Summary
- Reproduction of cnidarians can be either asexual by budding or sexual using gametes.
- Depending on the species, cnidarians can be monoecious or dioecious.
- Cnidarians usually cycle between a medusa stage and a polyp stage during their life cycle.
What are the differences between Cnidaria and other phylums?
The layer that faces outwards, known as the ectoderm ("outside skin"), generally contains the following types of cells:
- Epitheliomuscular cells whose bodies form part of the epithelium but whose bases extend to form muscle fibers in parallel rows. ...
- Cnidocytes, the harpoon-like "nettle cells" that give the phylum Cnidaria its name. ...
- Nerve cells. ...
- Interstitial cells, which are unspecialized and can replace lost or damaged cells by transforming into the appropriate types. ...
What animals belong to the Cnidaria phylum?
Phylum Cnidaria include jellyfish, sea anemones, and sponges. These classes share basic phylum Cnidaria traits. Cnidaria are multicellular. They are also invertebrates. Invertebrates are animals with no backbone. Most Cnidarians are marine animals. Cnidarians have radial symmetry. Unlike phylum Porifera they have body tissues. However, they lack organs.
How do cnidarians reproduce sexually?
Summary
- Reproduction of cnidarians can be either asexual by budding or sexual using gametes.
- Depending on the species, cnidarians can be monoecious or dioecious.
- Cnidarians usually cycle between a medusa stage and a polyp stage during their life cycle.
What are facts about the phylum cnidarian?
Phylum Cnidaria
- Most Cnidarians do not have eyes or any type of developed organs.
- The phylum cnidarian consists of about 10,000 species of simple animals found only in marine habitats.
- It is best not to touch very small jellyfish, or any jellyfish AT ALL. ...
- Jellyfishes are made up of more than 95% water and they have no brains, blood or nervous system.
Can Cnidaria reproduce through regeneration?
INTRODUCTION. The freshwater polyp Hydra, a member of the ancient phylum Cnidaria, is famous for its regenerative capacity. Just like the multiheaded monster in Greek mythology that grew two new heads for every one cut off, a cnidarian polyp can regenerate a new head after decapitation.
How do sea anemones Cnidaria reproduce?
The data on different modes of reproduction in sea anemones are generalized. These animals can reproduce sexually in an ordinary way or by parthenogenesis. Asexual reproduction occurs in various forms, such as transverse and longitudinal fission, pedal laceration, or autotomy of tentacles.
What is the asexual way of reproduction exhibited by cnidarians called?
Cnidarians switch from the polyp to the medusa stage by a form of asexual reproduction in which the polyp develops a stack of medusoid structures that can then bud off to become independent medusae. This process is called strobilation and is depicted in Figure below.
Can sea anemone reproduce through binary fission?
Continued feeding resulted in frequent asexual reproduction by binary fission, and consequently rapid population growth.
What happens to a cnidarian after it grows?
After growing and maturing, the young adult cnidarian then releases itself from the sea floor (unless it is to be a sessile creature like corals and anemones) to become a free swimming medusa-form adult.
What are the members of the phylum Cnidaria?
Members of the phylum Cnidaria include many famous ocean invertebrates, like jellyfish, coral and sea anemones. Cnidarians contain specialized stinging cells known as cnidocytes, which are used for capturing prey and sometimes protection.
What is the alternation of generations in jellyfish?
Some species, particularly the jellyfish, will also experience what is known as an alternation of generations, in which they split themselves into two during their sessile growth phase.
What are the spawning events in the water column?
In the water column, sperm and egg meet and fertilization occurs. What forms from this fertilization is referred to as larva.
How to grow a bud from a parent?
Option one is to produce a bud off the side of its body, which will then grow and mature into an identical copy of the parent. Option two is to split itself down the middle of its body or near its base, after which each side of the body will then begin to grow and develop back into a whole individual again.
Can cnidarians reproduce?
When it comes to cnidarians, asexual reproduction might be an easier process for us to picture. All species of cnidarian are able to reproduce this way, both for reproductive purposes as well as to regenerate lost body parts. This is similar to how a starfish is able to replace a lost limb.
Do cnidarians release their sperm?
There are many different types of cnidarians, each with a unique body structure, but the general reproductive process is the same. Male and female members of a species release their sperm and eggs into the water column.
How do cnidaria reproduce?
Cnidaria is a phylum that consists of over 10,000 known species of animals found in aquatic and marine environments.#N#Cnadrians reproduce both sexually and asexually, using polyps and medusae, which are two forms of cnadria. Polyps and medusae reproduce asexually by budding, but also take part in sexual reproduction for some cnadrians. One example of this is in jelly fish. A larva swims around until it finds a good site, and then becomes a polyp. It then undergoes a process called Storbilation, where the polyp absorbs tentacles and splits horizontally into a series of disks that become juvenile medusae. The juveniles swim off, and slowly mature. While maturing the polyp re-grows and may continue to storbilate. The juvenile forms into an adult and develops gonads in gastroderm. The gonads then release ova and sperm into the water during breeding season. Another way that cnadrian sexually reproduce is through a process called spawning. Spawning is when the eggs and sperm of an aquatic animal are released in water. It is caused by environmental factors such as changes in water temperature. Females release ova into the water, and males release sperm to fertilize the eggs. The release of ova and sperm are caused by lighting conditions such as sunrise, sunset, or the phase of the moon.#N#All known Cnadrians can reproduce asexually, by budding or splitting down the middle. For example Hydrozoan polyps only bud, while the medusae of some hydrozonans can only divide down the middle. Sycphozoan polyps can do both.
