ISSN 10630740, Russian Journal of Marine Biology, 2012, Vol. 38, No. 5, pp. 406–415. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © A.A. Anisimova, 2012, published in Biologiya Morya.
Hemocytes of bivalve mollusks take part in differ
ent physiological processes concerned with the main
tenance of homeostasis in the organism, the perfor
mance of the immune response, neuroendocrine reg
ulation, the transfer and digestion of nutrients, etc.
(see reviews [7, 11–13, 19, 29, 38, 44]). The signifi
cant role of these cells in providing the vital functions
of the organism explains the undiminishing interest of
scientists in their thorough investigation. The interest
is also increasing because bivalve mollusks are objects
of fishery and aquaculture and are widely used for the
purpose of biological and ecological monitoring.
The hemocytes of Bivalvia are traditionally divided
into two main morphotypes, granulocytes and agranu
locytes (hyalinocytes). Most examined species also
have socalled small agranulocytes (small hyali
nocytes), which are blastlike cells that are considered
as a cambial pool in the cell population [7, 11, 19, 44].
Both the granular and agranular cells possess a similar
set of enzymes and, to a greater or lesser degree, are
capable of adhesion, phagocytosis, the production of
reactive oxygen species and cytotoxic activity [16, 18,
33, 35, 39] and produce similar signal molecules .
However, the granulocytes that contain numerous
lysosomes and secretory granules in the cytoplasm are
the most active in the immune responses [7, 8, 18, 22,
23, 28, 33, 42, 44, 47], whereas agranulocytes are
mostly involved in the synthesis of the extracellular
matrix and hemostasis maintenance .
Thus, the modern classification of hemocytes in
bivalve mollusks is based on such properties as cell size
and the pattern of cytoplasmic inclusions. This allows
for the identification of different morphotypes of cir
culating cells of Bivalvia, using not only microscopic
analysis [1, 6, 16, 28, 31, 35–37, 39, 40, 42, 43, 46],
but also with the method of flow cytometry using light
scattering parameters [2, 4, 18, 20, 23, 24, 26, 27, 30,
34, 41, 48]. Under the conditions of flow cytometry
the value of forward light scattering reflects the size of
the cells, whereas the value of side light scattering
reflects their internal complexity (granularity). The
high rate of the analysis and the possibility of simulta
neous registration of several parameters make flow
cytometry a prospective technique for fast and reliable
assessment of the immunological status of mollusks in
experimental and monitoring studies.
In this paper we attempted to characterize the mor
phological parameters of hemocytes in the bivalve
(Bernard, 1983) combin
ing the methods of flow cytometry and light micros
copy. Other mussel species are fairly well studied with
respect to hemolymph cell composition [6, 8–10, 14,
15, 22, 37, 39, 41, 42]; but no information is available
so far for species of the genus
is a typical and common member of
benthic ecosystems in the northern part of Sea of
Japan, thus attracting definite interest in regional
investigations on ecological monitoring.
Flow Cytometric and Light Microscopic Identification
of Hemocyte Subpopulations in
A. A. Anisimova
Far Eastern Federal University, Vladivostok, 690950 Russia
Received March 29, 2012
—Flow cytometry using forward and side light scattering identified three cell subpopulations in the
(Mytilidae). Light microscopic data indicated that they correspond to four
, hemoblasts and agranulocytes (hyalinocytes);
, semigranulocytes; and
granulocytes. The hemoblasts, agranulocytes, and semigranulocytes had a basophilic endoplasm, while the
granulocytes were mainly eosinophilic. The proportion of the different cell morphotypes and the level of sub
population distinction substantially varied among individuals. This seems to be connected with the different
functional activities of the hemocytes, depending on the immunological status of the bivalves.
hemolymph, hemocytes, flow cytometry, light scattering,
, Mytilidae, Bivalvia