Sperm dumping in a haplogyne spider

The present study shows that females of Silhouettella loricatula (Arachnida: Araneae: Oonopidae) manage to process sperm in an unusual and previously unknown way. The male ejaculate consisting of spermatozoa and globular secretion is enclosed in a secretory sac. This may avoid the mixing of sperm from different males and at least severely limit sperm competition. The process of sperm enclosure occurs within the female's sperm storage site (receptaculum) as the ejaculate is not surrounded by a sac inside the male's sperm-transferring organs (palpal bulbs). The secretion forming the sac is produced by glands adjoining the receptaculum. The possibility that globular secretions in the male palpal bulbs partly contribute to the sac cannot be ruled out completely. It is suggested that in S. loricatula , the main function of sperm enclosure in a sac is enabling females to dump the ejaculate of a male. The present study represents the first report on sperm dumping in the family Oonopidae. During five first and three second copulations in the laboratory, the dumping of a sac was observed. One dumped sac was sectioned and contained spermatozoa. Two couples were flash-fixed with liquid nitrogen early during copulation, which revealed the mechanism of the sac dumping. By muscle contractions, the receptaculum is bent backwards and the sac moved into the genital opening. The actual sac dumping occurs most probably in cooperation with the male, which moves his pedipalps rhythmically during the entire copulation. Extensions and furrows on the emboli suggest that they may additionally be used as copulatory courtship devices. The enclosure of sperm from the current male in secretion takes place during or immediately following copulation as all mated females sacrificed after copulation had a new sac containing spermatozoa in the receptaculum. Dumping sperm of a previous male during the next copulation may allow females to bias sperm precedence.     

Functional morphology of female goblin spider genitalia (Arachnida: Araneae: Oonopidae) with notes on fertilization in spiders

The genital structures of most spiders are poorly investigated in respect of their functional morphology because the traditional taxonomic practice is to inspect slide-mounted genitalia only. The present study describes the female genitalia of three members belonging to the megadiverse haplogyne spider family Oonopidae by means of histological serial sections, scanning electron microscopy, and X-ray ultramicroscopy. The female genitalia of Neoxyphinus ogloblini, Dysderina sp., and Heteroonops spinimanus are complex and might have evolved under sexual selection by cryptic female choice. However, there is no direct evidence for cryptic female choice in these species based on the results of the present study. In N. ogloblini and Dysderina sp., spermatozoa and secretion are stored in a large receptaculum. Highly elongated gland cells filled with secretory vesicles extend over the receptaculum of N. ogloblini. In addition, sperm are present in the uterus internus of female N. ogloblini and Dysderina sp. The location of fertilization is still unknown for most spiders. One female of Dysderina sp. had sperm in the uterus and ovary strongly suggesting that fertilization in this species takes place in the ovary. An anterior sclerite with attached muscles should serve females to lock the uterus externus during copulation as suggested for other oonopids. The male palp of N. ogloblini shows a simple embolus whereas the embolus of Dysderina sp. is more complicated and accompanied by a cork-screw-shaped conductor. Females of H. spinimanus have an anterior sclerite in which thread-like gland ducts lead. The chitinized posterior diverticulum shows peculiar papillae in its anterior wall. The exact location of sperm storage in H. spinimanus remains unknown since spermatozoa were not present in the anterior sclerite and the posterior diverticulum. The anterior sclerite might be used to lock the uterus externus similar to N. ogloblini and Dysderina sp. H. spinimanus was previously suggested to be parthenogenetic and a male has only been recently associated with this species. The male was not investigated for this study.     

Complex genital system of a haplogyne spider (Arachnida, Araneae, Tetrablemmidae) indicates internal fertilization and full female control over transferred sperm

