Internal reproductive organs of the female humpbacked fly,Megaselia scalaris Loew (Diptera : Phoridae)

The female reproductive system of the humpbacked fly Megaselia scalaris Loew (Diptera : Phoridae) was examined in whole mount preparations and serial sections. The system includes 2 ovaries, paired lateral oviducts, a common oviduct, and a genital chamber, opening externally through a gonopore, anteriad and ventrad to the anus. The ducts of the 2 accessory glands open independently into the dorsal region of the genital chamber. The terminal duct of a 2-armed spermatheca joins the right posterior and ventral wall of the genital chamber, immediately inside the gonopore. Passing dorally, the spermathecal duct lies immediately ventral to the duct of the right accessory gland. A short distance posteriad, it divides into two branches, each supplying an arm of the spermatheca. The genital chamber extends both anteriorly and posteriorly from its junction with the common oviduct, creating anterior and posterior compartments. In the right lateral wall of the genital chamber, a distinctive loop-shaped thickening (plate) resembles a darkened thread when it is observed through the integument. Features likely to have taxonomic utility include the posterior and ventral location of the terminal portion of the spermathecal duct; and the asymmetrically arranged, loop-shaped plate.     

Anatomy and ultrastructure of the female reproductive system of Pleioplana atomata (Platyhelminthes: Polycladida)

The ultrastructure of the female reproductive system of the polyclad flatworm Pleioplana atomata is described. Numerous ovaries are scattered throughout the entire body but are mainly concentrated on the dorsal side. Within an ovary, a germinative zone with oogonia and prefolicular cells is located in the dorsal part of the ovary. The remaining part of the gonad is filled with previtellogenic and early vitellogenic oocytes enwrapped by follicular cells. During previtellogenesis, oocytes produce numerous eggshell globules, which are distributed into the cortical area of the cell in later stages. Eventually, these globules release their contents into the space between the eggshell cover and oolemma. Similar types of globules are also found in others flatworms, and may represent useful phylogenetic characters. Entolecital, vitellogenic oocytes pass to paired uteri, where vitellogenesis is completed. The remainder of the female reproductive system consists of paired thin uterine ducts that join a vagina. The distal part of the long, curved vagina forms a large Lang's vesicle, while the proximal part is connected to a female atrium leading to a female gonopore. We hypothesize that Lang's vesicle functions in the digestion of excess sperm received. Two kinds of different shell (cement) glands that release their secretion into the vagina are identified. Both are unicellular glands and each gland cell connects to the lumen of the vagina via an individual canal. Similar glands in other acotylean polyclads have been implicated in the formation of eggshell covers. J. Morphol. 2009. © 2008 Wiley‐Liss, Inc.     

Ultrastructure and overall organization of ligament sac, uterine bell, uterus and vagina in Paratenuisentis ambiguus (Acanthocephala, Eoacanthocephala) – the character evolution within the Acanthocephala

As an adaptation to their endoparasitic lifestyle, Acanthocephala (Palaeacanthocephala, Eoacanthocephala, Polyacanthocephala, Archiacanthocephala) have evolved a highly specialized reproductive system. Most of our present knowledge of the efferent duct system of the female is based on palaeacanthocephalan and archiacanthocephalan representatives. In order to provide a basis for further elucidating the phylogenetic relationships within the Acanthocephala, we herein describe ultrastructure and overall organization of the ligament sac and efferent duct system in females of Paratenuisentis ambiguus (Eoacanthocephala, Neoechinorhynchida). Only one ligament sac was found. The uterine bell consists of two contractile binucleate syncytia (bell wall syncytium, lateral pocket syncytium), two pairs of contractile cells (lappet cells, uterine bell retractors) and three pairs of noncontractile cells (median cells). The contractile uterus bears four nuclei. The vagina is composed of a syncytial epithelium (four nuclei) and two binucleate sphincters. A comparison of the present findings with literature data leads to the following conclusions: except for the uterine bell retractors, the uterine bell components found in P. ambiguus can be assumed to be autapomorphies for the Acanthocephala. The sheathing syncytium and median dorsal cell belong to the basal pattern (sensu ground pattern) of a palaeacanthocephalan subclade termed the Echinorhynchus‐group in the present study. The median oviduct syncytium and paired uterine bell retractors can be assumed to be basal pattern characteristics of the Archiacanthocephala and Neoechinorhynchida, respectively. The study includes a tabular survey of terminological synonyms used in the literature.     

