Sensory Papillae Research Articles

Redescription and New Host Record of Capsala laevis (Monogenoidea: Capsalidae: Capsalinae) from Gill of Roundscale Spearfish, Tetrapturus georgii (Perciformes: Istiophoridae) in the Northwestern Atlantic Ocean

Specimens of a capsalid collected from the gill arches of 2 roundscale spearfish, Tetrapturus georgii Lowe, 1840, (Perciformes: Istiophoridae), captured in the northwestern Atlantic Ocean were identified as Capsala laevis (Verrill, 1875) Johnston, 1929 by having the combination of papillae on the ventral surface of haptor, dorsomarginal body sclerites in a single column extending the entire body length, haptoral accessory sclerites, conical papillae distributing over the ventral body surface, and an anterior attachment organ with a fimbriated posterior margin. The new specimens plus the holotype were used to conduct a taxonomic redescription of C. laevis using light and scanning electron microscopy. We documented that the holotype (USNPC No. 7179) and the new specimens of C. laevis from roundscale spearfish each had papillae on the ventral surface of the anterior attachment organs and sensory papillae on the dorsal body surface. Although data are insufficient at this time to justify proposal of a new species, the new specimens differed from the holotype and published accounts of C. laevis by having a sinistral dorsomarginal patch comprising 27-35 sclerites whereas the holotype has a dorsomarginal patch comprising 60 sclerites. Capsala laevis morphologically most closely resembles Capsala ovalis (Goto, 1894) Price, 1938 , but can be most easily differentiated from it by having dorsomarginal body sclerites. This represents the first record of any parasite from the recently taxonomically resurrected roundscale spearfish, long considered by some as a junior subjective synonym of white marlin, Tetrapturus albidus Poey, 1860 and, concomitantly, a new host record for Capsalidae Baird, 1853. An updated list of host records for C. laevis is provided. A perusal of that literature reveals that the identity of the type host for C. laevis is indeterminate beyond Istiophoridae species and that subsequent reports of the type host as ' T. albidus ' are presumptuous (originally reported in 1875 by Verrill as "bill-fish" only). Our results indicated that 2 records of C. laevis from the swordfish, Xiphias gladius Linnaeus, 1758, (Perciformes: Xiphiidae) are dubious, i.e., study of the museum voucher USNPC No. 8154 indicates that Linton's 1940 record from the northwestern Atlantic Ocean likely represents a new species of Capsala Bosc, 1811 and that the Kayiş et al. 2010 record from the Aegean Sea likely depicts a species of Capsaloides Price, 1938.

Fischoederius cobboldi: A scanning electron microscopy investigation of surface morphology of adult rumen fluke

Adults Fischoederius cobboldi are conical-shaped, concave ventrally and convex dorsally, measures about 8–10mm in length and 4–6mm in width across the mid section. Scanning electron microscopy (SEM) of entire body showed that the tegumental surface exhibits highly corrugation and transverse folds alternating with grooves and without spines. At higher magnification, the surface of each fold is further increased with a meshwork of ridges separated by irregular-sized pits. The ventral surface has more complex corrugations and invaginations than those of the dorsal surface of the body. Both anterior and posterior suckers have thick edges covered with transverse folds and appear spineless. The genital pore is located at the anterior one-third of the body. There are two types of sensory papillae on the surface: type 1 is bulbous in shape and nipple-like tips, measuring 10–15μm in diameter at the base, and also type 2 is a similar shape and has short cilia on tips. These sensory papillae occur in large clusters, each having between 7 and 25 units depending on the region of the body. Clusters of papillae on the ventral surface and around the anterior suckers tend to be more abundant and larger in size. The dorsal side of the body exhibit similar surface features, but papillae appear less numerous and are smaller. Corrugations and invaginations of the dorsal aspect are also less extensive than those on the ventral surface of the body.

