In the last article (part 2) we mentioned how cilia (hairlike structures) are all over the starfish’s body, externally and internally. However, they may be “hairlike”, but they are VERY COMPLEX. Below are pictures of them and you can see for yourself that this isn’t just a “hairlike” structure. In fact, they are more like a thick cable with many thinner “wires” going through them with an inner mechanism that makes them bend. In fact, there’s 22 (11 x2) thin “wires” in them. 9 (x2) in a circle, on the inside perimeter of it, and 2(x2) in the center. How the cilia move back and forth, thereby moving forward the water in one direction, is a complex mechanized process, too complex for me to describe. One thing I will say is that they cilia move quickly to one side, thereby moving things in that direction, and then, at a much slower pace, they move back to their original starting point, ending straight up vertically, and then it again moves quickly to the other side, coming back slowly again, with the process continuing until a signal comes telling it to stop completely. The reason for this method is simple. If they would move quickly both ways, things wouldn’t get anywhere. They would go one way and then go right back the other way! Therefore, the cilia’s mechanism is perfectly pre-programmed to go quickly one way, and for the way back it goes just slow enough so that it doesn’t cause any backwards movement of the water. Hmmm. I wonder WHO programmed the cilia to work at those correct speeds?! Cilia are found in many of Hashems creations including in humans as well. They somehow “by accident” seemed to come about all over in many different creatures. In a starfish they are absolutely crucial for the moving about of the water that’s in the inner main parts of the starfish, so that nutrition and oxygen gets to the right place, and wastes are moved out as well. And as explained in the last article, the water needs to be moved around by the cilia over the outer surface of the starfish in order to bring fresh oxygenated water to the gills. Being they are so crucial for the starfish’s functionality; therefore, I mentioned them. Below are pictures of cilia.
Now, we will discuss a third part of the skeleton that we had previously mentioned. The pedicellaria. Here too, like cilia, is something that looks quite simple but it’s actually quite complex. (Everything in Hashem’s world is that way.) The pedicellaria are like pliers/scissors that are important for keeping the surface of the skeleton of the starfish clean. This is SO crucial since the gills, through which 80% of the gas exchange of oxygen and carbon dioxide takes place, must be clear of any debris. Because the starfish can often just lay around, going nowhere, there more of a chance that things that can grow on pretty much any surface, can end up growing on them (like Barnacles and the like). So, the pedicellaria can pry them off if they started to grow there. If any dirt gets stuck on it, it will remove it. (In some starfish species, where the pedicellaria are quite large, they can actually grab on to smaller fish and then it can become food for the starfish. How this works will be explained in the next article.) Here too, you need to see the pictures in order to get a better idea as to how it works, and how complex they are.
Here you can see that around the spine (the center of the picture) there’s a whole bunch of pedicellaria.
On the bottom center ones you can see clearer that they are shaped like an open plier.
In the picture below, you can see how complex these pedicellaria are. They can stretch out and bend over in order to remove things. Some pedicellaria (and spines) have toxins in them (harmful substances if touched or eaten) as do other parts of the starfish.
We will finish off this third article by mentioning that the starfish has at the end of its “arms” two things that are important to know. One, in spite of it not having a brain, it still has an eye at the end of each arm. They are somehow connected with the pretty complex nervous system of the starfish. However, they are not able to see anything more than light and darkn. Nothing colorful, or clear is seen by it, nevertheless it helps them with their moving around. The starfish also has light sensors over the top parts of its skeleton. At the end of the arms are also crucial sensory tube feet, which are different than the regular tube feet that they have. These feet are very sensitive at picking up scents of potential food. The starfish always “follows its nose”, in this case being the special tube feet at the end of their arms. The starfish will suddenly change directions if it smells food coming from a different direction.
Note that at the end of the arm, there’s a red dot. That’s its eye. Also, at the end of the arms are the special feet that are typically NOT used for walking, rather the end of the arms are typically lifted up a bit off the ground and they sway and swing around in the air, trying to pick up all types of signals of what is ahead of them, especially sniffing for food scent.
In the final article we will be discussing the 2 things that the starfish is the ONLY CREATURE known in the world that is capable of doing them. Stay tuned IY”H.
About the Author
Rabbi Shmuel Waldman has dedicated more than 50 years to religious education and leadership, drawing inspiration from the teachings of Rabbi Avigdor Miller ZTL and his close connection to Rav Don Segal, shlit”a. He began his career at Mirrer Yeshiva and later took on the role of Mashgiach at Yeshiva Mercaz Hatorah of Belle Harbor, where his guidance and lectures left a lasting impact on students. His book, Beyond A Reasonable Doubt: Convincing Evidence to the Truths of Judaism, is widely regarded as a classic in kiruv and has sold tens of thousands of copies since its publication in 2002. In addition to his role as a teacher at Yeshiva Tiferes Moshe and in various summer camps, Rabbi Waldman has recently completed a significant Sefer on the importance of proper prayer in Judaism. His latest endeavors include creating a blog that explores Intelligent Design and a YouTube channel that offers insights into religious education, further expanding his influence in the Jewish community.