The parasitic isopod Anilocra physodes (Cymothoidae; Crustacea) on its fish host from the Atlantic coast of Morocco

Document Type : Research Article

Authors

• Mourad Bendada ¹
• Abderrahmane Hadini ¹
• Youssef Moallaqat ²
• Khalid El Bekkaye ¹
• Khalid Chaabane ¹

¹ Laboratory of Agricultural Production Improvement, Biotechnology and Environment, Faculty of Sciences, Mohammed First University, Box 717, Oujda 60000, Morocco.

² The National Office of Fisheries, Laboratory Wholesale fish market of Oujda, Oujda 60000, Morocco.

10.22067/ijvst.2025.91719.1463

Abstract

This study investigated the parasitism of three species of fish species, Pagellus bogaraveo, (family Sparidae), Sardina pilchardus (family Clupeidae) and Umbrina canariensis (family Sciaenidae), collected from the Atlantic coast of Morocco. A total of 5419 fish specimens were examined. Among them, 3600 fish  individuals of Sardina pilchardus, 920 of Umbrina canariensis and 899 of Pagellus bogaraveo, were found to carry 328 isopod parasites of the species Anilocra physodes (family Cymothoidae). Most of these ectoparasitic isopods were primarily located on the body surface or within the gill chambers of their hosts. Parasitism was quantified using various parasitological indices (prevalence, intensity which is the mean number of parasites per infected host and abundance) calculated for each fish species. The results showed that infestation rates by A. physodes were relatively low and did not exceed prevalence of 11.11%. The mean infestation intensity is ranged between 1 and 2 parasites per infected fish, while, abundance values remain below 0.14 parasites per examined fish across all host species. These findings indicate that infestation levels are strongly associated with the host species. Overall, this study provides valuable insights into the effects of this ectoparasite crustacea on fish health, emphasizing the need for fisheries management strategies and marine conservation in the region.

Keywords

• Cymothoid isopods
• ectoparasites
• Anilocra physodes
• parasitic indices
• parasitism

