Ultrastructure and histochemistry of the male reproductive system of the genus Callinectes Stimpson, 1860 (Brachyura: Portunidae)

We described the ultrastructure and histochemistry of the reproductive system of five Callinectes species, and evaluate the seasonal variation in weight of the reproductive system and hepatopancreas by comparing annual changes of somatic indices. The somatic indices changed little throughout the year. In Callinectes, spermatogenesis occurs inside the lobular testes and, within each lobule, the cells are at the same developmental stage. Spermatogenesis and spermiogenesis follow the same development pattern in all Callinectes studied. Mature spermatozoa are released into the seminiferous ducts through the collecting ducts. Cells of the vas deferens are secretory as evidenced by rough endoplasmic reticulum, Golgi complex, and secretory vesicles that produce the seminal fluid. The anterior vas deferens shows two portions: proximal and distal. In proximal portion (AVDp), spermatozoa are clustered and embedded in an electron-dense, basophilic glycoproteinaceous secretion Type I. In the distal portion (AVDd), the spermatophore wall is formed by incorporation of a less electron-dense glycoproteinaceous secretion Type II. The secretion Type I change to an acid polysaccharide-rich matrix that separates the spermatophores from each other. The median vas deferens (MVD) stores the spermatophores and produces the granular glycoproteinaceous seminal fluid. The posterior vas deferens (PVD) has few spermatophores. Its epithelium has many mitochondria and the PVD seminal fluid changes into a liquid and homogeneous glycoprotein. Many outpocketings in the PVD and MVD help to increase the fluid production. Overall, the reproductive pattern of Callinectes is similar to other species that produce sperm plugs. The secretions of AVD, MVD, and PVD are responsible for the polymerization that forms the solid, waxy plug in the seminal receptacle. The traits identified here are common to all Portunidae species studied so far.     

Ultrastructure of the testes and spermatogenesis in the mite Anystis baccarum

The epithelial lining of testes in Anystis baccarum is glandular and produces a secretory product necessary to form spermatophores. The main stages of spermatogenesis occur in the lumen of the testis in groups of synchronously developing sister cells. Spermatogonia and late spermatids are encircled by glandular cells. Reorganization of developing spermatids is typical of the trombidiform mites and includes formation of the acrosomal complex, cytoplasm elimination, disappearance of the nuclear envelope and formation of invaginations of plasmalemma. The chromatin material condensation is not followed by the entire chromatin body formation. In mature spermatoza, dense chromatin strands (80b nm in diameter) lie along the cell in the peripheral layer of the cytoplasm. Mature spermatozoa lack axonema or any protrusions. A layer of microtubules, visible underneath the outer membrane, may serve for sperm movement in the female genital duct. The acrosomal complex consists of acromal granule, acrosomal filament and subacrosomal substance. This, as well as two aggregates of typical mitochondria, looks plesiomorphic.     

The plasama membrane of Xenopus laevis spermatozoon

Xenopus laevis sperm plasma membrane ultrastructure has been studied by means of freeze-fracture, deep-etching, and lectin-gold binding. Xenopus spermatozoa differ from those of other species in that their plasma membrane does not exhibit topographical domains. In fact, no geometric arrangement or characteristic array of particles is present on fractured plasma membrane. Fractures rarely occur in acrosomal or nuclear membranes. Wheat germ agglutinin receptors are distributed homogeneously, on the plasma membrane of the sperm head and tail.     

Ultrastructure of sperm storage and male genital ducts in a male holocephalan, the elephant fish, Callorhynchus milii.