Cystacanths of Acanthocephala in notothenioid fish from the Beagle Channel (sub-Antarctica)

The morphology of relaxed cystacanths of polymorphid acanthocephalans collected from notothenioid fishes in the Beagle Channel (Magellanic subregion of sub-Antarctica) is described. A parasite of birds, Andracantha baylisi (Zdzitowiecki, 1986), was found in Patagonotothen longipes and Champsocephalus esox. It has: a proboscis 0.82–0.89 mm long; a proboscis hook formula of 16 rows of 9/10–10/11, including 4–5 basal hooks; distal hooks with the longest blades; a fore-trunk not separated from the hind-trunk by a constriction; large somatic spines arranged in two zones separated by a zone of small, loosely dispersed spines; and only the anterior 36–40% of ventral side of the trunk is covered with spines. One male specimen of Corynosoma sp. was found in Patagonotothen tessellata. It differs from A. baylisi in that the distal proboscis hooks are similar in length to the prebasal hooks, it has a smaller proboscis (0.77 mm) and in the distribution of the somatic spines, which are contiguous with the genital spines on the ventral side of the trunk and lack a zone of small spines between zones of larger spines. A parasite of seals and fur seals, Corynosoma evae Zdzitowiecki, 1984, was found in P. longipes and Champsocephalus esox. It has: a proboscis 0.61–0.78 mm long; a proboscis hook formula of 20–22 rows of 12–13, including 3/4–4 basal hooks; prebasal hooks with the longest blades; a trunk divided into fore-trunk and hind-trunk; somatic spines covering the anterior 64–74% of the ventral side of the trunk; genital spines present only in males; and a terminal genital opening in both sexes. Corynosoma beaglense n. sp. was found in Champsocephalus esox. It has: an almost cylindrical proboscis (length 0.52–0.56 mm); a proboscis hook formula of 16 rows of 9/10–10/11, including 4–4/5 basal hooks; distal hooks shorter than the prebasal hooks; a fore-trunk not separated from the hind-trunk by a constriction; somatic spines contiguous with the genital spines on the ventral side of the trunk of the male and covering the entire length of the ventral side of the female trunk, and the presence of genital spines surrounding the terminal genital pore of the male. The definitive host of this species is unknown.     

Morphology of urogenital system in female Echinopardalis atrata (Acanthocephala)

Four major areas of the urogenital system of Echinopardalis atrata are examined: (1) capsular protonephridial system, (2) uterine bell complex, (3) uterus, (4) vagina. Photomicrographs of cross sections from wax preparations depict morphological changes along the length of this system. Diagrammatic illustrations show relationships between excretory ducts and oviducts in the uterine bell complex. Relative positions of dorsal and ventral ligament accessory cells, median wall cells, and sheathing syncytium are also shown in this complex. The common oviduct and excretory canal join to form a ciliated urogenital canal that empties into the lumen of the uterus along the latter's anterior mid-dorsal surface. The excretory bladder is located on the inside mid-dorsal surface of the bell wall and is serviced by 2 nephridial canals--1 from each of 2 capsular protonephridia. The vagina affixes the posterior terminus of the uterus to the tegument and consists of an internal and external sphincter surrounding a hypodermal lining.     

The anatomy of fertilization in the yellow dung fly Scathophaga stercoraria

Female yellow dung flies, Scathophaga stercoraria, can influence the traffic of sperm stored in their spermathecae to the site of fertilization in the bursa copulatrix. However, the anatomical mechanisms employed are largely unknown. We investigated the anatomy of the female genital tract, seeking structures involved in sperm transfer and egg fertilization. We found a membranous structure descending from the ends of the spermathecal and accessory gland ducts into the bursa copulatrix. We call this the prolatus. Sperm accumulate in the prolatus during oviposition. When an egg is in the bursa the egg micropyle, rather than being aligned towards the dorsal openings of the spermathecal ducts, lies on the opposite, ventral side. We also confirm the presence, and suggest a function for, a cuticularized pouch on the ventral wall of the anterior bursa copulatrix. This pouch, plus a previously undescribed chamber, may be homologous to the ventral receptacle/fertilization chamber found in other dipterans. Further, we describe a translucent cap, apparently transversed by channels, covering the micropyle. Sperm were observed to aggregate on and in the micropyle cap, which appears to attract and hold sperm. We interpret the prolatus as a structure that allows an ovipositing female to transfer a few sperm onto the ventral bursal wall and thus, indirectly, onto the micropyle cap. Such anatomy potentially gives the female a large degree of control over sperm traffic from storage to the site of fertilization.     

