2009年12月23日 · Tube feet not only help the urchin move, they also are used to grasp food, and they are part of the respiratory or breathing system. The tube feet are part of the urchins water vascular system. They work like a hydraulic system. The urchin contracts its muscles to push water into the tube feet. This extends the feet outwards.

Tube feet (technically podia) are small active tubular projections on the oral face of an echinoderm, such as the arms of a starfish, or the undersides of sea urchins, sand dollars and sea cucumbers; they are more discreet though present on brittle stars, and have only a feeding function in feather stars.

2011年3月30日 · The simultaneous expression of an opsin gene and the unique morphological features at the distal portion of the tube foot shows that sea urchin tube feet, among their many functions, have also evolved into a unique photosensory organ to sense and respond to changes in the underwater light field, and may also provide useful information related ...

2011年5月2日 · Using a specifically designed antibody against Sp-Opsin4 and in situ hybridization for both genes, we detected expression in two distinct groups of photoreceptor cells (PRCs) located in the animal's numerous tube feet.

2018年6月12日 · Sea urchins lack eyes, but can see with their tentacle-like tube feet instead, previous research has indicated. Now, researchers at Lund University in Sweden have tested their vision in a new study, and shown that while sea urchins have fairly low resolution vision - it is good enough to fulfil their basic needs.

2009年12月23日 · Watch Sea Urchin Tube Feet in Action. The tube feet are part of the urchins water vascular system. They work like a hydraulic system. The urchin contracts its muscles to push water into the tube feet. This extends the feet outwards. When the …

2011年3月30日 · All echinoderms have unique hydraulic structures called tube feet, known for their roles in light sensitivity, respiration, chemoreception and locomotion. In the green sea urchin, the most...

ABSTRACT Actin is the major extractable protein component from the tube feet of four different species of sea urchin: Arbacia punctulata, Strongylocentrotus purpuratus, Strongylo-centrotus droebachiensis, and Diadema setosum. Actin made up as muchas 60% of the total

2011年5月17日 · Using a specifically designed antibody against Sp-Opsin4 and in situ hybridization for both genes, we detected expression in two distinct groups of photoreceptor cells (PRCs) located in the animal's numerous tube feet.

All echinoderms have unique hydraulic structures called tube feet, known for their roles in light sensi-tivity, respiration, chemoreception and locomotion. In the green sea urchin, the most distal portion of these tube feet contain five ossicles arranged as a light collector with its concave surface facing towards the ambient light.