The female genital organs of the tetrablemmid Indicoblemma lannaianum are astonishingly complex. The copulatory orifice lies anterior to the opening of the uterus externus and leads into a narrow insertion duct that ends in a genital cavity. The genital cavity continues laterally in paired tube-like copulatory ducts, which lead into paired, large, sac-like receptacula. Each receptaculum has a sclerotized pore plate with associated gland cells. Paired small fertilization ducts originate in the receptacula and take their curved course inside the copulatory ducts. The fertilization ducts end in slit-like openings in the sclerotized posterior walls of the copulatory ducts. Huge masses of secretions forming large balls are detectable in the female receptacula. An important function of these secretory balls seems to be the encapsulation of spermatozoa in discrete packages in order to avoid the mixing of sperm from different males. In this way, sperm competition may be completely prevented or at least severely limited. Females seem to have full control over transferred sperm and be able to express preference for spermatozoa of certain males. The lumen of the sperm containing secretory balls is connected with the fertilization duct. Activated spermatozoa are only found in the uterus internus of females, which is an indication of internal fertilization. The sperm cells in the uterus internus are characterized by an extensive cytoplasm and an elongated, cone-shaped nucleus. The male genital system of I. lannaianum consists of thick testes and thin convoluted vasa deferentia that open into the wide ductus ejaculatorius. The voluminous globular palpal bulb is filled with seminal fluid consisting of a globular secretion in which only a few spermatozoa are embedded. The spermatozoa are encapsulated by a sheath produced in the genital system. The secretions in females may at least partly consist of male secretions that could be involved in the building of the secretory balls or play a role in sperm activation. The male secretions could also afford nutriments to the spermatozoa.     

Genital morphology of the haplogyne spider <Emphasis Type="Italic">Harpactea lepida</Emphasis> (Arachnida,Araneae, Dysderidae)

Female Harpactea lepida possess a single genital opening leading into a diverticulum. This diverticulum shows no secretory layer. It continues posteriorly into a receptaculum which is associated with gland cells. In the two already described dysderids, Dysdera crocata and D. erythrina, the bilobed spermatheca lies anteriorly to the diverticulum. Gland cells are associated with the spermatheca and the diverticulum. In H. lepida, the sclerotized genital structures lie dorsally to the diverticulum and consist of a posterior and an anterior part. The posterior part shows a lamella extending laterally to sclerites functioning as muscle attachments. The anterior part has two roundish structures. A hollow stalk-like sclerite functioning as muscle attachment extends towards anterior. The posterior and the anterior part of the sclerotized genital structures fit together. A narrow uterine valve connecting the uterus externus with the diverticulum forms between them. It may be opened by muscles as also suggested for D. erythrina. In H. lepida, spermatozoa embedded in secretion are found in the diverticulum and the receptaculum. There is no evidence that they are stored under different conditions like in D. erythrina. Additional spermatozoa are found in the uterus externus of H. lepida which could be an indication for internal fertilization. Spermatogenesis occurs in cysts in the testes of male H. lepida. In the vasa deferentia, the ductus ejaculatorius and the palpal bulb, the spermatozoa are embedded in homogenous secretion. The palpal bulb has a distal extension bearing a crown-like structure. The embolus is situated at the base of the extension. In memoriam of Konrad Thaler.     

Female genital morphology and mating behavior of Orchestina (Arachnida: Araneae: Oonopidae)

The unusual reproductive biology of many spider species makes them compelling targets for evolutionary investigations. Mating behavior studies combined with genital morphological investigations help to understand complex spider reproductive systems and explain their function in the context of sexual selection. Oonopidae are a diverse spider family comprising a variety of species with complex internal female genitalia. Data on oonopid phylogeny are preliminary and especially studies on their mating behavior are very rare. The present investigation reports on the copulatory behavior of an Orchestina species for the first time. The female genitalia are described by means of serial semi-thin sections and scanning electron microscopy. Females of Orchestina sp. mate with multiple males. On average, copulations last between 15.4 and 23.54 min. During copulation, the spiders are in a position taken by most theraphosids and certain members of the subfamily Oonopinae: the male pushes the female back and is situated under her facing the female's sternum. Males of Orchestina sp. possibly display post-copulatory mate-guarding behavior. The female genitalia are complex. The genital opening leads into the uterus externus from which a single receptaculum emerges. The dorsal wall of the receptaculum forms a sclerite serving as muscle attachment. A sclerotized plate with attached muscles lies in the posterior wall of the uterus externus. The plate might be used to lock the uterus during copulation. The present study gives no direct evidence for cryptic female choice in Orchestina sp. but suggests that sexual selection occurs in the form of sperm competition through sperm mixing.     

