Tube feet: Difference between revisions

Latest revision as of 14:23, 21 February 2025

Tube Feet[edit]

Tube feet are small, flexible, hollow appendages found in echinoderms, such as sea stars, sea urchins, and sea cucumbers. These structures are part of the water vascular system and play a crucial role in locomotion, feeding, and respiration.

Structure[edit]

Tube feet are typically composed of a bulbous upper section called the ampulla and a lower, tube-like section that extends outside the body. The ampulla is located inside the body cavity and is connected to the tube foot by a narrow canal. When the ampulla contracts, it forces water into the tube foot, causing it to extend.

The tube foot itself is often equipped with a sucker at the distal end, which allows the organism to adhere to surfaces. The walls of the tube feet are muscular and can contract to retract the foot or to create suction.

Function[edit]

Tube feet serve multiple functions in echinoderms:

Locomotion: By extending and retracting their tube feet, echinoderms can move across the substrate. The coordinated action of numerous tube feet allows for smooth and controlled movement.

Feeding: Tube feet can assist in capturing prey or in manipulating food items. For example, sea stars use their tube feet to pry open the shells of bivalves.

Respiration: Tube feet can facilitate gas exchange by increasing the surface area available for diffusion.

Sensation: Tube feet are sensitive to touch and chemical signals, aiding in environmental perception.

Types of Tube Feet[edit]

Different echinoderms have specialized tube feet adapted to their specific lifestyles:

Suckered tube feet: Found in many sea stars, these tube feet have a suction cup at the end, allowing for strong adhesion to surfaces.

Non-suckered tube feet: Found in some sea urchins, these tube feet lack a suction cup and are used more for sensory functions.

Pincer-like tube feet: Some species have tube feet that end in small pincers, used for cleaning the body surface.

Examples in Echinoderms[edit]

Sea Stars: Sea stars, such as the Pycnopodia helianthoides, use their tube feet for locomotion and feeding. They can extend their tube feet through small openings in their ambulacral grooves.

Sea Urchins: Sea urchins have tube feet that extend through their spines, aiding in movement and feeding.

Sea Cucumbers: These echinoderms use their tube feet primarily for locomotion and respiration.

Related Pages[edit]

Gallery[edit]