In chondrichthyes, the process of spermatogenesis produces a spermatocyst composed of Sertoli cells and their cohort of associated spermatozoa linearly arrayed and embedded in the apical end of the Sertoli cell. The extratesticular ducts consist of paired epididymis, ductus deferens, isthmus, and seminal vesicles. In transit through the ducts, spermatozoa undergo modification by secretions of the extratesticular ducts and associated glands, i.e., Leydig gland. In mature animals, the anterior portion of the mesonephros is specialized as the Leydig gland that connects to both the epididymis and ductus deferens and elaborates seminal fluid and matrix that contribute to the spermatophore or spermatozeugmata, depending on the species. Leydig gland epithelium is simple columnar with secretory and ciliated cells. Secretory cells have periodic acid-Schiff positive (PAS+) apical secretory granules. In the holocephalan elephant fish, Callorhynchus milii, sperm and Sertoli cell fragments enter the first major extratesticular duct, the epididymis. In the epididymis, spermatozoa are initially present as individual sperm but soon begin to laterally associate so that they are aligned head-to-head. The epididymis is a highly convoluted tubule with a small bore lumen and an epithelium consisting of scant ciliated and relatively more secretory cells. Secretory activity of both the Leydig gland and epididymis contribute to the nascent spermatophores, which begin as gel-like aggregations of secretory product in which sperm are embedded. Fully formed spermatophores occur in the ductus. The simple columnar epithelium has both ciliated and secretory cells. The spermatophore is regionalized into a PAS+ and Alcian-blue-positive (AB+) cortex and a distinctively PAS+, and less AB+ medulla. Laterally aligned sperm occupy the medulla and are surrounded by a clear zone separate from the spermatophore matrix. Grossly, the seminal vesicles are characterized by spiral partitions of the epithelium that project into the lumen, much like a spiral staircase. Each partition is staggered with respect to adjacent partitions while the aperture is eccentric. The generally nonsecretory epithelium of the seminal vesicle is simple columnar with both microvillar and ciliated cells.     

An ultrastructural investigation of the testes and spermiogenesis in Myobia murismusculi (Schrank) (Acari,Actinedida: Myobiidae)

Summary

The stages of spermiogenesis in Myobia murismusculi were investigated on the basis of ultrastructural analysis of both the testes and the female organs: receptaculum seminis and seminal duct. The walls of the testes consist of a thin epithelial layer. Germ and secretory cells lie free in the lumen of the testes. In the early stages of differentiation, both cell types represent clusters of sister cells joined by intercellular bridges. Each secretory cell contains prominent RER and Golgi complex, which produce single dense granule. Growing gradually the granule fills the whole volume of the cell's cytoplasm. Mature secretory cells disintegrate and the secretory product discharges into the testicular lumen. The germ cells are represented by the early, the intermediate and the late spermatids as well as the immature sperm (prospermia). Neither spermatogonia nor meiotic figures were observed in adult males. As spermiogenesis starts, numerous narrow invaginations of the outer membrane (peripheral channels) develop on the cell surface. They form a wide circumferential network connected to pinocytotic vesicles. Owing to the secretory activity of the Golgi complex, a large acrosomal granule is formed in the early spermatids. A long acrosomal filament runs along the intranuclear canal. Nuclear material condenses and forms two spherical bodies of different electron density. The lighter one can be observed until the stage of the late spermatids, when the nuclear envelope almost completely disappears. The electron-dense nuclear body transforms into a definite chromatin body, which is observed in the mature sperm as a cup-shaped structure. The late spermatids are characterized by the presence of a large electronlucent vacuole, which seems to be unique for the process of spermiogenesis in Actinedida. After the spermia enter the female genital tract, the peripheral channels disappear as well as the vacuole. The cells form long amoeboid arms with a special microtubular layer underneath the plasma membrane. The chromatin body is encircled by a large acrosomal granule of complex shape provided by long extensions running deep into the cytoplasm. The cytoplasm contains no organelles except for a group of unmodified mitochondria in the post-nuclear region. The main characteristics of the Myobia spermiogenesis are discussed with regard to other actinedid mites.     

Ultrastructure of the Spermatozoa and Spermatophores of the Zuwai Crab,Chionoecetes opilio (Majidae,Brachyura)

The fine structure of the spermatozoa and spermatophores of the zuwai crab, Chionoecetes opilio, was examined electron microscopically. The spermatophores embedded in the secretory droplets within the vasa deferentia showed a spherical structure with an extremely wrinkled envelope and contained numerous spermatozoa. The mature spermatozoa of this crab, similar to those of other brachyurans, were stellate in shape and had a globular acrosome surrounded by a cup-like nucleus with several radiating processes. The acrosome was ultrastructurally complex and its apical part was characterized by an electron-dense discoid structure, whereas its innermost part was occupied by an electron-lucent cylindrical structure containing assemblies of thin tubules and a reticular formation of electron-dense material. The cytoplasm interposed between the nucleus and acrosome was remarkably reduced in volume and displayed a membranous lamellar complex, few mitochondria, and a centriole. The nuclear chromatin was not condensed but represented by finely flocculent material. The morphological aspects of the zuwai crab spermatozoa are discussed in comparison with those of other decapod crustaceans.     