Comparative ultrastructure of coxal glands in unfed larvae of Leptotrombidium orientale (Schluger, 1948) (Trombiculidae) and Hydryphantes ruber (de Geer, 1778) (Hydryphantidae)

Coxal glands of unfed larvae Leptotrombidium orientale (Schluger, 1948) (Trombiculidae), a terrestrial mite parasitizing vertebrates, and Hydryphantes ruber (de Geer, 1778) (Hydryphantidae), a water mite parasitizing insects were studied using transmission electron microscopy. In both species, the coxal glands are represented by a paired tubular organ extending on the sides of the brain from the mouthparts to the frontal midgut wall and are formed of the cells arranged around the central lumen. As in other Parasitengona, the coxal glands are devoid of a proximal sacculus. The excretory duct, joining with ducts of the prosomal salivary glands constitutes the common podocephalic duct, opening into the subcheliceral space. The coxal glands of L. orientale are composed of a distal tubule with a basal labyrinth, an intermediate segment without labyrinth, and a proximal tubule bearing tight microvilli on the apical cell surface and coiled around the intermediate segment. The coxal glands of H. ruber mainly consist of the uniformly organized proximal tubule with apical microvilli of the cells lacking the basal labyrinth. This tubule shows several loops running backward and forward in a vertical plane on the side of the brain. In contrast to L. orientale , larvae of H. ruber reveal a terminal cuticular sac/bladder for accumulation of secreted fluids. Organization of the coxal glands depends on the ecological conditions of mites. Larvae of terrestrial L. orientale possess distal tubule functioning in re‐absorption of ions and water. Conversely, water mite larvae H. ruber need to evacuate of the water excess, so the filtrating proximal tubule is prominent.     

Primary homology assessment of structures in the female atrial system among species of the Polycystididae (Rhabditophora, Eukalyptorhynchia)

Abstract. The female atrial system of members of the Polycystididae has been studied at the light microscopical level and compared among the constituent taxa. Based on the criteria of position and conjunction, hypotheses of homology are put forward and compared with the assessments of homology found in earlier literature. Contradictory terminology is synonymized and adapted to fit new findings that recognize homology among structures in different taxa. Based on differences in position and structure, 2 types of female duct are recognized: female duct type I and female duct type II. The term “female bursa” is restricted to a sperm resorbing organ at the proximal end of the female duct type I and/or at the end of a common oviduct. Some species have bundles of glands at the place where the oviduct(s) enter the female duct type I, which are considered homologous among these species. Different types of seminal receptacles are recognized. The term “insemination duct” is restricted to the ducts which in some species, in addition to the oviducts, connect the ovaries with the female duct type I. A single muscular duct, the common oviduct, connects the joined oviducts with the female duct type I in species of Duplacrorhynchus and is considered homologous with the similar duct present in some other species. A uterus is always present, entering the common genital atrium through its frontal wall, or entering a female duct type II. This morphological review of the female atrial system reveals a mosaic distribution of characters if applied to previous phylogenies that are based primarily on the male reproductive system.     

Arhopalus ferus (Coleoptera: Cerambycidae): structure and function of the female reproductive system

Abstract

Arhopalus ferus (Mulsant) female pupae and adults were dissected, and both internal and external genitalia are described. The external genitalia involve segments 8 and 9. Segment 9 and its appendages are modified into a long ovipositor which telescopes with segment 8 into segment 7 when retracted. The internal genitalia include ovaries, bursa copulatrix, spermatheca, spermathecal gland, vagina, and accessory glands. The terminology applied to coleopteran genital anatomy is critically discussed.     

Deurithitrema gingae n.g., n.sp. (Digenea: Plagiorchioidea) from the kidneys of a salt-water crocodile (Crocodylus porosus Schneider) from Australia

Summary The name Deurithitrema gingae n. g., n. sp. is proposed for worms from the kidneys of one Crocodylus porosus from Darwin, Northern Territory, Australia. The following combination of characters distinguishes the new genus from all others: prepharynx very short; oesophagus absent; caeca reaching to posterior end of body; testes tandem in middle third of body, contiguous or amost so; cirrus-sac large, over-reaches ventral sucker, contains bipartite seminal vesicle, prostatic regions and ejaculatory duct with spines around its opening into genital atrium; genital pore immediately in front of ventral sucker; uterus coiled to posterior end of body; vitellaria lateral from ventral sucker to slightly behind testes; excretory vesicle small, receiving a single ventro-lateral duct from each side behind end of uterine loops. Deurithitrema belongs to the superfamily Plagiorchioidea Dollfus, 1930. It superficially resembles a number of genera, but its relationships within the superfamily are obscure.     

