitating respiration. The water vascular system operates through hydraulic pressure, allowing the sea star to extend and retract its ambulacral foot with precision. This ability enables the sea star to navigate across rocky surfaces, cling to substrates, and even open the shells of bivalves, which are a primary food source.Each ambulacral foot is equipped with a suction cup at its tip, which provides the necessary grip for the sea star to adhere to surfaces. When the sea star wants to move, it contracts the muscles around its tube feet, causing water to enter the foot through the madreporite—a sieve-like structure on the upper surface of the sea star. This hydraulic action allows the tube foot to extend and create a suction effect, enabling the sea star to pull itself forward. The coordinated movement of multiple ambulacral feet allows for fluid locomotion, making it appear almost graceful as it glides over the ocean floor.In addition to movement, the ambulacral foot plays a crucial role in feeding. Sea stars are opportunistic predators, often preying on mollusks, barnacles, and other small marine organisms. When a sea star encounters a bivalve, it uses its ambulacral feet to pry open the shell. Once the shell is slightly ajar, the sea star can evert its stomach into the shell, digesting the prey externally before pulling the partially digested food back into its body. This unique feeding strategy highlights the importance of the ambulacral foot in the sea star's survival.Moreover, the ambulacral foot is also involved in respiration. Echinoderms, including sea stars, lack gills; instead, they exchange gases through their tube feet. The thin walls of the ambulacral foot allow oxygen to diffuse directly into the sea star's body while carbon dioxide is expelled. This process is vital for maintaining the sea star's metabolic functions and overall health.In conclusion, the ambulacral foot is a remarkable adaptation that showcases the ingenuity of evolution in marine environments. Through its multifunctional capabilities—locomotion, feeding, and respiration—the ambulacral foot significantly contributes to the sea star's ability to thrive in the ocean. Understanding this unique feature not only enhances our appreciation for these fascinating creatures but also underscores the complexity of marine ecosystems. As we continue to explore the depths of our oceans, it is essential to recognize the intricate relationships between anatomy and behavior in the survival of marine life.

海洋是许多生物的家园，其中许多生物展现出迷人的适应性，使它们能够在独特的环境中繁衍生息。其中一种生物是海星，或称为星星鱼，它属于海星纲。这些海洋动物以其放射状对称和显著的再生能力而闻名。海星的一个关键特征是它们的足沟足，这是它们解剖结构中的一个重要组成部分，在运动和觅食中发挥着重要作用。术语足沟足指的是海星等棘皮动物水管系统的一部分，这些管足不仅负责运动，还具有捕捉猎物和促进呼吸等多种功能。水管系统通过液压压力运作，使海星能够精确地伸缩其足沟足。这种能力使海星能够在岩石表面上自由移动，紧贴基质，甚至打开双壳类的壳体，而双壳类是主要的食物来源。每个足沟足的尖端配有一个吸盘，这提供了必要的抓握力，使海星能够附着在各种表面。当海星想要移动时，它收缩围绕其管足的肌肉，使水通过母孔进入足部——这是海星上表面的一个筛状结构。这种液压作用使管足伸展并产生吸力，从而使海星能够向前拉动自己。多个足沟足的协调运动使海星能够流畅地移动，仿佛优雅地滑过海底。除了运动外，足沟足在觅食中也起着至关重要的作用。海星是机会捕食者，通常捕食软体动物、藤壶和其他小型海洋生物。当海星遇到双壳类时，它会使用其足沟足撬开壳体。一旦壳体微微开启，海星就可以将其胃翻转到壳内，在外部消化猎物，然后将部分消化的食物拉回体内。这种独特的觅食策略突显了足沟足在海星生存中的重要性。此外，足沟足还参与呼吸。包括海星在内的棘皮动物缺乏鳃；相反，它们通过管足进行气体交换。足沟足的薄壁使氧气能够直接扩散到海星的身体中，同时二氧化碳被排出。这个过程对于维持海星的代谢功能和整体健康至关重要。总之，足沟足是一种显著的适应性，展示了进化在海洋环境中的智慧。通过其多功能能力——运动、觅食和呼吸——足沟足显著促进了海星在海洋中的生存能力。理解这一独特特征不仅增强了我们对这些迷人生物的欣赏，还强调了海洋生态系统的复杂性。随着我们继续探索海洋深处，认识到解剖结构与行为之间的复杂关系对于海洋生物的生存至关重要。