| Erpobdella octoculata | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Class: | Clitellata |
| Subclass: | Hirudinea |
| Order: | Arhynchobdellida |
| Family: | Erpobdellidae |
| Genus: | Erpobdella |
| Species: | E. octoculata |
| Binomial name | |
| Erpobdella octoculata | |
Erpobdella octoculata is a freshwater leech in the Erpobdellidae family. [1] This species can be found in Europe, the Mediterranean, and the Middle East (Iran and Turkey). [2] [3] [4]
This tube-shaped species ranges from 3–7 cm long. [5] Like all leeches, E. octoculata has 32 fixed segments. [6] Segments 1–4 contain the head, along with the brain, and oral sucker. The mid-body is composed of segments 5–25 where bodily organs are. The tail sucker is housed in segments 26–32. [6]
The body color of E. octoculata ranges from yellow-green to a reddish-brown. [7] This color depends on the amount of non-pigmented spots surrounding the sensory buds. [7] Individuals with a higher percentage of non-pigmented spots on their dorsum appear yellow-green. Those with a higher percentage of pigment appear a reddish-brown. Body color also corresponds to different substrates at the bottoms of aqueous habitats such as stones (lighter color) or plants (darker color). [7]
Erpobdella octoculata has 4 pairs of black eyes. The two pairs of labial eyes can occur on segments 2 or 3. [8] The two buccal pairs of eyes are situated on segment 4. [8] The buccal eyes are smaller, only containing three layers of photoreceptor cells, while the labial eyes have six layers. [8]
E. octoculata is one of the most common freshwater leeches in Europe with documentation in over 20 countries. [7] [8] This species has been shown to be more abundant in fast moving streams and rivers with rocky bottoms than other leech species. [9] [10] E. octoculata prefers acidic bodies of water with low nutrient content. [10] This species was also found to be abundant in polluted streams in Poland. [11]
This species of leech can be used as a bioindicator due to its ability to survive in polluted waters. Levels of contamination can also be determined by the amount of pollutants in the tissues of E. octoculata, which was shown in a study by Macova et. al. [12]
Erpobdella octoculata is a predator and exhibits scavenging behavior. It feeds primarily on chironomid larvae and oligochaetes. [13] Due to the lack of jaws or a proboscis, this species uses a pharynx to swallow its prey whole. [14] In a laboratory study, it was found that E. octoculata will suck in pieces of dead or wounded animals including vertebrates such as fish. [13] In addition, when wounded chironomid larva is present, this species will uses its oral sucker to retrieve blood. [13] Newly hatched leeches feed on insect larvae and suck the blood from injured Chironomus larvae. [13] E. octoculata primarily hunts at night. [15]
E. octoculata uses vermiform crawling to move across the bottoms of stony streams. [8] Vermiform crawling involves an alternating shortening and extending of the body along the tail and oral suckers. [16] Both suckers start off relatively distant and are attached to a stone. Then only the oral sucker lifts itself and the entire body extends before the oral sucker reattaches itself. [16] The front of the body extends while the back shortens. Next the tail sucker lifts and the back of the body shortens. [16] When the tail sucker attaches back to a stone or substrate, it is relatively close to the oral sucker and the body is in a scrunched c-shape. [16] Along with vermiform crawling, E. octoculata also swims using oscillatory movements. [8]
Many leeches contain sensillae, which sense water movement and light with photoreceptors. [8] E. octoculata lacks developed sensillae and instead has sensory buds on its dorsal surface due to its predaceous nature and fast moving aqueous environment. [8] Spread through the center of each annulus, these sensory buds have a round, raised appearance on the dorsum of this species. These sensory buds are composed of bipolar sensory cells, which are chemoreceptive and perceive water movement. [17] This leech does also have a brain that is a mass of ganglia. [8]
In addition, E. octoculata also has mechanoreceptors located in its skin. They are activated by stimulation such as touch or attacks from predators. [8] Known predators include perch, water beetles, and caddisflies. [18]
Freshwater leeches need to constantly remove excess water along with waste products. Nephridia are organs that function similarly to kidneys. [8] They aid in this water and waste removal and the reabsorption of salts. [8] Nephridia occur on each segment in the mid-body. [6]
The life cycle of Erpobdella octoculata lasts 1–3 years. [19] Adult leeches are distinguished by the presence of a clitellum, where its oval shaped cocoons are secreted from. [8] [20] These cocoons have approximately 5–10 eggs each. [8] Most individuals lay cocoons within 1 year of hatching and subsequently die. [21] If an individual does not breed after 1 year, it breeds at 2 years of age and lays cocoons for a second time at 3 years old. [19] Variations between lengths of the life cycle can potentially be explained by environmental conditions such as water temperature, food availability and dissolved oxygen. [5]
Since Erpobdella octoculata is a hermaphrodite, it has male and female gonopores. [22] These gonopores have openings on the dorsum.