Mechanisms of Auditory Grouping in Cope’s Gray Treefrog

Event Abstract Back to Event Mechanisms of Auditory Grouping in Cope’s Gray Treefrog Katrina Schrode1* and Mark A. Bee1, 2 1 University of Minnesota, Graduate Program in Neuroscience, United States 2 University of Minnesota, Department of Ecology, Evolution, and Behavior, United States Many animals communicate acoustically in large, social aggregations, where the overlapping signals of conspecifics make it difficult to follow a particular signal. Part of the solution to this problem requires listeners to integrate or group sound elements by their sources. Humans use spectral proximity and other acoustic properties as auditory grouping cues, but less is known about the mechanisms other animals may use. Here, we tested the hypothesis that females of Cope’s gray treefrog (Hyla chrysoscelis) use spectral proximity to group sequential elements of communication signals. Males of this species produce a pulsed advertisement call, to which females exhibit robust approach behavior (phonotaxis). We manipulated the spectral proximity of pulses within an advertisement call by raising or lowering the frequency of some pulses from the baseline carrier frequency. Females were given a choice between this manipulated call and a shorter call with no spectral incoherence. When presented with two calls, females generally discriminate strongly against the shorter of the two, and against calls that are missing pulses. We expected if females were able to use spectral proximity to group pulses, at small ΔF they should perceive the longer signal as a coherent, attractive call, and prefer it to the shorter call. Conversely, when ΔF was large, pulses of the long call were less likely to be grouped, making short calls more attractive. Natural calls have a bimodal frequency spectrum, with peaks at 1.3 kHz and 2.6 kHz. Each of these frequencies is primarily encoded by a distinct sensory organ (papilla) in the frog’s inner ear. We tested females with calls that had only one of the natural frequencies as its carrier frequency. This design ensured that most stimuli were primarily encoded by one of the sensory papillae, but at high stimulus amplitudes, dual stimulation of the papillae was likely. To further elucidate the roles of the sensory papillae, we performed replicates of the experiment at levels of 85 dB, 73 dB, and 61 dB. The lower levels reduced the likelihood of dual activation and better isolate the roles of the individual papillae. Female responses indicated that they are able to group acoustic signals using frequency cues, but that the mechanism responsible seems to differ between the sensory papilla. Responses to low frequency stimuli suggested that females were grouping based on frequency proximity, as humans do, while responses to high frequency stimuli were indicative of a mechanism based on perceived level differences. Our results suggest that frogs, like humans, use frequency cues for auditory grouping, but that their use of frequency cues may be supported by two different neural mechanisms, one similar to that of humans, and one that differs. [Supported by NIDCD 5R01DC009582.] Keywords: auditory grouping, Hyla chrysoscelis, sound source segregation Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster Presentation (see alternatives below as well) Topic: Sensory: Audition Citation: Schrode K and Bee MA (2012). Mechanisms of Auditory Grouping in Cope’s Gray Treefrog. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00183 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 28 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Ms. Katrina Schrode, University of Minnesota, Graduate Program in Neuroscience, St. Paul, United States, schro641@umn.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. 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Revision of the genus 'Microbrotula' (Teleostei: Bythitidae), with description of two new species and a related new genus

Following recent systematic revisions of Anderson (2005, 2007), seven species of the viviparous genus Microbrotula (Teleostei: Bythitidae) have been described, all from the Indo-west Pacific Ocean. Six of these species are here recognised as valid: M. bentleyi, M. greenfieldi, M. punicea, M. queenslandica, M. randalli and M. rubra. Microbrotula polyactis is regarded as a junior synonym of M. bentleyi. Two additional new species, M. andersoni and M. hamata, obtained from Christmas Island (eastern Indian Ocean) and New Caledonia, respectively, are described herein. The main specific characters distinguishing the new species are the number of precaudal vertebrae, numbers of pectoral, caudal and dorsal fin rays, number and distribution of head pores, number and distribution of sensory papillae on the head and lateral line, presence or absence of a (mostly hidden) curved spine at the lower angle of the preopercle, and otolith morphology. The limits of the genus Microbrotula are redefined and the genus is compared with other shallow water bythitine genera. Calamopteryx is regarded as the genus that is most closely related to Microbrotula. As a result of the redefinition of Microbrotula, one of its previously assigned species, M. randalli, is placed in a new genus, Ematops, characterised by the head pore pattern, unique presence of scales partly covering the eye, number of precaudal vertebrae, number of pectoral and caudal fin rays and the otolith proportion.

