Serebriakova M.K.1,♦, Tokmakova A.S.1*,♦, Kurbatova O.V.2, Konyashin M.V.2, Petrichuk S.V.2, Ataev G.L.1 2026. Comparative analysis of the cellular composition of hemolymph in pulmonate and prosobranch mollusks // Invert. Zool. Vol.23. No.3: 393–410 [in English].
1 Laboratory of Experimental Zoology, Department of Zoology and Genetics, Faculty of Biology, Herzen State Pedagogical University of Russia, 48 Moika Embankment, St. Petersburg 191186 Russia.
2 Federal State Autonomous Institution “National Medical Research Center for Children’s Health” of the Ministry of Health of the Russian Federation, Lomonosovsky Prospect, Building 2, Building 1, Moscow 119991 Russia.
♦ These authors contributed equally to this study
* Corresponding author
Maria Serebriakova: m-serebryakova@yandex.ru https://orcid.org/0000-0003-2596-4220
Arina Tokmakova arina.tokmakova@gmail.com https://orcid.org/0000-0003-3202-4827
Olga Kurbatova putintseva@mail.ru https://orcid.org/0000-0002-9213-5281
Matvey Konyashin matele99@mail.ru https://orcid.org/0009-0004-3206-8090
Svetlana Petrichuk cito@list.ru https://orcid.org/0000-0003-0896-6996
Gennady Ataev ataev.gennady@gmail.com https://orcid.org/0000-0002-4740-2117
doi: 10.15298/invertzool.23.3.03
ABSTRACT: Despite numerous studies on the cellular composition of gastropod hemolymph, questions regarding cell classification and their functional heterogeneity remain debatable, especially in frame of comparative analysis of representatives from different systematic groups. This prompted us to conduct a comparative analysis of circulating cells in two species of freshwater snails — the pulmonate Planorbarius corneus and the prosobranch Viviparus viviparus. The study employed light microscopy, flow cytofluorimetry, and imaging cytometry. The presence of lysosomes, mitochondrial membrane potential, and spontaneous reactive oxygen species production in hemocytes were assessed using the fluorescent dyes LysoTracker (LT), MitoTracker (MT), and carboxy-H2DCFDA. In P. corneus, two hemocyte populations (A and B) were identified, while V. viviparus had three populations of hemocytes (A, AB, and B), which differed in size, granularity, presence of pseudopodia, and metabolic activity. An additional population C found in both mollusks was represented by cells at different stages of apoptosis. Analysis using LT showed that the presence of acidic granules correlates with high cell activity. In P. corneus, LT+ and LT– hemocyte populations were more discrete, indicating a clear separation of the active and the inactive forms. In V. viviparus, the ratio of such cells varies depending on the population, forming a gradient of functional activity. In P. corneus, hemocytes of population A were highly variable in respect of mitochondrial potential and production of reactive oxygen species, while hemocytes of population B were homogeneous by these characteristics. In V. viviparus, cells with different metabolic activity were present in all populations. The obtained data suggest that P. corneus is characterized by a linear pathway of hemocyte differentiation (from hyalinocytes to granulocytes). At the same time, the hemolymph of V. viviparus contains cells at different maturation stages, including transitional forms.
KEY WORDS: hemolymph, Planorbarius corneus, Viviparus viviparus, flow cytometry, imaging flow cytometry.