Daily production of spermatophores, sperm number and spermatophore size in two eriophyoid mite species

Under dissociated sperm transfer, (non-pairing) males deposit spermatophores on a substrate, while females seek spermatophores and pick up sperm on their own. Spermatophore expenditures of non-pairing males should be high, due to the increased uncertainty of sperm uptake by a female. In this study I examined spermatophore expenditures in two eriophyoid species that differed in the degree of dissociation between sexes: (1) Aculus fockeui (Nalepa and Trouessart) males rarely visit quiescent female nymphs (QFNs), and mostly deposit spermatophores all over the leaves, whereas (2) Aculops allotrichus (Nalepa) males guard QFNs for many hours and deposit several spermatophores beside them. Males of both species were collected from the field and tested in solitude. Aculus fockeui males deposited on average 19.1 spermatophores per day, whereas A. allotrichus deposited only 3.6 spermatophores per day, and had a very large coefficient of variation. Males and spermatophores of A. allotrichus were significantly smaller and contained less sperm than those of A. fockeui. In both eriophyoids, spermatophore size was fitted to the size of female genitalia and the height of females. The ratio between the diameter of spermatophore head and the width of a female genital coverflap was 0.6, whereas the ratio between the female leg and the length of spermatophore stalk was 0.5. Several factors could be responsible for the discrepancy in spermatophore expenditures between species. Among other factors, the effects of male size, male reproductive strategy and female genitalia size on spermatophore output and size of spermatophores are discussed.     

Proteomic analysis of sperm regions that mediate sperm-egg interactions

The sperm interacts with three oocyte-associated structures during fertilization: the cumulus cell layer surrounding the oocyte, the egg extracellular matrix (the zona pellucida), and the oocyte plasma membrane. Each of these interactions is mediated by the sperm head, probably through proteins both on the sperm surface and within the acrosome, a specialized secretory granule. In this study, we have used subcellular fractionation in order to generate a proteome of the sperm head subcellular compartments that interact with oocytes. Of the proteins we identified for which a gene knockout has been tested, a third have been shown to be essential for efficient reproduction in vivo. Many of the other presently untested proteins are likely to have a similarly important role. Twenty-five percent of the cell surface fraction proteins are previously uncharacterized. We have shown that at least two of these novel proteins are localized to the sperm head. In summary, we have identified over 100 proteins that are expressed on mature sperm at the site of sperm-oocyte interactions.     

Ultrastructure of testes and spermatogenesis in the trombiculid mite,Hirsutiella zachvatkini (Schluger)

Summary

Spermatogenesis and sperm ultrastructure of the trombiculid mite Hirsutiella zachvatkini (Schluger 1948) have been investigated using transmission electron microscopy and compared with other arachnids studied. Sperm differentiation takes place in groups of synchronously developed germ cells of the two large sac-like paired testes. Each testis is composed of a secretory epithelium, which occupies their medio-ventral regions, and of a germinative epithelium situated in the latero-dorsal parts of testes together with large somatic cells. The germ cells are represented on sections by spermatogonia, spermatocytes, early, middle and late spermatids, and mature spermatozoa. Spermatocytes and spermatids contain two centrioles, which disappear afterwards, and a small Golgi-like structure forming an acrosomal cistema. Mature spermatozoa, which lie both within the meshes of somatic cells and also free in the lumen of testes, are compact oval aflagellate cells provided with peripheral channels. They also contain an acrosome, flattened between the cell membrane and the round electron-dense chromatin body, an oval body of lesser density lying in close proximity to the chromatin body, and a group of 5–7 mitochondria with spherically arranged cristae situated immediately behind the nuclear bodies. An acrosomal filament may be sometimes seen beneath the acrosome in the middle spermatids and disappears in the mature spermatozoa. These findings show that the mode of differentiation and pattern of organization of the male sex cells in trombiculid mites are of rather primitive type compared with other acarine spermatozoa.     

