First case of chronic systemic spironucleosis in Freshwater Angelfish (Pterophyllum scalare Schultze, 1823) in Türkiye

Abstract

This study aimed to identify the cause of sustained mortality in freshwater angelfish (Pterophyllum scalare Schultze, 1823) kept at an ornamental fish production facility in Türkiye. Parasitological, bacteriological and histopathological examination were performed on moribund hybrid angelfish individuals. The moribund fish had haemorrhaged eyes, darkened skin, scale loss, ascites and false faeces. A pale liver, splenomegaly and a thinning of the intestinal wall were observed internally. The parasitological examination revealed flagellated protozoan endoparasite Spironucleus sp. in the intestine. A number of histopathological changes were observed including lipid degeneration in the liver, hemosiderin deposits as well as granulomas in the spleen, a large number of mast cells in the lamina propria of the intestine and enteritis. Numerous Spironucleus parasites were seen in the intestinal wall. According to physiological and biochemical tests, the bacterial isolates obtained from the visceral organs of some fish were identified as Citrobacter freundii. After oral metronidazole treatment, with a dose of 50 mg/kg fish daily for 5 days, a decrease in fish mortality and resumed feeding were noted. A chronic spironucleosis, which systemically affects fish by penetrating the intestinal mucosa, was identified as the cause of this sustained mortality in freshwater angelfish.

Keywords

• Angelfish
• Freshwater
• Pterophyllum scalare
• Spironucleosis
• Spironucleus

References

1. Balta F, Dengiz Balta Z (2018): Identification and Treatment of Hexamitiasis Observed in Rainbow Trout (Oncorhynchus mykiss) Fry. JAES, 3, 4-8.
2. Balta F, Dengiz Balta Z, Akhan S (2019): Seasonal distribution of protozoan parasite infections in rainbow trout (Oncorhynchus mykiss) farms in the Eastern Black Sea of Turkey. Bul Eur Assoc, 39, 31-39.
3. CLSI (2009): Clinical and Laboratory Standard Institute, Performance Standards for Antimicrobial Disk Susceptibility Test, Approved standard M2-A10.
4. Diler Ö, Görmez Ö, Terzioğlu S, et al (2018): Gökkuşağı Alabalığı (Oncorhynchus mykiss) Yetiştiriciliğinde Görülen Spironucleosis Enfeksiyonlarının Tedavisinde Artemisia campestris (L)’in Kullanımı. Eğirdir Su Ürünleri Fakültesi Dergisi, 14, 312-323.
5. Drury RAB, Wallington EA (1980): Carleton’s Histological Technique. Fifth edition, Oxford University Press, ISBN 0-19-261310-3.
6. Gallani SU, Sebastiao FA, Valladao GMR, et al (2016): Pathogenesis of mixed infection by Spironucleus sp. and Citrobacter freundii in freshwater angelfish Pterophyllum scalare. Microbial Pathogenesis, 100, 119-123.
7. Garcia-Ulloa M, Gomez-Romero HJ (2005): Growth of angel fish Pterophyllum scalare (Gunther, 1862) juveniles fed inert diets. Rev AIA, 9, 49-60.
8. Jørgensen A, Sterud E (2006): The marine pathogenic genotype of Spironucleus barkhanus from farmed salmonids redescribed as Spironucleus salmonicida n. sp. J Eukaryot Microbiol, 53, 531-541.

