Histology and ultrastructure of the salivary glands in Bulla striata (Mollusca, Opisthobranchia)

Abstract. The ribbon‐shaped salivary glands in Bulla striata were studied with light microscopy and transmission electron microscopy (TEM). Secretion is produced in tubules formed by two types of secretory cells, namely granular mucocytes and vacuolated cells, intercalated with ciliated cells. A central longitudinal duct lined by the same cell types collects the secretion and conducts it to the buccal cavity. In granular mucocytes, the nucleus is usually central and the secretory vesicles contain oval‐shaped granular masses attached to the vesicle membrane. Glycogen granules can be very abundant, filling the space around the secretory vesicles. These cells are strongly stained by PAS reaction for polysaccharides. Their secretory vesicles are also stained by Alcian blue, revealing acidic mucopolysaccharides, and the tetrazonium reaction detects proteins in minute spots at the edge of the vesicles, corresponding to the granular masses observed in TEM. Colloidal iron staining for acidic mucopolysaccharides in TEM reveals iron particles in the electron‐lucent region of the vesicles, while the granular masses are free of particles. In vacuolated cells, which are thinner and less abundant than the granular mucocytes, the nucleus is basal and the cytoplasm contains large electron‐lucent vesicles. These vesicles are very weakly colored by light microscopy techniques, but colloidal iron particles could be observed within them. The golf tee‐shaped ciliated cells contain some electron‐dense lysosomes in the apical region. In these cells, the elongated nucleus is subapically located, and bundles of microfibrils are common in the slender cytoplasmic stalk that reaches the basal lamina. The morphological, histochemical, and cytochemical data showed some similarities between salivary glands in B. striata and Aplysia depilans. These similarities could reflect the phylogenetic relationship between cephalaspidean and anaspidean opisthobranchs or result from a convergent adaptation to an identical herbivorous diet.     

Spatial heterogeneity of diatom silicification and growth in a eutrophic reservoir

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Distribution of phototrophic microbes in the flat laminated microbial mat at Laguna Figueroa, Baja California, Mexico

The microbial mat community in the saltmarsh/evaporate flat interface at Laguna Figueroa involved in the deposition of laminated sediments was investigated. Pigment analysis, light microscopy and transmission electron microscopy were used to determine the relative abundance and distribution of phototrophic species. The community is vertically stratified into four distinct phototrophic populations. The layering could be distinguished by pigment and species composition. The two layers closest to the surface contained mostly oxygenic phototrophs and chlorophyll a as the primary photosynthetic pigment. Anoxic phototrophs predominated in the bottom two layers with bacteriochlorophylls a and c in the third layer and bacteriochlorophyll a and b in the bottom layer. The surface yellow layer was composed primarily of Navicula, Rhopalodia and other diatom species as well as the cyanobacteria Aphanothece sp. and Phormidium sp. Microcoleus chthonoplasces and Chroococcidiopsis sp. were the major cyanobacteria in the green colored second layer. In the third layer, pinkish-purple in color, purple photographs (Chromatium sp., Thiocapsa roseoparsicina) and filamentous green phototrophs (Chloroflexus sp., Oscillochloris sp.) were abundant. The fourth and deepest photosynthetic layer was salmon colored and composed primarily of Thiocapsa pfennigii, and other purple sulfur phototrophs. The pattern of alternating light (oxygenic community) and dark (anoxygenic community) layering preserved in older laminae is a consequence of this community structure. Study of the flat laminated mat over the 10-year period (1978-1988) including and after its destruction by catastrophic flooding events in 1978 and 1980, showed a succession of stratified communities culminating in the return of Microcoleus and the full compliment of layers by the fall of 1984.     

Environmental implications of oncoids and associated sediments from the Remoredo Formation (Lower Jurassic) Mendoza, Argentina

Lower Jurassic deposits of the middle member (19 m) of the Remoredo Formation at Arroyo Montañesito, southwestern Mendoza Province (Neuquén Basin, Argentina), and its oncoids are described. Four lithofacies constitute the lacustrine deposits of the Remoredo Formation: (1) laminated green to gray calcareous shales; (2) laminated to massive dark gray mudstones; (3) massive to upward-coarsening dark gray oncolite wackestones; and (4) massive dark gray packstones with abundant macro-oncolites. According to layer configuration, two types of oncoids were recognized: (a) those having distinctly banded, well defined concentric and continuous lamination (Type I); and (b) those having a vertical arrangement of irregular and discontinuous laminae (Type I³–I). The continuous micritic laminations suggest growth during agitated conditions, and the discontinuous laminations reflect short periods of non agitation or tranquility in the water mass. The oncolites are associated with a well preserved faunal assemblage of ostracods (Darwinula sp. and possible members of the Subfamily Iliocypridinae) and some fragments of bivalves that are indicative of shallow water conditions. The facies association is a coarsening-upward sequence interpreted as the product of deposition in a shallow nearshore lacustrine environment, and a progressive infilling by pyroclastic subaereal flows.     

