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''' are small active tubular projections on the oral face of an [[echinoderm]], whether it be a [[starfish]], [[sea urchin]], or [[sea cucumber]]. They are part of the [[water vascular system]].
+== Tube Feet ==
-==Structure and Function==
+[[File:Sea_urchin_Tube_feet_extended_past_the_Spines.jpg|thumb|right|Sea urchin tube feet extended past the spines]]
-Tube feet function in locomotion and feeding, they are the primary means of locomotion for the sea urchin and the starfish. The tube feet are filled with seawater, which the echinoderm brings in through its [[madreporite]], a sort of sieve plate. This water is then circulated throughout the body and is used to inflate and deflate the tube feet. When a tube foot deflates, it contracts and bends to create a sort of walking motion. In addition to this, the tube feet also function in feeding by carrying food particles along the [[ambulacral grooves]] to the mouth.
-==Anatomy==
+'''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.
-The structure of the tube foot has two main parts: the disc and the stem. The disc is the end part that is used for walking and for attaching to surfaces. The stem is the long, hollow part that is connected to the radial canal of the water vascular system. The tube foot has a layer of muscle running longitudinally along the tube foot, and when this muscle contracts, it causes the tube foot to become shorter and wider.
+== Structure ==
+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:Podia_de_Colobocentrotus_atratus.JPG|thumb|left|Podia of Colobocentrotus atratus]]
+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 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 ==
+[[File:Star_Fish_Tube_Feet.jpg|thumb|right|Starfish tube feet]]
+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 ==
+[[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 ==
-==See also==
 * [[Echinoderm]]
-* [[Starfish]]
-* [[Sea urchin]]
-* [[Sea cucumber]]
 * [[Water vascular system]]
-* [[Madreporite]]
+* [[Locomotion in echinoderms]]
-* [[Ambulacral groove]]
+[[File:Pycnopodia_helianthoides_on_glass.jpg|thumb|right|Pycnopodia helianthoides on glass]]
+== Gallery ==
-[[Category:Anatomy]]
+<gallery>
-[[Category:Marine biology]]
+File:T._gratilla_podia_(1).jpg|T. gratilla podia
-[[Category:Echinoderms]]
+File:Mithrodia_clavigera_bras.jpg|Mithrodia clavigera
+File:Pycnopodiahelianthoides-tubefeet.jpg|Pycnopodia helianthoides tube feet
+</gallery>
-{{stub}}
+[[Category:Echinoderm anatomy]]