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.     

Internal anatomy and ultrastructure of the male reproductive system of the Norway lobster Nephrops norvegicus (Decapoda: Astacidea)

The Norway lobster (Nephrops norvegicus) is economically important in Europe. However, apart from the female reproductive system, very little is known about its internal anatomy. This article focuses on studying the internal anatomy and ultrastructure of the male reproductive system. This system follows the general pattern found among decapod crustaceans, with several peculiarities. Testes are composed of lobular sperm ducts in which the spermatozoa are fully constituted. The spermatozoa present three lateral arms and a long acrosome, which gives a false appearance of flagellated spermatozoa. The two testes form a double H under the heart, and the vas deferens (VD) arise from each side at the posterior edge of the double H. The main characteristic of the VD is the presence of a sphincter in the enlarged area of the distal end of the middle VD. The MVD here shows an increase in musculature of the wall as compared to the VD, which regulates the passage of the sperm cord to the distal VD (DVD) and thence to the thelycum of the female. The wall of the spermatophore is formed in the distal part of the proximal VD, which surrounds the unique sperm cord present in the VD. Isolated spermatophores are not observed in the VD. The sperm cord is pinched off during copulation by the musculature of the DVD. Then, a portion of the sperm cord is transferred from each VD to form the isolated spermatophores. The wall of the spematophores and the spermatozoa that are observed inside the thelycum have the same morphology as those observed in the VD. J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.     

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.     

Description of the male reproductive system of Paguristes eremita (Anomura, Diogenidae) and its placement in a phylogeny of diogenid species based on spermatozoal and spermatophore ultrastructure

The male gonopores, male reproductive apparatus, spermatophore and spermatozoa of the Mediterranean hermit crab Paguristes eremita are described, using interference phase microscopy, scanning electron microscopy and transmission electron microscopy. A correlation is made between the gonopore morphology and the different kinds of setae accompanying them, and the reproductive biology of these crabs. Each testes merges into a tubular duct made up of four zones: (1) the collecting tubule with free spermatozoa; (2) the proximal zone, where the ampulla of the spermatophores starts to be formed; (3) the medial zone, where the ampulla is completed, the stalk lengthens and the pedestal is formed; (4) the distal zone, where the mature spermatophores are stored. The sizes of the different parts of the spermatophore and of the sperm are given and their exterior morphology and ultrastructure described and compared to congeners. The morphology of the gonopore, male reproductive system, spermatophore and spermatozoa of P. eremita are species-specific, clearly distinguishing the species from the other members of the family. The available spermatozoal and spermatophore data is used to place P. eremita within a sperm phylogeny of the hermit crab family Diogenidae.     

Sperm storage by spermatodoses in the spermatheca of Trioza alacris (Flor, 1861) hemiptera,psylloidea, triozidae: A structural and ultrastructural study

Female insects generally store sperm received during mating in specific organs of their reproductive tract, i.e., the spermathecae, which keep the sperm alive for a long time until fertilization occurs. We investigated spermatheca morphology and ultrastructure in the psylloidean insect Trioza alacris (Flor, 1861 ) in which spheroidal sperm packets that we refer to as ‘spermatodoses’ are found after mating. The ectoderm‐derived epithelium of the sac‐shaped spermatheca that has a proximal neck, consists of large secretory and flat cuticle‐forming cells. Secretory cells are characterized by a wide extracellular cavity, bordered by microvilli, in which electron‐dense secretion accumulates before discharge into the spermathecal lumen. The cuticle‐forming cells produce the cuticular intima of the organ and a peculiar specialized apical structure, through which secretion flows into the lumen. At mating, the male transfers bundles of sperm cells embedded in seminal fluid into the spermathecal neck. Sperm cells proceed towards the spermathecal sac lumen, where they are progressively compacted and surrounded with an envelope that also encloses secretions of both male and female origin. We describe the formation of these sperm containing structures and document the contribution of the female secretion to spermatodose or female‐determined spermatophore construction. We also discuss the choice of the term ‘spermatodose’ for T. alacris and suggest it be used to refer to sperm masses constructed in the female reproductive organs, at least when they involve the contribution of female secretion. © 2011 Wiley Periodicals, Inc.     