瘤背石磺的精子结构

用光学显微镜和透射电子显微镜技术研究了瘤背石磺精子的结构特点,分析了其生理生态适应性以及在肺螺亚纲系统演化中的意义。瘤背石磺的精子由头部、中段和末段组成。头部由奶嘴形的顶体和长圆筒状的细胞核构成。顶体包括顶体囊和顶体构架体两部分;两者的内含物都分布均匀,电子密度稍低于细胞核;顶体基部平整,与核前端之间有一空隙,内含物电子密度极低。细胞核由电子密度高的均匀颗粒物质组成,并出现核泡;核的后端有一"杯形"的凹陷,称为核后窝。中段结构复杂,主要包括一对位于核后窝内的中心粒、轴丝、质膜、线粒体及由线粒体衍生的糖原质螺旋体、基质层和类晶体层等。末段由"9 2"结构的轴丝及外包的质膜组成,无糖原质螺旋体和其它线粒体衍生物。比较瘤背石磺精子与肺螺亚纲其它物种的精子结构,我们认为该物种的精子属于"进化型",是一类在进化地位中比基眼目高等的动物。     

Structure of the zona pellucida and cumulus oophorus in three species of native Australian rodents

The sperm head of many Australian hydromyine rodents has three curved hooks projecting from its anterior margin; the structure of the hooks has been characterized, but their function is unknown. In this study, we have investigated whether the hooks might have evolved to assist sperm penetration through more formidable egg vestments, particularly the zona pellucida. Cumulus-oocyte complexes were obtained from two species that possess a three-hooked sperm head (Pseudomys australis and P. nanus) and one species that does not (Notomys alexis) and examined by light and electron microscopy. After fixation in the presence of ruthenium red, the zona pellucida was found to consist of a fibrillar meshwork, but there were no interspecific structural differences. A corona radiata was absent, and the cumulus extracellular matrix was composed of filaments and electron-dense granules in each species. Measurements of the zona thickness in freshly ovulated, unfixed oocytes revealed that it was thinnest (7.8 μm) in P. australis. Which has a three-hooked sperm head, and thickest (11.4 μm) in N. alexis, the species in which the ventral hooks are absent. Hence, no correlation was found between the thickness of the zona pellucida or the structure of the cumulus-oocyte complex, and the presence of three hooks on the sperm head. We conclude, therefore, that it is unlikely that the evolution of the three-hooked sperm head is an adaptation for penetration of increased barriers around the oocyte.     

Sperm Bundles in the Seminal Vesicle of the Crematogaster victima (Smith) Adult Males (Hymenoptera: Formicidae)

This study establishes the presence of spermatodesm in the seminal vesicles of sexually mature males of Crematogaster victima (Smith). In this species, the spermatozoa are maintained together by an extracellular matrix in which the acrosomal regions are embedded. This characteristic has not yet been observed in any other Aculeata. However, the sperm morphology in this species is similar to that described for other ants. The spermatozoa measure on average 100 μm in length, and the number of sperm per bundle is up to 256. They are composed of a head formed by the acrosome and nucleus; this is followed by the flagellum, which is formed by the centriolar adjunct, an axoneme with a 9?+?9?+?2 microtubule pattern, two mitochondrial derivatives, and two accessory bodies. The acrosome is formed by the acrosomal vesicle and perforatorium. The nucleus is filled with compact chromatin with many areas of thick and non-compacted filaments. Both mitochondrial derivatives have the same shape and diameters. The presence of sperm bundles in sexually mature males differentiates C. victima from other ants; however, the similarities in the sperm ultrastructure support the monophyly of this insect group.     

When do the Costs of Spermatogenesis Constrain Sperm Expenditure? Remarks on the Pattern of the Spermatogenic Cycle

The costs of spermatogenesis constrain sperm expenditure when sperm production per day is limited. Thus, males are challenged to allocate available resources to sperm production and other life history functions. However, this prevailing assumption is not applicable to species in which spermatogenesis becomes quiescent during the breeding season. Males of these species prepare large quantities of sperm before the breeding season. Among these species, constraints on ejaculates have been intensively investigated in salamanders that deposit spermatophores. Although it is predicted that sperm expenditure should not be limited because of abundantly prepared sperm, spermatophore deposition is often limited during the breeding season when vas deferens are full of sperm. We tested a hypothesis regarding limited spermatophore deposition by measuring sperm quantity and volume of spermatophores sequentially deposited by male eastern newts Notophthalmus viridescens. A male newt rarely deposits more than three spermatophores per mating. If depletion of non‐sperm components of spermatophores limits spermatophore deposition, we predicted that spermatophore volume decreases while sperm quantity remains constant as a male deposits more spermatophores. Alternatively, some regulative mechanisms allow a limited portion of available sperm to be expended per mating, in which sperm quantity is predicted to decrease while the spermatophore volume remains constant. Finally, depletion of non‐sperm components may regulate sperm expenditure, which predicted that both spermatophore volume and sperm quantity decrease. We found that both sperm quantity and the spermatophore volume decreased as a male deposited more spermatophores during a single mating. Sperm expenditure was constrained without the costs involved in active spermatogenesis, and depletion of non‐sperm components likely regulate sperm quantity loaded in spermatophores. In dissociated spermatogenesis, constrained sperm expenditure do not mean that costly spermatogenesis is directly limiting male mating capacity but rather suggest that the evolution of physiological mechanisms regulating sperm expenditure per mating maximizes male reproductive success.     

