Sucker (zoology)

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Scolex of Taenia solium with four suckers and two rows of hooks Taenia solium tapeworm scolex with its four suckers and two rows of hooks 5262 lores.jpg
Scolex of Taenia solium with four suckers and two rows of hooks

A sucker in zoology is a specialised attachment organ of an animal. It acts as an adhesion device in parasitic worms, several flatworms, cephalopods, certain fishes, amphibians, and bats. It is a muscular structure for suction on a host or substrate. In parasitic annelids, flatworms and roundworms, suckers are the organs of attachment to the host tissues. In tapeworms and flukes, they are a parasitic adaptation for attachment on the internal tissues of the host, such as intestines and blood vessels. [1] In roundworms and flatworms they serve as attachment between individuals particularly during mating. In annelids, a sucker can be both a functional mouth and a locomotory organ. [2] The structure and number of suckers are often used as basic taxonomic diagnosis between different species, since they are unique in each species. In tapeworms there are two distinct classes of suckers, namely "bothridia" for true suckers, and "bothria" for false suckers. In digeneal flukes there are usually an oral sucker at the mouth and a ventral sucker (or acetabulum) posterior to the mouth. Roundworms have their sucker just in front of the anus; hence it is often called a pre-anal sucker.

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Among chordates, some fishes and mammals have suckers, which are used as a holdfast to substrata. Among fishes some members of the order Perciformes have modified fins that form a sucker. Some bats, the Madagascar and the Western sucker-footed bat have unusual suckers on their limbs that are useful during roosting. Some amphibians such as the frog have adhesive pads on their toes to help with their locomotion.

In helminths

Turbellaria

In the class Turbellaria, only the species of the order Temnocephalida are parasitic and possess an adhesive disc. The sucker is present at the posterior end on the ventral side. [3] It is lined with syncytial epidermis and numerous microvilli. Beneath the apical membrane are many vacuoles and dense bodies. It is attached to the body through a short stalk. Densely packed muscle fibres link the sucker with the main body through the stalk. [4]

Udonellidae

Udonellids are symbiotic to fishes, on which body they remain attached using a sucker. The sucker is a membranous extension of the posterior end. It has an indistinct stalk and the anterior surface is lined with microvilli. Some portion of the tegument has interconnected surface extension appearing as loops. The interior is divided into several compartments which are surrounded by interconnected connective tissue. The connective tissues are linked with muscles that extend into the main body. [4]

Tapeworms

In tapeworms, the sucker is called bothridium (plural "bothridia") [5] to differentiate it from the sucker-like protrusion called bothrium in some species. [1]

Flukes

Various aspects of anterior sucker of a zoogonid digenean Peerj-292-fig-7 Zoogonidae.png
Various aspects of anterior sucker of a zoogonid digenean

Among the flukes belonging to class Digenea, there are two suckers, namely an oral sucker and a ventral sucker (often called acetabulum). [7] The oral sucker is at the tip of the anterior body and directly surrounds the mouth. The ventral sucker is located halfway to the middle of the body on the ventral side. They are both used for attachment to intestinal wall and blood vessels. The detailed structure of the suckers, presence or absence of hooks, and their exact position on the body are major taxonomic keys between species. [8]

In the class Monogenea, buccal organs, also known as buccal suckers, are present in worm parasites of the order Mazocraeidea. They are known to have muscular, glandular, and sensory components thought to play some role in blood feeding. In other species like Anoplodiscus, the sucker is a posterior extension, connected to the main body through a small stalk. The surface is profusely covered with microvilli. It is used for symbiotic association with fishes. [4]

Nematodes

Parasitic roundworms such as species of Ascaridia and Heterakis possess a single sucker at the posterior end of the body, just in front of anus, hence is often called a pre-anal sucker. Only the male roundworms have them, and are used for attachment to female during mating. The sucker is a protruding cuticle and circular in shape. [9] [10]

In annelids

A medicinal leech with its oral sucker Sucking leech.jpg
A medicinal leech with its oral sucker

Annelid worms such as leeches all have an anterior (oral) sucker formed from the first six segments of their body, which is used to connect to a host for feeding. It also releases an anaesthetic to prevent the host from feeling pain while it sucks blood. They use a combination of mucus and suction (caused by concentric muscles in those six segments) to stay attached and secrete an anti-clotting enzyme, hirudin, into the host's blood stream. The medicinal leech ( Hirudo medicinalis ) has two suckers, one at each end, called the anterior and posterior sucker. The posterior is mainly used for leverage while the anterior sucker, consisting of the jaw and teeth, is where the feeding takes place. [11] During locomotion directional movement of the body is done by successive attachment and detachment of the oral sucker and the acetabulum. [2]