New Species of Cardicola (Digenea: Aporocotylidae) from Heart of Atlantic Croaker, Micropogonias undulatus (Perciformes: Sciaenidae), of the South Atlantic Bight

Cardicola parvus n. sp. (Digenea: Aporocotylidae) infects the heart of Atlantic croaker, Micropogonias undulatus (Linnaeus, 1766) (Perciformes: Sciaenidae), in the South Atlantic Bight off Cow Island (34°38'49″N, 76°33'41″W, type locality) and Figure Eight Island (34°15'48″N, 77°44'27″W), North Carolina, USA, and off Jacksonville Beach (30°08'23″N, 81°20'52″W), Florida, USA. The new species is most easily differentiated from other members of Cardicola Short, 1953 by the combination of having a minute adult body (≤ 1 mm total length) that is 3.1-4.7× longer than wide, widely dispersed ventral tegumental sensory papillae, ~180 tegumental spine rows per side of body, a spheroid anterior sucker that is apparently aspinous, an esophagus that is 38-39% of the body total length, a male genital pore that is anterior to the ootype, a uterus that transitions from ascending to descending portions posterolaterally to the ovary, and a nearly transverse oviducal seminal receptacle. The new species is the second named aporocotylid from a littoral fish of the South Atlantic Bight and the fifth aporocotylid species reported from fishes of the northwestern Atlantic Ocean.

Two new species of Parspina Pearse, 1920 (Digenea: Cryptogonimidae) from freshwater fishes (Gymnotiformes) of the Paraná River basin in Argentina

Two new species of the cryptogonimid genus Parspina Pearse, 1920 are described from gymnotiform fishes of the Paraná River basin, P. carapo n. sp. from the banded knifefish Gymnotus carapo Linnaeus and P. virescens n. sp. from the glass knifefish Eigenmannia virescens (Valenciennes). Parspina carapo differs from P. virescens in the number of oral spines (32-39 vs 30-33) and their length (28-47 vs 16-28μm), the distribution of tegumental spines and their anchorage, the types of sensory papillae on the body surface (three vs two types), the extent of body length posterior to the caeca (5 vs 13% of the total body length), the dimensions of the pars prostatica (52×34 vs 24×10μm), and in the absence of a gonotyl (vs presence). Both P. carapo and P. virescens differ from P. bagre Pearse, 1920 and P. argentinensis (Szidat, 1954) in the number of oral spines (20-21 and 21-28 in the latter pair) and their length (28-32 and 35-60μm), and in total body length. Additionally, the two new species differ from P. argentinensis in the arrangement of the vitelline follicles (one continuous band vs two groups on each side of the body) and in having a smaller pars prostatica (149×49μm in the latter). Parspina carapo is the fifth intestinal helminth found in G. carapo, and P. virescens is the first found in E. virescens.

Efficacy of methanolic extract of Balanites aegyptiaca fruits on Toxocara vitulorum

In this study, the effect of the methanolic extract of Balanites aegyptiaca fruits (BAE) on adult Toxocara vitulorum was evaluated after incubating the parasites in Ringer solution containing 10, 30, 60, 120 and 240μg/ml of the methanolic extract, for 24h using light and scanning electron microscopic observations. Differences in response to BAE action were concentration dependent. These changes occurred in definite sequences in response to BAE concentration and were consisted of slightly swelling which became pronounced and so severe, with lips showed wrinkled cuticular surface and deformed sensory papillae on increasing the BAE concentration. The strongest effects were reached with the highest BAE concentration, where disorganization of the cuticle and body musculature was observed. Additionally, the ovicidal effect of BAE, at the previous concentrations, on the development of T. vitulorum eggs was examined after 12h exposure. The inhibitory activity of BAE on egg development was concentration dependent and the highest value reached to 100% with the concentration of 240μg/ml. These results were compared with those observed in the worm cuticle and eggs following incubation in albendazole, as it was a broad-spectrum nematodicidal compound with well-known ovicidal activity.

