Histological structure of the male reproductive organs and spermatogenesis in a copulating sculpin, <Emphasis Type="Italic">Radulinopsis taranetzi</Emphasis> (Scorpaeniformes: Cottidae)

Characteristics of the structure and function of male reproductive organs in the copulating sculpin Radulinopsis taranetzi were investigated based on histological observations. The male reproductive organs comprised three parts: a pair of testes, a seminal vesicle, and a penis. Germinal cells matured in cysts located in the small seminal lobules. Asynchronous spermatogenesis advanced rapidly from the posterior to the anterior region of the testes. After sperm matured in the posterior part of the testes, the seminiferous epithelium of the seminal lobules synthesized and secreted eosinophilic fluid that showed a positive periodic acid–Schiff (PAS) reaction into the seminal lobules. Spermatozoa excreted from the posterior part of the testes were stored together with the secretion in the seminal vesicle and showed no activity in the seminal fluid. Histological observations throughout the year suggest that the fluid is secreted and spermatozoa are stored in the seminal vesicles during February to July, which is presumably when mating occurs. The importance of testicular maturation and the secretion of eosinophilic fluid during this long reproductive period is also discussed.     

Structural and ultrastructural studies of male reproductive tract and spermatozoa in Xylocopa frontalis (Hymenoptera,Apidae)

Fiorillo, B. S., Zama, U., Lino‐Neto, J. and Báo, S. N. 2010. Structural and ultrastructural studies of male reproductive tract and spermatozoa in Xylocopa frontalis (Hymenoptera, Apidae). —Acta Zoologica (Stockholm) 91 : 176–183. In Xylocopa frontalis the reproductive tract is composed of testes, deferent ducts, seminal vesicles, accessory glands and an ejaculatory duct. Each testis comprises four testicular tubules in which multiple cysts are present containing approximately 64 spermatozoa per cyst. The seminal vesicle consists of an epithelium, a thick basement lamina and a muscular external sheet. In the luminal region some vesicles can be observed; however, the epithelial cells of the seminal vesicle do not display morphological features associated with secretory functions. The spermatozoa, measuring approximately 260 µm long, are similar to the hymenopteran pattern. The head region consists of an acrosome with an inner perforatorium that penetrates an asymmetrical nuclear tip. The nucleus is linear, electron‐dense and its posterior tip projects into the beginning of the axoneme. The centriolar adjunct is asymmetric with many electron‐lucent lacunae interspersed throughout. The axoneme has the 9 + 9 + 2 pattern of microtubules and in the posterior region the central microtubules finish first, followed by the doublets and finally the accessory microtubules. The mitochondrial derivatives are asymmetric in both length and diameter with paracrystalline material present only in the larger one. These features may be useful characters for taxonomy and phylogenetic studies.     

First record of intersex in neotenic reproductives of the termite Cryptotermes brevis (Isoptera: Kalotermitidae)

Drywood termites of the family Kalotermitidae present a very flexible developmental pattern, in which pseudergates are totipotent and may become reproductives. In this study, three colonies of Cryptotermes brevis headed by neotenic reproductives were used: (i) colony A, with a primary king and a neotenic queen; (ii) colony B, with a primary queen and a neotenic king; and (iii) colony C, with neotenic king and queen. The primary king from colony A and the neotenic king from colony B presented well‐developed reproductive systems, with conspicuous testicular lobes and cysts containing spermatozoa also observed in the seminal vesicles. The neotenic queen of colony A and the primary queen of colony B had ovaries with several oocytes in early developmental stages with some of them already vitellogenic and terminal, which suggests egg‐laying activity. Both of these queens presented the spermathecae lumen filled with spermatozoa. The queen of colony C had vitellogenic oocytes; however, the oocytes were not terminal and the lumen of spermathecae was devoid of spermatozoa and secretions. The seminal vesicles of colony C neotenic king have no spermatozoa. This king displayed a previtellogenic oocyte among its testicular lobes, which suggested that this individual was an intersex.     