What is the process of a jellyfish becoming a polyp?
One example of this is in jelly fish. A larva swims around until it finds a good site, and then becomes a polyp. It then undergoes a process called Storbilation, where the polyp absorbs tentacles and splits horizontally into a series of disks that become juvenile medusae. The juveniles swim off, and slowly mature.
Why do animals spawn?
Spawning is when the eggs and sperm of an aquatic animal are released in water. It is caused by environmental factors such as changes in water temperature. Females release ova into the water, and males release sperm to fertilize the eggs.
Do juvenile gonads release sperm?
The juvenile forms into an adult and develops gonads in gastroderm. The gonads then release ova and sperm into the water during breeding season.
Voice of the Sea: Jellyfish Lake
In the phylum Porifera we saw a body formed of aggregated cells with no organization into tissue layers or organs. Cnidarians have a slightly more organized body plan, and have tissues, but no organs. Most cnidarians have two tissue layers. The outer layer, the ectoderm, has cells that aid in capturing food and cells that secrete mucus.
Weird Science: Deadly Box Jellyfish
Fig. 3.27. Hydrostatic skeleton of a sea anemone ( A) Hydrostatic skeleton filled with water and extending anemone tentacles ( B) Hydrostatic skeleton emptied with anemone tentacles contracted Image by Byron Inouye
How does a cnidarian amphimixis grow?
This grows normally, on the other hand, these organisms absorb their tentacles and split them horizontally into a series of disks that become juvenile medusae, through a process called strobilation. The juveniles swim off and slowly grow to maturity, while the polyp re-grows and should continue strobilation periodically. The adults have gonads that are found within the gastrodermis, and these are involved in the release of ova and sperm into the water within the breeding season. This phenomenon of succession is organized differently among generations is sometimes called "alternation of asexual and sexual phases" or it is also known as "metagenesis". But these alteration processes should not be confused with the alternation of generations as found in plants as both of them are different in nature.
How do cnidarians eat?
Cnidarians feed in several ways such as predation, absorbing the dissolved organic chemicals, filtering the food particles that are present in the water, obtaining nutrients from the symbiotic algae within their cells, and parasitism. By the process of predation, most of the cnidarians obtain a majority of their food. But some, including the corals such as Hetroxenia and Leptogorgia, depend completely on their endosymbionts and on absorbing the dissolved nutrients. Indigestible remains of prey are expelled through the mouth. The main waste of cells that takes place during the internal processes is ammonia, which is removed by the external and internal water currents.
How do anthozoa use their digestive system?
Some Anthozoa has ciliated grooves on their tentacles that allow them to pump water out of and into the digestive cavity without opening the mouth. This improves the process of respiration after feeding and the animals which use the cavity as a hydrostatic skeleton, in order to regulate the water pressure within the cavity without expelling undigested food. The animals produce large quantities of antioxidants to neutralize the surplus oxygen.
What is the process of polymorphism?
Polymorphism is a process that refers to the occurrence of structurally and functionally quite two differing types of people within an equivalent organism. It is a characteristic feature of Cnidarians, particularly in the case of polyp and medusa forms, or of zooids that are found within colonial organisms such as Hydrozoa. In Hydrozoans, colonial individuals arise from individuals such as zooids who will take on separate tasks.
Do cnidarians have brains?
Cnidarians are generally thought to have no brain s or even central nervous systems. However, they have integrative areas of neural tissue that are considered as some sort of centralization. Most of their bodies are innervated by decentralized nerve nets that control their swimming musculature. These nerve nets connect with sensory structures, even though each clade consists slightly of different structures. These sensory structures are usually known as rhopalia. These can generate the signals in response to varied sorts of stimuli such as light, pressure, etc.
Can cnidarians regenerate?
All cnidarians can regenerate, allowing them to get over injury and to breed asexually. Medusae have limited ability to regenerate, but polyps can do so from small pieces or maybe collections of separated cells. This enables corals to recover even after apparently being destroyed by predators.
What is the cnidaria phylum?
The Cnidaria phylum mostly consists of different types of corals,jellyfish and sea anemones. Cnidarians reproduce both sexually and asexually. Many species in the Cnidarian phylum have complex life cycles with asexual polyp stages and sexual medusae, but some omit either the polyp or the medusa stage.
How do sea nettles reproduce?
