hydrostatic skeleton
Definition
A hydrostatic skeleton is a type of skeleton that uses water pressure to maintain its shape. It is found in soft-bodied animals, such as jellyfish and worms.
The hydrostatic skeleton is made up of a fluid-filled cavity surrounded by muscles. The fluid in the cavity is called the coelom. The muscles that surround the coelom are called the myocoel.
When the myocoel contracts, it squeezes the coelom, which creates pressure. This pressure helps to maintain the shape of the animal's body. The hydrostatic skeleton is also used for movement. When the muscles contract, they push the fluid in the coelom in one direction, which causes the animal to move in the opposite direction.
Hydrostatic skeletons are very flexible and can change shape easily. This allows soft-bodied animals to move through tight spaces and change their shape to catch food.
Hydrostatic skeletons are also very lightweight. This is important for animals that live in water, as it helps them to float.
Hydrostatic skeletons are a very efficient way for soft-bodied animals to support their bodies. They are also very flexible and lightweight, which are important adaptations for animals that live in water.
How can the word be used?
The earthworm's hydrostatic skeleton allows it to burrow through the soil.
Different forms of the word
Hydrostatic skeleton: This is the most common spelling.
Hydroskeleton: This is a less common spelling, but it is still correct.
Etymology
The word "hydrostatic skeleton" comes from the Greek words "hydro" (water) and "statikos" (standing still). It was first used in English in the early 20th century to describe a type of skeleton that is supported by fluid pressure.
Question
What is a hydrostatic skeleton?
AQA Science Exam Question and Answer
Question:
Explain the concept of a hydrostatic skeleton in invertebrates, detailing how it provides support, locomotion, and flexibility, and discuss its advantages over other skeletal systems.
Answer:
A hydrostatic skeleton is a structural framework found in certain invertebrates, such as earthworms and jellyfish, that provides support, locomotion, and flexibility without the use of bones. It consists of a fluid-filled cavity enclosed by muscles. When these muscles contract, they exert pressure on the fluid, causing the animal to change shape or move.
In earthworms, for instance, circular and longitudinal muscles surround the fluid-filled coelom. When circular muscles contract, the body elongates, while contraction of longitudinal muscles causes the body to shorten and thicken, facilitating crawling.
Hydrostatic skeletons offer several advantages over rigid skeletons. They allow for precise and coordinated movements, as muscles can act on specific regions of the body independently. This flexibility enables invertebrates to navigate complex environments and adopt various shapes, enhancing their survival and feeding strategies.
Furthermore, hydrostatic skeletons enable efficient movement in aquatic environments, where the buoyancy of water assists in supporting the body.
In conclusion, the hydrostatic skeleton is a remarkable adaptation in certain invertebrates, providing a versatile and effective means of support, locomotion, and flexibility. Its advantages lie in its adaptability, precise movements, and suitability for aquatic habitats, showcasing the diverse strategies that organisms have evolved for survival and adaptation in different ecological niches.