Morphology and histochemistry of the adrenal medulla. I. Various types of primary catecholamine-storing cells in the mouse adrenal medulla.

Semithin sections (Araldite) of mouse adreno-medullary tissue were examined in the light microscope after perfusion fixation with glutaraldehyde, glutaraldehyde/formaldehyde or after freeze-drying followed by a treatment with hot formaldehyde gas. The following methods were employed: (i) aldehyde-induced fluorescence of catecholamines, (ii) Schmorl's ferric ferricyanide reaction, (iii) argentaffin reaction, and (iiii) staining with alkaline lead citrate followed by Timm's silver sulphide reaction. The correspondence of results obtained by the various methods was proven in consecutive sections or by successively applying different methods to identical sections. Four types of primary catecholamine-storing cells were identified. NA1 cells contain cytoplasmic granules up to 0.3 mum in diameter which stain black with ammoniacal silver and display a bright white to yellow fluorescence. NA2 cells show smaller cytoplasmic granules which stain brown with the argentaffin method and give white catecholamine fluorescence. NA3 cells appear yellow-earth after applying the argentaffin reaction and show greenish fluorescence. NA4 cells are hardly identified in the light microscope. These cells are significantly smaller than the above mentioned cells and characterized by a high nucleo-cytoplasmic ratio. They become straw coloured with ammoniacal silver and show greenish fluorescence. The argentaffin reaction was also used to identify these cells in semithin sections of glutaraldehyde/osmium tetroxide fixed material. The fine structure of the various noradrenalin-storing cells was studied in consecutive thin sections. NA1 cells were found to contain two populations of granules, the larger ones measuring between 300 and 350 nm, the smaller ones about 175 nm. The granules in NA2 cells correspond to this latter population (175 nm). NA3 cells contain an uniform granule population with a main diameter of 120 nm. The smallest granules are seen in NA4 cells being in the dimension of 80 nm. Granules in NA1 and NA2 cells show uniformly high density, whereas those in NA3 and NA4 cells display cores of varying density. Granules with moderately dense cores in NA3 and NA4 cells may represent partially emptied sites of noradrenalin storage or dopamin containing particles.     

Variations hydrologiques et extension des lacs holocenes du Desert Danakil

During the Holocene period, lake basins existed in some parts of the Danakil Desert. These basins were supplied either by the Awash River or by ground waters flowing through highly fissured basaltic flows. It is possible to reconstruct the areas and fluctuations of lake levels because of the preservation of old shore lines. Calcareous and diatomaceous bottom deposits give information about lacustrine paleo-environments (isotopic analyses, diatoms). It is suggested that the Holocene period started with an extensive lacustrine episode between 11,000 and 7,000 years B.P. At least one other transgressive stage, of lesser importance, took place between about 2,000 and 1,000 years B.P. The lakes mainly supplied with ground waters (Afrera) exhibit evidence of chemical and biochemical sedimentation. The depostion continued after 7,000 years B.P., and indicates a buffering effect owing to the aquifers. Hence, these basins do not have the simple behaviour of a rain gauge recording the local climate fluctuations of the Danakil Desert. The Dobi Graben can be partly related to this kind of basin.Because of the strong turbidity of the flood waters, the lakes with both shallow and underground supplies are quickly filled up in the head of the alluvial plain of the Awash River. The lakes at the downward part of the plain (Gamari and terminal Lake Abhé) have been preserved from the solid supply during the two humid episodes. During the intermediate stage, the lacustrine regression allowed the transport of silts and muds as far as Lake Abhé. The Awash River has not ceased flowing and the progression of the alluvial deposits isolates some area of retention on the margins of the plain (lacustrine relicts at about 4,000 and 5,000 years B.P.).After subtracting the local hydrological influences, by means of comparison with the recent phenomena, this succession fits into the general pattern of the Holocene climatic events of the southern margin of the Sahara.     

