Cytomorphological changes in the cerebral and ventral ganglionic neurosecretory cells during copulation in epigeic earthworms

  • Dipanwita Banik Department of Zoology, Tripura University, Tripura, India
  • Priyasankar Chaudhuri Department of Zoology, Earthworm Research Laboratory, Tripura University, Suryamaninagar-799022, Tripura, India
  • Anurag Bhattacharjee Department of Zoology, Ramthakur College, West Tripura, India
Keywords: Copulation, Copulatory behavior, Eisenia foetida, Eudrilus eugeniae, Neurosecretory cells, Neurosecretion, Cerebral ganglia, Ventral ganglia


In spite of hermaphroditism, most earthworm species reproduce by cross fertilization i.e. by the process of copulation of two mature partners. Mechanism of copulation in few earthworm species (Lumbricus terrestris) is known. However literature on neurosecretory control of copulation in earthworm is lacking. In the present study 30 pairs of conjugating earthworms of Eisenia fetida were collected from laboratory culture beds during 2016 of monsoon season. Cerebral and ventral ganglia of 10 pairs of conjugating earthworms and 20 pairs of post conjugation (2 hrs after separation, 4 hrs after separation) earthworms were fixed in Bouin’s fluid for cytomorphological studies on their cerebral neurosecretory cells. Earthworms (10 numbers) debrained through anterior transection of first five segments (brain present in 3rd segment) by sterilized paragon knife were studied to observe conjugation if any. Cerebral and ventral ganglia of 5 pairs of pre-conjugating earthworms were considered as control. Cerebral and ventral ganglia of earthworms displayed chiefly two types of neurosecretory cells such as A cells and B cells. The A cells are deeply stained AF-positive cells arranged in upper cortical tier beneath the perineurium and generally exhibiting process of axonal transport. The B cells, generally larger in size than A cells, are lightly or moderately stained with or without axonal transport and lie in between cortical A cells and central fibrous neuropile. In the cerebral ganglia the A cells outnumbered the B cells, while in the ventral ganglia the opposite is true. Debrained E. fetida survived but did not conjugate. Secretory dynamics in the cerebral and ventral ganglionic neurosecretory cells A and B were recorded in pre-conjugating, conjugating and post-conjugating earthworms. Absence of conjugation in debrained worms and exhibition of the same in earthworms with brain and its changes in neurosecretory profile clearly indicate involvement of cerebral neurosecretion in the phenomenon of conjugation in earthworm. Our result indicates probable involvement of cerebral neurohormone in the process of conjugation in E. fetida.



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1. Cosín D, Novo M, Fernandez R. Reproduction of earthworms: sexual selection and parthenogenesis. Biol Earthworms Soil Biol. 2011; 24: 69-84.

2. Dominguez J, Velando A, Aira M, Monroy F. Uniparental reproduction of Eisenia fetida and E. andrei (Oligochaeta: Lumbricidae): evidence of self insemination. Pedobiologia. 2003; 47: 530-534.

3. Monroy F, Aira M, Velando A. Size-assortative mating in the earthworm Eisenia fetida (Oligochaeta, Lumbricidae). J Ethology. 2005; 23: 69-70.

4. Novo M, Almodóvar A, Fernández R, Gutiérrez M, Díaz Cosín DJ. Mate choice of an endogeic earthworm revealed by microsatellite markers. Pedobiologia. 2010; 53: 375-379.

5. Olive PJW, Clark RB. Physiology of reproduction. In: Mill PJ, ed. Physiology of annelids. Academic, London. 1978; 271-368.

6. Nuutinen V, Butt KR. The mating behaviour of the earthworm Lumbricus terrestris (Oligochaeta: Lumbricidae). J Zool London. 1997; 242: 783-798.

7. Wallwork JA. Earthworm biology. 1st edn. Edward Arnold Publishers Ltd., London. 1983.

8. Michiels NK, Hohner A, Vorndran IC. Pre copulatory mate assessment in relation to body size in the earthworm Lumbricus terrestris: avoidance of dangerous liaisons? Behav Ecol. 2001; 12: 612-618.

9. Koene JM, Ter Maat A. The distinction between pheromones and allohormones. J Compar Physiol A. 2002; 188: 163-164.

10. Koene JM, Ter Maat A. Allohormones: A class of bioactive substances favoured by sexual selection. J Compar Physiol A. 2001; 187: 323-326.