Molluscs

An octopus displaying its suckers Octopus sinensis.jpg
An octopus displaying its suckers

Cephalopods are characterised by elongated appendages for locomotion and grasping objects. There are two main types: arms, such as in octopus, bearing numerous suckers along its ventral surface; and tentacles, such as in squid and cuttlefish, having a single sucker at the tip. [12] Each sucker is a circular and bowl-like curved disc. It in turn has two distinct parts: an outer shallow cavity called infundibulum and a central hollow cavity called acetabulum. Both these structures are thick muscles, and are covered with chitinous cuticle to make a protective surface. [13] It is used for grasping substratum, catching prey and for locomotory accessory. When the sucker attaches itself on an object, the infundibulum mainly provides adhesion while the central acetabulum is quite free. The sequential muscle contraction the infundibulum and acetabulum causes attachment and detachment. [14] : 1146–1148  [15]

In fish

Eumicrotremus phrynoides and Eumicrotremus orbis - lumpsuckers demonstrating adhesive pelvic discs. Toad and spiny lumpsuckers.jpg
Eumicrotremus phrynoides and Eumicrotremus orbis – lumpsuckers demonstrating adhesive pelvic discs.

Gobies, remoras and lumpsuckers have suckers which are modified fins. These fishes use their suckers to cling to substrata or to bigger fishes. In gobies the disc-shaped sucker is formed from fused pelvic fins. Amphidromous gobies particularly use their suckers for climbing through waterfalls during their developmental migrations. [16] [17] In remoras the sucker is a modified dorsal fin. In lumpsuckers, also known as lumpfish, the sucker is formed from modified pelvic fins, located ventrally, and behind the pectoral fins.

A fish family the Catostomidae are known as suckers. These fish have a suckermouth.

In bats

Certain species of bats such as Madagascar sucker-footed bat and Western sucker-footed bat, are generally called "sucker-footed bats" because of suckers on their limbs. They are members of the family Myzopodidae and endemic to Madagascar. They have small cups of suckers on their wrists and ankles. They roost inside the rolled leaves of palm trees, using their suckers to attach themselves to the smooth surface. [18] [19]

Related Research Articles

<span class="mw-page-title-main">Octopus</span> Soft-bodied eight-limbed order of molluscs

An octopus is a soft-bodied, eight-limbed mollusc of the order Octopoda. The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids. Like other cephalopods, an octopus is bilaterally symmetric with two eyes and a beaked mouth at the center point of the eight limbs. The soft body can radically alter its shape, enabling octopuses to squeeze through small gaps. They trail their eight appendages behind them as they swim. The siphon is used both for respiration and for locomotion, by expelling a jet of water. Octopuses have a complex nervous system and excellent sight, and are among the most intelligent and behaviourally diverse of all invertebrates.

<span class="mw-page-title-main">Flatworm</span> Phylum of soft-bodied invertebrates

The flatworms, flat worms, Platyhelminthes, or platyhelminths are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates. Unlike other bilaterians, they are acoelomates, and have no specialised circulatory and respiratory organs, which restricts them to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both ingestion and egestion ; as a result, the food cannot be processed continuously.

<span class="mw-page-title-main">Squid</span> Superorder of cephalopod molluscs

A squid is a mollusc with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting these criteria. Like all other cephalopods, squid have a distinct head, bilateral symmetry, and a mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius or pen, made of chitin.

<span class="mw-page-title-main">Trematoda</span> Class of parasitic flatworms

Trematoda is a class of flatworms known as flukes or trematodes. They are obligate internal parasites with a complex life cycle requiring at least two hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive host, where the flukes sexually reproduce, is a vertebrate. Infection by trematodes can cause disease in all five traditional vertebrate classes: mammals, birds, amphibians, reptiles, and fish.

<span class="mw-page-title-main">Digenea</span> Class of flukes

Digenea is a class of trematodes in the Platyhelminthes phylum, consisting of parasitic flatworms with a syncytial tegument and, usually, two suckers, one ventral and one oral. Adults commonly live within the digestive tract, but occur throughout the organ systems of all classes of vertebrates. Once thought to be related to the Monogenea, it is now recognised that they are closest to the Aspidogastrea and that the Monogenea are more closely allied with the Cestoda. Around 6,000 species have been described to date.

