How do you pronounce planula?
noun, plural plan·u·lae [plan-yuh-lee].
What is planula larva?
Planula, plural planulae, free-swimming or crawling larval type common in many species of the phylum Cnidaria (e.g., jellyfish, corals, and sea anemones). The planula body is more or less cylindrical or egg-shaped and bears numerous cilia (tiny hairlike projections), which are used for locomotion.
What does the planula develop into?
Following external or internal fertilization, a free-swimming planula larva develops, that soon attaches to a suitable substratum, and evolves into a hydra or a hydroid colony.
Why are a large number of Planulae produced?
Large numbers of planulae are produced to compensate for the many hazards, such as predators, that they encounter as they are carried by water currents. The time between planulae formation and settlement is a period of exceptionally high mortality among corals.
What is Parenchymula larva?
Parenchymula is the larval stage found in phylum Porifera. Among all the options, Leucosolenia belongs to phylum Porifera while Hydra belongs to phylum Coelentrata, Ascaris belongs to phylum Nematoda and Pheretima belongs to phylum Annelida. So, the correct answer is ‘Leucosolenia’.
How do jellyfish reproduce asexually?
Ephyra are the free-swimming jelly stage that comes before full-grown medusa. Jellyfish reproduce both sexually and asexually. At the polyp stage, jellies resemble tiny anemones and reproduce asexually by strobilation. When a polyp strobilates—segmenting its body to reproduce—it releases tiny ephyra into the water.
What do coral spit out?
When water is too warm, corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white. This is called coral bleaching. When a coral bleaches, it is not dead.
Which is the best description of a planula?
Definition of planula. : the very young usually flattened oval or oblong free-swimming ciliated larva of a cnidarian.
How did the planula larva get its name?
The name Planula signifies “wandering animal,” because the Planula larva swims about by means of cilia. The Turbellarians have some features in common with the Cœlenterate planula.
Why is the planula called a wandering animal?
Planula, plan′ū-la, n. the locomotory embryo of the cœlenterates. The upper surface of the planula then becomes depressed and forms a gullet, and in time a complete animal is formed. The name Planula signifies “wandering animal,” because the Planula larva swims about by means of cilia.