Female genitalia of goblin spiders (Arachnida: Araneae: Oonopidae): a morphological study with functional implications

Abstract. Fine morphological details of the genitalia have large potential consequences for the understanding of the reproductive biology of a particular species, especially when mating behavioral studies are difficult to conduct. Oonopidae are a highly diverse spider family comprising a variety of species with complex female reproductive systems, which may have evolved under sexual selection by cryptic female choice. The present study describes the female genitalia of five oonopid species belonging to both conventionally recognized subfamilies by means of semi‐thin sections and scanning electron microscopy. In addition, the male palps are briefly described. The organization of the female genitalia in Scaphiella hespera and Scaphiella sp. resembles the entelegyne type. A chitinized canal connects the receptaculum, where sperm are stored, with the uterus. Sperm are also present in the uterus and the canal is suggested to function as fertilization duct. The genitalia of the parthenogenetic species Triaeris stenaspis are surprisingly complex. A large sac with glands is proposed to represent the equivalent of a receptaculum in sexually reproducing females. In females of Opopaea recondita, sperm are stored in a bulge derivating from the uterus. Contractions of muscles attached to the bulge may lead to sperm dumping. The uterus can be closed by a sclerite in its anterior wall. The receptacula of females of Stenoonops reductus are joined together and contain masses of spermatozoa. Additional sperm were found in the receptacula connection suggesting that fertilization takes place there. The male palps of all the investigated species, except for S. hespera, seem to lack a distincly sclerotized sperm duct. Spermatozoa and secretions are stored in a large reservoir inside the genital bulb surrounded by glandular epithelium.     

Complex genital structures indicate cryptic female choice in a haplogyne spider (Arachnida,Araneae, Oonopidae,Gamasomorphinae)

Female genital structures with their allied muscles of the haplogyne spider Opopaea fosuma are described. A functional explanation of this system is given, which indicates that cryptic female choice may occur in these spiders: the anterior wall of their spermatheca is strongly sclerotized and possesses a cone-shaped hole in its upper part. A transverse sclerite that serves as muscle attachment bears a nail-like structure and lies in a chitinized area of the anterior wall of the uterus externus. Muscle contraction presses this nail into the hole of the spermatheca. In this way, the uterus externus gets both locked and fixed. Furthermore, as this occurs the copulatory orifice is enlarged and the resulting suction probably leads to previously deposited sperm being drawn from the spermatheca and dumped. This is a common mechanism used by females to influence a male's chances of fathering their offspring in a process known as cryptic female choice.     

Ultrastructure of the Accessory Glands in Female Genitalia of Pholcus phalangioides(Fuesslin, 1775) (Pholcidae; Araneae)

Pholcus phalangioidesdoes not possess receptacular seminis. The uterus externus (genital cavity) itself functions as a sperm storage structure. Two accessory glands are situated in the dorsal part of the uterus externus; they discharge their secretory product into the genital cavity. The secretion is considered to serve primarily as a matrix for sperm storage, i.e. to keep the spermatozoa in a fixed position. The accessory glands consist of numerous glandular units, each being composed of four cells: two secretory cells are always joined and surrounded twice by an inner and an outer envelope cell. Both envelope cells take part in forming a cuticular ductule that leads from the secretory cells to the pore plates of the uterus externus. The inner envelope cell produces the proximal part of the canal close to the microvilli of the secretory cells, whereas the outer envelope cell produces the distal part of the canal leading to the pore plate. Close to the pore the latter exhibits prominent microvilli that might indicate additional secretory activity.     

Genital morphology of female goblin spiders (Arachnida: Araneae: Oonopidae) with functional implications

Spider genital morphology usually provides the best characters for taxonomy. Furthermore, functional genital morphology helps to understand the evolution of complex genitalia and their role in the context of sexual selection. The genital systems of most haplogyne spider families are poorly investigated with respect to their morphology. The present study investigates the female genitalia of the oonopids Oonops pulcher, Oonopinus kilikus, and Pseudotriaeris sp. by means of light microscopy and SEM. The male palps are briefly described. Females of O. pulcher store spermatozoa in an anterior and a posterior receptaculum (PRe). The genitalia resemble the primitive dysderoid genitalia supporting the hypothesis that the subfamily Oonopinae contains more basal oonopids. In O. kilikus, the anterior receptaculum is reduced to a sclerite. Spermatozoa are stored in a PRe. The receptacula of Pseudotriaeris sp. are reduced to sclerites. Spermatozoa in the uterus internus indicate that fertilization happens there or in the ovary. The anterior sclerite might serve females to lock the uterus during copulation as suggested for other gamasomorphines. The male palp of O. kilikus is simple, whereas the palps of O. pulcher and Pseudotriaeris sp. appear more complex. Complicated structures on the palp of Pseudotriaeris sp. indicate that males exert copulatory courtship.     