Surface Ultrastructure of Juvenile and Adult Acanthoparyphium tyosenense (Digenea: Echinostomatidae)

The tegumental ultrastructure of juvenile and adult Acanthoparyphium tyosenense (Digenea: Echinostomatidae) was observed by scanning electron microscopy. One- to 3-day-old juveniles and 10-day-old adults were harvested from chicks experimentally fed metacercariae from a bivalve, Mactra veneriformis. The juvenile worms were minute, curved ventrally, and had 23 collar spines characteristically arranged in a single row. The lips of the oral sucker had 7 single aciliated sensory papillae and 4 grouped uniciliated sensory papillae. The ventral sucker had 25 aciliated round swellings on its lip. The anterolateral surface between the 2 suckers was densely packed with tongue-shaped tegumental spines, and the ventral surface just posterior to the ventral sucker was covered with peg-like spines. Retractile, peg-like spines were seen on the anterolateral surface, whereas scale-like spines with round tips and broad bases were sparsely distributed posterior to the ventral sucker. The cirrus was characteristically protruding and armed with minute spines. The surface ultrastructure of A. tyosenense was unique, especially in the number and arrangement of collar spines, shape, and distribution of tegumental spines and in distribution of sensory papillae.

Ultrastructural changes of adult Schistosoma mansoni worms recovered from C57BL/6 mice passively immunized with normal and vaccinated rabbit sera in vivo

The purpose of the study is to explore the role of humoral immunity against Schistosoma mansoni infection in C57BL/6 mice using highly resistant rabbits that had been exposed to three separate immunizations with ultraviolet (UV)-irradiated cercariae (8,000 attenuated cercariae/rabbit in each immunization), and their sera were tested for their ability to transfer protection against S. mansoni challenge. The present study showed the reduction in challenge worm burden had reached 32.76-43.64% when compared with recipients of normal serum or no serum. The surface topography of the worms collected from immunized mice with either normal rabbit sera (NRS) or vaccinated rabbit sera (VRS) revealed severe tegumental alterations, especially in the VRS group. Worms collected from groups that were immunized by NRS or VRS postinfection (200 normal cercariae/mouse) by day42. Worms from group immunized with NRS showed damage in the tegument, characterized by severe swelling or erosion of tegumental folds, accompanied by changes in tubercles, swelling, shortening, and loss of spines in male worms. The alteration in female tegument was characterized by swelling of tegumental folds, atrophy of ventral sucker, damage of sensory papillae along all the body, severe peeling in some regions, and appearance of few small blebs. VRS induced more severe tegumental damage than NRS in both male and female worms. Severe shrunken vesicles were protruded from the surface between the two suckers. The tegument of the male showed a collapse of tubercles followed by the appearance of vesicles on their surfaces, fusion, erosion, and superficial focal peeling of tegumental folds. In the female worms, severe damage to the oral sucker, the surface between the two suckers, extensive peeling, severe swelling of the tegument, and damage of sensory papillae. In conclusion, the present study support the hypothesis that high levels of antibodies were developed in rabbit sera after multiple exposures to attenuated cercariae of S. mansoni. Furthermore, immunization might have transferred protection against the infection, indicated by severe morphological alterations, a sign of elimination of the worms. Further investigation is being carried out to reveal the molecular mechanisms underlying the transfer of protection.

