Architecture of the nervous system in metacercariae of Diplostomum pseudospathaceum Niewiadomska, 1984 (Digenea)

  • Anatoly A. PetrovEmail author
  • Irina M. Podvyaznaya
  • Olga V. Zaitseva
Helminthology - Original Paper


The development of metacercariae of Diplostomum pseudospathaceum Niewiadomska, 1984 is accompanied by profound morphological transformations often characterized as metamorphosis, which makes these metacercariae an interesting case for studying the morphogenesis of the digenean nervous system. Although the nervous system of D. pseudospathaceum is one of the most extensively studied among digeneans, there are still gaps in our knowledge regarding the distribution patterns of some neuroactive substances, most notably neuropeptides. The present study addresses these gaps by studying pre-infective metacercariae of D. pseudospathaceum using immunochemical staining and confocal microscopy to characterize the distribution patterns of serotonin (5-HT) and two major groups of flatworm neuropeptides, FMRFamide-related (FaRPs) and substance P-related (SP) peptides. The general morphology of the nervous system was examined with antibodies to alpha-tubulin. The nervous system of the metacercariae was shown to conform to the most common morphology of the nervous system in the hermaphroditic generation, with three pairs of posterior nerve cords and four pairs of anterior nerves. The patterns of FaRP- and 5-HT immunoreactivity (IR) were similar to those revealed in earlier studies by cholinesterase activity, which is in accordance with the known role of these neurotransmitters in controlling muscle activity in flatworms. The SP-IR nervous system was significantly different and consisted of mostly bipolar cells presumably acting as mechanoreceptors. The architecture of the nervous system in D. pseudospathaceum metacercariae is discussed in comparison to that in cercariae of D. pseudospathaceum and metacercariae of related digenean species.


Nervous system Metacercariae 5-HT Substance P FMRFamide Alpha-tubulin 



Confocal microscopy was performed at the “Taxon” Research Resource Centre (Zoological Institute, Russian Academy of Sciences) (

Funding information

This work was supported by budget funding (projects АААА-А17-117030110029-3 and АААА-А17-117030310322-3) of the Russian Academy of Sciences and by the Russian Foundation for Basic Research (grant 16-04-00593).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