Internal anatomy and ultrastructure of the male reproductive system of the spider crab Maja brachydactyla (Decapoda: Brachyura)

The morphology and function of the male reproductive system in the spider crab Maja brachydactyla, an important commercial species, is described using light and electron microscopy. The reproductive system follows the pattern found among brachyuran with several peculiarities. The testis, known as tubular testis, consists of a single, highly coiled seminiferous tubule divided all along by an inner epithelium into germinal, transformation, and evacuation zones, each playing a different role during spermatogenesis. The vas deferens (VD) presents diverticula increasing in number and size towards the median VD, where spermatophores are stored. The inner monostratified epithelium exocytoses the materials involved in the spermatophore wall formation (named substance I and II) and spermatophore storage in the anterior and median VD, respectively. A large accessory gland is attached to the posterior VD, and its secretions are released as granules in apocrine secretion, and stored in the lumen of the diverticula as seminal fluids. A striated musculature may contribute to the formation and movement of spermatophores and seminal fluids along the VD. The ejaculatory duct (ED) shows a multilayered musculature and a nonsecretory pseudostratified epithelium, and extrudes the reproductive products towards the gonopores. A tissue attached to the ED is identified as the androgenic gland.     

Motility and dynamics of eupyrene and apyrene sperm in the spermatheca of the monandrous swallowtail butterfly Byasa alcinous

Lepidopteran males produce two sperm types: nucleated eupyrene sperm and non‐nucleated apyrene sperm. Although apyrene sperm are infertile, both sperm types migrate from the spermatophore to the spermathecal after copulation. As a dominant adaptive explanation for migration of apyrene sperm in polyandrous species, the cheap filler hypothesis suggests that the presence of a large number of motile apyrene sperm in the spermatheca reduces female receptivity to re‐mating. However, apyrene sperm are also produced in males of the monandrous swallowtail butterfly Byasa alcinous Klug. To identify the role of apyrene sperm in these males, the present study examines the number of spermatozoa produced and transferred and the dynamics and motility of spermatozoa in the spermatheca for each type of sperm. Apyrene sperm represents approximatey 89% of the sperm produced and transferred, which is comparable to polyandrous species. Two‐day‐old males transfer approximately 17 000 eupyrene and 230 000 apyrene spermatozoa to a spermatophore; approximately 5000 eupyrene and 47 000 apyrene spermatozoa arrive at the spermatheca. Eight days after copulation, most eupyrene spermatozoa remain in the spermatheca and a quarter of them are still active. However, the number of apyrene spermatozoa decreases and those remaining lose their motility after the arriving at the spermatheca. Consequently, 8 days after copulation, no motile apyrene sperm are found. The high proportion of apyrene sperm in the spermatophore, as well as in sperm migration, suggests that the production and migration of apyrene sperm is not simply an evolutionary vestigial trait. The possible functions of apyrene sperm in monandrous species are discussed.     

Morphology and function of reproductive organs in Neodasys chaetonotoideus (Gastrotricha: Neodasys) with a phylogenetic assessment of the reproductive system in Gastrotricha

The reproductive system of the important basal gastrotrich Neodasys chaetonotoideus is described and reconstructed on the basis of light microscopy, serial ultrathin sections (ultrastructure) and scanning electron microscopy. Starting frontally, the hermaphroditic reproductive system consists of paired and tube shaped lateral testes that do not possess elongated seminal ducts but most likely open directly via paired ventral pores. The unpaired, medio‐dorsal ovary region contains early oogenic stages that mature caudally towards the uterus region, where the most mature egg is positioned laterally to the midgut. The ovary region is not covered with an epithelial lining whereas the uterus region possesses a distinct epithelial wall. Between ovary and uterus region, we have detected a conspicuous section of the female gonad, the vitellogenic oviduct that consists of a thick epithelial wall which forms cellular protuberances into the developing oocytes passing the oviduct. We interpret this as a special, hitherto undescribed mode of vitellogenesis in Gastrotricha. Further caudally, the uterus continues with the fronto‐caudal organ, a complex of two substructures that are apparently homologous to the frontal organ and the caudal organ of many species of the Gastrotricha Macrodasyida. Neodasys chaetonotoideus obviously engages in spermatophore formation and transfer. In this study we develop a morpho‐functional scenario for the gonads and accessory organs in terms of spermatophore production, exchange and oviposition. We compare our newly obtained data with already published results on the reproductive organs of several species of Gastrotricha by means of a species‐character matrix and provide a computer aided evaluation by a parsimonious character optimization. A reconstruction of the reproductive system of the stem species of Gastrotricha on the basis of three recent phylogenetic analyses is presented. These reconstructions give support for a Neodasys‐like reproductive system in the ground pattern of Gastrotricha with slight morphological differences and direct transfer of spermatozoa rather than spermatophore transfer. The evolution of selected characters is traced thus revealing some incidents of convergent evolution as well as the evolutionary replacement of the ancestral frontal organ by the derived frontal sac in at least two separated lineages.     