Comparative Analysis of the Male Reproductive System in Bothriuridae Scorpions: Structures Associated with the Paraxial Organs and the Presence of Sperm Packages (Chelicerata, Scorpiones)

The male reproductive system of seven species of the family Bothriuridae are compared. These scorpions are Bothriurus flavidus Kraepelin, B. cordubensis Acosta, B. bonariensis (C. L. Koch), B. chacoensis Maury & Acosta, Brachistosternus ferrugineus (Thorell), Timogenes dorbignyi (Guérin-Méneville), T. elegans (Mello-Leitão) and Urophonius brachycentrus Pocock (Bothriuridae). Additional comparisons are made with the buthid Zabius fuscus (Thorell). Observations on the structures associated with the paraxial organs (testis, seminal vesicle and accessory glands) are given. Sperm obtained from the male reproductive tract and fresh spermatophores as well as from the female's genital atrium and seminal receptacles are examined. Accessory glands occur in six out of eight studied bothriurids and in the buthid Z. fuscus. In most species the distal portion of vas deferens has a developed ampulla. All structures vary in size and shape depending on species. Sperm packages were observed in all bothriurids. In contrast, there is no packaged spermatozoa in Z. fuscus. Each sperm package consists of many spermatozoa surrounded by a common membrane that breaks after the spermatophore capsule is everted into the female genital atrium, releasing the spermatozoa. One hour after insemination, the spermatozoa are found in the atrium and in the seminal receptacles of B. flavidus females, but after 24h spermatozoa are found only in the seminal receptacles. The functional significance of the accessory glands and the presence-absence of sperm packages are discussed.     

Two new species of Anchylodiscus Johnston & Tiegs, 1922 (Monogenea) from Plotosus canius (Plotosidae)

Two new species of Anchylodiscus Johnston & Tiegs, 1922, A. malayensis n. sp. and A. liewi n. sp., were obtained from the gills and the dendritic (or arborescent) organ of Plotosus canius, respectively. The two new species have two seminal vesicles; the seminal vesicle nearer the testis is a distension of the vas deferens, while the distal one is similar to the blind seminal vesicle of the majority of freshwater ancylodiscoidines. The blind seminal vesicle suggests that Anchylodiscus should be placed in the subfamily Ancylodiscoidinae.     

The spermiogenesis and the early spermatozoa of <Emphasis Type="Italic">Armorloricus elegans</Emphasis> (Loricifera,Nanaloricidae)

The spermiogenesis consisting of five spermatid stages and the early spermatozoon has been investigated in Armorloricus elegans (Loricifera) with the use of transmission electron microscopy. The male reproductive system consists of three parts; testes, vasa deferentia and seminal vesicles. Caudally, the two seminal vesicles merge together in a ciliated duct and the excretory/gonadal—and digestive systems continue through the recto-urogenital canal, which opens via the lateral gonopores and the temporarily closed anal system. Spermiogenesis mainly occurs in the testes, whereas further maturation of the late spermatids and early spermatozoa occurs in the vasa deferentia and seminal vesicles. A maturation gradient (from spermatocytes to spermatozoa) is found from the posterior peripheral part of the testes to the anterior periphery and then centrally. During spermiogenesis the round nucleus becomes more osmiophilic and condensation of chromatin occurs. Later the nucleus elongates until it becomes rod-shaped in the early spermatozoa. In the second spermatid stage, a large vesicle is formed by saccules developed from the Golgi complex. This vesicle develops further and consists of three different osmiophilic parts with some crystal-like structures inside and is on the outside almost entirely surrounded by thick striated filaments. In the mid-piece the flagellum has a typical 9 × 2 + 2 axoneme and the two mitochondria are fused into a single sheet surrounding the flagellum. In the early spermatozoon stage an acrosomal-like cap structure with an acrosome filament appears proximal to the protruded rod-shaped nucleus. This cap is not formed by the Golgi complex and therefore might not be a true acrosome. Comparing the early spermatozoa of A. elegans with other cycloneuralians has shown some similarities with especially Kinorhyncha and Priapulida. These similarities are thought to be plesiomorphic.     

