How do turbellarians reproduce?
Turbellarians are simultaneous hermaphrodites and lay eggs bundled into cocoons. The young undergo direct development and hatch as juveniles. Spiral cleavage is prevalent. Some turbellarians can reproduce asexually by fission.
What is the male copulatory organ of some flatworms called?
The penis papilla is a permanent structure that occupies part or the whole male atrium and is protruded during copulation, thus also called a protrusible penis.
What influences the type of reproduction that would occur in turbellarians?
A few species live on land in damp habitats like leaf litter. Turbellarians reproduce by fission and regeneration, or sexually. Turbellarians that reproduce sexually are hermaphroditic—sperm from one animal will fertilize eggs from another, and the eggs then hatch into small turbellarians.
How do Acoelomates reproduce?
They are hermaphrodites and have both male and female reproductive organs (testes and ovaries). Sexual reproduction is most common and happens as two planarians mate, fertilizing eggs in both flatworms. Planarians may also reproduce asexually through fragmentation.
What is the digestive organ of turbellarians?
The digestive system of turbellarians typically consists of mouth, pharynx, and intestine. In the order Acoela, however, only a mouth is present; food passes directly from the mouth into the parenchyma, to be absorbed by the mesenchymal cells. The excretory system consists of protonephridia.
What is reproductive organ of the flatworms?
With very few exceptions, platyhelminthes are hermaphroditic, and their reproductive systems are generally complex. Numerous testes but only one or two ovaries are usually present in these flatworms.
Which of the following is the copulatory organ in human males?
The penis. The penis, the male organ of copulation, is partly inside and partly outside the body. The inner part, attached to the bony margins of the pubic arch (that part of the pelvis directly in front and at the base of the trunk), is called the root of the penis.
What is the function of cilia in turbellarians?
They range in size from a few millimeters to a half meter long. Small turbellarians use cilia for their propulsive force, and some very small forms swim through fluid. A lot of energy is used for the production of mucus to lubricate and protect the surface of the body and to help capture prey.
How does flatworm reproduce asexually?
Through a process called “fission,” planarians can reproduce asexually by simply tearing themselves into two pieces — a head and a tail — which then go on to form two new worms within about a week. When, where and how this process unfolds has remained a puzzle for centuries due to the difficulty of studying fission.
What type of asexual reproduction is flatworms platyhelminthes?
Flatworm Reproduction Asexually, flatworms procreate via fragmentation and budding. Fragmentation, also called cloning, occurs when a flatworm splits off a part of its body, allowing the separated portion to regenerate into a new worm. With budding, a flatworm grows an extension from its body.
How are turbellarians different from other flatworms?
Unlike their parasitic cousins in the flatworm group (the tapeworms and flukes), most turbellarians are free-living, and most are carnivores, eating tiny aquatic invertebrates such as rotifers, small crustaceans, and other worms.
How do flatworms reproduce asexually?
Freshwater planarians, found around the world and commonly known as “flatworms,” are famous for their regenerative prowess. Through a process called “fission,” planarians can reproduce asexually by simply tearing themselves into two pieces— a head and a tail—which then go on to form two new worms within about a week.
What type of asexual reproduction is flatworms?
What is a copulatory organ?
An organ utilized by the male animal for insemination, that is, to deposit spermatozoa directly into the female reproductive tract. Various types of copulatory organs are found among the vertebrates, whereas cloacal apposition occurs in most other vertebrates which lack these structures.
What is the name of the male reproductive organ?
The male genitals include: the testicles (pronounced: TESS-tih-kulz) the duct system, which is made up of the epididymis and the vas deferens. the accessory glands, which include the seminal vesicles and prostate gland.
What is the reproductive organ of platyhelminthes?
Flatworms are hermaphrodites. Hermaphrodites are organisms that have both male and female sexual organs. Platyhelminthes are able to reproduce asexually and sexually, but sexual reproduction is preferable. Parasitic Platyhelminthes deposit their eggs in their host or bore themselves into the host tissues.
How do platyhelminthes reproduce asexually?
How acoelomates are formed?
Acoelomates have a triploblastic body plan, meaning that their tissues and organs develop from three primary embryonic cell (germ cell) layers. These tissue layers are the endoderm (endo-, -derm) or innermost layer, mesoderm (meso-, -derm) or middle layer, and the ectoderm (ecto-, -derm) or outer layer.
What is the reproductive system of turbellarians?
All turbellarians are simultaneous hermaphrodites, having both female and male reproductive cells, and fertilize eggs internally by copulation. Some of the larger aquatic species mate by penis fencing, a duel in which each tries to impregnate the other, and the loser adopts the female role of developing the eggs.
Where are the male copulatory organs located in spiders?
In spiders, the paired male copulatory organs are situated on the pedipalps, which are paired body appendages anterior to the four pairs of walking legs. The use of pedipalps as intromittent organs in males is a synapomorphy for the Araneae .
How do two turbellarians mate?
Two turbellarians mating by penis fencing. Each has two penises, the white spikes on the undersides of their heads. Many turbellarians clone themselves by transverse or longitudinal division, and others, especially acoels, reproduce by budding. The planarian Dugesia is a well-known representative of class Turbellaria.
What is the shape of the body of turbellarians?
Like many other members of the Phylum Platyhelminthes, Turbellarians have a dorsoventrally flattened body that is bilaterally symmetrical. The flattened body shape in these organisms is attributed to the fact that flatworms do not have a true body cavity, as such, they are known as acoelomates .