11. Edward CA, Bohlen PJ. Biology and ecology of earthworm. Chapman and Hall, London. 1996.

12. Tombes AS. An introduction to invertebrate endocrinology. Academic press, New York. 1970.

13. Golding ML, Whittle AC. Neurosecretion and related phenomenon in Annelids. In: International review of cytology. Supplement. Academic press, New York. 1977; 5: 189-292.

14. Golding DW. Neuroendocrine phenomenon in non-arthropod invertebrates. Biol Rev. 1974; 49: 161-234.

15. Hagadorn IR. Functional correlates of neurosecretion in the rhynchobdellid leech, Theromyzon rude. General Compar Endocrinol. 1962; 2: 516-540.

16. Malecha J. Influence de la température sur la spermatogenèse et l'activité neurosécrétrice d'Hirudo medicinalis L. (Hirudinée Gnathobdelliforme). General Compar Endocrinol. 1970; 14(2): 368-380.

17. Ranganathan LS, Parthasarathi K. Precocious development of Lampito mauritii and Eudrilus eugeniae reared in pressmud. Pedobiologia. 1999; 43: 904-908.

18. Cameron ML, Steele JE. Simplified aldehyde fuchsin staining of neurosecretory cells. Staining Technol. 1959; 34: 265-266.

19. Bargmann W. Über die neurosekretorische Verknüpfung von Hypothalamus und Neurohypophyse. Zeitschrift für Zellforschung und mikroskopische Anatomie. 1949; 34: 610-634.

20. Novo M, Riesgo A, Ferna´ndez-Guerra A, Giribet G. Pheromone evolution, reproductive genes, and comparative transcriptomics in Mediterranean earthworms (Annelida, Oligochaeta, Hormogastridae). Mol Biol Evol. 2013; 30(7): 1614-1629.

21. Dash MC. Charles Darwin’s plough-tools for vermitechnology. I.K. International publishing house Pvt. Ltd., New Delhi. 2012.

22. Koene JM, Pförtner T, Michiels NK. Piercing the partner’s skin influences sperm uptake in the earthworm Lumbricus terrestris. Behav Ecol Sociobiol. 2005; 59: 243-249.

23. Bhattacharjee G, Chaudhuri PS. Cocoon production, morphology, hatching pattern and fecundity in seven tropical earthworm species – a laboratory based investigation. J Bio-Sci. 2002; 27: 283-294.

24. Nanda DK, Chaudhuri PS. Regeneration of the neurosecretory system of the nerve ring in Earthworm, Metaphire peguana. Acta Biol Cracov. 1983; 25: 63-67.

25. Herlant Meewis H, Van Damme N. In: Neurosecretion. Heller H, Clark RB, eds. Academic Press, New York. 1962; 287-295.

26. Banik D, Chaudhuri PS. Histogenesis of neurosecretory system in the nerve ring of Eudrilus eugeniae during anterior regeneration. Uttar Pradesh J Zool. 2019; 40(3): 96-104.

27. Banik D, Chaudhuri PS. Regeneration ability in seventeen top soil and sub soil earthworm species. J Environ Biol. 2017; 38: 393- 399

28. Lattaud C. Endocrine control of gametogenesis in the oligochaete annelid Eisenia fetida. Sav. evidence for synthesis of testicular androgen. In: On Earthworms. Bovicini Pagliai AM, Omedeo P, eds. Selected Symphosia and Monographs. Ucenye Zapiski Instituta Istoriii. 1987; 33-52.

29. Gunasekaran G. Studies on the functional differentiation of the prostate gland and the role of neurosecretory cells in the brain of Lampito mauritii (Annelida-Oligochaeta). Ph.D. thesis, Annamalai University, India. 1989.

30. Parthasarathi K, Ranganathan LS. Influence of pressmud on the development of the ovary, oogenesis and the neurosecretory cells of the earthworm Eudrilus eugeniae (Kinberg). Afr Zool. 2000; 35: 281-286.

31. Siekierska E. The structure of the ovary and oogenesis in gonadotropin-deprived earthworm, Dendrobaena veneta (Rosa). Zool Poloniae. 2002; 47(3-4): 37-48.
How to Cite
Banik, D.; Chaudhuri, P.; Bhattacharjee, A. Cytomorphological Changes in the Cerebral and Ventral Ganglionic Neurosecretory Cells During Copulation in Epigeic Earthworms. European Journal of Biological Research 2020, 10, 207-216.
Research Articles