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Earthworms have many internal parasites, including protozoa, platyhelminthes, mites, and nematodes; they can be found in the worms' blood, seminal vesicles, coelom, or intestine, or in their cocoons (e.g. the mite Histiostoma murchiei is a parasite of earthworm cocoons [53]).
Earthworms and their kin, in the subclass Oligochaeta, lack eyes but have photoreceptor cells in the skin, especially in the dorsal portion of the anterior end. They also lack parapodia and appendages on the prostomium, the body and the periproct (terminal segment on which the anus is located).
Most animals called "worms" are invertebrates, but the term is also used for the amphibian caecilians and the slowworm Anguis, a legless burrowing lizard. Invertebrate animals commonly called "worms" include annelids , nematodes , flatworms , nemerteans , chaetognaths , priapulids , and insect larvae such as grubs and maggots .
Rotifers have a small cerebral ganglion, effectively its brain, located just above the mastax, from which a number of nerves extend throughout the body. The number of nerves varies among species, although the nervous system usually has a simple layout. [17] The nervous system comprises about 25% of the roughly 1,000 cells in a rotifer. [18]
[8] [12] Their bodies are covered by a cuticle (outer covering) that does not contain cells but is secreted by cells in the skin underneath, is made of tough but flexible collagen [8] and does not molt [23] – on the other hand arthropods' cuticles are made of the more rigid α-chitin, [8] [24] and molt until the arthropods reach their full ...
A boa constrictor in the U.K. gave birth to 14 babies — without a mate. The process is called parthenogenesis, from the Greek words for “virgin” and “birth.” It tends to occur in ...
Oligochaetes are well-segmented worms and most have a spacious body cavity (coelom) used as a hydroskeleton.They range in length from less than 0.5 mm (0.02 in) up to 2 to 3 metres (6.6 to 9.8 ft) in the 'giant' species such as the giant Gippsland earthworm (Megascolides australis) and the Mekong worm (Amynthas mekongianus).
In ecosystems, earthworms such as Lumbricus rubellus increase the rate of transfer between trophic levels by making it easier for plants to uptake nutrients. In food chains, earthworms such as Lumbricus rubellus are primary consumers whose role is converting the energy synthesized by photosynthetic plants into food for animals at higher trophic ...