T. gratilla podia
Mithrodia clavigera
Pycnopodia helianthoides tube feet

@@ Line 1: / Line 1: @@
 == Tube Feet ==
-[[File:Sea_urchin_Tube_feet_extended_past_the_Spines.jpg|thumb|Sea urchin tube feet extended past the spines]]
+[[File:Sea_urchin_Tube_feet_extended_past_the_Spines.jpg|thumb|right|Sea urchin tube feet extended past the spines]]
-[[File:Podia_de_Colobocentrotus_atratus.JPG|thumb|Podia of Colobocentrotus atratus]]
-Tube feet are small, flexible, hollow appendages found in [[echinoderms]], such as [[sea stars]], [[sea urchins]], and [[sea cucumbers]]. These structures are part of the [[water vascular system]], a hydraulic system unique to echinoderms, which facilitates movement, feeding, and respiration.
+'''Tube feet''' are small, flexible, hollow appendages found in [[echinoderms]], such as [[sea stars]], [[sea urchins]], and [[sea cucumbers]]. These structures are part of the [[water vascular system]] and play a crucial role in locomotion, feeding, and respiration.
 == Structure ==
-Tube feet are typically composed of an internal ampulla and an external podium. The ampulla is a bulb-like structure that resides within the body cavity, while the podium extends outside the body. The podium is often equipped with a sucker at its distal end, allowing the organism to adhere to surfaces.
+Tube feet are typically composed of a bulbous upper section called the [[ampulla]] and a lower, tube-like section that extends outside the body. The ampulla is located inside the body cavity and is connected to the tube foot by a narrow canal. When the ampulla contracts, it forces water into the tube foot, causing it to extend.
-[[File:Star_Fish_Tube_Feet.jpg|thumb|Starfish tube feet]]
+[[File:Podia_de_Colobocentrotus_atratus.JPG|thumb|left|Podia of Colobocentrotus atratus]]
-The movement of tube feet is controlled by the water vascular system. Water is pumped into the ampulla, causing it to contract and extend the podium. When the podium is extended, the sucker can attach to a surface. By coordinating the extension and retraction of multiple tube feet, echinoderms can move across the substrate.
+The tube foot itself is often equipped with a sucker at the distal end, which allows the organism to adhere to surfaces. The walls of the tube feet are muscular and can contract to retract the foot or to create suction.
 == Function ==
-Tube feet serve several functions in echinoderms:
+Tube feet serve multiple functions in echinoderms:
-* '''Locomotion''': By extending and retracting their tube feet, echinoderms can move across the ocean floor. This is particularly evident in sea stars, which use their tube feet to "walk."
+* '''Locomotion''': By extending and retracting their tube feet, echinoderms can move across the substrate. The coordinated action of numerous tube feet allows for smooth and controlled movement.
-* '''Feeding''': Tube feet can assist in feeding by helping to open shells of prey, such as bivalves, or by transporting food particles to the mouth.
+* '''Feeding''': Tube feet can assist in capturing prey or in manipulating food items. For example, sea stars use their tube feet to pry open the shells of bivalves.
-* '''Respiration''': In some echinoderms, tube feet also play a role in gas exchange, allowing oxygen to diffuse into the body and carbon dioxide to diffuse out.
+* '''Respiration''': Tube feet can facilitate gas exchange by increasing the surface area available for diffusion.
-* '''Attachment''': The suckers on tube feet allow echinoderms to adhere to surfaces, providing stability in turbulent waters.
+* '''Sensation''': Tube feet are sensitive to touch and chemical signals, aiding in environmental perception.
-== Examples ==
+== Types of Tube Feet ==
-[[File:T._gratilla_podia.jpg|thumb|T. gratilla podia]]
+[[File:Star_Fish_Tube_Feet.jpg|thumb|right|Starfish tube feet]]
-[[File:T._gratilla_podia_(1).jpg|thumb|Another view of T. gratilla podia]]
-* '''Sea Stars''': Sea stars, or starfish, have hundreds of tube feet located on their underside. These tube feet are used for locomotion and feeding.
+Different echinoderms have specialized tube feet adapted to their specific lifestyles:
-* '''Sea Urchins''': Sea urchins have tube feet that extend past their spines. These tube feet help in movement and in securing the urchin to surfaces.
+* '''Suckered tube feet''': Found in many sea stars, these tube feet have a suction cup at the end, allowing for strong adhesion to surfaces.
-* '''Sea Cucumbers''': Sea cucumbers use their tube feet primarily for locomotion and feeding. Some species have modified tube feet around their mouth that function as tentacles.
+* '''Non-suckered tube feet''': Found in some sea urchins, these tube feet lack a suction cup and are used more for sensory functions.
+* '''Pincer-like tube feet''': Some species have tube feet that end in small pincers, used for cleaning the body surface.
+== Examples in Echinoderms ==
+[[File:T._gratilla_podia.jpg|thumb|left|T. gratilla podia]]
+* '''Sea Stars''': Sea stars, such as the [[Pycnopodia helianthoides]], use their tube feet for locomotion and feeding. They can extend their tube feet through small openings in their [[ambulacral grooves]].
+* '''Sea Urchins''': Sea urchins have tube feet that extend through their spines, aiding in movement and feeding.
+* '''Sea Cucumbers''': These echinoderms use their tube feet primarily for locomotion and respiration.
 == Related Pages ==
@@ Line 41: / Line 51: @@
 * [[Echinoderm]]
 * [[Water vascular system]]
-* [[Sea star]]
+* [[Locomotion in echinoderms]]
-* [[Sea urchin]]
-* [[Sea cucumber]]
+[[File:Pycnopodia_helianthoides_on_glass.jpg|thumb|right|Pycnopodia helianthoides on glass]]
+== Gallery ==
+<gallery>
+File:T._gratilla_podia_(1).jpg|T. gratilla podia
+File:Mithrodia_clavigera_bras.jpg|Mithrodia clavigera
+File:Pycnopodiahelianthoides-tubefeet.jpg|Pycnopodia helianthoides tube feet
+</gallery>
 [[Category:Echinoderm anatomy]]