The giant and complex genital plug of the asper group of Bothriurus (Scorpiones, Bothriuridae): morphology and comparison with other genital plugs in scorpions

The genital plugs of two species of the asper group of Bothriurus (Scorpiones: Bothriuridae) are described and compared with other genital plugs reported in the family Bothriuridae. In both species, B. asper and Bothriurus sp., the genital plug is cone-shaped and formed by fusion of the basal lobes of the hemispermatophore. Fusion is complete in B. asper and the surface of the plug has many microspines that anchor it to the female genital atrium. In Bothriurus sp., the basal lobes are partially fused, but free on the dorsal side, and the plug has a smooth surface with a dorsal curvature. Both genital plugs completely fill the genital atrium of inseminated females, pressing against the cuticular wall of the atrium. Given the large size and complex shape, the genital plug of the B. asper group is unique, not only among Bothriuridae, but in the order Scorpiones. This new type of genital plug resembles the genital plugs of the scorpion families Urodacidae and Vaejovidae. A comparison of the four major types of genital plugs reported in Bothriurus species and some other bothriurids is provided, as well as a comparison with other genital plugs reported in more distantly related families of scorpions.     

Functional morphology and neuronal innervation of the prothoracic defence gland in Timema

Timema is the most basal genus of Phasmatodea and the sister group to the remaining stick and leaf-insects (Euphasmatodea). An autapomorphy of all phasmids is the paired prothoracic exocrine defence glands. In this study, the anatomy and innervation of the defence glands in Timema petita and Timema chumash are described and compared with the data on Euphasmatodea. In all phasmids, the glands consist of a cuticular epithelium, a secretory epithelium and muscular fibres that compress the lumen. In Timematodea, the muscular part of the gland is less developed than in Euphasmatodea and the ejection of the defence secretion depends on the dorsal longitudinal neck muscles. On the neuroanatomical level, Timema petita and Timema chumash lack neurons that are involved in the independent contraction of the gland in euphasmids. In both studied species of Timema, neck muscles play an active role in the gland function which is not observed in any other phasmid. Considering the basal position of this genus, this supports the hypothesis that in euphasmids, the muscular part of the gland evolved from the dorsal longitudinal neck muscles. Additionally, the same nerves that innervate the dorsal longitudinal neck muscles in all Polyneoptera also innervate the defence glands in phasmids.     

The skin of primates. XL. The skin of the cottontop pinché Saguinus (=Oedipomidas) oedipus

The skin of Saguinus (= Oedipomidas) oedipus Linnaeus, is basically similar to that of the red-mantled tamarin, Saguinus (= Tamarinus) fuscicollis Spix; it has several peculiarities: (1) a circumscribed tuft of vibrissae on the ulnar aspect of the wrist; (2) an accumulation of apocrine glands over the sternum; and (3) an extensive posterior abdominal field of gigantic sebaceous glands admixed with large apocrine glands, better developed in the female. The epidermis, dermis, hair follicles, sebaceous ducts, and apocrine excretory ducts are all heavily pigmented. Hairs are arranged in linear perfect sets; the epithelial sac of quiescent follicles is devoid of glycogen and phosphorylase. Eccrine sweat glands are restricted to the volar friction surfaces and contain no glycogen. Only the coiled excretory ducts of the eccrine glands contain phosphorylase. All cutaneous nerve fibers are more reactive for acetylthan butyrylcholinesterase.     

Morphological characterization of female accessory sex glands of Eupolybothrus fasciatus (Newport) (Chilopoda Lithobiomorpha)

The female reproductive system of Eupolybothrus fasciatus (Newport) (Chilopoda Lithobiomorpha) includes three types of well-developed accessory glands, viz. large glands, small glands, and the periatrial gland. External morphology and the ultrastructural organization of these glands have been investigated by light and electron microscopy. The small and large glands are paired and have coiled ducts that open, respectively, into and externally to the genital atrium. By contrast, the periatrial gland is unpaired and is located on the ventral wall of the atrium into which it opens via several small canals. Ultrastructural features show that all three glands consist of two different types of cells: secretory cells and ductule cells. The secretary cells contain prominent secretory granules and are similar to a class of insect epidermal gland cells (class 3) organized as acini surrounding an extracellular lumen into which microvilli project. The granules, which have different morphological features in each gland, could be responsible for important differential functions such as producing a sexual attractant, providing a coating material that protects eggs laid on the ground, and contributing to a fluid that digests spermatophores. © 1996 Wiley-Liss, Inc.     