<span class="mw-page-title-main">Monogenea</span> Class of ectoparasitic flatworms

Monogeneans, members of the class Monogenea, 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.

<span class="mw-page-title-main">Aspidogastrea</span> Species of fluke

The Aspidogastrea is a small group of flukes comprising about 80 species. It is a subclass of the trematoda, and sister group to the Digenea. Species range in length from approximately one millimeter to several centimeters. They are parasites of freshwater and marine molluscs and vertebrates. Maturation may occur in the mollusc or vertebrate host. None of the species has any economic importance, but the group is of very great interest to biologists because it has several characters which appear to be archaic.

<span class="mw-page-title-main">Cephalopod limb</span> Limbs of cephalopod molluscs

All cephalopods possess flexible limbs extending from their heads and surrounding their beaks. These appendages, which function as muscular hydrostats, have been variously termed arms, legs or tentacles.

Entobdella soleae is a monogenean (Platyhelminth) skin parasite of the common sole, Solea solea, an important food fish. They are approximately 2 to 6 mm in length. It is flat, translucent, and has a large, disc-shaped haptor, a posterior organ used for semi-permanent attachment to the host. 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.

<span class="mw-page-title-main">Leech</span> Parasitic or predatory annelid worms

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.

<span class="mw-page-title-main">Worm</span> Limbless invertebrate animal

Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes.

<span class="mw-page-title-main">Cestoda</span> Class of flatworms

Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, known as tapeworms. Their bodies consist of many similar units known as proglottids—essentially packages of eggs which are regularly shed into the environment to infect other organisms. Species of the other subclass, Cestodaria, are mainly fish infecting parasites.

Diphyllobothrium mansonoides is a species of tapeworm (cestodes) that is endemic to North America. Infection with D. mansonoides in humans can result in sparganosis. Justus F. Mueller first reported this organism in 1935. D. mansonoides is similar to D. latum and Spirometra erinacei. When the organism was discovered, scientist did not know if D. mansonoides and S. erinacei were separate species. PCR analysis of the two worms has shown the two to be separate but closely related organisms.

<span class="mw-page-title-main">Pelvis</span> Lower torso of the human body

The pelvis is the lower part of the trunk, between the abdomen and the thighs, together with its embedded skeleton.

Homalometron pallidum is a species of marine trematodes in the family Apocreadiidae. It is an endoparasite of the mummichog, Fundulus heteroclitus, a small fish found in brackish water along the east coast of the United States and Canada. It has a complex life cycle and lives inside several different host species at different stages.

<span class="mw-page-title-main">Fish fin</span> Bony skin-covered spines or rays protruding from the body of a fish

Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles.

Acetabulum in invertebrate zoology is a saucer-shaped organ of attachment in some annelid worms and flatworms. It is a specialised sucker for parasitic adaptation in trematodes by which the worms are able to attach on the host. In annelids, it is basically a locomotory organ for attaching to a substratum. The name also applies to the suction appendage on the arms of cephalopod molluscs such as squid, octopus, cuttlefish, Nautilus, etc.

<span class="mw-page-title-main">Haptor</span>

The haptor is the attachment organ of the monogeneans, a group of parasitic Platyhelminthes. The haptor is sometimes called opisthaptor to emphasize that it is located in the posterior part of the body, and to differentiate it from the prohaptor, a structure including glands located at the anterior part of the body. According to Yamaguti (1963), the chief adhesive organ of the monogeneans, the haptor, is posterior, more or less discoid, muscular, may be divided into alveoli or loculi, is usually provided with anchors, has nearly always marginal larval hooklets, or is in a reduced form with anchors. The haptor may consist of symmetrical or asymmetrical, sessile or pedunculate, muscular suckers or clamps with or without supporting sclerites; accessory adhesive organs may be present in form of armed plaques, lappets or appendices.

<span class="mw-page-title-main">Pelvic fin</span> Paired fins located on the ventral surface of fish

Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins. The pelvic fins are homologous to the hindlimbs of tetrapods, which evolved from lobe-finned fish during the Middle Devonian.

Glaridacris catostomi is a flatworm of the family Caryophyllaeidae. It is commonly found in freshwater environments of North America and is a known internal parasite of fishes of the family Catostomidae.

