Search results
Results From The WOW.Com Content Network
The alimentary canal consists of a mouth, buccal cavity (generally running through the first one or two segments of the earthworm), pharynx (running generally about four segments in length), esophagus, crop, gizzard (usually), and intestine. [28] Food enters at the mouth. The pharynx acts as a suction pump; its muscular walls draw in food.
Leeches either have a pharynx that they can protrude, commonly called a proboscis, or a pharynx that they cannot protrude, which in some groups is armed with jaws. [ 38 ] In the proboscisless leeches, the jaws (if any) of Arhynchobdellids are at the front of the mouth, and have three blades set at an angle to each other.
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).
The structure and physiology of the calciferous glands of earthworms are described. Many hypotheses had been advanced for their function; Darwin believed them to be primarily for excretion and secondarily a digestion aid. Thin leaves are seized with the mouth, while thick ones are dragged by creating a vacuum.
Earthworms store their partners' sperm in spermathecae ("sperm stores") and then the clitellum produces a cocoon that collects ova from the ovaries and then sperm from the spermathecae. Fertilization and development of earthworm eggs takes place in the cocoon. Leeches' eggs are fertilized in the ovaries, and then transferred to the cocoon.
However, 'earthworm' can be a source of confusion since, in most of the world, other species are more typical. For example, through much of the unirrigated temperate areas of the world, the "common earthworm" is actually Aporrectodea (=Allolobophora) trapezoides, which in those areas is a similar size and dark colour to L. terrestris.
The crop is an anatomical structure in vertebrate animals, such as birds, and invertebrate animals, such as gastropods (snails and slugs), earthworms, [1] leeches, [2] and insects. [ 3 ] Insects
The genus Lumbricus contains some of the most commonly seen earthworms in Europe among its nearly 700 valid species. [2] Characteristics of some commonly encountered species are: Lumbricus rubellus is usually reddish brown or reddish violet, iridescent dorsally, and pale yellow ventrally. They are usually about 25–105 mm in length, and have ...