Discovery of males of Simocephalus himalayensis (Cladocera, Simocephalus), with the re-description of females

The lack of data concerning the morphology of male cladocerans greatly impedes our understanding of the systematics of cladocerans. This is because the differentiation of males is of significant importance for distinguishing closely related species. Simocephalus himalayensis himalayensis Chiang & Chen, 1974 (Cladocera, Simocephalus) is an endemic cladoceran species in the Tibetan plateau, China. To date, no information has been available regarding the morphology and biology of its males. In this study, we provide the morphological and biological data of the males that were produced in laboratory populations. The male individuals are about 1.01-1.20 mm long; the margin of antennulae possess two sensory papilla; dorsal valve margin smooth. Two vas deferens are located between the supra-anal angle and the proximal anal teeth. Sperm is round with a diameter of two micrometers. An updated morphological description and reproductive data of the females of this species are also provided.

Redescription of Parspina argentinensis (Szidat, 1954) (Digenea: Cryptogonimidae) from freshwater fishes (Pimelodidae) in the basins of the Paraná and La Plata Rivers, Argentina, with comments on P. bagre Pearse, 1920

The type-specimens of Parspina argentinensis (Szidat, 1954) from Pimelodus maculatus Lacépède, and new material from Iheringichthys labrosus (Lütken), Parapimelodus valenciennis (Lütken), Pimelodella gracilis (Valenciennes), Pimelodus albicans (Valenciennes), P. argenteus Perugia and P. maculatus caught in the basins of the La Plata and Paraná Rivers, Argentina, were studied to elucidate its taxonomic status. The type-specimens of Parspina bagre Pearse, 1920 from Pimelodella metae Eigenmann in Lake Valencia, Venezuela, were also studied and new observations on its morphology recorded. The amendation of the generic diagnosis of Parspina Pearse, 1920 is proposed based on the study of both species, which revealed, among other features, the absence of a thin walled-membrane enclosing the male terminal genitalia. Parspina argentinensis is characterised by the following features: absence of a gonotyl; presence of a bipartite seminal vesicle, pars prostatica and ejaculatory duct; caeca of nearly equal length; uterus extending from the level of the ventral sucker to end of body; testes symmetrical to slightly oblique; ovary transversely elongate, compact and variable in shape; and the utilisation of a wide range of freshwater fishes as hosts. The tegumental surface of this species is covered with pectinate spines arranged quincuncially. Spines decrease in size and density from forebody to hindbody. There are two types of sensory papillae, ciliated and dome-shaped. Ciliated papillae are distributed on the surface of the oral region and on the dorsal and ventral surfaces of the body, whereas dome-shaped papillae are found on the surface of the ventral rim of the oral sucker associated with a ciliated papilla. Gland-duct openings are interspersed with the spines of the oral crown. In addition, the infection indices of P. argentinensis vary widely, not only among different hosts but also between the Paraná and La Plata River basins. Higher prevalences of P. argentinensis are recorded in the La Plata River, and Pimelodus albicans, P. maculatus and Iheringichthys labrosus are the principal final hosts in this area.

Two new species of Oregodasys (Gastrotricha: Macrodasyida: Thaumastodermatidae) from Carrie Bow Cay, Belize with ultrastructural observations of the epidermal glandular system

This study represents the first report of Gastrotricha from the coast of Belize. Two new species of Oregodasys (Macrodasyida: Thaumastodermatidae) are described from sublittoral sediments around the island of Carrie Bow Cay in the Belizean barrier reef complex. Oregodasys norenburgi sp. nov. is unique in the possession of paired red ocelli and in the quantity and distribution of lateral and posterior adhesive tubes. Oregodasys katharinae sp. nov. is allied with species that possess ventrolateral cirri in the posterior body region, but is distinguished based on the quantity of cirri and adhesive tubes and the bipartite structure of the caudal organ. Ultrastructural analysis of the bodywall of O. katharinae sp. nov. reveals a highly glandular epithelium covered by a bilayered cuticle consisting of a thin exocuticle and thicker endocuticle containing electron-dense elements. At least three types of papillae are present beneath the cuticle: blunt papillae, triangle-shaped papillae, and sensory papillae. The sensory papillae are two-part structures consisting of a porous epidermal cell and a monociliated epidermal cell. The ultrastructure of blunt papillae was not examined, but triangular papillae are formed from neck-like extensions of underlying glandulocytes and contain a pore to the external environment. Insunk glandulocytes are present between the various papillae and have an elongate neck that extends between epidermal cells. All glandulocytes contain a variety of membrane-bound secretory vesicles with a wide range of staining characteristics, from electron lucent to electron dense.