  1. Barton CL, Halton DW, Shaw C, Maule AG, Johnston CF (1993) An immunocytochemical study of putative neurotransmitters in the metacercariae of two strigeoid trematodes from rainbow trout (Oncorhynchus mykiss). Parasitol Res 79:389–396CrossRefGoogle Scholar
  2. Bettendorf H (1897) Ueber Musculatur und Sinneszellen der Trematoden. Zool Jahrb Abt Anat Ontog Tiere 10:307–358Google Scholar
  3. Biserova NM (2015) Chapter 11. Platyhelminthes: Neodermata. In: structure and evolution of invertebrate nervous systems. Oxford University Press, Oxford, New YorkGoogle Scholar
  4. Bullock TH, Horridge GA (1965) Structure and function in the nervous system of invertebrates, vol 2. W.H. Freeman and Company, San-Francisco, LondonGoogle Scholar
  5. Conn DB, Goater CP, Bray D (2008) Developmental and functional ultrastructure of Ornithodiplostomum ptychocheilus diplostomula (Trematoda: Strigeoidea) during invasion of the brain of the fish intermediate host, Pimephales promelas. J Parasitol 94:635–642CrossRefGoogle Scholar
  6. Czubaj A, Niewiadomska K (1990) Histofluorescent and ultrastructural demonstration of biogenic amines in daughter sporocyst of Diplostomum pseudospathaceum Niewiadomska, 1984 (Digenea). Ann Parasitol Hum Comp 65:183–187CrossRefGoogle Scholar
  7. Czubaj A, Niewiadomska K (1991) Sensory endings in the daughter sporocyst of Diplostomum pseudospathaceum Niewiadomska, 1984 (Digenea, Diplostomidae). Acta Parasitologica Polonica 3:115–120Google Scholar
  8. Czubaj A, Niewiadomska K (1996) Ultrastructure of sensory endings in Diplostomum pseudospathaceum Niewiadomska, 1984 cercariae (Digenea, Diplostomidae). Int J Parasitol 26:1217–1225CrossRefGoogle Scholar
  9. DeVane CL (2001) Substance P: a new era, a new role. Pharmacother: J Human Pharmacol Drug Ther 21:1061–1069CrossRefGoogle Scholar
  10. Fairweather I, Halton DW (1991) Neuropeptides in platyhelminths. Parasitology 102:77–92CrossRefGoogle Scholar
  11. Galaktionov KV, Dobrovolskij AA (2003) The biology and evolution of trematodes. Kluwer, DordrechtCrossRefGoogle Scholar
  12. Ginetsinskaya T (1988) Trematodes, their life cycles, biology and evolution. Amerind, New DelhiGoogle Scholar
  13. Goater CP, Bray D, Conn DB (2005) Cellular aspects of early development of Ornithodiplostomum ptychocheilus metacercariae in the brain of fathead minnows, Pimephales promelas. J Parasitol 91:814–821CrossRefGoogle Scholar
  14. Gustafsson MKS (1987) Immunocytochemical demonstration of neuropeptides and serotonin in the nervous system of adult Schistosoma mansoni. Parasitol Res 74:168–174CrossRefGoogle Scholar
  15. Gustafsson MKS (1988) Helminth nervous system. In: Parasitology in focus. Facts and trends. Springer, Berlin, Heidelberg, New York, pp 295–310Google Scholar
  16. Gustafsson MKS, Nässel D, Kuusisto A (1993) Immunocytochemical evidence for the presence of substance P-like peptide in Diphyllobothrium dendriticum. Parasitology 106:83–89CrossRefGoogle Scholar
  17. Gustafsson MKS, Halton DW, Kreshchenko ND, Movsessian SO, Raikova OI, Reuter M, Terenina NB (2002) Neuropeptides in flatworms. Peptides 23:2053–2061CrossRefGoogle Scholar
  18. Halton D, Maule A (2004) Flatworm nerve-muscle: structural and functional analysis. Can J Zool 82:316–333CrossRefGoogle Scholar
  19. Halton DW, Shaw C, Maule AG, Smart D (1994) Regulatory peptides in helminth parasites. Adv Parasitol 34:163–227CrossRefGoogle Scholar
  20. Havet J (1900) Contribution à l'étude du système nerveux des trématodes (Distomum hepaticum). La Cellule 17:353–381Google Scholar
  21. Hӧglund J (1991) Ultrastructural observations and radiometric assay on cercarial penetration and migration of the digenean Diplostomum spathaceum in the rainbow trout Oncorhynchus mykiss. Parasitol Res 77:283–289CrossRefGoogle Scholar
  22. Komiya Y (1938) Die Entwicklung des Exkretionssystems einiger Trematodenlarven aus Alster und Elbe, nebst Bemerkungen über ihren Entwicklungszyklus. Parasitol Res 10:340–385Google Scholar
  23. Magee RM, Fairweather I, Johnston CF, Halton DW, Shaw C (1989) Immunocytochemical demonstration of neuropeptides in the nervous system of the liver fluke, Fasciola hepatica (Trematoda, Digenea). Parasitology 98:227–238CrossRefGoogle Scholar
  24. Matisz CE, Goater CP (2010) Migration, site selection, and development of Ornithodiplostomum sp. metacercariae (Digenea: Strigeoidea) in fathead minnows (Pimephales promelas). Int J Parasitol 40:1489–1496CrossRefGoogle Scholar
  25. Matisz CE, Goater CP, Bray D (2010) Migration and site selection of Ornithodiplostomum ptychocheilus (Trematoda: Digenea) metacercariae in the brain of fathead minnows (Pimephales promelas). Parasitology 137(4):719–731CrossRefGoogle Scholar
