Genital system development of Williamia radiata (Gastropoda, Siphonariidae)

The adult anatomy and development of the genital system of the limpet Williamia radiata (Siphonariidae, Gastropoda) was investigated by means of 3D computer reconstruction and visualization of serial resin and paraplast light microscopical sections. As is characteristic for siphonariid species, the adult genital system consists of a single duct, the spermoviduct leading from the nidamental glandular system to the anteriorly located genital atrium with opening. The copulatory complex as well as the bursa copulatrix also open into the common genital atrium. The genital system develops from three separate anlagen. The posterior one appears first at a body length of 0.7 mm and gives rise to the ovotestis and part of the hermaphrodite duct. The nidamental glandular complex, the fertilization pouch-spermatheca complex, part of the hermaphrodite duct, the posterior part of the spermoviduct, and the bursa copulatrix develop later from the pallial anlage. Finally, the anterior anlage is formed on the right side of the head and gives rise to the genital atrium, the copulatory complex, and the anterior spermoviduct. This formation of the genital system from three, locally separated anlagen, differs strikingly from that of most other species of the Euthyneura. In both the Nudibranchia (Opisthobranchia) and the Stylommatophora (Pulmonata) development proceeds from a single site. We regarded this as a secondary condition as a result of derived features like heterochronies in development in these taxa. Comparison of development with that of other species of the Pulmonata allows conclusions on homology. The homology of the bursa copulatrix within the pulmonates is confirmed. The two separate chambers inside the spermoviduct of W. radiata correspond to oviduct and vas deferens of the freshwater Basommatophora.     

Anatomical and histological structure of the spermoviduct in the ovoviviparous snail Ruthenica filograna (Pulmonata,Clausiliidae)

The spermoviduct is a multifunctional part of the hermaphroditic reproductive system of stylommatophoran pulmonates. In this study, the anatomical and histological features of the spermoviduct in the ovoviviparous Ruthenica filograna are described for the first time. The spermoviduct is composed of three grooves that are not fully separated: the oviductal channel, autospermiduct, and allospermiduct. The wall of each groove is composed of specific subepithelial glandular cells and non-secretory epithelial cells. The prostatic gland is well developed in the proximal part of the spermoviduct and connected to the autospermiduct. In the distal part, the autospermiduct diverges, forming a free vas deferens, while the rest of the spermoviduct becomes a free oviduct. Initially, the free oviduct still contains the allospermiduct and the oviductal channel. Along the spermoviduct is a small diverticulum, that in the proximal section adheres to the allospermiduct, remaining an independent duct, opening into the bursa copulatrix stalk. The reproductive system of R. filograna is similar to those of semitriaulic Stylommatophora, but the allospermiduct, unlike in Helix species, continues in the distal part of the spermoviduct and in the proximal part of the free oviduct.     

Morphological and histological study of the genital ducts ofCryptazeca monodonta (Pulmonata,Orthurethra), with special emphasis on the auxiliary copulatory organ

Summary The genital system ofCryptazeca monodonta is very similar to those reported for semidiaulic stylommatophores, but with some specific features. The fertilization pouch is simple and surrounded by subepithelial goblet gland cells. The spermoviduct has two different grooves: the oviductal channel and the spermatic groove, which run together with a blind-ending allospermiduct that opens into the lumen of the free oviduct. The vagina has a thick muscular wall with numerous pigmentary cells embedded in it. The vas deferens diverges from the spermiduct and becomes mainly glandular just before it joins the penis. This genital system is equipped with an auxiliary copulatory structure that consists of two independent and complementary organs. One of them is located just before the fusion of the free oviduct and the spermatheca stalk lumina and consists mainly of a thick mass of connective tissue. The other is a muscular sarcobellum located inside the penis. Both these organs are covered by small papillae whose connective cells are stacked. Each papilla has a solid spine on its top, which seems to be of mesenchymatous origin. As in other stylommatophores, the auxiliary copulatory organ is equipped with an adjoining gland, which inCryptazeca is next to the sarcobellum.Abbreviations ACO auxiliary copulatory organ - ag albumen gland - al allospermiduct - c connective aggregate of ACO - cc connective cells of ACO papillae - cf connective fibres - ep epiphalus - fo free oviduct - fp fertilization pouch - gl.c gland cells of sarcobellum - hd hermaphroditic duct (distal portion) - m muscle fibres - ov oviduct - p penis - pc penial caecum - pp papillae of ACO - pr prostatic gland - prm penial retractor muscle - p.sh penial sheath - s spermatheca - sc sarcobellum - SEM scanning electron micrograph - sov spermoviduct - sp spine - spd spermiduct - ss spermatheca stalk - v vagina - vd vas deferens     