Male internal reproductive structures of european pea crabs (Crustacea,Decapoda, Brachyura,Pinnotheridae): Vas deferens morphology and spermatozoal ultrastructure

Pea crabs of the subfamily Pinnotherinae (Pinnotheridae) have a high investment in reproduction and an outstanding reproductive output, probably as an adaptation to the required increase in reproductive rate due to the pinnotherids small size and their parasitic, host‐dependant way of life. In the present study, we investigate the male internal reproductive structures and the ultrastructure of spermatozoa of Pinnotheres pisum and Nepinnotheres pinnotheres by histological methods and both scanning‐ and transmission electron microscopy. In the Brachyura, the male internal reproductive systems generally consist of paired testes and corresponding vasa deferentia where spermatozoa develop and mature. Spermatozoal ultrastructure of the investigated pinnotherids conforms to the thoracotreme type, however, N. pinnotheres has an accessory opercular ring and a periopercular rim, neither of which are present in spermatozoa of P. pisum. Spermatozoa are enclosed within spermatophores in the secretory proximal vas deferens. Two types of secretions were observed in P. pisum and N. pinnotheres: an electron dense substance secreted in the proximal vas deferens involved in spermatophore formation, and large electron‐luscent vesicles constituting the seminal plasma in the medial and distal vas deferens. The medial vas deferens is strongly widened compared to other brachyurans to purpose storing spermatophores embedded in seminal plasma. Tubular appendices, which produce and store large amounts of seminal plasma, arise from the distal region of the vas deferens. The appendices extend into the ventral cephalothorax and also in the first pleomere. The latter being an exceptional location for reproductive structures among male brachyurans. J. Morphol. 274:1312–1322, 2013. © 2013 Wiley Periodicals, Inc.     

Effect of Nandrolone decanoate induced-oxidative stress on rat testes,prostate, and seminal vesicle: Biochemical,morphometric and histopathological studies

Nandrolone decanoate (Nd) is a highly abused androgenic-anabolic steroid among body builders. Even though it has weak androgenic effects, its prolonged use may have harmful impact on male reproductive system which needs to be evaluated. This study aimed to reinvestigate its possible oxidative stress induced alteration on male rat reproductive system. Twenty-eight male rats were divided into two groups. Nd treated group (n = 18) injected intramuscular with 10 mg/kg body weight once a week for four weeks. While, the control group (n = 10) was injected with physiologic saline by the same route for four weeks. Body weight was recorded for all rats and after animal dissection weight of testes, prostate and seminal vesicles were also recorded. The results showed that the average testicular weight was decreased in treated group compared to the control. The average weights of the prostate and seminal vesicles were increased compared to the control. Morphometric study revealed that in Nd treated group, there was a decrease in the width of seminiferous tubules and the height of spermatogenic cell layer compared to the control. Testicular degeneration was expressed by presence of spermatid giant cells, vacuolation, and degenerated spermatozoa. Tunnel technique showed scattered positive reaction among the spermatogenic cell layers and interstitial cells. Severe alterations of the prostate were expressed by benign prostate hyperplasia and retained secretions. Lipid peroxidation products (malonaldehyde concentration as ng/g of testicular tissue) were increased in treated group compared to the control and suggested the occurrence of oxidative damage. Nd induced severe alterations in the male genital organs were resulted from oxidative stress. It is concluded that the male genital organs are highly sensitive to the anabolic steroids and there is a high extent of reproductive risk associated with the use of AASs.     

Ultrastructure of the Genital Organs in the Interstitial Syllid Petitia amphophthalma (Annelida,Polychaeta)

Abstract The gonochoristic syllid Petitia amphophthalma is one of the truly interstitial polychaetes. P. amphophthalma does not show any epitokous modifications at maturity such as those that usually occur in syllids. The reproductive structures are unique: the male genital organs consist of a seminal vesicle in chaetigers 6–10, subdivided into a dorsal part tightly filled with spermatozoa and a ventral part with contents in different stages of spermatogenesis, one pair of sperm ducts and conspicuous gland cells situated in chaetigers 10 and 11. Their glandular secretions are discharged into the sperm duct together with those of other types of gland cells that form the duct. The oocytes develop freely within the body cavity of the females. Each of the fertile segments possesses a paired oviduct ending in a large ciliated funnel. Sperm ducts and oviducts are probably modifications of excretory organs; nephridia are absent in segments where gonoducts occur. A direct sperm transfer by lytic opening of the integument of the female and internal fertilization are inferred. Copyright © 1996 Published by Elsevier Science Ltd on behalf of the Royal Swedish Academy of Sciences     