External sense receptors in microdrile oligochaetes (Annelida, Clitellata) as revealed by scanning electron microscopy: Typology and patterns of distribution in the main taxonomic groups

This work summarizes the observations on 30 species of microdriles belonging to the families Naididae (Rhyacodrilinae, Pristininae, Naidinae, Phallodrilinae, and Tubificinae), Phreodrilidae, Lumbriculidae, and Enchytraeidae using scanning electron microscopy. The lumbricid Eiseniella tetraedra, a megadrile species common in typical microdrile habitats, was used for comparison. Microdriles display external ciliate sense structures along the entire body; even at the clitellum and in budding and regeneration zones. According to the shape of the cilia, these sense structures can be divided into receptors of blunt cilia, receptors of sharp cilia, and composed receptors. Sense receptors can be morphologically unconspicuous or clearly defined on sensory buds or papillae. All microdriles studied have receptors of blunt cilia. Enchytraeids have characteristic receptors of short cilia. Pristina (Pristininae), Chaetogaster, Ophidonais, and Stylaria (Naidinae) have receptors of long blunt cilia. Composed receptors were found only in some microdriles and E. tetraedra. Receptors of sharp cilia have been found in most microdriles. Enchytraeids might be the only exception, but sharp cilia are probably present in the amphibiotic Cognettia sphagnetorum. Sensory cells with long sharp cilia might play a rheoreceptor role, and their presence in E. tetraedra and C. sphagnetorum would imply the reappearing of an ancient character that was probably lost with the transit from aquatic to terrestrial habitats. Some lumbriculids have ciliated fields. Anatomically, these structures appear as intermediate between the typical isolate sensory structures of microdriles and the sensillae of the hirudineans. The general pattern in microdriles is that uniciliate receptors and multiciliate receptors are separated, which supports the presumed aquatic origin of the clitellates.

Status and phylogeny of Milyeringidae (Teleostei: Gobiiformes), withhe description of a new blind cave-fish from Australia, Milyeringa brooksi, n. sp.

A phylogeny of Milyeringidae is reported and a new species, Milyeringa brooksi, is described from Cape Range National Park in the North West Cape (Cape Range Peninsula) of Australia. This species is distinguished on the basis of morphological and molecular characters from its only congener Milyeringa veritas. These diagnostic characters are related to a unique pattern of sensory papillae on the body and synapomorphies in three genes (cytochrome c oxidase I, cytochrome b, and NADH dehydrogenase 2). The new species is known only from the southern portion of the North West Cape spanning roughly 50 kilometers of subterranean habitat. This habitat is exceedingly rare and measures to preserve it and its fauna should be taken.

Parioglossus interruptus, a new species of goby from the Western Pacific

A new species of goby, Parioglossus interruptus sp. nov. is described from specimens from Iriomote Island, Okinawa Prefecture, Japan. It is distinguished from congeneric species as follows: scales imbricate; anterior oculoscapular canal with pores C', D, E and F; preopercular canal with pores N' and O'; a single sensory papilla in the symphysial line; a narrow, black lateral band extending from the posterior edge of the eye through the upper part of the opercle and along the lower half of the trunk, fading gradually above the anal fin, not extending to caudal fin base; a black triangular to oblong blotch on the caudal fin, between 5th or 6th and 15th or 16th segmented rays, not extending onto fin base. A key to the species of Parioglossus is given