The anatomy of Addisonia (Mollusca,Gastropoda)

Summary The organization of Addisonia lateralis (Requien, 1848) and A. brophyi McLean, 1985 is described. Addisonia species have a thin, asymmetrical, cup-like shell and a very simple shell muscle. Eyes, oral lappets and epipodial tentacles are absent and the right cephalic tentacle is also used as a copulatory organ. Most characteristic is the enormously developed gill which is enlarged into the right subpallial cavity. It is composed of about 30 leaflets with skeletal rods and its epithelia are uniquely arranged. The heart is large and the single auricle is situated anteriorly left. There are two kidneys: the left is small, while the right forms large coelomic cavities and has no connection with the pericardium or the hermaphroditic genital system. Testis and ovary are separate: both have a simple duct proper (vas deferens, oviduct). They are connected to the copulatory organ by an open seminal groove; a small receptaculum is present. The mouth opening is typically triangular, with no jaws or subradular sense organs. Addisonia possesses tuft-like salivary glands, a radula diverticulum and distinct, tubular oesophageal glands. The oesophagus itself is simple. The radula and the posterior alimentary tract are unique; the stomach is completely reduced and the intestine forms a pseudostomach. The streptoneurous, hyoathroid nervous system has pedal cords with three commissures. The visceral loop is also cord-like. A single (left) osphradium is present and the small statocysts have several statocones.The peculiarities and unique combination of primitive and advanced characters in Addisonia reflect a highly enigmatic organization among the Archaeogastropoda. Possible relationships to other archaeogastropod groups are discussed.     

The Vas Deferens of the Spanish Lobster,Scyllarus chacei

Summary

The male reproductive tract of Scyllarus chacei consists of paired testes and vasa deferentia that conduct sperm containing spermatophores to the genital pores at the base of each fifth walking leg. The testis is joined to the vas deferens which can be divided into four regions: (1) the anterior vas deferens can be further divided into three regions. It is highly convoluted and is the region in which the sperm become encapsulated in ovoid spermatophores of approximately 100 sperm as well as produces seminal fluids. (2) The middle vas deferens is the primary site of sperm storage and adds to seminal fluids which formed in the anterior region. (3) The posterior region is highly muscularized and may serve for limited sperm storage. (4) The most distal portion is the ejaculatory duct which is highly muscularized for extruding the spermatophoric mass for transfer to the female. A final seminar product is added here.     

耳河螺生殖器官和精子的形态学研究

耳河螺「Ｒｉｖｕｌａｒｉａ ａｕｒｉｃｕｌａｔａ （Ｍａｒｔｅｎｓ）」为雌雄异体。雄性生殖器官由精巢,输精小管,贮精囊,输精管,前列腺和阴茎组成。精巢内有精子,精子有典型精子和非典型精子两种。扫描电镜下,典型精子头部呈螺旋状,尾端只有一根较粗壮;非典型精子头部和中部为棒状,尾部呈扫帚状,由８－１５根鞭毛组成。     

长足大竹象生殖系统的形态解剖研究

解剖研究了长足大竹象雌雄虫牛殖系统的构造.该虫的雌性生殖系统包括一对卵巢、一对侧输卵管、中输卵管、交配囊、受精囊、生殖腔、产卵器;雄性生殖系统由一对睾九、一对输精管、一对附腺、射精管和交配器组成.     

Difference of fertilizing capacity between testicular sperm and vas deferens sperm in Cynops pyrrhogaster

The fertilizing capacity was compared between testicular and vas deferens sperm in Cynops pyrrhogaster. The testicular sperm was not capable of fertilizing jelly eggs. In contrast, the vas deferens sperm was already capable of fertilizing the newt jelly eggs. There was no inhibitory factor for fertilizing jelly eggs in the testis. These results suggest that the testicular sperm is immature as to the fertilizing capacity. The testicular sperm gained the fertilizing capacity for the jelly eggs by treatment with Holtfreter's solution or 1/20 strength Holtfreter's solution. The treatment may promote the step of maturation to achieve the fertilizing capacity. The treated testicular sperm did not fertilize dejellied eggs, although vas deferens sperm fertilized dejellied eggs. Therefore, the maturation state of the treated testicular sperm is different from that of vas deferens sperm. Newt sperm may be matured within the vas deferens, as the newt does not have an organ like the mammalian epididymis.     