Genital Morphology and Sperm Storage in Pholcus phalangioides(Fuesslin, 1775) (Pholcidae; Araneae)

The genital morphology of female Pholcus phalangioidesis examined to clarify the composition of the uterus externus and the place of sperm storage in this species. Two conspicuous pore plates serve as exits for glandular secretion that gets discharged into the uterus externus. The secretion accumulates close to the pore plates and to some extent in the region of the heavily sclerotized valve that separates the uterus externus from the uterus internus. During copulation, the male transfers spermatozoa and male secretions into the female genital tract where they are embedded and stored in the female secretion. As Ph. phalangioidesdoes not possess any separate sperm storage organs such as receptacula seminis, the glandular secretion serves to store and fix the sperm mass in a specific position within the uterus externus itself.     

Anatomy and ultrastructure of the reproductive systems ofAcarus siro (Acari: Acaridae)

Anatomy and ultrastructure of the female and male reproductive system inAcarus siro L. were investigated by light and electron microscopy. The female system consists of paired ovaries of nutrimentary type in which oogonia and oocytes are connected by bridges with a large central cell. The oviducts empty into the uterus, which passes into preoviporal duct lined bycuticle, and opening as a longitudinal slit (oviporus). An elongated accessory gland composed of one type of secretory cell is located along each oviduct. The copulatory opening occurs at the posterior margin of the body and leads, via the inseminatory canal, to the receptaculum seminis, consisting of the basal and saccular part. Both inseminatory canal and basal part of receptaculum seminis are lined by cuticle, whereas the wall of the sac is formed by cells covered only by long, numerous microvilli. The basal part of the receptaculum seminis joins the ovaries via two lumenless transitory cones.The male reproductive system contains paired testes, in which spermatogonia tightly surround the central cell. The proximal part of the paired vasa deferentia serves as a sperm reservoir, while the distal one has a glandular character. An unpaired, cuticle-lined ejaculatory duct opens into the apex of the aedeagus. The single accessory gland is located asymmetrically at the level of, or slightly posterior to, coxae IV.The structure of the genital papillae, which are topographically related to the genital opening in both sexes, is also briefly described.     

Functional genital morphology of armored spiders (Arachnida: Araneae: Tetrablemmidae)

This study describes the female genitalia of the tetrablemmid spiders Brignoliella acuminata, Monoblemma muchmorei, Caraimatta sbordonii, Tetrablemma magister, and Ablemma unicornis by means of serial semi‐thin sections and scanning electron microscopy and compares the results with previous findings on Indicoblemma lannaianum. Furthermore, the male palps and chelicerae are briefly described. The general vulval organization of females is complex and shows similarities in all of the investigated species. The copulatory orifice is situated near the posterior margin of the pulmonary plate. The opening of the uterus externus lies between the pulmonary and the postgenital plate. Paired copulatory ducts lead to sac‐like receptacula. Except for A. unicornis, the male emboli of all investigated species are elongated and thread‐like. However, they are too short to reach the receptacula. Hence, the spermatozoa have to be deposited inside the copulatory ducts. The same situation was also found in I. lannaianum. Females of this species store sperm encapsulated in secretory balls in their receptacula. The secretion is produced by glands adjoining the receptacula. The presence of paired fertilization ducts and spermatozoa in the uterus internus suggested that fertilization takes place internally in I. lannaianum. Secretory balls in the receptacula are found in all of the investigated species in this study, showing that sperm are stored in the same way. The place of fertilization may also be identical since dark particles, presumably spermatozoa, are located in the uterus internus of all investigated species except for T. magister. However, fertilization ducts are only found in B. acuminata and M. muchmorei. A sclerotized central process with attached muscles is present in A. unicornis, M. muchmorei, C. sbordonii and T. magister. Only in A. unicornis does the central process show an internal lumen and hold spermatozoa. In the other species, it could be used to lock the uterus during copulation in order to prevent sperm from getting into it as suggested for certain oonopid species. The uterus externus of all investigated species shows a sclerotized dorsal fold with attached muscles, previously described as “inner vulval plate.” Contractions of the muscles lead to a widening of the dorsal fold, thus creating enough space for the large oocytes to pass the narrow uterus externus. The males of all investigated species have apophyses on their chelicerae. At least in B. acuminata and A. unicornis, where females have paired grooves on the preanal plate, these apophyses allow males to grasp the female during copulation as described for I. lannaianum. © 2008 Wiley‐Liss, Inc.     