Sperm plasma membrane breakdown during Drosophila fertilization requires sneaky, an acrosomal membrane protein

Fertilization typically involves membrane fusion between sperm and eggs. In Drosophila, however, sperm enter eggs with membranes intact. Consequently, sperm plasma membrane breakdown (PMBD) and subsequent events of sperm activation occur in the egg cytoplasm. We previously proposed that mutations in the sneaky (snky) gene result in male sterility due to failure in PMBD. Here we support this proposal by demonstrating persistence of a plasma membrane protein around the head of snky sperm after entry into the egg. We further show that snky is expressed in testes and encodes a predicted integral membrane protein with multiple transmembrane domains, a DC-STAMP-like domain, and a variant RING finger. Using a transgene that expresses an active Snky-Green fluorescent protein fusion (Snky-GFP), we show that the protein is localized to the acrosome, a membrane-bound vesicle located at the apical tip of sperm. Snky-GFP also allowed us to follow the fate of the protein and the acrosome during fertilization. In many animals, the acrosome is a secretory vesicle with exocytosis essential for sperm penetration through the egg coats. Surprisingly, we find that the Drosophila acrosome is a paternally inherited structure. We provide evidence that the acrosome induces changes in sperm plasma membrane, exclusive of exocytosis and through the action of the acrosomal membrane protein Snky. Existence of testis-expressed Snky-like genes in many animals, including humans, suggests conserved protein function. We relate the characteristics of Drosophila Snky, acrosome function and sperm PMBD to membrane fusion events that occur in other systems.     

Fine structure of spermiogenesis, spermatozoa and spermatophore of Saxidromus delamarei (Saxidromidae, Actinotrichida, Acari)

Ultrastructural details of spermiogenesis, spermatozoa and the spermatophore of the early derived actinedid mite Saxidromus delamarei are described. Spermatids and mature sperm cells are provided with up to four acrosomal complexes and nuclei derivatives (chromatin bodies). Due to this reason, the sperm cells may be classified as synspermia, a sperm type found only in some spiders until now. The acrosomal complex is composed of a remarkably complicated vacuole and filament. Other peculiarities of sperm structure correspond to those found in prostigmatic mites, i.e. penetration of the chromatin body by the acrosomal filament and the presence of peripheral invaginations of the plasmalemma. The sperm cells are covered by a thin secretion layer of probably proteinaceous material. Stalked spermatophores are rather large, but simply structured and contain relatively few sperm cells. The results are discussed taking systematical and behavioural aspects into account. In particular, it is suggested that the peculiar mating behaviour of these mites secures both sperm transfer and first male's sperm priority and that this allowed reduction of sperm numbers.     

AN ELECTRON MICROSCOPE STUDY OF SPERMATID DIFFERENTIATION IN THE TOAD, BUFO ARENARUM HENSEL

The differentiation of the spermatids of Bufo arenarum has been described from a study of electron micrographs of thin sections of testis. The development of the acrosome from the Golgi complex takes place in much the same manner as in mammalian spermatogenesis but no acrosome granule is formed. A perforatorium is described for the first time in this species. It is formed by a convergence of dense filaments that arise between the nuclear membrane and the head cap. During maturation of the spermatid the chromatin undergoes striking physicochemical alterations. Fine chromatin granules uniformly dispersed in the karyoplasm are replaced by larger and larger aggregates and these ultimately coalesce to form a very dense sperm head. Two centrioles of cylindrical form are situated very near the base of the sperm head. The longitudinal fibrils of the tail flagellum take origin from one, and the dense fibrous substance of the undulating membrane is closely related to the other. Phase contrast cinematographic observations on the swimming movements of living toad sperm, when considered in relation to the fine structural components of the tail, suggest that there is a contractile component in the undulating membrane as well as in the axial fibrils. The differences in the structure of mammalian and amphibian sperm tails are discussed in relation to differences in the character of their movements.     

