The Orinoco is one of the longest rivers in South America at 2,250 kilometres (1,400 mi). Its drainage basin, sometimes known as the Orinoquia, covers 880,000 km2 (340,000 sq mi), with 76.3 percent of it in Venezuela and the remainder in Colombia. It is the fourth largest river in the world by discharge volume of water. The Orinoco River and its tributaries are the major transportation system for eastern and interior Venezuela and the Llanos of Colombia. The environment and wildlife in the Orinoco's basin are extremely diverse.
Lumbricus terrestris is a large, reddish worm species thought to be native to Western Europe, now widely distributed around the world. In some areas where it is an introduced species, some people consider it to be a significant pest for out-competing native worms.
The Rio Negro, or Guainía as it is known in its upper part, is the largest left tributary of the Amazon River, the largest blackwater river in the world, and one of the world's ten largest rivers by average discharge.
The Lumbricidae are a family of earthworms. About 33 lumbricid species have become naturalized around the world, but the bulk of the species are in the Holarctic region: from Canada and the United States and throughout Eurasia to Japan. An enigmatic species in Tasmania is Eophila eti. Currently, 670 valid species and subspecies in about 42 genera are recognized. This family includes the majority of earthworm species well-known to Europeans.
Oligochaeta is a subclass of animals in the phylum Annelida, which is made up of many types of aquatic and terrestrial worms, including all of the various earthworms. Specifically, oligochaetes comprise the terrestrial megadrile earthworms, and freshwater or semiterrestrial microdrile forms, including the tubificids, pot worms and ice worms (Enchytraeidae), blackworms (Lumbriculidae) and several interstitial marine worms.
Amazonas State is one of the 23 states (estados) into which Venezuela is divided. It covers nearly a fifth of the area of Venezuela, but has less than 1% of Venezuela's population.
Bolívar is one of the 23 states into which Venezuela is divided. The state capital city is Ciudad Bolívar, but the largest city is Ciudad Guayana. Bolívar State covers a total surface area of 242,801 km2 (93,746 sq mi) and as of the 2011 census, had a population of 1,410,964. The state contains Angel Falls.
The Megascolecidae is a taxonomic family of earthworms which is can be found native in Australia, New Zealand and both South East Asia and North America. All species of Megascolecidae belong to the Citellata class. Megascolecidae are a large family of earthworms and they can grow up to 2 meters in length. The intercontinental distribution of Megascolecidae helps in favouring the Continental Drift theory.
Eisenia fetida, known under various common names such as manure worm, redworm, brandling worm, panfish worm, trout worm, tiger worm, red wiggler worm, etc., is a species of earthworm adapted to decaying organic material. These worms thrive in rotting vegetation, compost, and manure. They are epigean, rarely found in soil. In this trait, they resemble Lumbricus rubellus.
The Orinoco crocodile is a critically endangered crocodile. Its population is very small, and it can only be found in freshwater environments in Colombia and Venezuela. Extensively hunted for their skins in the 19th and 20th centuries, it is one of the most endangered species of crocodiles. It is a very large species of crocodilian; males have been reported up to 6.8 m in the past, but such sizes do not exist today, 5.2 m being a more widely accepted maximum size. A large male today may attain 4.1 m in length and can weigh 380 kg (840 lb), while females are substantially smaller with the largest likely to weigh around 225 kg (496 lb). Sexual dimorphism is not as profound as in other crocodilian species. The coloration is light even in adults.
The Clitellata are a class of annelid worms, characterized by having a clitellum - the 'collar' that forms a reproductive cocoon during part of their life cycles. The clitellates comprise around 8,000 species. Unlike the class of Polychaeta, they do not have parapodia and their heads are less developed.
Spenceriella is a genus of worms in the family Megascolecidae that is now included in the prior genus Anisochaeta although some other species are transferred to Celeriella.
An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan, are externally segmented with corresponding internal segmentation, and usually have setae on all segments. They occur worldwide where soil, water, and temperature allow. Earthworms are commonly found in soil, eating a wide variety of organic matter. This organic matter includes plant matter, living protozoa, rotifers, nematodes, bacteria, fungi, and other microorganisms. An earthworm's digestive system runs the length of its body. It respires through its skin. It has a double transport system made of coelomic fluid that moves within the fluid-filled coelom and a simple, closed circulatory system. It has a central and peripheral nervous system. Its central nervous system consists of two ganglia above the mouth, one on either side, connected to a nerve running along its length to motor neurons and sensory cells in each segment. Large numbers of chemoreceptors concentrate near its mouth. Circumferential and longitudinal muscles edging each segment let the worm move. Similar sets of muscles line the gut, and their actions move digesting food toward the worm's anus.
Dendrodrilus rubidus is a species of earthworm in the family Lumbricidae. It is native to Europe, and it is a widespread introduced species, occurring on every continent except Antarctica, as well as many islands. It is often invasive. It is sometimes used as fishing bait, and is marketed under many nonspecific names, including red wiggler, jumping red wiggler, red trout worm, jumbo red worm, and pink worm. Other common names include bank worm, tree worm, and gilt tail.
Samuel James is an American scientist, a researcher specializing in evolutionary biology, focusing on earthworm taxonomy. James, with fellow researchers, has discovered numerous species of annelids, including Diplocardia californiana, Diplocardia woodi, Diplocardia montana, and a new species related to the Giant Palouse earthworm.
Octochaetus multiporus, commonly known as the New Zealand earthworm, is a megascolecid worm endemic to New Zealand. It is mainly found in the south of Manawatu but may also be found along the east coast of the South Island. A bioluminescent worm, Octochaetus multiporus secretes a luminescent fluid from its mouth when disturbed or punctured.
Moniligastridae is a family of earthworms native to South and Eastern Asia, containing around 200 species and five genera.
Amynthas mekongianus, the Mekong worm or Mekong giant earthworm, previously known as Megascolex mekongianus, is a species of earthworm in the family Megascolecidae. It is native to the vicinity of the River Mekong in southeastern Asia and may have more than 500 segments and grow to a length of 2.9 m (10 ft).
Pontoscolex is a genus of earthworms in the family Glossoscolecidae, or alternatively, in the family Rhinodrilidae.
Bimastos is a genus of lumbricid worm thought to be native to North America but has since been introduced to every continent apart from Antarctica. Recent molecular analysis has subsumed Dendrodrilus and Allolobophoridella under this genus. The clade holding Bimastos and Eisenoides seems to have diverged from Eurasian lumbricid Eisenia during the Late Cretaceous, approximately 69.2–76.1 years ago. This, along with the discovery of an earthworm cocoon attributed to B. rubidus from lake sediment dated over 7,000 years old in Ontario, Canada contradicts the widely held notion that Bimastos and its junior synonyms are invasive worms from Europe which have colonized North America. It's ancestors likely entered North America via the Bering Land bridge or the De Geer route and colonized elsewhere after European contact. This genus is one of the few remaining native earthworms in many North American environments, for example it appears to be the only extant earthworm native to the Alaskan interior.
