Hemibdella soleae

Hemibdella soleae
Scientific classification
Kingdom:	Animalia
Phylum:	Annelida
Class:	Clitellata
Subclass:	Hirudinea
Order:	Rhynchobdellida
Family:	Piscicolidae
Genus:	Hemibdella
Species:	H. soleae
Binomial name
	Hemibdella soleae; (van Beneden & Hesse, 1863) [1]

Last updated June 17, 2019

Hemibdella soleae is a marine species of leech in the family Piscicolidae and the type taxon of its genus. Found in the northeastern Atlantic Ocean, it is a parasite of flatfish such as the common sole.

In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. While these definitions may seem adequate, when looked at more closely they represent problematic species concepts. For example, the boundaries between closely related species become unclear with hybridisation, in a species complex of hundreds of similar microspecies, and in a ring species. Also, among organisms that reproduce only asexually, the concept of a reproductive species breaks down, and each clone is potentially a microspecies.

Leeches are segmented parasitic or predatory worms that belong to the phylum Annelida and comprise the subclass Hirudinea. They are closely related to the oligochaetes, which include the earthworms, 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 external annulations that do not correspond with their internal segmentation. The body is relatively solid, and the spacious body cavity found in other annelids, the coelom, is reduced to small channels.

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.

Description

This small leech grows to a length of about 10 mm (0.4 in) when extended. It is roughly cylindrical, thicker in the middle and narrowing somewhat to a sucker at each end. Newly-hatched larvae are yellowish and transparent and have a pair of eyespots. As they grow they become opaque, with black speckles, and lose the eyespots; later they become beige or grey, and finally black.^[2]

Distribution and habitat

The range of Hemibdella soleae extends across the northeastern Atlantic Ocean, the North Sea and the Mediterranean Sea. Like the flatfish it parasitizes, it is benthic and demersal (living on and just above the seabed) and occurs at depths down to about 200 m (660 ft).^[2]

The North Sea is a marginal sea of the Atlantic Ocean located between the United Kingdom, Denmark, Norway, Sweden, Germany, the Netherlands, Belgium and France. An epeiric sea on the European continental shelf, it connects to the ocean through the English Channel in the south and the Norwegian Sea in the north. It is more than 970 kilometres (600 mi) long and 580 kilometres (360 mi) wide, with an area of 570,000 square kilometres (220,000 sq mi).

The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Southern Europe and Anatolia, on the south by North Africa and on the east by the Levant. Although the sea is sometimes considered a part of the Atlantic Ocean, it is usually identified as a separate body of water. Geological evidence indicates that around 5.9 million years ago, the Mediterranean was cut off from the Atlantic and was partly or completely desiccated over a period of some 600,000 years, the Messinian salinity crisis, before being refilled by the Zanclean flood about 5.3 million years ago.

A flatfish is a member of the order Pleuronectiformes of ray-finned demersal fishes, also called the Heterosomata, sometimes classified as a suborder of Perciformes. In many species, both eyes lie on one side of the head, one or the other migrating through or around the head during development. Some species face their left sides upward, some face their right sides upward, and others face either side upward.

Ecology

H. soleae is an ectoparasite of flatfish such as the common sole (Solea solea). Like other marine leeches, it feeds on its host's blood, but unlike most freshwater species, it does not drop off the fish after it has fed, instead remaining attached by its anterior sucker. In the juvenile leech, the remnants of each blood meal is visible through the transparent skin as a small red ball inside.^[2] In the northern part of its range, the common sole is the main host, but further south, other fish are also parasitized; these include the Senegalese sole (Solea senegalensis), the wedge sole (Dicologlossa cuneata), the bastard sole ( Microchirus azevia), the Klein's sole (Synapturichthys kleinii), the sand sole (Pegusa lascaris) and the Portuguese sole (Dagetichthys lusitanica). In the English Channel, small common sole may have one or two leeches on them while large fish may have forty or more of the parasites.^[2]

The common sole, Dover sole, or black sole is a species of flatfish in the family Soleidae. It lives on the sandy or muddy seabed of the northern Atlantic and the Mediterranean Sea where it often semi-immerses itself in the substrate. The upper side is greyish-brown while the underside is white. It grows to a maximum length of about 70 cm (28 in). The species is prized as a food fish, being caught mostly by trawling on the seabed.

In biology and medicine, a host is an organism that harbours a parasitic, a mutualistic, or a commensalist guest (symbiont), the guest typically being provided with nourishment and shelter. Examples include animals playing host to parasitic worms, cells harbouring pathogenic (disease-causing) viruses, a bean plant hosting mutualistic (helpful) nitrogen-fixing bacteria. More specifically in botany, a host plant supplies food resources to micropredators, which have an evolutionarily stable relationship with their hosts similar to ectoparasitism. The host range is the collection of hosts that an organism can use as a partner.

Solea senegalensis, the Senegalese sole, is a species of flatfish from the family of the true soles, the Soleidae, from the eastern Atlantic and the Mediterranean Sea.