The ultrastructure of the ejaculatory duct in the springtail Orchesella villosa (Geoffroy) (Hexapoda, Collembola) and the formation of the spermatophore

The initial part of the ejaculatory duct of Orchesella villosa contains a “valve” and a “sorter” avoiding respectively the reflow and allowing the separation of the secretion for the spermatophore stalk from the sperm fluid. For most of its length, the ejaculatory duct lumen is divided into two parts: in the dorsal part the sperm fluid flows while in the ventral district the secretion for the stalk occurs. Laterally, on both sides of the duct, longitudinal muscle fibers are present. The epithelium of the dorsal region consists of two types of long secretory cells; the most peculiar of them are those provided with extracellular cisterns flowing directly into the duct lumen as it occurs in 1st type of epidermal cells. These cells could be involved in the control of the viscosity of the sperm fluid. The second type of cells produce a secretion probably involved in the formation of the outer coat of the apical sperm droplet. The ventral epithelium consists of short cells contributing to the enrichment of the secretion for the spermatophore stalk and perhaps also to the viscosity of the secretion flowing in the lumen. In the distal part of the ejaculatory duct, the ventral district is provided with a thick layer of muscle fibers and with 3 + 3 cuticular laminae dividing the lumen into a series of slits through which the secretion of the stalk is squeezed out into filaments. This organization allows the twisting and hardening of these filaments. A drop of sperm fluid is laid on top of the long and rigid spermatophore stalk.     

Structural changes in the spermatophore of the freshwater 'red claw' crayfish Cherax quadricarinatus (Von Martens, 1898) (Decapoda, Parastacidae)

López Greco, L.S. and Lo Nostro, F.L. 2007. Structural changes in the spermatophore of the freshwater ‘red claw’ crayfish Cherax quadricarinatus (Von Martens, 1898) (Decapoda, Parastacidae). —Acta Zoologica (Stockholm) 88 : 000–000 The structure of the spermatophore was studied in Cherax quadricarinatus. Pieces of the distal vas deferens and transferred spermatophore from the females were fixed, cut and stained. Within the distal vas deferens, the primary layer and the secondary layer of the spermatophore were distinguishable. In the latter, two components were detected: cytoplasmic droplets and a homogeneous matrix. During the first 10 minutes post‐extrusion the cytoplasmic droplets drastically changed from looking like ‘empty droplets’; at this time the spermatophore changed from a liquid stage to a sticky one. One hour after extrusion the spermatophore began to harden and within the first 24–48 h post‐mating it was a solid and intense white structure tightly attached to the female; after 72 h it acquired a softer aspect, completely dehiscing between 96 and 120 h post‐mating. Histologically, the primary layer maintained its integrity surrounding the spermatozoa while the secondary layer lost the cytoplasmic droplets. The spermatophore began to hydrate between 24 and 48 h and by 72–96 h many sections of the sperm cord began to coalesce. From 48 h post‐mating some fissures appeared within the matrix that enlarged between 72 and 120 h. We propose that both manipulation by the female and hydration are the mechanisms involved in the release of the spermatozoa from the spermatophore.     