Main Subjects

• Parasitology

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References

1.     Brusca RC. A monograph on the Isopoda Cymothoidae (Crustacea) of the eastern Pacific. Zoological Journal of the Linnean Society.1981;73(2):117‑99. Doi:10.1111/j.1096-3642.1981.tb01592.x.
2.     Smit NJ, Bruce NL, Hadfield KA. Global diversity of fish parasitic isopod crustaceans of the family Cymothoidae. International Journal for Parasitology: Parasites and Wildlife. 2014;3(2):188‑97. Doi: 10.1016/j.ijppaw.2014.03.004.
3.     Bullar JF. The generative organs of the parasitic Isopoda. Journal of Anatomy and Physiology. 1876.19(1):118‑123. 
4.     Bunkley-Williams L, Williams EH. Isopods Associated with Fishes: A Synopsis and Corrections. The Journal of Parasitology. 1998;84(5):893-896. PMID: 9794626.
5.     Horton T, Okamura B. The distribution of Ceratothoa steindachneri (Crustacea: Isopoda: Cymothoidae) parasitic in Echiichthys vipera in the north-east Atlantic. J Mar Biol Ass. 2002;82(3):415‑7. Doi: 10.1017/S0025315402005660.
6.     Bruce NL , Wong HP.-S. An overview of the marine Isopoda (Crustacea) of Singapore. Raffles Bulletin of Zoology. 2015; Suppl31:152‑68. 
7.     Bunkley-Williams L, Williams EH Jr, Bashirullah AKM. Isopods (Isopoda: Aegidae, Cymothoidae, Gnathiidae) associated with Venezuelan marine fishes (Elasmobranchii, Actinopterygii). Rev Biol Trop. 2006;54(Suppl 1):175-88.
8.     Adlard RD. The effects of the parasitic isopod Anilocra pomacentri on the population dynamics of the reef fish Chromis nitida [PhD thesis]. Brisbane: The University of Queensland; 1989 [cited 2025 Jan 17]. Available from: https://espace.library.uq.edu.au/view/UQ:366166
9.     Brusca RC, Gilligan MR. Tongue replacement in a marine fish by a parasitic isopod. Copeia. 1983;1983(4):813-6. doi:10.2307/1444352
10.     Horton T, Okamura B. Post-haemorrhagic anaemia in sea bass caused by Ceratothoa oestroides. J Fish Dis. 2003;26(7):401-6. doi:10.1046/j.1365-2761.2003.00476.x.
11.     Romestand B, Trilles JP. Influence of the cymothoid isopods on growth of hosts. Z Parasitenkd. 1979;59(2):195-202. doi:10.1007/BF00927401.
12.     Adlard RD, Lester RJG. Dynamics of interaction between Anilocra pomacentri and Chromis nitida. Parasitology. 1994;109(3):311-24. doi:10.1017/S0031182000078343.
13.     Horton T, Okamura B. Cymothoid isopod parasites in aquaculture. Dis Aquat Org. 2001;46:181-8. Doi: 10.1017/s003118200007834.
14.     Euzet L, Combes C. Les problèmes de l’espèce chez les animaux parasites. Mem Soc Zool Fr. 1980;40:239-85
15.     Lymbery AJ. Host specificity, host range and host preference. Parasitol Today. 1989;5:1-298. doi:10.1016/0169-4758(89)90021-5
16.     Ravichandran S, Rameshkumar G, Trilles JP. New records of two parasitic cymothoids from Indian fishes. J Parasit Dis. 2011;35(2):232-4. Doi: 10.1007/s12639-011-0046-3.
17.     Trilles JP. Les Cymothoidae… II. Zool Meded. 1979;54:245-75.
18.     Trilles JP. Les Cymothoidae d’Afrique. Bull Mus Natl Hist Nat. 1986;4:617-36. Doi: 10.5962/p.326714.
19.     Trilles JP. Les Cymothoidae du monde. Studia Marina. 1994;1:1-288.
20.     Junoy J, Castelló J. Catálogo de las especies ibéricas y baleares de isópodos marinos. Graellsia. 2003;59(2-3):293-325.
21.     Öktener A, Alaş A, Türker D. First record of Anilocra physodes on Phycis blennoides. Jordan J Biol Sci. 2018;11(2):1-8
22.     Boyko CB, Bruce NL, Hadfield KA, Merrin KL, Ota Y, Poore GCB, et al. World Marine… Isopod Crustaceans database: Anilocra Leach, 1818 [Internet]. WoRMS; 2008 [cited 2022 May 9]. Available from: http://www.marinespecies.org/aphia.php?p=taxdetails&id=146493.
23.     Trilles JP, Raibaut A. Aegidae et Cymothoidae parasites de poissons tunisiens. Bull Inst Natl Sci Tech Mer Salammbô. 1971;2:71-86.
24.     Trilles JP, Raibaut A. Sur les Cymothoidae parasites de poissons marins de Tunisie (2e note). Bull Mus Hist Natl. 1973;3:273-81. Doi: 10.5962/p.272639.
25.     Salal P, Faliex E, De Buron I, Morand S. Sex discriminatory effect of Acanthocephaloides propinquus. Parasite. 2001;8(3):231-6.Doi: 10.1051/ parasite/2001083231.
26.     Fogelman RM. Effect of Anilocra apogonae on cardinal fish [MPhil thesis]. Brisbane: The University of Queensland; 2005 [cited 2025 Apr 7]. Available from: https://espace.library.uq.edu.au/view/UQ:4d7e5a8. 
27.     Brusca RC. Studies on Cymothoid fish symbionts I. Crustaceana. 1978;34:141-54. Doi: 10 .1163/156854078X00718.
28.     Zander CD, Kesting V. Colonization and seasonality of goby parasites. Parasitol Res. 1998;84(6):459-66. Doi:10.1007/s004360050430.
29.     Dollfus RP, Trilles JP. Cymothoidae of Morocco and Algeria. Bull Mus Hist Natl. 1976;3:821-30.
30.     Ternengo S, Levron C, Marchand B. Metazoan parasites in sparid fish in Corsica. Bull Eur Assoc Fish Pathol. 2005;25(6):262-9
31.     Dufour CM, Engels NM, Burns CW. Distribution and habitat of Austridotea lacustris. N Z J Mar Freshw Res. 2007;41(3):299-307. Doi:10 .1080/00288330709509917.
32.     Zharikova TI. Adaptive reaction of gill ectoparasites of bream. Parasitologia. 2000;34:50-5.
33.     Combes C. Interactions durables: écologie et évolution du parasitisme. Paris: Masson; 1995. 524 p.
34.     Margolis L, Esch GW, Holmes JC, Kuris AM, Schad GA. The use of ecological terms in parasitology. J Parasitol. 1982;68(1):131-3. Doi:10 .2307/3281335.
35.     Bush AO, Lafferty KD, Lotz JM, Shostak AW. Parasitology meets ecology. J Parasitol. 1997;83(4):575-83. Doi:10 .2307/3284227.
36.     Trilles JP. Sur deux espèces d’Anilocres mal connues. Ann Parasitol Hum Comp. 1965;40(5):575-94.
37.     Trilles JP. Les Cymothoidae du Rijksmuseum… Méditerranée et Atlantique. Zool Meded. 1977;51:7-17. 
38.     Trilles JP. Les Cymothoidae des Antilles. Bull Mus Natl Hist Nat. 1981;3(2):583-602.Doi:10 .5962/p.285837.
39.     Lloris D, Rucabado J. Guide d’identification des ressources marines du Maroc [Internet]. Rome: FAO; 1998. 263 p. Available from: https://openknowledge.fao.org/handle/20.500.14283/w9160f.
40.     Froese R, Pauly D. Sardina pilchardus [Internet]. WoRMS; 2022 [cited 2022 Jan 3]. Available from: https://www.marinespecies.org/aphia.php?p=taxdetails&id=126421
41.     Froese R, Pauly D. Umbrina canariensis [Internet]. WoRMS; 2022 [cited 2022 Jan 3]. Available from: https://www.marinespecies.org/aphia.php?p=taxdetails&id=127011
42.     Froese R, Pauly D. Pagellus bogaraveo [Internet]. WoRMS; 2022 [cited 2022 Jan 3]. Available from: https://www.marinespecies.org/aphia.php?p=taxdetails&id=127059