Tests of the annual hypothesis and temporal calibration of a 6375‐varve fish‐bearing interval,Eocene horsefly beds,British Columbia,Canada

Eocene lake sediments from Horsefly, British Columbia are rich in fossils of the catostomid fish Amyzon aggregatum. Previous studies of this fish in a 700‐year sequence of varves have demonstrated their potential use in studies of fine‐scale temporal variation in taphonomy and morphology. Tests of the annual (varve) hypothesis for the layers, together with reliable temporal calibration, are necessary prerequisites to any such application. In the present study, a longer continuous sequence from this deposit is subjected to additional tests of the annual hypothesis and is temporally calibrated. Tests include spectral analysis of varve thicknesses, scanning electron microscopy and elemental analysis of dark and light laminae, and analysis of within‐couplet distribution of seasonal fossils. Results support the hypothesis that the couplets are true varves.

Some 6375 varves occur in the studied interval. Each varve is composed of a diatom‐dominated summer lamina and a winter lamina richer in clays, pyrite, and gypsum. Occasional turbidites and thin layers of volcanic ash allow counting and identification of individual varves under low‐power magnification. Fish are rare in the upper 2000 varves but abundant and extensively distributed in the lower 4000 varves of the sequence, making these a potentially valuable interval for studies of microstratigraphic variation in morphology and taphonomy.     

Synthesis,storage and degradation of polyglucose in chlorobium thiosulfatophilum

Cultures of Chlorobium thiosulfatophilum form polyglucose during growth. The polyglucose is laid down within the cells as rosette-like granules, which are made up from smaller grains. The size of each granule appears to be limited to less than 30 nm, since an increase in polyglucose content leads to more granules being formed rather than an increase in granule size.The polyglucose in washed cells is fermented in the dark to acetate, propionate, caproate and succinate, of which acetate by far comprises the largest fraction (68%). During incubation of washed cells without hydrogen donor, the level of polyglucose decreases regardless of whether the cells are incubated in the dark or in the light. Since the products formed from polyglucose under the two different conditions are not the same, it is suggested that polyglucose in the dark serves as an energy source, whereas when in the light the role of polyglucose is mainly to provide the cell with reducing power.     

Mitochondrial trafficking through Rhot1 is involved in the aggregation of germinal granule components during primordial germ cell formation in Xenopus embryos

In many animals, the germ plasm is sufficient and necessary for primordial germ cell (PGC) formation. It contains germinal granules and abundant mitochondria (germline‐Mt). However, the role of germline‐Mt in germ cell formation remains poorly understood. In Xenopus, the germ plasm is distributed as many small islands at the vegetal pole, which gradually aggregates to form a single large mass in each of the four vegetal pole cells at the early blastula stage. Polymerized microtubules and the adapter protein kinesin are required for the aggregation of germ plasm. However, it remains unknown whether germline‐Mt trafficking is important for the cytoplasmic transport of germinal granules during germ plasm aggregation. In this study, we focused on the mitochondrial small GTPase protein Rhot1 to inhibit mitochondrial trafficking during the germ plasm aggregation. Expression of Rhot1ΔC, which lacks the C‐terminal mitochondrial transmembrane domain, inhibited the aggregation of germline‐Mt during early development. In Rhot1‐inhibited embryos, germinal granule components did not aggregate during cleavage stages, which reduced the number of PGCs on the genital ridge at tail‐bud stage. These results suggest that mitochondrial trafficking is involved in the aggregation of germinal granule components, which are essential for the formation of PGCs.     