Morphology of the female genital ducts of the blue land crab Cardisoma guanhumi (Crustacea: Brachyura: Gecarcinidae)

This is a histological and histochemical analysis of the terminal portion of the female reproductive system and genital ducts of the blue land crab (Cardisoma guanhumi). Animals were collected in the Jaguaribe estuary (Ceará, Brazil) and dissected. Genital duct fragments were fixed and submitted to different staining techniques. The female reproductive system consists of a pair of ovaries and a pair of genital ducts. In the mid‐posterior portion of each lobe, the ovaries communicate with the genital ducts, which are subdivided into oviduct, spermatheca, vagina, and gonopore. Histologically, the spermatheca of C. guanhumi is composed of columnar secretory epithelium and is divided into a dorsal zone and a ventral zone, the latter covered internally by a cuticle layer. Both zones are enveloped by a thin layer of loose connective tissue. Histological cross sections revealed the vagina to be concave, a pattern considered phylogenetically more advanced than the simple, tubular form. Our findings suggest fertilization is internal, favoring sperm from the most recent copulation.     

Status of Corynosoma (Acanthocephala: Polymorphidae) based on anatomical, ecological, and phylogenetic evidence, with the erection of Pseudocorynosoma n. gen

The possession of genital spines has been considered as a key taxonomic trait to differentiate Corynosoma from other genera of the Polymorphidae. However, Corynosoma currently consists of 2 groups of species with clear ecological and morphological divergences: the "marine" group (with ca. 30 species) infects mammals and piscivorous birds in the marine realm, whereas the "freshwater" group (with ca. 7 species) infects waterfowl in continental waters. Species from these groups differ in shape of body and neck, trunk spination, lemnisci length and shape, testes arrangement, and number and shape of cement glands. We tested whether species from these 2 groups formed a monophyletic assemblage based on a phylogenetic analysis by using 15 morphological characters. We also included species of Andracantha, Polymorphus, and Hexaglandula with which potential taxonomic conflicts could most likely arise. We obtained 108 equally most parsimonious trees of 32 steps, with a consistency index (CI) = 0.59, and a retention index (RI) = 0.82. The strict consensus tree indicated that the "freshwater" species of Corynosoma form a monophyletic assemblage closely related to some species of Polymorphus, whereas the "marine" species of Corynosoma are grouped together with Andracantha. Accordingly, Corynosoma is not a monophyletic assemblage, and Pseudocorynosoma n. gen. is proposed for the "freshwater" species of Corynosoma. This decision was strongly supported by (1) a functional comparison of foretrunk muscles between species of Polymophus, Andracantha, and Corynosoma; (2) a multivariate morphometric study of proboscis characters and egg size; and (3) an analysis of ecological patterns of host-parasite relationships.     

The effect of host species on growth and variability of Echinorhynchus salmonis Müller, 1784 (Acanthocephala: Echinorhynchidae), with special reference to the status of the genus

Summary The sex and age (as measured by length) of Echinorhynchus salmonis Müller, 1784 and the host species of this acanthocephalan considerably affected worm body form and size, as well as size of proboscis, proboscis hooks, proboscis receptacle, lemnisci, testes and cement glands. Linear regression analysis indicated that curves describing the growth pattern of these characters by worm length were significantly different as a function of host species. The larger worms recovered from bloater (Coregonus hoyi: Salmonidae) almost invariably showed higher regression coefficient compared to those from smelt (Osmerus mordax: Osmeridae) in all characters. Taxonomic implications of these findings are discussed. Abnormalities in body wall, proboscis hook orientation, lemnisci and cement gland ducts as well as variations in proboscis hook and cement gland numbers are reported, some for the first time. Findings from studies of cement gland pattern invalidate Petrochenko's (1956) splitting up of the genus into three: Echinorhynchus, Metechinorhynchus and Pseudoechinorhynchus. It is proposed that the designation of the last two genera as junior synynoms of the first be accepted. ac]19791205     

Unusual membranous network with spines in the uterus of Xiphinema coomansi (Nematoda: Longidoridae)

An ultrastructural study of the uterus of Xiphinema coomansi reveal that the numerous uterine spines present in this species are not anchored to the inner wall of the tubular uterus, but are symmetrically arranged and attached in a membranous network suspended throughout the entire length of the uterus. The spines are solid, hexagonal structures enveloped and connected in tri-radial fashion to each other, as well as to the inner uterine wall by a continuous thin undulating membrane. The network membrane thus formed encloses numerous compartments on the luminal side of the uterus, which seems to create a type of barrier between the plicated uterine wall and a rather constricted central lumen. No such membranous intrauterine network has been reported previously in the reproductive system of nematodes.