Morphology of the male system and spermatophores of the arrowworm Ferosagitta hispida (Chaetognatha)

Transmission electron microscopy reveals that the somatic testicular tissues and sperm ducts are elaborations of the epithelial lining of the tail coelom. The testes consist of closely packed spermatogonia embedded between specialized lateral field cells. These cells contain few organelles and appear to function mainly as a compartment boundary. Masses of spermatogenic cells are released into the tail coelom from the anterior end of the testes. The sperm ducts, lined by simple cuboidal ciliated epithelium, collect mature spermatozoa from the tail coelom and convey them to the blindly ending seminal vesicles. The sperm ducts also modify coelomic fluid entering them along with the spermatozoa. The seminal vesicles consist of a simple glandular lining epithelium embedded in the stratified epidermis. Secretions of the lining epithelium surround the enclosed sperm mass and correspond in position to a noncellular spermatophore coat visible by light microscopy around released sperm masses. Spermatophores leave the seminal vesicles through a temporary split that forms between microfilament-containing suture cells. Maturation of spermatozoa and filling of the seminal vesicles is cyclical, occurring late each day. © 1994 Wiley-Liss, Inc.     

Anatomic,Histologic and Certain Enzymatic Studies on the Male Genital Organs of Hemiechinus auritus collaris Gray,the Indian Long Eared Hedgehog

Anatomically the male reproductive organs of Hemiechinus auritus collaris are of considerable interest and present a unique pattern of arrangement of different glands. The testes are inguinal and a true scrotum is absent. A pair of accessory glands, the seminal vesicles, are situated dorsal to the bladder. A pair of obviously lobulated glands, ventral to the bladder, represent the internal prostate and a pair of compact glands situated outside the pelvis in para-anal position the external prostate. The Cowper's gland and the gland of ampulla are absent. The present studies also concern enzymes of the phosphatase group, including both specific and non-specific phosphatases, in the testes and the sex accessory glands during both active and inactive periods in this insectivore.     

Testes of fed and unfed Amblyomma cajennense ticks (Acari: Ixodidae). First morphological data

The tick species Amblyomma cajennense is of great medical importance, as it is the vector of the Rickettsia rickettsii, agent of Rocky Mountain spotted fever. The objective of this study was to perform a morphological and histological analysis of the male reproductive system of fed and unfed A. cajennense. The male reproductive system is formed by a pair of tubular testes dorsolaterally arranged in opisthosoma. They were divided into three regions: proximal region (next to vas deferens), median region and distal region (nearest to the blind ending of testis). Proximal regions are connected to the seminal vesicles by the deferent ducts and to accessory glands, similar to what was observed for other Ixodidae. Feeding plays a fundamental role in the development of the reproductive system, as in unfed individuals, the testes, the seminal vesicles and the accessory glands were smaller comparing with the fed individuals. In addition, the prospermia, precursors of the spermatozoa, were only observed in fed individuals. The germ cells were organized in spermatocysts, enveloped by a connective tissue. The cells in more advanced stages of spermatogenesis were localized in the distal region, in accord with studies in other ticks, but opposite to what was observed for other arthropods.     