Late Glacial and Holocene Ostracoda of the Gulf of Gdańsk,the Baltic Sea,Poland

To trace environmental changes in water hydrology and salinity in the Late Glacial to Holocene of the Gulf of Gdańsk, a south‐eastern bay of the Baltic Sea within the maritime zone of Poland, the distribution of ostracod valves was studied in 20 sediment cores collected from both the shallow‐ and deep‐water zones (depth 10.9–67.5 m). The studied sediment sequences yielded ca. 3000 valves of 21 ostracod species, of which only five are known to live today in the Gulf, which has a present maximum depth of 118 m and water salinity up to 7–8‰. The majority of the studied sediment layers that contained ostracod valves corresponded to the period of the Late Glacial to Mid‐Holocene and was dominated by non‐marine species, of which the most common were Candona neglecta (present in 17 cores), Cytherissa lacustris (15 cores) and Candona candida (14 cores). By clustering classification five major ostracod assemblage types were recognised in the studied cores. Initial assemblage types dominated mostly by inhabitants of the profundal/sub‐littoral zones of modern oligo‐mesotrophic lakes (C. lacustris and C. neglecta) in some sediment sequences were replaced in stratigraphical order by the assemblages dominated by brackish‐water species (Cyprideis torosa or Cytheromorpha fuscata). The structure and species composition of the distinguished ostracod assemblage types as well as their successional transitions indicate that the studied sediments were deposited initially in the Late Glacial in freshwater lacustrine conditions, and subsequently, during the Holocene marine transgression, covered by marine sands. The present results confirm and consolidate inferences based on previously published data on ostracods from the western part of the Gulf of Gdańsk as well as on other biotic (molluscs, diatoms) and abiotic (seismoacoustic) indices from this area (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Taphonomy of the middle Cambrian (Drumian) Ravens Throat River Lagerstätte,Rockslide Formation,Mackenzie Mountains,Northwest Territories,Canada

The Middle Cambrian (series 3, Drumian, Bolaspidella Biozone) Ravens Throat River Lagerstätte in the Rockslide Formation of the Mackenzie Mountains, northwestern Canada, contains a Burgess Shale‐type biota of similar age to the Wheeler and Marjum formations of Utah. The Rockslide Formation is a unit of deep‐water, mixed carbonate and siliciclastic facies deposited in a slope setting on the present‐day northwestern margin of Laurentia. At the fossil‐bearing locality, the unit is about 175 m thick and the lower part onlaps a fault scarp cutting lower Cambrian sandstones. It consists of a succession of shale, laminated to thin‐bedded lime mudstone, debris‐flow breccias, minor calcareous sandstone, greenish‐coloured calcareous mudstone and dolomitic siltstone, overlain by shallow‐water dolostones of the Broken Skull Formation, which indicates an overall progradational sequence. Two ~1‐m‐thick units of greenish calcareous mudstone in the upper part exhibit soft‐bodied preservation, yielding a biota dominated by bivalved arthropods and macrophytic algae, along with hyoliths and trilobites. It represents a low‐diversity in situ community. Most of the fossils occur in the lower unit, and only the more robust components are preserved. Branching burrows are present under the carapaces of some arthropods, and common millimetre‐sized disruptions of laminae are interpreted as bioturbation. The fossiliferous planar‐laminated calcareous mudstone consists of chlorite, illite, quartz silt, calcite and dolomite and is an anomalous facies in the succession. It was deposited via hemipelagic fallout of a mixture of platform‐derived and terrestrial mud. Geochemical analysis and trace‐element proxies indicate oxic bottom waters that only occasionally might have become dysoxic. Productivity in the water column was dominated by cyanobacteria. Fragments of microbial mats are common as carbonaceous seams. Complete decay of soft tissues was interrupted due to the specific sediment composition, providing support for the role of clay minerals, possibly chlorite, in the taphonomic process.     

Actinoptychus splendens (Shadbolt) Ralfs (Bacillariophyceae): a biostratigraphic marker for the later part of the Holocene coastal deposits along the southern North Sea

Actinoptychus splendens is a conspicuous and widely distributed marine diatom. At present it is common in the coastal waters of the southern North Sea, but it appears to be absent in the older Holocene deposits along the Dutch and Belgian coasts. Its first postglacial appearance here can be dated at between 4400 and 4100 BP. By 3800 BP it is well established in the region. Although generally not abundant, it can be found in nearly every sample of younger marine or brackish deposits. The large amount of material investigated from the area, as well as the high preservation potential and easy recognition of the species, preclude any other explanation for its apparent absence along southern North Sea shores prior to ±4100 BP, than a late natural immigration. This appears to be quite exceptional, all the common species which generally occur in association with A. splendens being present from the onset of Holocene sedimentation. A. splendens may become an important marker taxon in the Holocene stratigraphy of the coastal plains along the southern North sea.     

