Sponges are multicellular organisms that live permanently attached to an underwater rock or coral reef.These organisms were once thought to be plants, but now scientists know that they are animals. Sponges come in various sizes, colors, and shapes, and there are both marine and freshwater sponges available in the world.There are more than 5000 species of sponges in the phylum Porifera (meaning bearing pores), and all sponges need some solid matter to attach and grow. There are holes, or pores, called Ostia around their body that allow food particles and water into the sponges. Sponges can undergo both sexual reproduction and asexual reproduction. The sponges are well adapted to their habitats and invertebrates that have not gone through evolution for millions of years. Most of them live in the coral reefs on the ocean floor. However, you can also find freshwater sponges. Much of the sponges in the world are filter-feeders, but there are some carnivorous ones in the ocean. The nutrient-poor environment might have made these sponges carnivorous in life.Many sponges live in large groups or colonies. Adult sponges are unable to move around. Similar to trees, root-like structures hold an adult sponge to rocks and coral reefs. Many would not know, but a sponge body has an internal skeleton called an exoskeleton that protects and supports. The endoskeleton includes short sharp rods called spicules made of silica, calcium carbonate, and spongin, a tough protein that grows from specialized cells in most sponges.Pores are needed for food and water, but sponges also use them for asexual reproduction and sexual reproduction. Asexual reproduction happens through budding, where small individual bumps develop and grow on the parent sponge. The young of the asexual sponges later detaches from the parent to form a colony.In sexual reproduction, on the other hand, sponges are known to produce eggs and sperm. In many species, a single sponge can produce both eggs and sperm (one at a time). Sponge species do not self-fertilize as snails do; instead, the sperm of a sponge is released in the water through the part called the osculum. Collar cells trap these sperm when they enter through the pores in female sponges. The sperm is then deposited into eggs, where fertilization takes place. The eggs then turn into zygotes and then into sponge larvae. Babies can move and swim around, unlike adults.If you enjoyed this article, why not also read about how do sharks mate and why do animals reproduce here on Kidadl?How do sea sponges reproduce?As we have discussed, sponges are known for both sexual and asexual reproduction. We will discuss both methods of mating here.The sea sponges reproduce by asexual methods due to the fragmentation of the body. This is usually the result of exposure to unfavorable environmental conditions, but it can also be part of a normal life cycle. This type of reproducing is called budding. Lateral buds appear from the body of the adult sponge and later differentiate into young sponges. These sponges attached to the body then separate and form a new individual marine sponge. A bud separates from the parent sponge and creates a new sponge that can either stay in the colony or live individually. Unlike their parents, sponge larvae can swim.The members of the phylum Porifera also reproduce sexually. As they stay attached to a solid surface, physical contact between the sponge and the sponge cells and sperm of other sponge species is impossible. The sponge bodies nearby release a large amount of sperm into the water. The sperm are released into the water through the osculum. The sperm in the water travels through the pores with the nutrients and oxygen a sponge requires for survival. The sperm then attaches to the collar cells similar to the collar cells trapping food and water (the collar cells function as traps for these filter-feeders). The cells that have sperm in the collar cells change into archaeocytes and travel to the eggs for fertilization. The female parent sponge later releases the larvae from the sponge body into the water. Larvae then attach themselves to a solid surface, and the body structure evolves with time. The young sponge soon turns into a mature sponge.Do sea sponges reproduce internally or externally?The invertebrates that reproduce asexually can do both internal and external budding.External budding is a form of producing life where a portion of the sponge breaks off and becomes an entirely new organism with newer cells and regenerating power.The internal budding is slightly different. Internal buds formed are called gemmules. Gemmules are a culmination of several types of cells which are protected by a covering. This method is for harsh conditions when there are fewer chances of the parent surviving. The protective shell can keep the cell stored inside the parent sponge, and when the conditions become more favorable, a new sponge will form.Do sponges have more than one method to reproduce?Some species of sponges reproduce sexually, and some asexually. It depends on the family in the species.As we have already discussed earlier, sponges have two methods of reproduction. These regenerating water organisms can produce both sperm and eggs, though not at the same time. It is fascinating to watch them closely. The movement in adults is limited as they stay attached to corals and rocks.Do sponges reproduce in a single stage or two stages?Sponges reproduce both sexually and asexually. Asexual reproduction takes place in two stages. The first stage is the growth stage, where bud forms and grows in size. The second stage is when the bud either remains attached and develops as part of the parent sponge or detaches and forms a new sponge elsewhere.During sexual reproduction, one sponge produces and then releases sperm into the water during the first stage. The second stage requires another sponge to take that sperm in through their pores and use it to fertilize eggs. Once the eggs are fertilized, they develop into larvas inside the parent sponge before being released into the water to attach to nearby rocks or coral reefs.Did you know?These filter-feeders are known to live in colonies. The bud seen in a sponge is an outgrowth from the body wall of the sponge, which later becomes a new member of the colony. A bud will usually attach itself to the rock or coral reef close to the parent sponge.You already know pores are present in a sponge’s body that helps them take in food and water. The water is pumped into the body of the sponge through the holes. As the water flows through it, food particles like bacteria and phytoplankton are filtered out. The water flowing through the ocean brings this bacteria, which gets trapped in the tiny hairs of the collar cells. Sponges also have flagella that are used to create a flow of water within the body. This water is then released through the osculum regulates the correct amount of water flow for the sponge.Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for how do sponges reproduce, then why not take a look at why do whales breach or are birds warm-blooded?
Sponges are multicellular organisms that live permanently attached to an underwater rock or coral reef.