Ontogenesis and ultrastructure of seminal vesicles of the catfish,Clarias gariepinus

The ontogenesis and structural characteristics of the seminal vesicles in Clarias gariepinus (sharptooth catfish) were studied by light and electron microscopy and are described in detail. The seminal vesicles, beginning as simple protrusions from the vas efferentia, becomes more complex with age. Their distal ends become fingerlike and the bases form palm-like extensions. Juvenile male organs do not reveal any signs of seminal vesicles although spermatogenic tissue is already well delineated. The developing gonads contain clusters of large cells, close to the sperm duct and cysts of the testis, from which seminal vesicles are formed. Secretory epithelium lines the tubules of the seminal vesicles and becomes columnar as the tissue matures. Electron micro-graphs of these epithelial cells reveal two types of cells: opaque cells and cells with very vacuolized cytoplasm. Dense pinocytotic vesicles are present between the membranes of neighbouring seminal tubules and apical cell membranes facing the lumen. Maturation and onset of secretion by the secretory cells is accompanied by morphological changes. Protruding cylindrical cells become shortened, modified to cuboidal, rounded cells that send tubular extensions into the lumen. In the final stage of differentiation, only connective tissue membranes supporting the tubule walls remain intact. At the points of contact between the testis, seminal vesicles, and sperm duct, the epithelia of these organs often become confluent. The distal parts of the seminal vesicles, rarely contain sperm; during spawning sperm accumulated in the proximal tubules of the vesicles. © 1994 Wiley-Liss, Inc.     

Reproduction of the male eastern pipistrelle, Pipistrellus subflavus, in the north-eastern United States

The major reproductive events in the male eastern pipistrelle, are similar to those of other hibernating vespertilionids. The eastern pipistrelle stores epididymal spermatozoa throughout hibernation, a time when the testes are involuted but accessory gland activity is maintained. However, this species differs from others in that epididymal and testicular spermatozoa persist longer and the weights of the accessory glands are not strongly differentiated between winter and spring/summer. It is suggested that the reproductive period is extended in this species as a function of a more prolonged period of hibernation, resulting in only a brief period of sexual quiescence in mid-summer. The eastern pipistrelle (Pipistrellus subflavus) resembles the canyon bat (P. hesperus) in that some testicular spermatozoa persist during winter. Many aspects of the reproductive anatomy and chronology of these two species are similar; however, eastern pipistrelles apparently lack a seminal vesicle and possess a distinctly different baculum.     

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.     

Influence of dietary selenium on metabolism of cadmium and mercury in reproductive tissues of rats

Dietary selenium supplementation for rats resulted in a greater deposition of ¹⁰⁹Cd in testis, but caused decreased deposition of the isotope in seminal vesicles, epididymis and prostate gland. In contrast, dietary selenium caused increased deposition of ²⁰³Hg in seminal vesicles and prostate gland but drastically reduced the levels of this radioisotope in testis and epididymis. Selenium diverted the binding of ¹⁰⁹Cd in cytosols in testis, seminal vesicles, epididymis and prostate gland, but had minimal effects on the binding of ²⁰³Hg in these reproductive organs. Selenium deficiency caused increased excretion of ¹⁰⁹Cd in feces and urine, and increased excretion of ²⁰³Hg in urine of rats. The biological half-lives of the two radioisotopes in the −Se and +Se rats were calculated to be, respectively, 202 and 219 days for ¹⁰⁹Cd, and 2 and 6 days for ²⁰³Hg.     

Functions of the testicular gland in two blenniid fishes, Salaria (=Blennius) pavo and Lipophrys (= Blennius) dalmatinus (Blenniidae, Teleostei) as revealed by electron microscopy and enzyme histochemistry

The functions of the testicular gland in two different blenniid fishes, Salaria pavo and Lipophrys dulmutinus , are described by fine structural and enzyme histochemical methods. In the testes of the two fishes no mature spermatozoa are found. Sperrniogenesis occurs only until the spermatidal stage. Spermatids are released into the testicular gland. During the spawning period the testicular gland functions in differentiation of spermatids, nutrition of spermatids, and secretion of sialomucins. After spawning, the testicular gland has phagocytotic functions in resorbtion of remaining spermatids, which are transformed into lipids in the gland cells. During the interspawning period the testicular gland is a storage reservoir for lipids and phospholipids which are re-transformed into testicular gland secretion in the next reproductive season. Testicular gland cells themselves do not have steroidogenetic functions, but steroids are synthesized by interstitial cells homologous to Leydig cells in other fish. Possible explanations for the reduction of the testis in L. dalmatinus and implications of the testicular gland in taking over testicular functions are discussed.     

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.