Diplectanidae Explained

The Diplectanidae are a family of monopisthocotylean monogeneans. They are all parasitic on the gills of fish (marine or freshwater). Diplectanids are small animals, generally around 1 mm in length. As parasites, they can be extremely numerous, up to several thousand on an individual fish.

History

The family Diplectanidae was proposed by the Italian parasitologist Monticelli in 1903 (as subfamily Diplectaninae).^[1] The status of the family and its components was later examined by various authors, including Johnston & Tiegs (1922),^[2] Price (1937),^[3] Bychowsky (1957),^[4] Yamaguti (1963),^[5] and Oliver (1987).^[6]

Morphology

Diplectanids are diagnosed by the combination of these three characters:

• Presence of accessory adhesive organs on dorsal and ventral part of the haptor, called squamodiscs when they are made up of rodlets and lamellodiscs when they include lamellae
• In the haptor, three transversal bars (one ventral, two lateral (dorsal), connected to two pairs of hooks (one pair dorsal, one pair ventral)
• A germarium (or ovary) which is anterior to the testis and loops around the right intestinal caecum

Genera

The genera recognized in WoRMS ^[7] are:

• Acanthocercodes Kritsky & Diggles, 2015 ^[8]
• Acleotrema Johnston & Tiegs, 1922 ^[9]
• Aetheolabes Boeger & Kritsky, 2009 ^[10]
• Anoplectanum Boeger, Fehlauer & Marques, 2006 ^[11]
• Calydiscoides Young, 1969 ^[12]
• Darwinoplectanum Domingues, Diamanka & Pariselle, 2011 ^[13]
• Diplectanocotyla Yamaguti, 1953 ^[14]
• Diplectanum Diesing, 1858 ^[15]
• Echinoplectanum Justine & Euzet, 2006 ^[16]
• Furcohaptor Bijukumar & Kearn, 1996 ^[17]
• Lamellodiscus Johnston & Tiegs, 1922 ^[9]
• Latericaecum Young, 1969 ^[12]
• Laticola Yang, Kritsky, Sun, Zhang, Shi & Agrawal, 2006 ^[18]
• Lepidotrema Johnston & Tiegs, 1922 ^[9]
• Lobotrema Tripathi, 1959 ^[19]
• Monoplectanum Young, 1969 ^[12]
• Murraytrema Price, 1937 ^[3]
• Murraytrematoides Yamaguti, 1958
• Nasobranchitrema Yamaguti, 1965 ^[20]
• Neodiplectanum Mizelle & Blatz, 1941 ^[21]
• Oliveriplectanum Domingues & Boeger, 2008 ^[22]
• Paradiplectanum Domingues & Boeger, 2008 ^[22]
• Protolamellodiscus Oliver, 1969 ^[23]
• Pseudodiplectanum Tripathi, 1955 ^[24]
• Pseudolamellodiscus Yamaguti, 1953 ^{[14] [25]}
• Pseudomurraytrematoides Domingues & Boeger, 2008 ^[22]
• Pseudorhabdosynochus Yamaguti, 1958 ^[26]
• Pseudorhamnocercoides Chero, Cruces, Sáez, Iannacone & Luque, 2017 ^[27]
• Rhabdosynochus Mizelle & Blatz, 1941 ^[21]
• Rhamnocercoides Luque & Iannacone, 1991 ^[28]
• Rhamnocercus Monaco, Wood & Mizelle, 1954 ^[29]
• Sinodiplectanotrema Zhang in Zhang, Yang & Liu, 2001 ^[30]
• Spinomatrix Boeger, Fehlauer & Marques, 2006 ^[11]
• Telegamatrix Ramalingam, 1955 ^[31]
• Teraplectanum Lim, 2015 ^[32]

