ISSN 10630740, Russian Journal of Marine Biology, 2010, Vol. 36, No. 5, pp. 367–372. © Pleiades Publishing, Ltd., 2010.
Published in Russian in Biologiya Morya.
The morphology of cells is defined by a set of fac
tors, including the behavior of the cells, as well as their
genetic, functional [9, 11], biochemical, and physio
logical [4, 14, 21, 27] features. Cell morphology can
vary in response to the effects of outer agents, includ
ing hormones and cytokines [20, 25]. This depends on
the features of the extracellular matrix [15, 22, 28], the
mechanical properties of the substrate , cytoskeletal
structures [6, 10, 12, 16, 19, 23, 24], and on the set of
cell adhesion molecules . Thus, the modeling of
morphogenesis at the cellular level is relevant for
understanding the features of cell behavior and physi
ology. Such modeling needs, in turn, a quantitative
description of cell morphology.
In Zavarzin’s work  based on light microscopy,
the morphology of hemocytes of invertebrates was
described in detail, and the classification of hemocytes
by phylogenetic, physiological, and morphological
criteria was suggested. A.A. Zavarzin hypothesized
that cells of the connective tissue and blood of inverte
brates are rather poorly differentiated and are pre
sented by several basic types, which are common to all
invertebrates. The individual specialized types of cells
that occur in various invertebrate species or the mor
phofunctional distinctions of cells are variations of the
initial general types.
Hine  systematized the data on the cell struc
ture and typology of the hemolymph cells of bivalves.
He distinguished granular hemocytes as a uniform
group and subdivided agranular hemocytes into three
The article was translated by the authors.
types, blastoid cells with basophilic cytoplasm, mac
rophagoid cells with basophilic cytoplasm, and hyali
nocytes with colorless cytoplasm. Granulocytes most
likely had agranular predecessors. To identify dis
tinctly agranular and granular cell is impossible, as,
unlike leukocytes of vertebrates, they are insufficiently
well differentiated and distinguishable. Moreover,
functional heterogeneity is possible within each mor
The conventional morphological criteria for the
differentiation of types of molluscan hemocytes are
cell size, nucleus/cytoplasm ratio, and the size of
granules contained in the cytoplasm. Compared with
granulocytes, the hyaline cells, as a rule, are of smaller
size and have a larger nucleus, i.e., they are character
ized by a high nucleocytoplasm ratio, and their cyto
plasm is more electron dense, because of a significant
number of small (50 nm in diameter) inclusions .
Hemocytes of the Pacific mussel
subdivided into three classical groups, viz., hyali
nocytes and two types of granulocytes . The large,
eosinophilic granulocytes of
, compared with
hyalinocytes, have a more pronounced ability for
phagocytosis, development of active forms of oxygen,
and manifestation of cytotoxic activity .
According to the literature, the cellular structure of
hemolymph of the Japanese scallop
is heterogeneous and consists of cell forms that
are morphologically transitive between different types
of cells. Large agranulocytes compose the base of the
cell population and granulocytes are about 4% of the
total number of amoebocytes . Data that demon
Comparative Morphological Analysis of in Vitro Cultured Hemocytes
from Two Species of Bivalve Mollusks
Yu. A. Karetin
Institute of Marine Biology, Far East Branch, Russian Academy of Sciences, Vladivostok, 690041 Russia
Far East State University, Vladivostok, 690000 Russia
Received October 19, 2009
—A comparative analysis of the morphology of hemocyte spreading on cover glasses from two bivalve
species, the Japanese scallop
and Pacific mussel
, was carried out.
Parameters for the quantitative analysis of cell morphology were suggested. The interspecific comparison of
single spreading hemocytes and cell communities from two and three adjoining cells revealed significant dif
ferences in a number of studied parameters, which testified to the taxa specificity of the given cell features and
the fundamental possibility of the numerical description and differentiation of complicated forms of cell
spreading in vitro.
, Pacific mussel