Plasma membrane structure in spermatogenic cells of the swordtail (teleostei,Xiphophorus helleri)

The plasma membrane of spermatogenic cells of the teleost Xiphophorus helleri was examined ultrastructurally and cytochemically in order to characterize the temporal development of the membrane specializations characteristic of the mature spermatozoon. Mature sperm display a mosaic distribution of Concanavalin A and Ricinus comrnunis I binding sites; the anterior region of the head displays an intense binding that is not seen in other surface regions. This asymmetric binding is evident in early spermatids and the area of lectin binding appears associated with the plasma membrane overlying the nucleus. Transmission electron microscopy reveals that the plasma membrane over the anterior region of the head is characterized by an ordered glycocalyx and a tight adherence to the underlying nucleus. Additional membrane differentiations were revealed both in the midpiece region where a “submitochondrial net” is attached to the plasma membrane and at the base of the axoneme where the plasma membrane possesses a “collar-like” arrangement of circumferential rings. The possible functions of these differentiations, as well as their correlation to differentiations seen in sperm of other animal groups, are discussed.     

四种淡水养殖鱼类血细胞的细微结构

四种淡水鱼的血细胞形态基本相似。红血球形态与其他低等脊椎动物基本相似。淋巴球绝大部分是小淋巴球:单核球数量较少;四种鱼的嗜中性白血球形态结构差不多,胞核多为蚕豆形,很少见分叶核,分叶一般也只有二叶,这与哺乳类显然不同;嗜酸性白血球的形态结构与其他脊椎动物基本相似;在少数血涂片中看到了嗜碱性白血球。       

Repeated visitations of spermatophores and polyandry in females of eriophyoid mites

Eriophyoid females store sperm either asymmetrically in one spermatheca, or symmetrically in both spermathecae. Previous studies have suggested that species in which females store sperm asymmetrically pick up sperm from only one spermatophore, while those with symmetrical sperm storage pick up sperm from two or more spermatophores during their lifetime. The aim of this study was to examine spermatophore visitation behaviour and symmetry of sperm storage in Aculops allotrichus from the black locust tree and Cecidophyopsis hendersoni from the yucca. This would indicate monandry or polyandry in these species. In both eriophyoids, the spermatophore visitation consisted of three phases: mounting, lying on the spermatophore and dismounting. Aculops allotrichus stored sperm asymmetrically. However, nearly one-third of the observed females visited two spermatophores, rather than only one in their lives. When A. allotrichus females visited two spermatophores they spent a similar amount of time at the first and at the second visitation. Also, the times of visitation of the first of the two spermatophores and the single spermatophore in a female lifetime did not differ significantly. This would suggest that apart from monandry, double insemination also occurs in this species. By contrast, C. hendersoni females were polyandrous. They stored sperm symmetrically and visited several spermatophores, on average 1.54 (max 6) per day, and up to 33 spermatophores in their lives. The benefits of repeated spermatophore visitation and the possible mechanisms of sperm storage in both species are discussed.     

