According to the book Laboratory and Field Investigation in Marine Life they reproduce through broadcast spawning, which is realizing a bunch of sperm and eggs into the water with the chance of one becoming fertilized.
They reproduce both sexually and asexually.
I think its asexual reproduction.
asexual
All the Coelenterates that I know of (jellyfish, sea anemones, etc) and some Platyhelminthes (flatworms). There are undoubtedly others, but I can't think of them offhand.
There are tons of organisms that reproduce asexually. As for ANIMALS - A lot of species of fish do (some sharks partake in parthenogenesis - a type of asexual reproduction), some species of wasps, whiptail lizards, sea anemones, coral, starfish, snails. All fungi, bacteria, Archaea, Protist and amoebas reproduce asexually. Some plants are capable of reproducing asexually, such as strawberry, onions and potatoes.
There are a few forms of life on Earth that reproduce by the act of "budding". A lot of sea life, such as coral, reproduce by spreading spores from buds into the ocean, while a lot of plant life, like blueberry plants, reproduce by budding fruit that is eaten and spread by animals.
Sweet gum tree.
Bacteria (by fission), some plants (by budding), and some sea life such as sea stars (regeneration- when a sea star is torn apart let's say into a 4-piece part and a 1-piece part, they both start to regenerate other arms to make 2 sea stars each with the normal 5 arms.). This is true. If you don't believe me consider this: I get an A+ in Science. If you still don't believe me, check a Science Textbook. Hope this helped! :)-Anonymous Source
sea urchins can either reproduce sexually or asexually sea urchins can either reproduce sexually or asexually
They reproduce asexually and sexually.
sometimes, when they see a full moon
Sponges can reproduce sexually or asexually
Sea urchins generally have separate sexes and spawn seasonally every year. Eggs and sperm are usually released to the water column where fertilisation occurs.
Sea Stars reproduce both asexually and sexually.
They can do both! A strategy that has evolved in some sea stars and brittle stars is the ability to reproduce asexually by dividing in two halves while they are small juveniles, while turning to sexual reproduction when they have reached sexual maturity.
Sexually. They are hermaphrodites and have both sets of sex organs, but sperm still has to meet egg.
Sea urchins generally have separate sexes and spawn seasonally every year. Eggs and sperm are usually released to the water column where fertilisation occurs.
by mating with another GIANT red sea urchin!
Starfish are able to reproduce sexually and asexually. Asexually, the starfish are able to reproduce if part of the starfish's arm is removed, along with part of the central body. From that detached piece, another starfish will form, along with the first starfish regenerating a new arm where the original arm was located.
All the Coelenterates that I know of (jellyfish, sea anemones, etc) and some Platyhelminthes (flatworms). There are undoubtedly others, but I can't think of them offhand.