Morphometric variation of Seminavis pusilla (Bacillariophyceae) and its relationship to salinity in inter‐dune lakes of the Badain Jaran Desert,Inner Mongolia,China

We used light and scanning electron microscope analyses to quantify morphometric features (valve length, width, stria density, lineola density and valve curvature) from the observation of valves representing Seminavis pusilla. Cluster analysis based on Gaussian mixture models and the expectation‐maximization algorithm was used for delineating two species, Seminavis pusilla sensu stricto and Seminavis lata (Krammer) Rioual comb. et stat. nov. By comparison with S. pusilla, S. lata is characterized by wider valves and lower stria density. The two species have also markedly different ecology. S. pusilla is most abundant in the most saline lakes of the dataset, while S. lata is most abundant in the less saline lakes. Our results indicate that combining the two species into S. pusilla sensu lato would lead to a loss of ecological information and a decrease of the performance of transfer functions developed for quantitative reconstruction of past salinity from fossil diatom assemblages in sediment cores.     

The Taxonomy and Phylogeny of the Poorly known Heterotrich Ciliate Ampullofolliculina lageniformis Hadži, 1951 (Ciliophora: Heterotrichea)

Ampullofolliculina Had?i, 1951 is a monotypic genus, the only species being A. lageniformis which was first discovered in estuarine habitats in the U.S. and has never been redescribed. In the present study, we investigated the taxonomy and phylogeny of A. lageniformis Had?i, 1951 based on analyses of a population collected from a brackish wetland in Ningbo, China. The main characteristics of this species are as follows: trophont about 450–700 μm long in vivo with two short, rounded peristomial lobes of equal size; lorica flask‐shaped, transparent and smooth with a short, wide neck at the base of which two transparent valves are asymmetrically inserted; cortex with brownish to reddish cortical granules and greenish pigment granules; about 80 somatic kineties evenly arranged; moniliform macronucleus with 4–8 ellipsoidal nodules; swarmer dark green, vermiform in shape, about 200–350 μm long in vivo, with about 60 adoral membranelles and 85 somatic kineties, no mouth nor paroral membrane. Phylogenetic analyses inferred from SSU rDNA sequences show that A. lageniformis is closely related to Folliculina and Eufolliculina which nest within a large clade that comprises five families, i.e. Stentoridae, Blepharismidae, Fabreidae, Maristentoridae, and Folliculinidae.     

A Simple Polychrome Stain for Conventionally Fixed Epon-Embedded Tissues

The described technique, based upon a one-step Mallory-Heidenhain stain, can be applied as a routine stain for glutaraldehyde or OsO₄ fixed, Epon embedded tissues of various organs. The technique consists of a short treatment of the sections with H₂O₂, a nuclear staining with celestine blue B and a final staining in a modified Cason's solution. The different tissue and cell components are displayed as follows: dark brown nuclei, yellow cytoplasm, red collagen fibers and blue elastic' fibers. Intra cytoplasmic components as glycogen and mucus are stained respectively blue and violet, whereas other inclusions such as leucocyte granules are colored orange to red.     

The first non‐marine ostracod fauna from the Lower Barremian dysodiles of Lebanon

Dysodiles are finely laminated sedimentary rocks rich in organic matter and in exceptionally well‐preserved fossils, hence their petroleum and palaeontological interest. However, few studies focused on the dysodiles of Lebanon, leaving their palaeontological content and their depositional environment largely unknown. Our previous investigations show a variety of well‐preserved lacustrine fossils including ichthyofauna, chelonians, insects, plant debris, gastropods, palynomorphs and ostracods. The present study focuses on the ostracods of five sampling localities from the Lower Barremian of Lebanon. Being the most abundant fossils, ostracods raise some taphonomic and palaeoecological questions that may help us understand the depositional environment and enrich the story of these Early Barremian lakes. Faunal differences between the sampled sections provide clues to the specific characteristics of each lake. The abundance of ‘butterfly’ preservation of carapaces, together with the association of adults and juveniles, indicates calm depositional environments without post‐mortem transport. The assemblages comprise ostracods with known swimming ability (Cyprois and Zonocypris) or that are thought to have been swimmers (Cypridea), while non‐swimmers are absent, suggesting that nektobenthonic ostracods must have lived only in the shallow margins of the lakes or among floating vegetation because hypolimnion conditions were hostile to benthos. This study provides different scenarios on how this fauna ended up preserved in the laminated lake sediments.     

Late Quaternary diatoms in the sediments of Przedni Staw Lake (Polish Tatra Mountains)

The paper presents a diatom succession in the Late Glacial and Holocene sediments of the Przedni Staw lake in the Pie Stawów Polskich Valley High Tatra Mts. Ten diatom phases are distinguished and presented against a pollen diagram from the analyzed core showing continuous sedimentation from the Oldest Dryas to the Subatlantic period. The diatom flora in the Late Glacial sediments is predominantly littoral — Fragilaria, Navicula, Nitzschia, Diploneis, Pinnularia and Amphora species. The Holocene sediments enclose more abundant planktonic species such as Cyclotella quadriiuncta, Asterionella formosa and Melosira distans.     