9. Jørgensen A, Torp K, Bjørland MA, et al (2011): Wild Arctic char Salvelinus alpinus and trout Salmo trutta: host and reservoir of the salmonid pathogen Spironucleus salmonicida (Diplomonadida; Hexamitidae). Dis Aquat Org, 97, 57-63.
10. Kayış Ş, Balta F, Serezli R, et al (2013): Parasites on different ornamental fish species in Turkey. J FisheriesSciences.com, 7, 114-120.
11. Kent ML, Ellis J, Fournie JW, et al (1992): Systemic hexamitid infection in seawater pen-reared chinook salmon. Dis Aquat Org, 14, 81-89.
12. Kulda J, Lom J (1964): Spironucleus elegans Lavier, parasite of fish. Cesk Parasitol, 11, 187-192.
13. Mo TA, Poppe T, Iversen L (1990): Systemic hexamitosis in salt-water reared Atlantic salmon. Bull Eur Assoc Fish Pathol, 10, 69.
14. Noga EJ (2010): Fish Disease: Diagnosis and Treatment. Second edition, Iowa State University Press, Iowa, 99-058466.
15. O'Brien GM, Ostland VE, Ferguson HW (1993): Spironucleus-associated necrotic enteritis in angelfish (Pterophyllum scalare). Can Vet J, 34, 301-303.
16. Ortega-Salas AA, Cortes GI, Reyes-Bustamante H (2009): Fecundity, growth, and survival of the angelfish Pterophyllum scalare (Perciformes: Cichlidae) under laboratory conditions. Rev Biol Trop, 57, 741- 747.
17. Poynton SL, Fraser W, Francis-Floyd R, et al (1995): Spironucleus vortens n. sp. from the freshwater angelfish Pterophyllum scalare morphology and culture. J Eukaryot Microbiol, 42, 731-742.
18. Poynton SL, Morrison CM (1990): Morphology of diplomonad flagellates: Spironucleus torosa n. sp. from Atlantic God Gadus morhua L., and haddock Melanogrammus aeglefinus (L.) and Hexamita salmonis Moore from brook trout Salvelinus fontinalis (Mitchill). J Protozool, 37, 369-383.
19. Poynton SL, Sterud E (2002): Guidelines for species descriptions of diplomonad flagellates from fish. Journal of Fish Disease, 25, 15–31.
20. Puk K, Guz L (2014): Effects of medical plant extracts on the growth of the fish parasite Spironucleus vortens. Med Weter, 70, 165-168.
21. Raja K, Aanand P, Padmavathy S, et al (2019): Present and future market trends of Indian ornamental fish sector. Int J Fish Aquat Sci, 7, 06-15.
22. Rodger HD, Kobs M, Macartney A, et al (1997): Systemic iridovirus infection in freshwater angelfish, Pterophyllum scalare (Lichtenstein). J Fish Dis, 20, 69–72.
23. Sangmaneedet S, Smith SA (1999): Efficacy of various chemotherapeutic agents on the growth of Spironucleus vortens, an intestinal parasite of the freshwater angelfish. Dis Aquat Organ, 38, 47-52.
24. Sterud E (1998): Electron microscopical identification of the flagellate Spironucleus torosa (Hexamitidae) from burbot Lota lota (Gadidae) with comments upon its probable introduction to this freshwater host. J Parasitol, 84, 947-953.
25. Sterud E, Mo TA, Poppe TT (1998): Systemic spironucleosis in sea-farmed Atlantic Salmon Salmo salar, caused by Spironucleus barkhanus transmitted from feral Arctic char Salvelinus alpinus? Dis Aquat Org, 33, 63-66.
26. Sterud E, Poynton SL (2002): Spironucleus vortens (Diplomonadida) in the ide, Leuciscus idus (L.) (Cyprinidae): a warm water hexamitid flagellate found in north Europe. J Eukaryot Microbiol, 49, 137-145.
27. Turgay E (2020): Edwardsiellosis in freshwater angelfish (Pterophyllum scalare). The Israeli Journal of Aquaculture - Bamidgeh, IJA.72.2020.1167548.
28. Ürkü Ç, Yardımcı RE (2013): Melek baliklarinda (Pterophyllum scalare) Capilaria sp. enfestasyonu ve bakteriyel septisemi. Journal of FisheriesSciences.com, 7, 232-240.
29. Vlachos N, Mente E, Hotos GN, et al (2008): Commercial production of Pterophyllum scalare (CN: Angelfish, Pisces Ciclidae) in Aquarium. In: 4th International Congress on Aquaculture, Fisheries Technology and Environmental Management. Athens, Greece.
30. Williams CF, Lloyd D, Poynton SL, et al (2011): Spironucleus species: Economically-Important Fish Pathogens and Enigmatic Single-Celled Eukaryotes. J Aquac Res Development, S2, 002.
31. Wootten R (2012): The Parasitology of Teleosts. In: Fish Pathology. 4th Edition. Ed. By R. Roberts Wiley–Blackwell.