Structure of the male reproductive system of the blue swimmer crab Portunus pelagicus (Decapoda: Portunidae)

An attempt was made here to study the structure of the male reproductive system of Portunus pelagicus, which would improve the knowledge base on the reproductive biology of the species and also help in the maintenance of broodstock under controlled conditions. Male P. pelagicus of different sizes were collected from the Palk Bay off Mandapam (9°17′ N, 79°9′ E) and maintained under controlled conditions for the study. Tissues from testis, anterior vas deferens (AVD), median vas deferens (MVD), posterior vas deferens (PVD), ejaculatory duct and penis were fixed in Bouin's fluid and 2.5% buffered glutaraldehyde separately and processed for light and electron microscopic studies, respectively. The reproductive system consisted of testis, commissure, vas deferens, ejaculatory duct and penis. The vas deferens was divided based on the morphology and/or histology into AVD, MVD and PVD. The AVD was further divided based on histology into proximal and distal regions, and the MVD, based on diameter into major and minor coils. The testicular lobe had several lobules with a central seminiferous tubule, which continued till the penis. The seminiferous tubule was lined by a layer of cuboidal or columnar epithelium. The lining of the central tubule of the vas deferens formed several ‘folds’, which at times formed ‘pouches’. High incidence of cell organelles in the columnar epithelial cells, aggregations of vesicles and occurrence of blebs at the luminal periphery and the projection of numerous microvilli containing electron‐dense materials into the lumen from the cell lining denoted high secretory activity of the epithelial cells.     

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.     

Zinc and copper content in rat epididymis and vas deferens

The zinc and copper content in the different epididymal segments and vas deferens of castrated rats were investigated with the help of atomic absorption spectrophotometer. The vas deferens showed maximum zinc content as compared to that of different parts of epididymis in all groups whether castrated unilaterally, bilaterally or in the intact control. Zinc content was reduced in the epididymis and vas deferens ipsilateral to the castrated side as compared to that of contralateral control and intake animals. Lowest zinc content was observed in the epididymis and vas deferens of bilaterally castrated animals from that of other groups. Absence of sperms was observed in all segments of epididymis and vas in bilaterally castrated animals and from the unilaterally castrated side. Copper content was unaltered in all epididymal segments and vas deferens. There appears to be a correlation between the absence of sperms in the male genital tract and the decrease in zinc content.     

Neuronal input contributes to sequence of Aplysia egg laying behaviors

Egg laying in Aplysia is controlled by the bag cell neuroendocrine system, which releases multiple peptides during a long-lasting electrical discharge. Following the discharge, a fixed sequence of head and neck movements is performed in which two phases can be distinguished: an appetitive or preparatory phase, in which the substrate is prepared, and a consummatory phase, when the egg string is deposited. During egg laying, feeding responses are suppressed. In this study, Aplysia fasciata was used. When the movement of the egg string through the genital groove was prevented by ligation, lesions of the nerve innervating the genital pore completely abolished the consummatory egg-laying behaviors. This shows that a nervous connection between the genital pore area and the central nervous system is important for the consummatory egg-laying behaviors.We found that suppression of feeding responses to seaweed occurred only during the consummatory phase of egg laying in controls, but animals with ligated genital grooves continued to show normal responses to food. It is hypothesized that a neuronal feedback, possibly together with the bag cell peptides, is critical for the temporal organization of egg-laying behavior in Aplysia.Abbreviations CNS central nervous system - ELH egg laying hormone     

Morphology and development of the male reproductive tract in Callinectes danae (Crustacea: Brachyura)

The aim of this study was to characterize the morphology and function of each section of the reproductive system of male Callinectes danae, as well as the stages of reproductive development and their relation to secondary sexual characteristics. Development of their reproductive system begins after completion of the pubertal moult. The growth of the gonopodium showed negative allometry for both juveniles and adults. The reproductive system is divided into portions with different functions. There is a germinal zone in the testes containing spermatogonia, a zone of maturation containing spermatocytes, spermatids or spermatozoa, as well as a collecting duct, which carries spermatozoa to the vas deferens. There are two matrices in the anterior vas deferens that initiate the separation of spermatozoa groups, one composed of polysaccharide acids (matrix I) and another consisting of neutral polysaccharides (matrix II). In the median vas deferens, the matrix II forms an acellular capsule, which forms the spermatophores. In the posterior vas deferens, the matrices are accumulated, initially with a granular texture and are homogenous for the final portion. The ejaculatory duct and penis have muscle lining to expel the spermatophores at copulation. Even after copulation, males retain a stock of spermatophores, allowing copulation with other females.     