Ultrastructural pathology of the epidermis of molting elaterid larvae (Coleoptera) with a fungus and a bacterium in the ecdysial space

Toxins produced by the fungus Metarrhizium anisopliae and the bacterium Pseudomonas aeruginosa in the ecdysial space of a molting wireworm are absorbed through the thin new cuticle and ultrastructurally change the epidermal cells into two distinct types. One is a rounded, degenerative type characterized by a “light” cytoplasm with vesiculated rough endoplasmic reticulum, rounded mitochondria with degenerated cristae, little ground plasm, and a rounded nucleus with little nucleoplasm and large globules of condensed chromatin from which chromatin fibrils separate in loose folds or granulelike tight folds. The other type has very irregular outlines and is characterized by a “dark” cytoplasm with abundant, whorled laminae of rough endoplasmic reticulum and abundant free ribosomes in a dense ground plasm, large rounded clear vacuoles, and apparently normal mitochondria and nuclei. The fungal toxins are believed to be primarily responsible for the formation of the light cells, and the bacterial toxins, for the separation of the chromatin into fibrils in the light cells, the fusion of their nuclei into large nuclear bodies, and the changes in the cytoplasmic contents of the dark cells. The dark cells, although abnormal, appear to retain a limited secretory activity.     

Fluid preservation causes minimal reduction of parasite detectability in fish specimens: A new approach for reconstructing parasite communities of the past?

Long‐term datasets are needed to evaluate temporal patterns in wildlife disease burdens, but historical data on parasite abundance are extremely rare. For more than a century, natural history collections have been accumulating fluid‐preserved specimens, which should contain the parasites infecting the host at the time of its preservation. However, before this unique data source can be exploited, we must identify the artifacts that are introduced by the preservation process. Here, we experimentally address whether the preservation process alters the degree to which metazoan parasites are detectable in fluid‐preserved fish specimens when using visual parasite detection techniques. We randomly assigned fish of three species (Gadus chalcogrammus, Thaleichthys pacificus, and Parophrys vetulus) to two treatments. In the first treatment, fish were preserved according to the standard procedures used in ichthyological collections. Immediately after the fluid‐preservation process was complete, we performed parasitological dissection on those specimens. The second treatment was a control, in which fish were dissected without being subjected to the fluid‐preservation process. We compared parasite abundance between the two treatments. Across 298 fish individuals and 59 host–parasite pairs, we found few differences between treatments, with 24 of 27 host–parasite pairs equally abundant between the two treatments. Of these, one pair was significantly more abundant in the preservation treatment than in the control group, and two pairs were significantly less abundant in the preservation treatment than in the control group. Our data suggest that the fluid‐preservation process does not have a substantial effect on the detectability of metazoan parasites. This study addresses only the effects of the fixation and preservation process; long‐term experiments are needed to address whether parasite detectability remains unchanged in the months, years, and decades of storage following preservation. If so, ecologists will be able to reconstruct novel, long‐term datasets on parasite diversity and abundance over the past century or more using fluid‐preserved specimens from natural history collections.     

Light and electron microscopic studies of crayfish hemocytes

Using light and electron microscopy, three hemocyte types are described in the hemolymph of the crayfish. The coagulocyte comprises 65% of the total hemocyte number and contains medium-sized cytoplasmic granules, abundant dilated rough endoplasmic reticulum, and a highly developed Golgi complex. It rapidly undergoes cytolysis in vitro and participates in coagulation by releasing the contents of its granules to the hemolymph. The granulocyte comprises 31% of the total hemocyte number and is capable of phagocytosis. It contains large, irregularly shaped cytoplasmic granules, a moderately developed Golgi complex, and moderate amounts of non-dilated rough endoplasmic reticulum. During coagulation in vitro, the cell attaches and spreads onto the substratum; this is followed by a slow intracellular granule breakdown and cytolysis. The amebocyte comprises 4% of the total hemocyte number and it is also capable of phagocytosis. It possesses small cytoplasmic granules, many vacuoles, a moderately developed Golgi complex, and large amounts of smooth endoplasmic reticulum. It is distinguished from the other two cell types by being stable and motile in vitro.