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. 2024 Dec 18;123(12):412.
doi: 10.1007/s00436-024-08436-2.

Occurrence of 'soft flesh' condition induced by Kudoa thyrsites parasite in the Iberian European sardine stock

Lucilla Giulietti  1 , Gema Hernandez-Milian  2 , Paolo Cipriani  3   4 , Miguel Bao  3 , Hui-Shan Tung  3 , Carmen Hernández  5 , Arne Levsen  3
Affiliations

Occurrence of 'soft flesh' condition induced by Kudoa thyrsites parasite in the Iberian European sardine stock

Lucilla Giulietti et al. Parasitol Res. .

Abstract

European sardine Sardina pilchardus is a commercially valuable coastal pelagic fish species. Spain is one of the largest sardine suppliers in Europe and the Iberian stock is of particular significance. Kudoa parasites are known to infect sardines causing the so-called 'soft flesh' condition; however, data on the occurrence of 'soft flesh' in this sardine stock are limited. This study investigates the occurrence of Kudoa-induced 'soft flesh' in the Iberian sardine stock caught in 2023 off the northern Spanish Atlantic coast (Division 8.c). Five hundred specimens were examined for 'soft flesh' by manual texture testing and visual inspection 48 h post-catch using standardized procedures. 'Soft flesh' was detected in 5.4% (27/500) of the sardines. Microscopic examination of muscle samples revealed the presence of Kudoa thyrsites-like myxospores in all 'soft flesh'-affected fish, which based on SSU rDNA gene sequence analysis was identified as K. thyrsites. The unsightly appearance of infected fillets represents a substantial food quality issue for the Iberian sardine stock that could reduce marketability and consumer confidence in both local and international markets. This is particularly relevant since larger Iberian sardines, which are highly appreciated by consumers, appear to be the most affected.

Keywords: Kudoa thyrsites; European sardine; Iberian sardine stock; Quality reducing parasite; Spanish fishery; ‘Soft flesh’.

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Conflict of interest statement

Declarations. Ethics approval: Not applicable. Consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Illustration of Kudoa-induced ‘soft flesh’ condition in Iberian sardines from off the northern Spanish Atlantic coast (Cantabrian Sea) (ICES division 8.c.)
Fig. 2
Fig. 2
Spores of K. thyrsites–like morphotype from Iberian sardine
See this image and copyright information in PMC

References

    1. Bolin JA, Schoeman DS, Evans KJ, Cummins SF, Scales KL (2021) Achieving sustainable and climate-resilient fisheries requires marine ecosystem forecasts to include fish condition. Fish Fish 22:1067–1084. 10.1111/faf.12569 - DOI
    1. Casal G, Soares EC, Rocha S, Silva TJ, Santos EL, Nascimento R, Oliveira E, Azevedo C (2019) Description of a new myxozoan Kudoa eugerres n. sp. and reclassification of two Sphaerospora sensu lato species. Parasitol Res 118:1719–1730. 10.1007/s00436-019-06324-8 - DOI - PubMed
    1. Castro R, Cavaleiro FI, Rangel LF, Rocha S, Severino R, Casal G, Santos MJ (2018) Myxozoan parasites of the European sea bass, Dicentrarchus labrax (Teleostei: Moronidae): correlates of infections at the micro- and macroenvironmental scales. Aquaculture 485:17–24. 10.1016/j.aquaculture.2017.11.013 - DOI
    1. Cheng JH, Sun DW, Han Z, Zeng XA (2014) Texture and structure measurements and analyses for evaluation of fish and fillet freshness quality: a review. Compr Rev Food Sci Food Saf 13:52–61. 10.1111/1541-4337.12043 - DOI - PubMed
    1. Cruz C, Silva A, Saraiva A (2011) Intensity of Kudoa sp. infection and alterations of muscle texture in Sardina pilchardus in Portugal. Bull Eur Assoc Fish Pathol 31:205–210

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