Adult leeches attached to the underside of fish lay eggs on the seabed in locations where the fish like to semi-bury themselves in the sediment; the eggs have stalks and are anchored to grains of sand. The free-swimming larvae search out a host fish and attach to the anterior end of the dorsal surface, the only part of the fish not buried in sediment. After a short period of development, the larvae migrate to the ventral surface of the fish. Here they attach to the host with their front sucker oriented towards the front of the fish.^[3]

Related Research Articles

The true soles are a family, Soleidae, of flatfishes. It includes saltwater and brackish water species in the East Atlantic, Indian Ocean, and West and Central Pacific Ocean. Freshwater species are found in Africa, southern Asia, New Guinea, and Australia.

Monogeneans are a group of ectoparasitic flatworms commonly found on the skin, gills, or fins of fish. They have a direct lifecycle and do not require an intermediate host. Adults are hermaphrodites, meaning they have both male and female reproductive structures. Monogeneans have a series of hooks which are used to attach onto fish, and as a result, could lead to infections.

The yellowbelly flounder is a flatfish of the genus Rhombosolea, found around New Zealand. A different species from the genus Rhombosolea is found in Australia and also goes by the name yellow-belly flounder. The Māori people have commonly fished for R.leporina, and many other species of flatfish, throughout New Zealand's coastal waters for hundreds of years. The Māori name for this species is 'patiki totara'.

The New Zealand sand flounder is a righteye flounder of the genus Rhombosolea, found around New Zealand in shallow waters down to depths of 100 m.

The silver lamprey is a lamprey commonly found in the Northern and Central United States, as well as a large part of southern Canada. Its binomial name means "sucking fish" in Greek and "one-pointed" in Latin. The silver lamprey is a member of the Class Agnatha, sometimes referred to as cyclostomes (round-mouths). Other common names include: Bloodsucker, Blue Lamprey, Hitch-hiker, Lamper, Lamprey Eel. The silver lamprey should not to be confused with the sea lamprey, which has caused considerable damage to native fish populations in the Great Lakes region.

Entobdella soleae is a monogenean (Platyhelminth) skin parasite of the common sole, Solea solea, an important food fish. Typically, 2-6 parasites are found on wild sole, but in intensive fish farms this can rise to 200-300 parasites per fish, causing skin inflammation and sometimes death of the sole. E. soleae can live up to 120 days in seawater.

The Pacific sand sole, also known as simply sand sole, is a flatfish species inhabiting the northeastern Pacific waters where it lives on sandy bottoms. The only species in the genus, Psettichthys, it ranges from the Bering Sea to Northern California.

Microcotyle is a genus which belongs to the phylum Platyhelminthes and class Monogenea. Species of Microcotyle are ectoparasites that affect their host by attaching themselves as larvae on the gills of the fish and grow into adult stage. This larval stage is called oncomiracidium, and is characterized as free swimming and ciliated.

The purple sunstar, northern sunstar, or smooth sun star, Solaster endeca, is a species of starfish in the family Solasteridae.

The Monopisthocotylea are a subclass of parasitic flatworms in the class Monogenea.

Argulus japonicus, common name Japanese fishlouse or Japanese fish louse, is a species of crustaceans in the family Argulidae, the fish lice. This species is light brown in colour and may be between 4 and 9 mm long and 3 to 6 mm wide. It has a stumpy tail, and is shaped somewhat like a round shield.

The Egyptian sole is a species of flatfish in the true sole family, Soleidae. It lives on the sandy or muddy seabed of the Mediterranean Sea, and is now colonising the Red Sea. It often semi-immerses itself in the substrate. The upper side is greyish-brown while the underside is white. It grows to a maximum length of about 70 cm (28 in). This fish is used for human consumption and is prized as a food fish. It is caught mostly by trawling on the seabed.

Acanthocotyle is a genus of monogenean fish skin parasites.

Acanthobdella peledina is a species of leech in the infraclass Acanthobdellidea. It feeds on the skin and blood of freshwater fishes in the boreal regions of northern Europe, Asia and North America.

Theromyzon tessulatum is a species of leech in the family Glossiphoniidae. It is a haematophagous (blood-sucking) leech, found in freshwater habitats in Europe.

Lernaeenicus sprattae is a species of copepod in the family Pennellidae. It is a parasite of the European sprat and certain other fish and is sometimes known as the sprat eye-maggot.

Microcotyle donavini is a species of monogenean, parasitic on the gills of a marine fish. It belongs to the family Microcotylidae.

References

↑ Kolb, Jürgen (2018). "Hemibdella soleae (van Beneden & Hesse, 1863)". World Register of Marine Species . Retrieved 2 May 2018.
1 2 3 4 "Sangsue des soles: Hemibdella soleae (van Beneden & Hesse, 1863)" (in French). DORIS. Retrieved 2 May 2018.
↑ Kearne, G.C. (2009). "The life cycle of the monogenean Entobdella soleae, a skin parasite of the common sole". Parasitology. 53 (1–2): 253–263. doi:10.1017/S0031182000072723.

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.

[WoRMS-1] Kolb, Jürgen (2018). "Hemibdella soleae (van Beneden & Hesse, 1863)". World Register of Marine Species . Retrieved 2 May 2018.

[DORIS-2] 1 2 3 4 "Sangsue des soles: Hemibdella soleae (van Beneden & Hesse, 1863)" (in French). DORIS. Retrieved 2 May 2018.

[Kearne-3] Kearne, G.C. (2009). "The life cycle of the monogenean Entobdella soleae, a skin parasite of the common sole". Parasitology. 53 (1–2): 253–263. doi:10.1017/S0031182000072723.