Path followed:
- Is the fault in the components that perform any physical action?
Answer: Yes
- Is the fault in components that move?
Answer: Yes
- Is the fault in components that make the mechanism move?
Answer: Yes
- Is the faulty component designed to move the mechanism around?
Answer: Yes
- Is the faulty component needed for stability?
Answer: Yes
- Does the faulty component manipulate smaller objects?
Answer: Yes
- Does the surrounding environment affect the process of regeneration?
Answer: No
- Are there any external resources that can be used by the mechanism?
Answer: Yes
12) Brittle Stars, Amphuira filiformis
Brittle Stars are similar to sea stars but have a smaller central disk, which may be under one inch. The specimen may grow from under an inch to 10 times that length (De Kluijver and Ingalsuo). They live in the North, Scandinavian, and Mediterranean seas. Brittle Stars are able to reproduce an arm if it was amputated.
The brittle star undergoes post autotomy after getting its arm amputated. Once the arm has been amputated a blastema is formed by undifferentiated pluripotent cells and dedifferentiated myocytes (Czarkwiani et al.). Re-differentiation of the cells into muscle and skeletal structures start to divide into metameric units that added onto the proximal end. The arm continues to differentiate and add on more metameric units until there are pronounced muscle and skeletal structures in the newly regenerated arm. The spines and podia are formed below the distal growth zone from buds (Czarkwiani et al.). Podia are specifically formed from the elongation of the radial water canal to allow for the water vascular system to interact with the new arm (Czarkwiani et al.).
De Kluijver, M. J., and S. S. Ingalsuo. “Macrobenthos of the North Sea – Echinodermata.” Marine Species Identification Portal : Amphiura Filiformis. Key of Nature, 2004. Web. 20 Nov. 2014.
http://species-identification.org/species.php?species_group=echinodermata&id=91
Czarkwiani, Anna, David V. Dylus, and Paola Oliveri. “Expression of Skeletogenic Genes during Arm Regeneration in the Brittle Star Amphiura Filiformis.” Gene Expr Patterns 13.8 (2013): 464-72. NCBI. Web. 20 Nov. 2014.