Planarians are bilaterian flatworms that lack a fluid-filled body cavity, and the space between their organ systems is filled with parenchyma. [5][13] Planarians lack a circulatory system, and absorb oxygen through their body wall. They uptake food to their gut using a muscular pharynx, and nutrients diffuse to internal tissues.

Planarian, any of a group of widely distributed, mostly free-living flatworms of the class Turbellaria (phylum Platyhelminthes). The name planarian is used to designate any member of the family Planariidae and related families.

Planarian is a general term that includes many flatworms under the traditional class of Turbellaria. Turbellaria is one of three branches under the phylum of Platyhelminthes. Most Turbellaria are free-living flatworms.

Land planaria, which are also called terrestrial flatworms (and some of which are called hammerhead worms), are flattened, small to large worm-like animals that live in moist, terrestrial environments. Species in North America are typically yellow …

Currently the genus Planaria is defined as freshwater triclads with oviducts that unite to form a common oviduct without embracing the bursa copulatrix and with an adenodactyl present in the male atrium. The testes occur along the whole body.

Dec 8, 2020 · These worms are often variously called land planarians, terrestrial flatworms, or hammerhead worms (specific to a particular group; see Identification section for discussion). Terrestrial flatworms are most diverse in the tropics, especially SE …

6 days ago · A planarian worm (planaria is the plural form) is a flatworm. Contrary to popular belief, it’s not strictly parasitic. It indeed exhibits parasitic behavior, but these little guys can survive on their own in your fish tank.

Unlike their parasitic cousins in the flatworm group, turbellarians, or planarians, are tiny carnivores or detritus-eaters that glide smoothly across submerged leaves and other objects.

Aug 15, 2024 · As you see, planaria are stubborn little flatworms that are dangerous to the tiny critters in your tank. And, it can be heart-wrenching to see them wriggling all over your aquarium glass, as they quickly take over.

Planaria are flatworms in the phylum Platyhelminthes with amazing regeneration abilities giving them the title 'immortal under the edge of a knife'. There are many different species that inhabit freshwater, marine and terrestrial ecosystems.