References

  1. 1 2 Castro GA (1996). "Helminths: Structure, Classification, Growth, and Development". In Baron S (ed.). Medical Microbiology (4 ed.). Galveston (TX): University of Texas Medical Branch at Galveston. ISBN   978-0-9631172-1-2. PMID   21413252.
  2. 1 2 Stern-Tomlinson W, Nusbaum MP, Perez LE, Kristan WB Jr (1986). "A kinematic study of crawling behavior in the leech, Hirudo medicinalis". J Comp Physiol A. 158 (4): 593–603. doi:10.1007/bf00603803. PMID   3723440. S2CID   9669237.
  3. ↑ Hosie, Andrew. "Friendly Flatworms: The Temnocephalida". Government of Western Australia. Retrieved 14 February 2014.
  4. 1 2 3 Rohde, K.; Watson, N. A. (1995). "Comparative ultrastructural study of the posterior suckers of four species of symbiotic Platyhelminthes, Temnocephala sp, Udonella caligorum, Anoplodiscus cirrusspiralis, and Philophthalmus sp" (PDF). Folia Parasitologica. 42 (1): 11–28.
  5. ↑ Bothridium on www.merriam-webster.com
  6. ↑ Bray, RA.; Justine, J-L. (2014). "A review of the Zoogonidae (Digenea: Microphalloidea) from fishes of the waters around New Caledonia, with the description of Overstreetia cribbi n. sp". PeerJ. 2: e292. doi: 10.7717/peerj.292 . PMC   3961169 . PMID   24688868.
  7. ↑ Neuhaus, Walter (1985). "Die Arbeitsweise des Bauchsaugnapfes digenetischer Trematoden am Beispiel desDicrocoelium dendriticum". Zeitschrift für Parasitenkunde. 71 (1): 53–60. doi:10.1007/BF00932918. PMID   3984451. S2CID   20727635.
  8. ↑ Baker, David G. (2008). Flynn's Parasites of Laboratory Animals (2nd ed.). Hoboken: John Wiley & Sons. pp. 31, 138. ISBN   9780470344170.
  9. ↑ "Heterakis gallinae". Bioinformatics Centre, North-Eastern Hill University. Retrieved 14 February 2014.
  10. ↑ Park, Sang-Ik; Shin, Sung-Shik (2010). "Concurrent Capillaria and Heterakis Infections in Zoo Rock Partridges, Alectoris graeca". The Korean Journal of Parasitology. 48 (3): 253–7. doi:10.3347/kjp.2010.48.3.253. PMC   2945802 . PMID   20877506.
  11. ↑ Farnesi RM, Marinelli M, Tei S, Vagnetti D (1981). "Morphological and ultrastructural aspects of Branchiobdella pentodonta Whit. (Annelida, Oligochaeta) suckers". J Morphol. 170 (2): 195–205. doi:10.1002/jmor.1051700206. PMID   7299828. S2CID   21324648.
  12. ↑ Boumis R (2013). "Animals With Tentacles". Pawnation. AOL Inc. Retrieved 2013-06-08.
  13. ↑ Walla G (2007). "A study of the Comparative Morphology of Cephalopod Armature". tonmo.com. Deep Intuition, LLC. Retrieved 2013-06-08.
  14. ↑ Kier, W.M.; Smith, A.M. (2002). "The structure and adhesive mechanism of octopus suckers". Integrative and Comparative Biology . 42 (6): 1146–1153. doi: 10.1093/icb/42.6.1146 . PMID   21680399.
  15. ↑ Octopuses & Relatives. "Learn about octopuses & relatives: locomotion". asnailsodyssey.com. Retrieved 2013-06-08.
  16. ↑ Maie, T.; Schoenfuss, H. L.; Blob, R. W. (2012). "Performance and scaling of a novel locomotor structure: adhesive capacity of climbing gobiid fishes". Journal of Experimental Biology. 215 (22): 3925–3936. doi: 10.1242/jeb.072967 . PMID   23100486.
  17. ↑ Knight, K. (2012). "Climbing gobies have small but powerful suckers". Journal of Experimental Biology. 215 (22): ii. doi: 10.1242/jeb.081273 . PMID   23256209.
  18. ↑ Macdonald, D., ed. (1984). The Encyclopedia of Mammals . New York: Facts on File. pp.  807. ISBN   978-0-87196-871-5.
  19. ↑ Brown University News, December 2009, Bats Don’t Use Suction After All
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