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Starfish
Also known as sea stars, these echinoderms are 2,000 species strong and found in seas and oceans all over the world. They can vary in size from less than half an inch to more than four feet across.
1,388 Questions
What are the benefits of a Roho cushion?
The benefits of a ROHO seat cushion are increased comfort for wheelchair users. They adjust to the shape of the user and fit better. This provides less strain and stiffness.
They help the digestive systems and help digest any food
What is the heavyest sea star?
Thromidia catalai is the heavyest known sea star (although other sea stars can grown larger in terms of diameter/arm span.
It weighs over 6kg, and can have a span of up to 63cm.
It has no common name, but due to its appearance, it is often nicknamed "fat star".
What kind of surroundings do protists live in?
Protists live in oceans, streams, ponds, and also human and animal digestive tracts.
What is symbiotic with a brittle star?
the brittle star shows a young indonesian girls innocence and virginity
This is a weird hypothesis that I thought up when I was renaming some paper pdfs I've collected. It was inspired by a speculation I've seen that vertebrate side fins / limbs are ectopic tails; this was inspired by how limbs express Hox genes that are also expressed in tails.
Ectopic tails may be able to form more easily because vertebrate tails extend past the anus, which is to the rear of most of the internal organs. Compare the situation of arthropods, annelids, and others, where the anus is at the absolute rear of the body, with no tail extending past it.
Post-anal tails are shared by other chordates and by hemichordates. Which leaves echinoderms the remaining group of deuterostomes; the aforementioned terminal-anus animals are protostomes. How chordates, hemichordates, and echinoderms are related has been revised as a result of molecular evidence. An obvious overall-feature tree is:
((chordates, hemichordates), echinoderms)
But molecular evidence suggests:
(chordates, (hemichordates, echinoderms))
Which suggests that post-anal tails are an ancestral feature of deuterostomes, meaning that echinoderms have had an ancestor with them. But where might we find such a feature in living ones?
Consider starfish and brittle-star anatomy. A starfish has a central disc with most of the internal organs, and with five arms radiating outwards. The mouth is on the bottom of the disc, the anus on the top.
And those arms could possibly have originally been extra tails; their anatomy fits, since like chordate and hemichordate tails, they have only a limited set of internal organs.
The main problem with the five-tail hypothesis is how the other echinoderms fit in; they also have radial symmetry, but they do not have comparable limbs. Info from internet
How do male starfish and female starfish find there match?
This question presupposes that starfish only mate with starfish that are "their match." Of course, there is no such thing as one starfish being "the match" of another. To the contrary, starfish simply mate with other starfish at random wherever they find them. And some species of starfish are hermaphroditic, meaning that each starfish has both male and female reproductive systems. Other species of starfish are sequentially hermaphroditic, meaning that they start out life having male reproductive systems and then become female later in life.
In humans, over the last two centuries, it has become popular for couples to marry based on their perception of compatibility and sexual attraction. However, the success of such marriages is debatable, as the current divorce rate in the United States is between 40 and 50 percent, which is much higher than the divorce rate when marriages were arranged based on other criteria. In fact, many modern marriages that end up being successful, in spite of the fact that they are often based only on sexual compatibility, would likely have been successful anyway even if they had married based on older and more traditional methods of finding a match.
The bodies of starfish feel slightly course to the touch. They are not soft in the way that a sponge is soft, but they are flexible enough that they bend when touched. Starfish have many legs and can even re-grow a body part when it is removed.
How do starfish get rid of their undigested food?
Because of their method of digesting food externally, there is not much food that gets undigested within a sea star. Wastes from digestion are excreted through the anus on top of the sea star or through the water vascular system.
How does protists have an impact on society?
One very important impact protists have on the living world is a pathogens (disease causers). Case in point is Endaomeba histolytica a causative agent of dysentery. In many organisms they aid in the gut digesting food. The shells of Sarcodina (Radioloaia) are used as an abrasive. Plasmodium vivax causes malaria.
How does starfish make sure thet conditions are to hot or to cold for it?
A starfish reserves energy. They are one of the only creatures that can do this "manually." They will save it up when in warmer temperatures, and use it in colder temperatures to warm themselves up.
Possibly...it is shown that after about 500,000 years of evolution a species often have a jump of rapid evolution that has physical and internal effects. This jump isn't as fast as you would think, it happens over about 100 years. In the past these "jumps" have included appearance of tails on a species once tail-less, an extra finger/toe on each hand/ foot (dinosaurs and other animals only had 4 fingers/toes on each hand/foot) Scientists don't know what humans next jump will be. However, it is quite unlikely to have it be a third arm it is quite possible, but it is more likely to be something less dramatic.
What is a sea star with many legs?
The name of the sea star that has many legs is the sun star. The sun star can have up to 40 arms.