Mechanisms of sperm release from the receptaculum seminis of Schistocerca vaga Scudder (Orthoptera: Acrididae)

Release of spermatozoa from the receptaculum seminis of Schistocerca vaga was studied by means of electrical and mechanical stimulation. Electrical stimulation of the receptaculum nerve, or the ductus aperture nerve, leads to release of spermatozoa from the receptaculum seminis, provided the spermathecal innervation is intact. Mechanical stimulation of the ductus aperture in the genital chamber also leads to sperm release, provided the neural loop, ductus aperture/terminal abdominal ganglion/receptaculum seminis, has not been interrupted at any point. Ten somata in the terminal abdominal ganglion, including 6 dorsal unpaired medial (DUM) neurons, innervate the receptaculum seminis; some of these somata may be neurosecretory. Approximately 80 presumed sensory axons run from the ductus aperture to the same ganglion. On the basis of these neuroanatomical data and the results of electrical and mechanical stimulation, a schema of how the release mechanisms operate in S. vaga is proposed.     

Female genital system of the folding-trapdoor spider Antrodiaetus unicolor (Hentz, 1842) (Antrodiaetidae, Araneae): ultrastructural study of form and function with notes on reproductive biology of spiders

The genitalia of the female folding-trapdoor spider Antrodiaetus unicolor are characterized by two pairs of spermathecae that are arranged in a single row and connected to the roof of the bursa copulatrix. Each single spermatheca is divided into three main parts: stalk, bowl, and bulb, which are surrounded by the spermathecal gland. The epithelium of the spermathecal gland is underlain by a muscle meshwork and consists of different types of cells partly belonging to glandular cell units (Class 3 gland cells) that extend into pores in the cuticle of the stalk and bowl. Interestingly, the bulb lacks glandular pores and is characterized by a weakly sclerotized cuticle. This peculiarly structured bulb probably plays an important role in the discharge of the sperm mass. It is suggested that by contraction of the muscle layer the sperm mass may be squeezed out, when the bulb invaginates and expands into the spermathecal lumen, pushing the sperm to the uterus lumen. Each glandular unit consists of usually one or two central secretory cells that are for the most part surrounded by a connecting cell that again is surrounded by a canal cell. The canal cell, finally, is separated from the other epithelial cells (intercalary cells) located between the glandular units by several thin sheath cells that form the outer enveloping layer of the unit. The secretions are released through a cuticular duct that originates proximally between the apical part of the connecting cell and the apical microvilli of the secretory cells and runs into a pore of the spermathecal cuticle. The glandular products of the Class 3 gland cells likely contribute to the conditions allowing long-term storage of the spermatozoa in this species. Details regarding the ovary, the uterus internus, and the uterus externus are reported. Most of the secretion that composes the chorion of the egg is produced in the ovary. Glandular cell units observed in the uterus externus differ structurally from those in the spermathecae and likely play a different role. Finally, we briefly discuss our results on the female genitalia of A. unicolor in the light of knowledge about the reproductive biology of spiders.     

The neural control of spermathecal contractions in the locust,Locusta migratoria

The innervation of the spermatheca and demonstration of neural control of spermathecal contractions in Locusta migratoria was illustrated using anterograde and retrograde fills, combined with electrophysiological stimulation and recording. The anterior portion of the spermatheca receives innervation via the receptaculum seminis nerve (N2B2) from two large ventral neurons and one dorsal neuron. All were bilaterally paired and situated in the VIIIth abdominal ganglion. Three ventral bilaterally paired neurons situated in the VIIIth abdominal ganglion also provide innervation to the posterior portion of the spermatheca via the ductus seminalis aperture nerve (N2B3). Six DUM neurons, located in the VIIIth abdominal ganglion, in addition to two centroposteriorly situated DUM neurons in the VIIth abdominal ganglion, are also associated with these two nerves. N2B4 also provides innervation to the posterior portion of the spermatheca. N2B6b is associated with sensory cells identified in the anterior lateral regions of the genital chamber. The spermatheca contracts spontaneously, with peristaltic contractions beginning at the spermathecal sac and continuing along the length of the spermathecal duct. However electrical stimulation of the ventral ovipositor nerve (VON or N2B), receptaculum seminis nerve (N2B2) and the ductus seminalis aperture nerve (N2B3) indicates that contractions are also under neural control. In particular contractions of the spermathecal sac, coil duct and anterior straight duct are initiated via motor projections from the receptaculum seminis nerve (N2B2) and posterior straight duct contractions are controlled by motor input from the ductus seminalis aperture nerve (N2B3). The results suggest that spermathecal contractions of the anterior and posterior portions of the spermatheca are under separate neural control.     