Notes and References

1. Monticelli . F.C. . 1903 . Per una nuova classificazione degli "Heterocotylea" . Monitore Zoologico Italiano . 14 . 334–336 .
2. Johnston . T.H. . Oscar Werner Tiegs . Tiegs . O.W. . 1922 . New Gyrodactyloid Trematodes from Australian fishes together with a reclassification of the Super-Family Gyrodactyloidea . Proceedings of the Linnean Society of New South Wales . 47 . 83–131 .
3. Price, E. W. 1937: North American Monogenetic Trematodes. I. The superfamily Gyrodactyloidea Journal of the Washington Academy of Sciences 27, 146-164. PDF
4. Bychowsky, B. E. (1957) Monogenetic Trematodes. Their systematic and phylogeny. Akad. Nauka. USSR. English translation by the American Institute of Biological Science, Washington. 509 pp
5. Yamaguti, S. (1963) Systema Helminthum IV. Monogenea and Aspidocotylea. London-New York, Interscience Publishers. 699 pp.
6. Guy. Oliver. Les Diplectanidae Bychowsky, 1957 (Monogenea, Monopisthocotylea, Dactylogyridea). Systématique. Biologie. Ontogénie. Écologie. Essai de phylogenèse.. 2015 . Figshare . 10.6084/M9.FIGSHARE.1295274. thesis . free.
7. WoRMS (2018). Diplectanidae Monticelli, 1903. Accessed at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=119228 on 2018-12-22
8. Kritsky. Delane C.. Diggles. Ben K.. Acanthocercodes n. g. (Monogenoidea: Diplectanidae) for species parasitising threadfins (Perciformes: Polynemidae), with description of Acanthocercodes bullardi n. sp. from the Atlantic threadfin Polydactylus octonemus (Girard) and reassignment of three species of Diplectanum Monticelli, 1903 from the Indo-Pacific Ocean. Systematic Parasitology. 91. 3. 2015. 191–201. 0165-5752. 10.1007/s11230-015-9574-z. 26063297. 9699145 .
9. Johnston . T. A. . Tiegs . O. W. . 1922 . New gyrodactyloid trematodes from Australian fishes together with a reclassification of the super-family Gyrodactyloidea . Proceedings of the Linnean Society of New South Wales . 47 . 83–131 .
10. Boeger. Walter A.. Kritsky. Delane C.. Neotropical Monogenoidea. 54. Proposal of Aetheolabes n. g. (Dactylogyrinea: Diplectanidae), with the description of A. goeldiensis n. sp. from the gills of 'pescada' Plagioscion sp. (Teleostei: Sciaenidae) in Brazil. Systematic Parasitology. 74. 2. 2009. 137–142. 0165-5752. 10.1007/s11230-009-9193-7. 19731097. 24975451 .
11. Boeger. Walter A.. Fehlauer. Karin H.. Marques. Elineide E.. Neotropical Monogenoidea. 49. Four new species of the Diplectanidae (Dactylogyrinea) from the gills of some pachyurines (Teleostei: Sciaenidae) from the Rio Tocantins and Rio Doce Basins, with the proposal of Anoplectanum n. g. and Spinomatrix n. g.. Systematic Parasitology. 64. 1. 2006. 57–68. 0165-5752. 10.1007/s11230-005-9021-7. 16612657. 23843765 .
12. Young. P. C.. Some Monogenoideans of the Family Diplectanidae Bychowsky, 1957 from Australian teleost fishes. Journal of Helminthology. 43. 1–2. 1969. 223–254. 0022-149X. 10.1017/S0022149X00004053. 5381127. 39303396 .
13. Domingues . M. V. . Diamanka . A. . Pariselle . A. . Blatz . 2011 . Monogenoids (Diplectanidae, Polyonchoinea) from the gills of mojarras (Perciformes, Gerreidae) with the resurrection of Neodiplectanum Mizelle and the proposal of Darwinoplectanum n. gen . Zootaxa . 3010 . 1–19 . 10.11646/zootaxa.3010.1.1 .
14. Yamaguti . S . 1953 . Parasitic worms mainly from Celebes. Part 2. Monogenetic trematodes of fishes . Acta Medicinae Okayama . 8 . 3. 204–256 .
15. Diesing, K. M. 1858. Revision der Myzhelminthen. Abtheilung: Trematoden. Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften. Mathematisch-Naturwissenschaftliche Classe. Wien :K.-K. Hof-und Staatsdruckerei in Commission bei Karl Gerold's Sohn. pp. 307-390 Biodiversity Heritage Library