Structure and function of the spermathecal complex in the phlebotomine sandflyPhlebotomus papatasi Scopoli (Diptera: Psychodidae): II. Post-copulatory histophysiological changes during the gonotrophic cycle

The spermathecal complex ofPhlebotomus papatasi Scopoli (Diptera: Psychodidae) undergoes histological and physiological changes during its gonotropic cycle. The present histochemical study revealed a mucopolysaccharide secretory mass in the spermathecae of the newly emerged sandfly. Sperm competition occurs when two or more males compete to fertilize an ovum in the female reproductive tract. In this study, spermatophores of two or more competing males were deposited at the base of the spermathecal ducts, which originate from the female bursa copulatrix. This suggests that females play a role in sperm displacement, which is defined as any situation in which the last male to mate with a female fertilizes maximum number her eggs. A blood meal ingested by the female for ovary development and egg laying stimulates the release of sperm from the spermatophore. The spermatozoa then migrate to the lumen of the spermatheca. The ultrastructure of spermatozoa comprises a head with double-layered acrosomal perforatorium, an elongate nucleus, and the axoneme with a 9 + 9 + 0 flagellar pattern. This axomene differs from the aflagellate axoneme of other Psychodinae. Morphological changes, such as the casting off of the acrosomal membrane, and histological changes in the spermatophore are also described. Mating plugs that have been described previously in sandflies appear to be artefacts. Females ofP. papatasi may be inseminated more than once during each gonotrophic cycle, and additional inseminations may be necessary for each cycle. The relationships between the volumes of the sperm and the spermatheca were calculated to determine sperm utilization and fecundity ofP. papatasi. As the females ofP. papatasi mate polyandrously, the anatomical and physiological complexity of the spermathecal complex may be related to post-copulatory sexual selection.     

Structure of male accessory glands of Bolivarius siculus (fischer) (Orthoptera,Tettigoniidae) and protein analysis of their secretions

In Tettigoniidae (Orthoptera), male reproductive accessory glands are involved in the construction of a two‐part spermatophore; one part, the spermatophylax, is devoid of sperm and considered a nuptial gift. The morphology, ultrastructure, and secretion protein content of the male reproductive accessory glands from Bolivarius siculus were investigated. Two main groups of gland tubules open into the ejaculatory duct: the “first‐order” glands, a number of large anterior tubules, and the “second‐order” glands, smaller and more numerous tubules positioned posteriorly. Along with a further subdivision of the gland tubules, we here describe for the first time an additional gland group, the intermediate tubules, which open between first and second‐order glands. The mesoderm‐derived epithelium of all glands is a single layer of microvillated cells, which can be either flattened or cylindric in the proximal or distal region of the same gland. Epithelial cells, very rich in RER and Golgi systems, produce secretions of both electron‐dense granules and globules or electron‐transparent material, discharged into the gland lumen by apocrine or merocrine mechanisms, respectively. With one exception, a unique electrophoresis protein profile was displayed by each of the gland types, paralleling their unique morphologies. To assess the contribution of different types of accessory glands to the construction of the spermatophore, the protein patterns of the gland secretions were compared with those of the extracts from the two parts of the spermatophore. All samples showed bands distributed in a wide range of molecular weight, including proteins of very low molecular mass. However, one major high molecular weight protein band (>180 kDa) is seen exclusively in extracts from the first‐order glands, and corresponds to an important protein component of the spermatophylax. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.     

Description of the male reproductive system of Paguristes eremita (Anomura,Diogenidae) and its placement in a phylogeny of diogenid species based on spermatozoal and spermatophore ultrastructure

The male gonopores, male reproductive apparatus, spermatophore and spermatozoa of the Mediterranean hermit crab Paguristes eremita are described, using interference phase microscopy, scanning electron microscopy and transmission electron microscopy. A correlation is made between the gonopore morphology and the different kinds of setae accompanying them, and the reproductive biology of these crabs. Each testes merges into a tubular duct made up of four zones: (1) the collecting tubule with free spermatozoa; (2) the proximal zone, where the ampulla of the spermatophores starts to be formed; (3) the medial zone, where the ampulla is completed, the stalk lengthens and the pedestal is formed; (4) the distal zone, where the mature spermatophores are stored. The sizes of the different parts of the spermatophore and of the sperm are given and their exterior morphology and ultrastructure described and compared to congeners. The morphology of the gonopore, male reproductive system, spermatophore and spermatozoa of P. eremita are species-specific, clearly distinguishing the species from the other members of the family. The available spermatozoal and spermatophore data is used to place P. eremita within a sperm phylogeny of the hermit crab family Diogenidae.     