Gonad Development Characteristics and Sex Ratio in Triploid Chinese Shrimp (<Emphasis Type="Italic">Fenneropenaeus chinensis</Emphasis>)

This paper details for the first time the gonad development characteristics and sex ratio of triploid shrimp (Fenneropenaeus chinensis). In triploid shrimp the development of gonad is apparently impaired, especially in females. In the ovary of triploids, germ cells mainly remain at oogonia stage during September through December. From January to February of the next year, partial primary oocytes developed in the ovary lobes. Spermatocytes and spermatids could be observed in the testes of triploids, and a few sperm were observed in the vas deferens and spermatophores. The morphology of sperms in triploid shrimp was abnormal. Flow cytometry was used to detect the ploidy of sperm in the vas deferens. The data showed that triploidy could affect the sex ratio in Chinese shrimp. The female-to-male ratio in triploids of about 4:1 will favor triploid shrimp aquaculture.     

东方扁虾雄性生殖系统的解剖学和组织学研究

东方扁虾雄性生殖系统由精巢、输精管及雄性生殖孔三部分组成,输精管可分为前、中、后三段。精巢由卷绕的前、后收集管及持靠其上的许多生精腺囊所组成。同一腺囊内的精细胞发生基本同步,而不同腺囊内则可以不同步。收集管的主要功能是将精细胞团输送至输精管。精荚在输粗管内运行时一直进行着精子的形成过程,直至精子成熟。位于输精管末段不肌层外的索带状细胞团被认为是造雄腺。     

Die Struktur des samenableitenden Gangsystems bei Geophilus linearis Koch (Chilopoda)

Zusammenfassung Die männlichen Genitalwege von Geophilus linearis wurden licht- und elektronenmikroskopisch untersucht.Der schon makroskopisch sichtbaren Unterteilung des ableitenden Gangsystems in Vasa efferentia, dünnen und dicken Teil des Vas deferens entspricht die histologische Differenzierung ihres in allen drei Abschnitten einreihigen Epithels. Dem Epithel liegt außen eine auffallend dicke Basalmembran auf, die von einer meist einschichtigen Lage quergestreifter Muskulatur umgeben wird.Die Vasa efferentia sind durch hohe regelmäßige Einfaltungen der basalen Zellmembran, einen besonderen Mitochondrienreichtum und einen dichten Mikrovillibesatz charakterisiert. Der dünne Teil des Vas deferens fällt durch seine seitlichen Zellverzahnungen, die besondere apikale Zellbegrenzung in Form von Stereozilien und Zytoplasmaprotrusionen als Zeichen einer Sekretion auf. Der dicke Teil des Vas deferens zeichnet sich durch den Reichtum seiner Zellen an Organellen, vor allem Golgikomplexen und Ergastoplasma, aus. Die immer vorhandenen großen Mengen an Sekret im Lumen müssen damit in Zusammenhang stehen, obwohl deutliche Zeichen einer Sekretion in diesem Gangabschnitt nicht nachweisbar sind.

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The structure of the male genital ducts of Geophilus linearis Koch (Chilopoda)

Summary The male genital ducts of Geophilus linearis have been studied by means of light and electron microscopy.The subdivision of the ducts into vasa efferentia, a thin and a thick part of the vas deferens can be seen macroscopically and is confirmed by the microscopic results: a simple epithelium is surrounded by an extraordinary thick basement membrane and a very thin layer of striated muscles.The vasa efferentia are characterized by high regular folds of the basal cell membrane, richness of mitochondria, and a tight border of microvilli. The thin part of the vas deferens ist striking by the lateral interdigitations between the cells and their special apical limitation, stereocilia and cytoplasmic protrusions as symptoms of secretion. The thick part of the vas deferens is distinguished by a particular abundance of cell organelles, especially Golgi complexes and ergastoplasm. The great quantity of secretory products, always existing in the lumen, must be in correlation with these organelles although an evident secretory process cannot be demonstrated.