Results of examination the state of yesso scallop (Mizuhopecten yessoensis) on plantations of aquaculture in Primorye

High mortality of yesso scallop at the age of 0+–2+ is detected recently on aquaculture farms in Primorye (Japan Sea). Pathological changes and death of the mollusks are observed more and more frequently with increasing of their density and number of plantations. High values of damage and mortality of mollusks grown in cages are not caused by violation of the cultivation technology but by influence of pathogenic species. At the eastern coast of Primorye, high mortality of the scallop spat occurs because of their soft tissue detachment from the shells by alveolates of gen. Perkinsus (for instance, up to 78 % of scallops at the age of 5–6 months are damaged in the Moryak-Rybolov Bay). In Peter the Great Bay, 58–80 % of scallops at the age 2+ grown in cages have blackening, stratification and abnormal shape of shells, besides, all mollusks from the Voevoda Bight aged 2+ have large fouling (on average 8 % of their total weight). In the Nakhodka Bay, located between these areas, 60 % of the mollusks suffer both from soft tissue detachment and abnormal shape of their shells. In total, representatives of 14 groups of parasites are found in tissues and on shells of cultivated yesso scallop, including epibionts (macroalgae, sponges, ascidians, shellfish, bivalves and gastropods, polychaetes, barnacles) and pathogens (fungi, flagellates, ciliates, turbellaria, alveolates, bacteria). Some parasites are found on gills of scallops (ciliates Trichodina sp. for 22.2 % of mollusks, turbellaria for 37.1 %, flagellates for 100 %), whereas zoosporangia Perkinsus infect mantle, gills and muscle for 55.5 % of mollusks. However, the scallops collected from nature habitats in Peter the Great Bay, have no external signs of infection in the first year of life, the scallops at the age 1+ year have no lesions and changes of the shell shape, with minor exclusion, and only at the age 2+ their shells are damaged for 58–80 % of mollusks. The fouling of shell is not a direct cause of the scallops death, but contributes to their weakening and development of diseases. So far as external damages of shells are highly variable, mixed infection of cultivated mollusks can be assumed. 

1. Anikanova, V.S., Bugmyrin, S.V., and Ieshko, E.P., Metody sbora i izucheniya gel’mintov melkikh mlekopitayushchikh (Methods for collecting and studying helminths of small mammals), Petrozavodsk: KarNTS RAN, 2007.

2. Brovkina, E.P. and Kostina, E.A., The nature of the couts of epizootics during cage rearing of scallops in Primorye. Perkinsus is the likely cause of these diseases, Nauchn. Tr. Dal’rybvtuza, 2020. — Т. 53, вып. 3. — С. 41–52.

3. Gavrilova, G.S. and Kucheryavenko, A.V., Produktivnost’ plantatsii dvustvorchatykh mollyuskov v Primorye (Productivity of Bivalve Farms in Primorsky Krai), Vladivostok: TINRO-Tsentr, 2011.

4. Gavrilova, S.G., Sukhin, I.Yu., and Turabzhanova, I.S., First experience of cage cultivation of hatchery-produced juvenile scallop Mizuhopecten yessoensis at eastern coast of Primorye, Izv. Tikhookean. Nauchno-Issled. Inst. Rybn. Khoz. Okeanogr., 2019, vol. 197, pp. 208–218. doi 10.26428/1606-9919-2019-197-208-218.

5. Kurochkin, Yu.V., Tsimbalyuk, E.M., and Rybakov, A.V., Parasites and diseases, in Primorskii grebeshok (Yesso Scallop), Vladivostok: Dal’nevos. Nauchn. Tsentr Akad. Nauk SSSR, 1986, pp. 174–182.

6. Choi, K.-S. and Park, K.-I., Review on the protozoan parasite Perkinsus olseni (Lester and Davis 1981) infection in Asian waters, Coast. Environ. Ecos. Issues East China Sea, 2010, pp. 269–281.

7. Choi, K.-S., Park, K.-I., Cho, M.-J., and Soudant, P., Diagnosis, pathology and taxonomy of Perkinsus sp. isolated from the Manila clam Ruditapes philippinarum in Korea, J. of Aquaculture, 2005, vol. 18, no. 3, pp. 207–214.

8. Choi, K.-S. and Waki, T., Perkinsus olseni (Lester and Davis 1981) infection in the Manila clam (Ruditapes philippinarum) in Korea; species identification, impacts and spatio-temporal distribution, Bull. Jap. Fish. Edu. Agen., 2016, no. 42, pp. 23–27.

9. Coen, L.D. and Bishop, M.J., The ecology, evolution, impacts and management of host-parasite interactions of marine molluscs, J. Invertebr. Pathol., 2015, vol. 131, pp. 177–211. doi 10.1016/j.jip.2015.08.005

10. Dégremont, L., Garcia, C., and Allen, S.K.Jr., Genetic improvement for disease resistance in oysters: a review, J. Invertebr. Pathol., 2015, vol. 131, pp. 226–241. doi 10.1016/j.jip.2015.05.010

11. Robledo, J.A.F., Marquis, N.D., Countway, P.D., Record, N.R., Irish, E.L., Schuldt, M.M., Kingston, S.E., Bishop, T.J., Messerman, N.A., and Bowden, T.J., Pathogens of marine bivalves in Maine (USA): a historical perspective, Aquaculture, 2018, vol. 493, no. 6, pp. 9–17. doi 10.1016/j.aquaculture.2018.04.042

12. Shinn, A.P., Pratoomyot, J., Bron, J.E., Paladini, G., Brooker, E.E., and Brooker, A.J., Economic costs of protistan and metazoan parasites to global mariculture, Parasitology, 2015, vol. 142, pp. 196–270. doi 10.1017/S0031182014001437

13. Villalba, A., Reece, K.S., Ordás, M.C., Casas, S.M., and Figueras, A., Perkinsosis in molluscs: A review, Aquat. Living Resour., 2004, vol. 17, pp. 411–432. doi 10.1051/alr:2004050

14. Villanueva-Fonseca, L.C., García-Ulloa, M., López-Meyer, M., Villanueva-Fonseca, B.P., Hernández-Sepúlveda, J.A., Muñoz-Sevilla, N.P., and Góngora-Gómez, A.M., Perkinsus marinus in the pleasure oyster Crassostrea corteziensis cultivated on the southeast coast of the Gulf of California, Mexico, Lat. Am. J. Aquat. Res., 2020, vol. 48, no 4, pp. 529–437.

15. Petty, D., Perkinsus infections of bivalve mollusсs, Fish. Aquat. Sci. Dep., FA178, 2013. http://edis.ifas.ufl.edu. Cited June 27, 2021.

16. Aquatic animal health codе, 17th ed. World organisation for animal health, 2014.

17. Veterinarno-sanitarnyy kodeks vodnykh zhivotnykh (Veterinary and Sanitary Code of Aquatic Animals), 12th ed., World Organization for Animal Health (Oie), 2009.

18. Prikaz Ministerstva sel’skogo khozyaystva RF ot 14.12.2015 № 635 “Ob utverzhdenii Veterinarnykh pravil provedeniya regionalizatsii territorii Rossiyskoy Federatsii” (Order of the Ministry of Agriculture of the Russian Federation of December 14, 2015 no. 635 “On Approval of Veterinary Rules for the Regionalization of the Territory of the Russian Federation”).