Vergleichende Untersuchungen zur Fortpflanzungsbiologie der Pseudoscorpione

Zusammenfassung Das Verhalten, die Samenübertragungsweisen und die Spermatophoren verschiedener Arten von Pseudoscorpionen wurden beobachtet und beschrieben.Alle Pseudoscorpione setzen Spermatophoren ab, denen die Weibchen die Spermien entnehmen. Das Verhalten bei der Samenübertragung ist bei den verschiedenen Arten unterschiedlich; es läßt sich eine Evolution von einfachen zu komplizierteren Vorgängen feststellen.Das Verhalten vonChthonius tetrachelatus, Chthonius ischnocheles undNeobisium muscorum ist ursprünglich. Die Männchen setzen immer Spermatophoren ab, auch wenn keine Weibchen anwesend rind. Das Männchen vonChthonius stürzt alte Spermatophoren um und ersetzt sie durch neue. Die Weibchen werden von den Spermatophoren chemotaktisch angelockt. Nach kurzer Prüfung überschreiten sie sie hochbeinig und lösen mit einem Tropfen Flüssigkeit einen Quellungsvorgang aus, der die Spermien aus den Spermatophoren in das weibliche Genitalatrium treibt.Die Männchen der CheiridiidenCheiridium museorum undApocheiridium ferum setzen ihre Spermatophoren dagegen wahrscheinlich nur in Anwesenheit von Weibchen ab. Das Männchen vonCheiridium zeigt zuweilen vorher, wenn es einem Weibchen begegnet, eine vibrierende Bewegung einer Palpenhand. Die Weibchen suchen die Spermatophoren chemotaktisch auf. Wie die Männchen stürzen sie alte Spermatophoren m.Die Chernetiden und Cheliferiden bilden Paare. Die Männchen der Chernetiden überfallen jeden Artgenossen und versuchen, ihm einen Paarungstanz aufzuzwingen. Mit anderen Männchen gibt es dann einen Commentkampf, mit Weibchen einen Paarungstanz. Das Männchen faßt seine Partnerin an einer (Chernes cimicoides zu Anfang) oder beiden (Lasiochernes pilosus, Chernes hanhi, Chernes cimicoides) Händen und geht mit ihr mehrfach vor und zurück. Dann setzt es eine Spermatophore ab und zicht das Weibchen darüber. Die Männchen der beidenChernes-Arten bewegen beim Paarungstanz auffällig ihre Vorderbeine und berühren damit die Weibchen. Das Männchen vonLasiochernes hat in der Behaarung seines Palpenfemurs ein zusätzliches Reizmittel. Beim Paarungstanz hält es sein Weibchen so, daß dessen Palpenfinger diese Haare berühren.Die höchstentwickelten Verhältnisse zeigen die Cheliferiden. Ihre Männchen balzen die Weibchen an, wobei sie mit vorgestreckten zylindrischen Organen vibrierende Bewegungen des Körpers ausführen. Das Männchen vonChelifer besetzt vorher ein Revier, das es wahrscheinlich mit Duftmarken kennzeichnet. Hierfür dienen möglicherweise die Coxalsäcke. BeiDactylochelifer tanzen beide Partner miteinander vor und zurück, beiChelifer bewegt sich nur das Männchen. Zu einem engen Kontakt zwischen beiden Partnern kommt es bei den Cheliferiden erst nach der Bildung der Spermatophore. Das Männchen ergreift dann die Palpenfemora des Weibchens und hilft unter kräftigen Schubbewegungen mit seinen Vorderbeinen dem Weibchen bei der Aufnahme des Spermas.Die Spermatophoren sind langgestielt. Bei den Chthoniiden stehen sie senkrecht. An der Spitze tragen she einen nicht umhüllten Samentropfen, der durch einen Kragen vor Berührungen geschützt ist.Auch die Spermatophoren der Neobisiiden und Cheridiiden stehen senkrecht. Sie tragen an der Spitze eine in ein kugelförmiges Samenpaket eingeschlossene Samenmasse. Durch einen Quellungsvorgang, den das Weibchen mit Hilfe eines aus seiner Geschlechtsöffnung austretenden Tropfens auslöst, werden die Spermien aus dem Samenpaket in das weibliche Genitalatrium übertragen. Die Spermatophoren vonApocheiridium sind sekundär vereinfacht; she tragen einen nicht umhüllten, winzigen Samentropfen.Die Spermatophoren der Chernetiden und Cheliferiden stehen schräg. Sie tragen an der Spitze ein Samenpaket und darunter einen Tropfen Flüssigkeit, der bei der Samenübertragung die Quellung im Samenpaket auslöst. Bei den Chernetiden hat das Samenpaket die Gestalt zweier konvergierender Schläuche, die in einen gemeinsamen Ausführgang münden. Bei der Samenübertragung wird dieses Paket vom Weibchen abgenommen. Doch nur der Ausführgang wird in die weibliche Geschlechtsöffnung eingeführt. Gleichzeitig wird der unter dem Samenpaket hängende Tropfen abgestreift und gelangt zwischen die Schläuche des Samenpaketes, wo er durch die Wandung eindringt und den Quellungsvorgang auslöst, der die Samen wahrscheinlich direkt ins Receptaculum seminis entleert.Die kompliziertesten Spermatophoren haben die Cheliferiden. Ihr Samenpaket trägt fülgelförmige Anhänge, die wahrscheinlich bei der Samenübertragung die gequollene Samenmasse aus dem Samenpaket herauspressen und ins weibliche Genitalatrium entleeren.Die Verhaltensweisen bei Begegnungen mit Artgenossen sind verschieden. Die Chthoniiden stoßen gegeneinander vor, ohne einander zu berühren. Ähnlich verhalten sich zuweilen dieChernes-Arten. Apocheiridium undLasiochernes zucken auffällig mit den Palpen, wenn sie von Artgenossen bedrängt werden. Diese Verhaltensweise wird von anderen Artgenossen mit dem gleichen Palpenzucken beantwortet und pflanzt sich so oft über alle Tiere einer Gesellschaft fort.Bei den Chernetiden und Cheliferiden gibt es Commentkämpfe zwischen den Männchen.