Complex female genitalia indicate sperm dumping in armored goblin spiders (Arachnida,Araneae, Oonopidae)

In promiscuous females, sperm ejection from the sperm storage site can be a strong mechanism to influence sperm priority patterns. Sperm dumping is reported from different animals including birds, insects, and humans. In spiders, it has been documented for four species including the oonopid Silhouettella loricatula. Oonopidae are a diverse spider family comprising many species with peculiar female genitalia. Especially in species where studies of mating behavior are difficult, morphological investigations of the genitalia help to understand their function and evolution. In the present study, the genitalia of the oonopids Myrmopopaea sp., Grymeus sp., and Lionneta sp. are investigated by means of histological serial sections and scanning electron microscopy (SEM). The results are compared with previous findings on S. loricatula. In Myrmopopaea sp. and Grymeus sp., the same morphological components are present that are involved in sperm dumping in S. loricatula. Inside the receptaculum, sperm are enclosed in a secretory sac which can be moved to the genital opening and dumped during copulation by muscle contractions. The female genitalia of Lionneta sp. are asymmetric. They show the same characteristics as S. loricatula but all the investigated females were unmated. The results strongly suggest that sperm dumping occurs in Myrmopopaea sp., Grymeus sp., and Lionneta sp. and happens by the same mechanism as in S. loricatula. Sperm dumping might even be common within a clade of oonopids. As in S. loricatula, the sperm transfer forms in the investigated species consist of several spermatozoa. Papillae with unknown function occur on the receptacula of all females.     

Genital structures in the entelegyne widow spider Latrodectus revivensis (Arachnida; Araneae; Theridiidae) indicate a low ability for cryptic female choice by sperm manipulation

The female genital structures of the entelegyne spider Latrodectus revivensis are described using semithin sections and scanning electron microscopy. Apart from the tactile hairs overhanging the opening of the atrium, the contact zones of the female epigynum are devoid of any sensilla, indicating that the female does not discriminate in favor or against males due to their genital size or stimulation through copulatory courtship. The dumb-bell shape and the spatial separation of the entrance and the exit of the paired spermathecae suggest that they are functionally of the conduit type. Not described for other entelegyne spiders so far, the small fertilization ducts originating from the spermathecae of each side lead to a common fertilization duct that connects the spermathecae to the uterus externus. During oviposition, it is most likely that spermatozoa are indiscriminately sucked out of the spermathecal lumina by the low pressure produced by the contraction of the muscle extending from the epigynal plate to the common fertilization duct. As no greater amounts of secretion are produced by the female during oviposition, and no activated sperm are present within the female genital tract, the secretion produced by the spermathecal epithelium does not serve in displacement or (selective) activation of spermatozoa. These findings suggest that female L. revivensis are not able to exert cryptic female choice by selectively choosing spermatozoa of certain males.     

Histochemical studies on Raillietina (Raillietina) johri (Cestoda: Davaineidae). I. Nonspecific and specific phosphatases.

Certain phosphatases have been localized by histochemical techniques in various tissues of a pigeon cestode, Raillietina (Raillietina) johri. Acid phosphatase (AcPase), alkaline phosphatase (AlPase) and adenosine triphosphatase (ATPase) were present in almost all structures: tegument; subtegumental muscles; subtegumental cells; excretory canal; testes; sperm ductules; vas deferens; cirrus sac; cirrus; ovary; receptaculum seminis; vagina; vitelline gland cells; oocytes; uterus; embryonated eggs. AlPase was absent in parenchyma, spermatocytes, spermatids and spermatozoa. AlPase activity was more intense in the tegument of mature gravid proglottides. AcPase and ATPase were visualized in various stages of spermatogenesis of the parasite. ATPase activity was also observed in chromosomes. 5'-nucleotidase (AMPase) activity was restricted to embryonated eggs only. Functional significance of these phosphatases is discussed.