Eupyrene sperm migrates to spermatheca after apyrene sperm in the swallowtail butterfly, Papilio xuthus L. (Lepidoptera: Papilionidae)

When swallowtail butterflies, Papilio xuthus, are mated by the hand-pairing method, both types of sperm, eupyrene and apyrene sperm, are transferred from the male to the spermatheca via the spermatophore in the bursa copulatrix. This mechanism is demonstrated by two different kinds of experiments. The first set of experiments employed interrupted copulation, and the second set was examination of the sperm in the spermatophore and spermatheca after the termination of copulation. The sperm was transferred 30 min after the start of copulation. The eupyrene sperm was still in the bundle; the number of the bundles ranged from 9 to 108 (mean, 42.7; n = 27). The bundles were gradually released after the completion of copulation, and the free eupyrene spermatozoa then remained in the spermatophore at least 2 h before migrating to the spermatheca. On the other hand, about 160 000 apyrene spermatozoa were transferred to the spermatophore and remained there for more than 1 h. We observed 11 000 apyrene spermatozoa in the spermatheca 12 h after the completion of copulation, but most of this type of sperm disappeared shortly thereafter. In contrast, the eupyrene sperm arrived in the spermatheca more than 1 day after the completion of copulation and remained there at least 1 week. Therefore, these findings suggest that apyrene sperm migrate from the spermatophore to the spermatheca earlier than eupyrene sperm. Accordingly, if females mated multiply, the time difference might avoid the mixing of sperm. In addition, the predominance of sperm from the last mating session may occur not in the bursa copulatrix but in the spermatheca. Received: January 7, 2000 / Accepted: May 24, 2000     

Spermatogenesis and spermatophore production in the hawaiian red lobster Enoplometopus occidentalis (Randall) (Crustacea,nephropidae)

Light microscopy of the male reproductive tract of the Hawaiian red lobster Enoplometopus occidentalis documented the cyclic nature of spermatogenesis and spermatophore formation. Testes are composed of a convoluted collecting tubule bearing many spermatogenic follicles, all within a supporting mesentery. Spermatogonia are restricted to the basal side of the follicular epithelium and proliferate at onset of spermateleosis within the same follicle. Two generations of spermatogenic cells thus occupy each follicle, and accessory cells in the follicle form a basophilic epithelium between them. These accessory cells may detach with the spermatozoa at spermiation. The vas deferens lies outside the testicular mesentery and consists of a coiled proximal portion in which spermatophore production commences. Clusters of spermatozoa are here surrounded by a PAS-positive primary spermatophore layer, and a PAS-negative outer bounding layer is initiated. Completed further distally in the vas deferens, the outer bounding layer is thinner on the side of the spermatophore which adheres to the substratum after ejaculation; the thick side of this layer forms a broad cap. Outer circular and inner longitudinal muscular layers become well developed in the distal loop and descending portions of the vas deferens. The terminal portion of this duct contains no spermatophore prior to ejaculation. It has a longitudinally folded epithelium and an attached tubular gland which produces an extra-spermatophoral, gelatinous secretion. The androgenic gland is associated with this terminal segment of the vas deferens. These features are compared with those reported for other lobsters.     

Trehalase in the spermatophore from the bean-shaped accessory gland of the male mealworm beetle,Tenebrio molitor: purification,kinetic properties and localization of the enzyme