The clitellum is a thickened glandular and non-segmented section of the body wall near the head in earthworms and leeches, that secretes a viscid sac in which eggs are stored. It is located near the anterior end of the body, between the fourteenth and seventeenth segments. The number of the segments to where the clitellum begins and the number of segments that make up the clitellum are important for identifying earthworms. In microdrile earthworms, the clitellum has only one layer, resulting in a smaller quantity of eggs than that of the megadrile earthworms, which have larger multi-layered clitellum that have special cells that secrete albumin into the worms' egg sac.
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.
Erpobdella obscura is a freshwater ribbon leech common in North America. It is a relatively large leech and is commonly used as bait by anglers for walleye and other sport fish. In Minnesota, live bait dealers annually harvest over 45,000 kg of bait-leeches, raising concerns of over-harvest.
Euhirudinea, the true leeches, are an infraclass of the Hirudinea.
Arhynchobdellida, the proboscisless leeches, are a monophyletic order of leeches. They are defined by the lack of the protrusible proboscis that defines their sister taxon, the Rhynchobdellida. Arhynchobdellida is a diverse order, compromising both aquatic and terrestrial, besides sanguivorous and predatory, leeches. The order is divided into two suborders, Erpobdelliformes and Hirudiniformes.
Leeches are segmented parasitic or predatory worms that comprise the subclass Hirudinea within the phylum Annelida. They are closely related to the oligochaetes, which include the earthworm, and like them have soft, muscular segmented bodies that can lengthen and contract. Both groups are hermaphrodites and have a clitellum, but leeches typically differ from the oligochaetes in having suckers at both ends and in having ring markings that do not correspond with their internal segmentation. The body is muscular and relatively solid, and the coelom, the spacious body cavity found in other annelids, is reduced to small channels.
Erpobdella lineata is a leech found in Europe. These leeches show a preference for calcic waters and have a tolerance to pollution. They have a digestive tract that consists of mouth, pharynx, esophagus, six-chambered stomach, three-chambered intestine, rectum, and an anus. Its nervous system contains 21 pairs of cell compartments.
Motobdella montezuma is a species of leech which is only found in Montezuma Well, central Arizona, United States. It is a nocturnal pelagic predator that feeds almost exclusively on the endemic amphipod Hyalella montezuma, which it detects using passive sonar and swallows whole.
Erpobdella is a genus of leeches in the family Erpobdellidae. Members of the genus have three or four pairs of eyes, but never have true jaws, and are typically 20–50 millimetres (0.8–2.0 in) long. All members do not feed on blood, but instead are predators of small aquatic invertebrates, which they often swallow whole.
Haemopis sanguisuga is a species of freshwater leech in the family Haemopidae. It is commonly called the horse-leech, but that is due to the similarity of its appearance to the leech Limnatis nilotica, which sometimes enters the nasal cavities of livestock. Haemopis sanguisuga does not behave in this way. Another synonym for this leech is Aulastomum gulo.
Branchiobdellida is an order of freshwater leech-like clitellates that are obligate ectosymbionts or ectoparasites, mostly of astacoidean crayfish. They are found in the Northern Hemisphere and have a holarctic distribution in East Asia, the Euro-Mediterranean region and North and Central America, with the greatest species diversity being in North and Central America.
Hirudo verbana is a species of leech.
Erpobdellidae is a family of leeches. It is one of the four families belonging to the suborder Erpobdelliformes of the proboscisless leeches order, Arhynchobdellida.
The annelids, also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments.
Hirudo orientalis is a species of medicinal leech. It has been confused with Hirudo medicinalis, but has recently been recognized as a different species. This Asian species is associated with mountainous areas in the subboreal eremial zone and occurs in Azerbaijan, Iran, Uzbekistan and Kazakhstan. It occurs also in Georgia, and probably in Armenia.
Erpobdella punctata is a leech in the family Erpobdellidae. It is found in freshwater streams and ponds in many parts of North America.
The Piscicolidae are a family of jawless leeches in the order Rhynchobdellida that are parasitic on fish. They occur in both freshwater and seawater, have cylindrical bodies, and typically have a large, bell-shaped, anterior sucker with which they cling to their host. Some of the leeches in this family have external gills, outgrowths of the body wall projecting laterally, the only group of leeches to exchange gases in this way.
Acanthobdella peledina is a species of leech-like clitellate in the order Acanthobdellida. It feeds on the skin and blood of freshwater fishes in the boreal regions of northern Europe, Asia and North America.
Erpobdella mestrovi is a species of troglobitic leech found only in deep caves in Northern Velebit, part of the Dinaric Alps of Croatia. The leech was first found in Lukina jama in 1994, which at 1431 meters deep is the deepest cave in Croatia. The leech has been found in several other caves systems in Velebit such as Slovacka jama, Olimp and Velebita, and is currently considered endemic to Croatia.
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