  26. McKay DM, Halton DW, Johnston CF, Fairweather I, Shaw C (1990) Occurrence and distribution of putative neurotransmitters in the frog-lung parasite Haplometra cylindracea (Trematoda: Digenea). Parasitol Res 76:509–517CrossRefGoogle Scholar
  27. McKay DM, Halton DW, Johnston CF, Fairweather I, Shaw C (1991) Cytochemical demonstration of cholinergic, serotoninergic and peptidergic nerve elements in Goroderina vitelliloba (Trematoda: Digenea). Int J Parasitol 21:71–80CrossRefGoogle Scholar
  28. McVeigh P, Kimber MJ, Novozhilova E, Day TA (2005) Neuropeptide signalling systems in flatworms. Parasitology 131:41–55CrossRefGoogle Scholar
  29. Niewiadomska K (1996) The genus Diplostomum - taxonomy, morphology and biology. Acta Parasitol 41:55–66Google Scholar
  30. Niewiadomska K, Czubaj A (1996) Sensory endings in Diplostomum pseudospathaceum Niewiadomska, 1984 cercariae (Digenea, Diplostomidae). Acta Parasitol 41:20–25Google Scholar
  31. Niewiadomska K, Czubaj A (2000) Ultrastructure of the excretory system in the metacercaria of Diplostomum pseudospathaceum Niew., 1984 (Digenea). Acta Parasitol 45:307–321Google Scholar
  32. Niewiadomska K, Moczoń T (1982) The nervous system of Diplostomum pseudospathaceum Niewiadomska (Digenea, Diplostomatidae). Z Parasitenkd 68:295–304CrossRefGoogle Scholar
  33. Niewiadomska K, Moczoń T (1984) The nervous system of Diplostomum pseudospathaceum Niewiadomska, 1984 (Trematoda, Diplostomatidae). II. Structure and development of the nervous system in metacercariae. Z Parasitenkd 70:537–548CrossRefGoogle Scholar
  34. Niewiadomska K, Moczoń T (1987) The nervous system of Diplostomum pseudospathaceum Niewiadomska, 1984 (Trematoda, Diplostomatidae). III. Structure of the nervous system in the adult stage. Parasitol Res 73:46–49CrossRefGoogle Scholar
  35. Niewiadomska K, Moczoń T (1990) The nervous system of Diplostomum pseudospathaceum Niewiadomska, 1984 (Trematoda, Diplostomidae). IV. Nervous system and distribution of sensilla in the daughter sporocyst. Parasitol Res 76:635–637CrossRefGoogle Scholar
  36. Niewiadomska K, Maślińska D, Czubaj A, Pomorski P (1993) Distribution of serotonin immunoreactive (5HT-IR) neurons and fibers in metacercaria of Diplostomum paracaudum (Iles, 1959) (Digenea). Acta Parasitol 38:52–54Google Scholar
  37. Niewiadomska K, Czubaj A, Moczon T (1996) Cholinergic and aminergic nervous systems in developing cercariae and metacercariae of Diplostomum pseudospathaceum Niewiadomska, 1984 (Digenea). Int J Parasitol 26:161–168CrossRefGoogle Scholar
  38. Petrov A, Podvyaznaya I (2016a) Muscle architecture during the course of development of Diplostomum pseudospathaceum Niewiadomska, 1984 (Trematoda, Diplostomidae) from cercariae to metacercariae. J Helminthol 90:321–336CrossRefGoogle Scholar
  39. Petrov A, Podvyaznaya I (2016b) Сhanges in spination patterns over the course of metacercarial development of Diplostomum pseudospathaceum Niewiadomska, 1984 (Trematoda, Diplostomidae). Parazitologiya 50:331–339Google Scholar
  40. Podvyaznaya IM (1999) The fine structure of the tegument of cercariae and developing metacercariae of Diplostomum chromatophorum (Trematoda: Diplostomidae). Parazitologiya 33:507–519Google Scholar
  41. Podvyaznaya IM (2013) Ultrastructural changes in the digestive system during the metacercarial development in Diplostomum pseudospathaceum (Trematoda: Digenea: Diplostomidae). Proc Zool Instit 317:101–109Google Scholar
  42. Reuter M (1994) Substance P immunoreactivity in sensory structures and the central and pharyngeal nervous system of Stenostomum leucops (Catenulida) and Microstomum lineare (Macrostomida). Cell Tissue Res 276:173–180CrossRefGoogle Scholar
  43. Ribeiro P, El-Shehabi F, Patocka N (2005) Classical transmitters and their receptors in flatworms. Parasitology 131:19–40CrossRefGoogle Scholar
  44. Shigin AA (1986) Trematodes of the fauna of USSR. The genus Diplostomum. Metacercariae. Nauka, Moscow (In Russian)Google Scholar
  45. Solis-Soto JM, De Jong-Brink M (1995) An immunocytochemistry study comparing the occurrence of neuroactive substances in the nervous system of cercariae and metacercariae of the eye fluke Diplostomum spathaceum. Parasitol Res 81:553–559CrossRefGoogle Scholar
  46. Terenina NB, Gustafsson MKS (2014) The functional morphology of the nervouos system of parasitic flatworms (trematodes, cestodes). KMK scientific press, Moscow (In Russian)Google Scholar
  47. Tolstenkov OO, Akimova LN, Terenina NB, Gustafsson MK (2012) The neuromuscular system in freshwater furcocercaria from Belarus. II Diplostomidae, Strigeidae, and Cyathocotylidae. Parasitol Res 110:583–592CrossRefGoogle Scholar

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© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Zoological Institute of Russian Academy of SciencesUniversitetskaya nab., 1Saint-PetersburgRussia

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