| Haementeria ghilianii | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Clade: | Pleistoannelida |
| Clade: | Sedentaria |
| Class: | Clitellata |
| Subclass: | Hirudinea |
| Order: | Rhynchobdellida |
| Family: | Glossiphoniidae |
| Genus: | Haementeria |
| Species: | H. ghilianii |
| Binomial name | |
| Haementeria ghilianii de Filippi, 1849 | |
Haementeria ghilianii, commonly known as the Amazon giant leech, is one of the world's largest species of leeches.
Haementeria ghilianii is a species of leech in the Glossiphoniidae family, comprising freshwater proboscis-bearing leeches. Colloquially, they are known as the Amazon giant leech. Following its initial description in 1849, additional details were provided based on specimens from French Guiana in 1899, after which the species was largely forgotten for over 70 years. [1]
In the 1970s, Dr. Roy Sawyer discovered two adult specimens in a pond located in French Guiana. One of these leeches, dubbed Grandma Moses, founded a successful breeding colony at UC Berkeley. This specimen produced 750 offspring. [2] Following Grandma Moses' death, the specimen was placed in the Smithsonian's National Invertebrate Collection. [3]
Haementeria ghilianii is a jawless, blood-sucking leech. It can grow to 450 mm (17.7 in) in length and 100 mm (3.9 in) in width. [2] This makes it the largest freshwater leech known. [3] As adults, these leeches are a uniform greyish-brown color. Juveniles do not have a uniform color, but rather, a noncontinuous greyish-brown stripe and patches of color. The leeches form a "cobra hood" like shape that is widest in the center but tapers off on both ends. [2] [3] The wider end is where the proboscis is located, while the head is at the narrow end; H. ghilianii is made up 34 segments, each with its own ganglia. [4]
This species is hermaphroditic; the male reproductive system is 3 g (0.0066 lb) to 5 g (0.011 lb) while the female reproductive system is 10 g (0.022 lb). [3] [2] Growth is irregular, as the leech's body weight increases by 3 to 6 fold times per feeding. Fecundity is based upon the weight of the leech during oviposition; egg clutches range from 60 to 500 eggs. [1]
When stressed, leeches will produce mucus to evade predators. [4]
Unlike jawed leeches who use rows of teeth to puncture skin, Haementeria ghilianii uses a 10 centimetres (3.9 in) hypodermic needle-like proboscis to feed. Bites are kept open by the fibrinogenolytic (breaks up fibrinogen) enzyme hementin, which is secreted from the proboscis' lumen; secretion is neurologically controlled. Hementin dissolves clots within the proboscis by breaking up the fibrinogen links between individual platelets. Once attached to a host, they release anticoagulants to prevent clotting. Then, the leeches extract blood at a rate of up to 0.14 ml/min, consuming 15 ml of blood total. [2] [5] Blood is moved into the digestive system through a series of undulation movements, and leeches can go months without feeding. [4] [5] Observed host species include humans, rabbits, and cows. [2] [5] Claims from 1899 state that leeches could aggregate to the point of killing birds and cattle. [4]
Haementeria ghilianii is endemic to the northern portions of the Amazon river, ranging from Venezuela and the Guianas. [2]
A thrombus, colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of cross-linked fibrin protein. The substance making up a thrombus is sometimes called cruor. A thrombus is a healthy response to injury intended to stop and prevent further bleeding, but can be harmful in thrombosis, when a clot obstructs blood flow through a healthy blood vessel in the circulatory system.
Lachesis is a genus of pit vipers in the family Viperidae. Member species are found in forested areas of the Neotropics. The generic name refers to one of the Three Fates, Lachesis, who determined the length of the thread of life. Four species are currently recognized as being valid.
The arapaima, pirarucu, or paiche is any large species of bonytongue in the genus Arapaima native to the Amazon and Essequibo basins of South America. Arapaima is the type genus of the subfamily Arapaiminae within the family Osteoglossidae. They are among the world's largest freshwater fish, reaching as much as 3 m (9.8 ft) in length. They are an important food fish. They have declined in the native range due to overfishing and habitat loss. In contrast, arapaima have been introduced to several tropical regions outside the native range, where they are sometimes considered invasive species. In Kerala, India, arapaima escaped from aquaculture ponds after floods in 2018. Its Portuguese name, pirarucu, derives from the Tupi language words pira and urucum, meaning "red fish".
The black caiman is a crocodilian reptile endemic to South America. With a maximum length of around 5 to 6 m and a mass of over 450 kg (1,000 lb), it is the largest living species of the family Alligatoridae, and the third-largest crocodilian in the Neotropical realm. True to its common and scientific names, the black caiman has a dark greenish-black coloration as an adult. In some individuals, the pigmentation can appear almost jet-black. It has grey to brown banding on the lower jaw; juveniles have a more vibrant coloration compared to adults, with prominent white-pale yellow banding on the flanks that remains present well into adulthood. The banding on young animals helps with camouflage by breaking up their body outline, on land or in water, in an effort to avoid predation. The morphology is quite different from other caimans but the bony ridge that occurs in other caimans is present. The head is large and heavy, an advantage in catching larger prey. Like all crocodilians, caimans are long, squat creatures, with big jaws, long tails and short legs. They have thick, scaled skin, and their eyes and noses are located on the tops of their heads. This enables them to see and breathe while the rest of their bodies are underwater.