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Summary The behavior, the methods of sperm transfer, and the structure and function of spermatophores of the Pseudoscorpions have been studied and described.The males of the Pseudoscorpions deposit spermatophores from which the females take up the sperm. The method of sperm transfer is different among the different species; there is an evolution from simple to complicated procedures.The sperm transfer inChthonius tetrachelatus, Chthonius ischnocheles andNeobisium muscorum is primitive. The males deposit spermatophores even when females are not present. The male ofChthonius destroys old spermatophores and replaces them. The females are attracted chemotactically and examine the spermatophores. Then, they step over them on extended legs and release a drop of fluid which triggers a swelling mechanism that forces the spermatozoa out of the spermatophores and into the female genital opening.The males of the Cheiridiids (Cheiridium muscorum andApocheiridium ferum) presumably deposit spermatophores only when females are present. The male of Cheiridium often shows a vibrating movement of one pedipalpal hand when it encounters a female. Males and females destroy old spermatophores and the male replaces them with new ones. The female traces the spermatophores chemotactically.In the Chernetids and Cheliferids there is pairing. The male of the Chernetids attacks all members of its own species and tries to force a courtship dance upon them. With another male, a struggle follows the initial dance while with a female the courtship dance continues. The male grasps one (Chernes cimicoides at the beginning) or both (Lasiochernes pilosus, Chernes hahni, Chernes cimicoides) hands of the female and walks forward and backward several times. Then, it deposits a spermatophore and pulls the female over it. During the mating dance; the male of the two species ofChernes moves its first pair of legs, touching the female with it in a characteristic manner. The male ofLasiochernes has an accessory stimulant, the hair on its pedipalpal femora. During the mating dance, the fingers of the female pedipals touch this hair.The Cheliferids show the most advanced features. Their males court the females, showing extended ram's horn organs and vibrating movements of the body. The male ofChelifer occupies a territory before courting. It presumably marks this territory with an odorous secretion, possibly from the coxal sacs. InDactylochelifer the mates dance forward and backward together. InChelifer only the male moves. In Cheliferids, close contact between mates does not take place before the spermatophore has been deposited. Then, the male grasps the pedipalpal femora of the female. With his forelegs it assists the female in taking up the sperm and shows strong pushing movements.The spermatophores are long-stalked. In the Chthoniids, they stand straight up and have an uncovered sperm drop at the top which is protected against touching by a collar.The spermatophores of Neobisiids and Cheiridiids also stand straight up. At the top they bear a sperm mass enclosed in a globular sperm package. By a swelling mechanism, the spermatozoa are transferred from the sperm package into the female genital opening. The swelling mechanism is released by a drop of fluid, coming out of the female genital opening. InApocheiridium, the spermatophores are simplified, but not primitive. They have a small uncovered sperm drop.In the Chernetids and Cheliferids the stalk of the spermatophore is inclined. It bears a sperm package at the top and under this package a drop of fluid which releases the swelling mechanism in the sperm package during sperm transfer. In Chernetids, the sperm package has the form of two curved and converging tubes which open to a common duct. During sperm transfer, this package is taken by the female, but only the duct enters the female genital opening. At the same time the drop of fluid which was attached to the spermatophore under the sperm package, is pushed between the tubes of the sperm package. There, it enters the sperm mass through the wall of the sperm package and releases the swelling mechanism which presumably forces the sperm directly into the receptaculum seminis of the female.The Cheliferids have the most complicated spermatophores. Their sperm package has wing-like appendages, which presumably press the swelled sperm mass out of the sperm package and into the female genital opening during sperm transfer.The Pseudoscorpions act in different manners when meeting a member of their own species. The Chthoniids show quick movements towards each other without touching. The species ofChernes sometimes act in a similar manner. Apocheiridium andLasiochernes show characteristic short and quick movements of the pedipalps when they are attacked by members of their own species. Members of the same species react with the same movements of the pedipalps. This behavior often spreads to members of the crowd.In Chernetids and Cheliferids, the males sometimes fight against each other.