16. Justine. Jean-Lou. Euzet. Louis. Diplectanids (Monogenea) parasitic on the gills of the coralgroupers Plectropomus laevis and P. leopardus (Perciformes, Serranidae) off New Caledonia, with the description of five new species and the erection of Echinoplectanum n. g.. Systematic Parasitology. 64. 3. 2006. 147–172. 0165-5752. 10.1007/s11230-006-9028-8. 16786281. 22801754 . free.
17. Bijukumar. A.. Kearn. G. C.. Furcohaptor cynoglossi n. g., n. sp., an ancyrocephaline monogenean gill parasite with a bifurcate haptor and a note on its adhesive attitude. Systematic Parasitology. 34. 1. 1996. 71–76. 0165-5752. 10.1007/BF01531213. 28717414 .
18. Yang. Tingbao. Kritsky. Delane C.. Yuan. Sun. Jianying. Zhang. Suhua. Shi. Agrawal. N.. Diplectanids infesting the gills of the barramundi Lates calcarifer (Bloch) (Perciformes: Centropomidae), with the proposal of Laticola n. g. (Monogenoidea: Diplectanidae). Systematic Parasitology. 63. 2. 2006. 125–139. 0165-5752. 10.1007/s11230-005-9006-6. 16718593. 12959234 .
19. Tripathi . Y. R. . 1959 . Monogenetic trematodes from fishes of India . Indian Journal of Helminthology . 9 . 1/2. 1–149 .
20. Yamaguti . S . 1965 . New monogenetic trematodes from Hawaiian fishes, I. . Pacific Science . 19 . 55–95 .
21. Mizelle . J. D. . Blatz . V. . 1941 . Studies on monogenetic trematodes. VI. Two new dactylogyrid genera from Florida fishes . The American Midland Naturalist . 26 . 1. 105–109 . 10.2307/2420758 . 2420758 .
22. Domingues . M. V. . Boeger . W. A. . 2008 . Phylogeny and revision of Diplectanidae Monticelli, 1903 (Platyhelminthes: Monogenoidea) . Zootaxa . 1698 . 1–40 . 10.11646/zootaxa.1698.1.1 .
23. Oliver G., 1969. Recherches sur les Diplectanidae (Monogenea) parasites de Téléostéens du Golfe du Lion. II. Lamellodiscinae nov. sub-fam. Vie & Milieu. 20 (l-A): 43-72.
24. Tripathi . Y. R. . 1955 . Studies on the parasites of Indian fishes. II. Monogenea, Family: Dactylogyridae . Indian Journal of Helminthology . 7 . 1. 5–24 .
25. Rakotofiringa. S.. Maillard. C.. Helminthofaune des Teleostei de Madagascar. Révision du genre Pseudolamellodiscus Yamaguti, 1953. Annales de Parasitologie Humaine et Comparée. 54. 5. 1979. 507–518. 10.1051/parasite/1979545507. free.
26. Yamaguti . S. . Satyu Yamaguti . 1958 . Studies on the helminth fauna of Japan. Part 53. Trematodes of fishes, XII . Publications of the Seto Marine Biological Laboratory . 7 . 53–88 . 10.5134/174599 . free .
27. Chero. Jhon D.. Cruces. Celso L.. Sáez. Gloria. Iannacone. José. Luque. José L.. Diplectanids (Monogenea) parasitic on sciaenid fish from Peru with the proposal of Pseudorhamnocercoides n. gen., the description of Rhamnocercus dominguesi n. sp. and the redescription of Rhamnocercoides menticirrhi Luque and Iannacone, 1991. Acta Parasitologica. 62. 3. 2017. 541–548. 1896-1851. 10.1515/ap-2017-0065. 28682761. 2611260 .
28. Luque, J. L., & Iannacone, J. (1991). Rhamnocercidae (Monogenea: Dactylogyroidea) in Sciaenid fishes from Perú, with description of Rhamnocercoides menticirrhi n. gen, n. sp. and two new spedes of Rhamnocercus. Revista de Biología Tropical, 39(2), 193-201.
29. Monaco . L. H. . Wood . R. A. . Mizelle . J. D. . 1954 . Studies on Monogenetic Trematodes. XVI. Rhamnocercinae, a new subfamily of Dactylogyridae . The American Midland Naturalist . 52 . 1. 129–132 . 10.2307/2422048 . 2422048 .
30. Zhang, J. Y., Yang, T. B., & Liu, L. (2001). (Monogeneans of Chinese marine fishes). Beijing: Agriculture Press.
31. Ramalingam . K . 1955 . A remarkable organism, Telegamatrix pellona gen. et sp. nov. (Monogenea: Diplectaninae) parasitic in an Indian herring . Proceedings of the Indian Academy of Sciences, Section B . 42 . 5 . 209 . 10.1007/BF03050331 . 81751394 .
32. Lim. L.H.S.. Teraplectanum n. g. (Monogenea: Diplectanidae) from the banded grunter fish, Terapon theraps Cuvier (Perciformes: Terapontidae), off Peninsular Malaysia. Journal of Helminthology. 89. 3. 2014. 307–316. 0022-149X. 10.1017/S0022149X1400008X. 24698519. 2941424 .