The Pacific Sea Nettle is a Jellyfish that is capable of both sexual reproduction in the medusa stage and asexual reproduction in the polyp stage.The Medusa stage is the stage where the jellyfish is a free-swimming structure consisting of an umbrella-shaped body (called a bell), a fringe of tentacles that hang from the edge of the bell, and a mouth opening located on the underside of the bell. The polyp stage is a sessile stage, so called because the polyp is stationary and remains attached to a single spot on the sea floor.Reproduction begins when the females catch sperm released by the males to fertilize the eggs she has produced and holds it in her mouth. These fertilized eggs remain attached to her oral arms, and there they grow into flat bean-shaped planula. Once they grow into flower-shaped polyps, they are released into the ocean where they attach themselves to a solid surface and undergo budding.
Can corals reproduce sexually?
Most Reef Corals reproduce sexually, however they can reproduce asexually and become hermaphrodites. Much like the Porifera phylum, coral reproduces asexually through budding and gemmules. However Reef Coral has different parts to budding unlike the Porifera phylum. The Reef Coral can go through i ntratentacular or e xtratentacular budding. Intratentacular budding is from the corals oral discs and it produces a same-sized polyp within a ring of tentacles. Extratentacular budding occurs from the Reef Coral's base, and produces a smaller polyp.
What is the phylum of cnidaria?
The phylum Cnidaria is comprised entirely of aquatic organisms, including the corals, sea anemones, jellyfish, hydra, and sea pens. All Cnidarians are invertebrates and have bodies with radial symmetry, meaning the body is symmetrical around a centralized point. All Cnidarians possess some form of stinging cells, called nematocysts.
What is a cnidarian?
Cnidarians are a group of aquatic organisms that undergo a two-part life cycle. This lesson describes the Cnidarians, their characteristics, and the detailed (yet fascinating) reproductive process they employ. Create an account.
What is the term for the eggs that a medusa cnidarian releases?
Free-swimming medusa Cnidarians release their gametes ( eggs or sperm) into the surrounding water when they are ready to mate. Eggs are fertilized by sperm (sexual reproduction) and develop into the larval stage, during which they are still free-swimming and are called planulae.
What are the two forms of a cnidarian?
Cnidarians as a whole have two body forms: the polyp and the medusa. An individual with the polyp form is usually anchored to the substrate with the mouth facing upwards (the term 'substrate' refers to the materials at the bottom of a water body, like sand, rocks, and organic debris).
What are the steps of free swimming?
During steps 1-3, the free-swimming plaunlae are looking for a place to land to become polyps. During steps 4-8, the polyp is growing in size and maturing until it begins to undergo strobilation (steps 9-11). As the individual ephyra are released, they become free-swimming medusae.
What is the term for the process of releasing gametes?
In an alternating life cycle known as 'metagenesis', adult medusae release gametes to create a sexually reproduced larva. The larva eventually settles on substrate and morphs into a polyp and then begins to segment. These segments eventually break free from the parent polyp and become individual medusae organisms.
What is the term for the alternating sexual and asexual reproduction of ephyra?
This type of alternating sexual and asexual reproduction is called metagenesis. The following image shows an approximation of what this might look like.
How do cnidarians reproduce?
Cnidarians can reproduce asexually by budding (another organism grows off the main organism, such as in anemones), or sexually, in which spawning occurs. Male and female organisms release sperm and eggs into the water column, and free-swimming larvae are produced.
What is the phylum of cnidaria?
The Cnidaria ( Cnidaria spp.) is the phylum of animals that contains corals, jellyfish (sea jellies), sea anemones, sea pens, and hydrozoans. Cnidarian species are found throughout the world and are quite diverse, but they share many similar characteristics.
How big is a cnidaria?
The smallest Cnidaria is the Hydra, which measures under 3/4 of an inch; the largest is the lion's mane jellyfish which has a bell that can measure more than 6.5 feet in diameter; including its tentacles. it can exceed 250 feet long. Dania Chesham/Getty Images.
What are the two types of cnidarians?
There are two types of cnidarians, called polypoid and medusoid. Polypoid cnidarians have tentacles and a mouth that face up (think of an anemone or coral). These animals are attached to a substrate or colony of other animals. Medusoid types are those like jellyfish—the "body" or bell is on top and tentacles and mouth hang down.
How do cnidarians interact with humans?
There are many ways cnidarians may interact with humans: They may be sought-after in recreational activities, such as scuba divers going to reefs to look at corals. Swimmers and divers may also need to beware of certain cnidarians because of their powerful stings. Not all cnidarians have stings that are painful to humans, but some do, and some may even be fatal. Some cnidarians, such as jellyfish, are even eaten. Different cnidarian species may also be collected for trade for aquariums and jewelry.
What are the two layers of cells in a cnidarian?
Two Layers of Cells: Cnidarians have an epidermis, or outer layer, and a gastrodermis (also called the endodermis), which lines the gut. Separating the two layers is a jelly-like substance called the mesoglea, which is most visually apparent in jellyfish. Digestive Cavity (The Coelenteron): The coelenteron contains their stomach, gullet, ...
What is the scientific name of the cnidaria?
Scientific Name: Cinadaria. Jennifer Kennedy, M.S., is an environmental educator specializing in marine life. She serves as the executive director of the Blue Ocean Society for Marine Conservation. The Cnidaria ( Cnidaria spp.) is the phylum of animals that contains corals, jellyfish (sea jellies), sea anemones, sea pens, and hydrozoans.