Trehalase from the bean-shaped accessory glands of the male mealworm beetle, Tenebrio molitor, was purified by acid treatment, with subsequent chromatography on columns of DEAE-cellulofine and Sephacryl S-300. The molecular masses of the native and the denatured forms were estimated to be 43 and 62 kDa by gel filtration and SDS-PAGE, respectively, an indication that the trehalase may be composed of a single polypeptide. The optimum pH of the reaction catalyzed by trehalase was 5.6–5.8. The K _m for trehalose was 4.4 mmol·l^–1. Immunohistochemical experiments with trehalase-specific antiserum showed that the enzyme was localized in one specific type of secretory cell in the bean-shaped accessory gland epithelium and within the semisolid secretory mass that was a precursor to the wall of spermatophore. SDS-PAGE and immunoblotting analysis revealed the presence of a polypeptide of about 62 kDa in the spermatophore, Immunohistochemical observations showed that the trehalase was located at the outgrowth in the anterior portion of the spermatophore. When a fresh spermatophore was immersed in phosphate-buffered saline it discharged sperm in the same manner as in the bursa copulatrix of the female. Before the rupture of the expanded bulb of the spermatophore, almost all of the trehalase had dissolved in the phosphate-buffered saline. The addition of validoxylamine A to the saline, a specific inhibitor of trehalase, did not affect the expansion and evacuation of the spermatophore. These results demonstrate that trehalase, synthesized by a specific type of secretory cell in the bean-shaped accessory gland epithelium, is actively passed into the lumen of the bean-shaped accessory gland and then incorporated into the spermatophore. Trehalase appears to be one of the structural proteins of the spermatophore, although the possibility can not yet be completely ruled out that the trehalase-trehalose system functions for the nourishment and/or activation of the sperm in the bursa copulatrix of the female.Abbreviations BAG bean-shaped accessory gland(s) - DEAE diethylaminoethyl - Kpi buffer K₂HPO₄/KH₂PO₄ buffer (pH 7.0) - PAGE polyacrylamide gel electrophoresis - PBS phosphate-buffered saline - SDS sodium dodecy sulphate - Spph spermatophore(s) - TAG tubular accessory gland(s)     

Last–male sperm precedence in the bushcricket Poecilimon veluchianus (Orthoptera, Tettigonioidea) demonstrated by DNA fingerprinting

Males of the bushcricket Poecilimon veluchianus pass a large spermatophore to the female during mating. The spermatophore is eaten by the female after copulation. Because females mate with several males during their reproductive life, the competition between spermatozoa of different males affects a male's reproductive success. In order to determine the outcome of sperm competition, the paternity of the progeny of double–mated females was established by DNA fingerprinting with the oligonucleotide (GATA)₄. Typical P. veluchianus DNA fingerprints consisted of 15 scoreable fragments per individual. The proportion of bands shared between presumably unrelated bushcrickets was 17%. After the second copulation the second mating male clearly predominated at fertilization. The mean proportion of eggs fertilized by the second male was 90.1%. There was no significant relationship between the level of sperm precedence and the time of ovipositions after the second mating. If female P. veluchianus increase the fitness of their offspring by the incorporation of spermatophore–derived substances in developing eggs, there is little chance for the feeding male to fertilize eggs containing his nutrients, because of the very short mating intervals of females and the observed high level of last–male sperm precedence in this species. Under such conditions the last mating male would fertilize many eggs containing nutrients from a prior male. Because nuptial gifts, like the tettigoniid spermatophore, function only as paternal investment if the donating male's progeny benefit from the gift, a paternal investment function of the P. veluchianus spermatophore seems to be unlikely.     

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.     

Morphofunctional changes of female germinal epithelium to support spermatozoa along the annual reproductive cycle in an inseminating catfish (Trachelyopterus galeatus,Auchenipteridae)

The reproductive system of some fish species presents elaborate mechanisms by which the females store spermatozoa inside their ovaries, keeping them viable for fertilization for an extended period of time. However, as intriguing as this sperm storage is, it is not yet understood how the sperm can remain viable in the ovary. Aiming to understand this phenomenon, the epithelium covering the ovarian lamellae, that is, the germinal epithelium, of the Cangati (Trachelyopterus galeatus), an inseminating catfish, was evaluated taking into account the different stages of the annual reproductive cycle. The germinal epithelium morphology changed during the annual reproductive cycle, presumably in preparation to receive the spermatozoa and keep them viable until fertilization. There was a progressive increase of the epithelium height. Also the number of intercellular junctions, desmosomes, and extended tight junctions, apparently increased forming chains that could be regarded as a barrier to isolate the sperm from the female immune system. Synthetic organelles were active releasing cytoplasmic granules and secretion in the epithelial enfolds in which the spermatozoa were deeply embedded. Concomitantly, oogonium nests were formed in the germinal epithelium during early folliculogenesis. J. Morphol. 275:65–75, 2014. © 2013 Wiley Periodicals, Inc.