The Aldabra giant tortoise is a species of tortoise in the family Testudinidae and genus Aldabrachelys. The species is endemic to the Seychelles, with the nominate subspecies, A. g. gigantea native to Aldabra atoll. It is one of the largest tortoises in the world. Historically, giant tortoises were found on many of the western Indian Ocean islands, as well as Madagascar, and the fossil record indicates giant tortoises once occurred on every continent and many islands with the exception of Australia and Antarctica.
Hementin is an anticoagulant protease from the salivary glands of the giant Amazon leech. Hementin is a calcium-dependent protease with a molecular weight of 80–120 kDa, and it contains 39 amino acid sequences. Hementin is present in both the anterior and posterior salivary glands, however it is mostly produced from certain cells in the anterior glands. The secretion of hementin is limited to the lumen of the proboscis, which the Amazon leech inserts into the host to suck blood. Hementin dissolves platelet-rich blood clots and lets the blood flow through the proboscis. Hementin is able to dissolve a type of blood clots that cannot be dissolved by other compounds, such as streptokinase and urokinase.
The Mekong giant catfish, is a large, threatened species of catfish in the shark catfish family (Pangasiidae), native to the Mekong basin in Southeast Asia and adjacent China. It is considered critically endangered due to overfishing and habitat loss.
The Arrau turtle, also known as the South American river turtle, giant South American turtle, giant Amazon River turtle, Arrau sideneck turtle, Amazon River turtle or simply the Arrau, is the largest of the side-neck turtles (Pleurodira) and the largest freshwater turtle in Latin America. The species primarily feeds on plant material and typically nests in large groups on beaches. Due to hunting of adults, collecting of their eggs, pollution, habitat loss, and dams, the Arrau turtle is seriously threatened.
Rhynchobdellida, the jawless leeches or freshwater leeches, are an order of aquatic leeches. Despite the common name "freshwater leeches", species are found in both sea and fresh water. They are defined by the presence of a protrusible proboscis instead of jaws, and having colourless blood. They move by "inchworming" and are found worldwide. The order contains 110 species, divided into 41 genera and three families. Members of the order range widely in length, usually between 7 and 40 mm. They are hermaphrodite. The order is not monophyletic.
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.
Nannostomus trifasciatus,, commonly known as the three-lined or three-stripe pencilfish, is a freshwater species of fish belonging to the characin family Lebiasinidae. They are popular in the aquarium trade due to their small size, beautiful color pattern, and relative hardiness.
Glossiphoniidae are a family of freshwater proboscis-bearing leeches. These leeches are generally flattened, and have a poorly defined anterior sucker. Most suck the blood of freshwater vertebrates like amphibians, crocodilians and aquatic turtles, but some feed on invertebrates like oligochaetes and freshwater snails instead. Although they prefer other hosts, blood-feeding species will opportunistically feed from humans.
The twist-necked turtle, also known as the flat-headed turtle, is distributed widely across northern South America. Twist-necked turtles have extremely flat shells that help them hide from predators under rocks and debris. When threatened, this turtle withdraws by twisting its head into its shell. P. platycephala is the only species of the genus Platemys and occurs in northern and central South America. Platemys platycephala means "flat turtle, flat-head" and accurately describes the structure of the head and shell. This species inhabits shallow creek beds and frequently forages on the floor of the Amazon rainforest for insects, amphibians, and mollusks. Camouflage, head and body shape, and advanced sexual anatomy allow this species of turtle to effectively populate much of South America. Mating occurs during rainy months (March–December) and egg deposit occurs during dry months (January–March). Males have been known to behave aggressively towards females during copulation by squirting water from nostrils and biting. A few genomic studies show mosaicism exists among populations of the twist-necked turtle in Suriname. In other words, diploid and triploid levels exist among individuals at this particular location. No threats have been reported for this species and the International Union for Conservation of Nature does not have a current listing. Lack of human consumption due to the species' small size and its wide range explain why scientists are not concerned about this turtle species.
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Hematophagy is the practice by certain animals of feeding on blood. Since blood is a fluid tissue rich in nutritious proteins and lipids that can be taken without great effort, hematophagy is a preferred form of feeding for many small animals, such as worms and arthropods. Some intestinal nematodes, such as Ancylostomatids, feed on blood extracted from the capillaries of the gut, and about 75 percent of all species of leeches are hematophagous. The spider Evarcha culicivora feeds indirectly on vertebrate blood by specializing on blood-filled female mosquitoes as their preferred prey. Some fish, such as lampreys and candirus; mammals, especially vampire bats; and birds, including the vampire finch, Hood mockingbird, Tristan thrush, and oxpeckers, also practise hematophagy.
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Turtle leeches are a genus, Ozobranchus, of leeches (Hirudinea) that feed exclusively on the blood of turtles. Only two species—Ozobranchus margoi and Ozobranchus branchiatus—are found in the Atlantic coast of the United States and the Gulf of Mexico. Little is known about these leeches due to difficulties in studying their sea turtle hosts.
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Piscicola geometra is a species of leech in the family Piscicolidae. It is an external parasite of marine, brackish and freshwater fishes. It was first described as Hirudo geometra by the Swedish naturalist Carl Linnaeus in his Systema Naturae in 1758.
Barbronia weberi is a species of predatory freshwater leech in the family Salifidae. It is native to southeastern Asia but has spread to other parts of the world, including Australia, South America, southern Europe and the United States.