Paramphistomum cervi: Surface topography of the tegument of adult fluke

Adult Paramphistomum cervi or rumen fluke are pear-shaped, slightly concave ventrally and convex dorsally. The worm measures about 5–13 mm in length and 2–5 mm in width across the mid-section. As observed by scanning electron microscopy (SEM), the tegumental surface in all part of the body, appears highly corrugated with transverse folds alternating with grooves and is spineless. At high magnification, the surface of the fold is composed of microfolds or ridges separated by microgrooves or pits. Corrugations and invaginations of the ventral surface are also more extensive than on the dorsal surface of the body. Both anterior and posterior suckers have thick rims covered with transverse folds without spine. The genital pore is situated at the anterior third of the body. There are two types of sensory papillae on the surface: type 1 is bulbous in shape, measuring 10–15 μm in diameter at the base with nipple-like tips, and type 2 has a similar shape and size and also a short cilia on top. These sensory papillae usually occur in large clusters, each having between 5 and 20 units depending on the region of the body. Clusters of papillae on the ventral surface and around the anterior suckers tend to be more numerous and larger in size. The dorsal surface of the body has the least number of papillae.

Morphological, ecological and molecular characterization of the enigmatic planispiral snail genus Adeuomphalus (Vetigastropoda: Seguenzioidea)

Adeuomphalus Seguenza, 1876 is a little known genus among the skeneimorph vetigastropods, with very few specimens previously reported alive from the deep sea. We examined newly collected and museum-stored specimens from upper to lower bathyal depths in the Atlantic, Mediterranean, Pacific and Indian Oceans and recognize seven recent species in the genus: A. ammoniformis Seguenza, 1876, A. densicostatus (Jeffreys, 1884), A. trochanter Waren & Bouchet, 2001, A. sinuosus (Sykes, 1925) n. comb., A. guillei n. sp., A. elegans n. sp. and A. collinsi n. sp., along with a fossil species, A. bandeli (Schroder, 1995) from the Lower Cretaceous, Poland. These species are characterized by a minute and colourless shell with almost perfectly planispiral whorls, an orthocline aperture, distinct radial ribs and a deeply concave apex and base. At least three species are confirmed to be radula-less, while A. guillei n. sp. has a simplified (3 -2-1-2-3) rhipidoglossate radula. Anatomical investigations of A. collinsi n. sp. and A. trochanter revealed the following traits: a monopectinate ctenidium, blunt and tapering cephalic tentacles with sensory papillae, a cylindrical snout, a simple right neck lobe, a large foot with the anterior corners drawn out into finger-like projections, a smooth ESO-tentacle and a single, micropapillate epipodial tentacle on each side of the foot; absence of pigmented eyes, eye lobes, cephalic lappets and subocular peduncles. Three species collected by submersibles in the vicinity of hydrothermal vents co-occurred with carnivorous sponges of the family Cladorhizidae; a parasitic mode of life is suggested based on the lack of the radula and the peculiar, tube-like shape of the snout. Separate and combined phylogenetic analyses of mitochondrial (COI and 16S rRNA) and nuclear (histone H3 and 18S rRNA) gene sequences revealed six monophyletic groups in Seguenzioidea: Seguenziidae, Chilodontidae, Calliotropidae, Cataegidae, Spinicalliotropis and skenei- morph seguenzioids. Three included skeneimorphs (A. elegans n. sp., Xyloskenea sp. and Ventsia tricari- nata) were ambiguously grouped together with long branches and low statistical supports, possibly suggesting a vast, undiscovered phylogenetic diversity of the group. Taxonomic composition, mor- phological characteristics and evolutionary history are discussed for the skeneimorphs and five other groups in the superfamily.

Tegumental surface changes in adult Paramphistomum microbothrium (Fischoeder 1901) following in vitro administration of artemether

The treatment of paramphistomiasis, a neglected tropical disease, has been carried out with different fasciolicidal compounds, all showing weak efficacy. Therefore, the search for alternative paramphistomicidal drugs is warranted. In the present study, the in vitro effects of artemether on adult Paramphistomum microbothrium were evaluated, for the first time, using scanning electron microscopy. After 24 h of incubation with 10 microg ml(-1) artemether, tegumental damage of both anterior and posterior ends of the fluke had occurred in the majority of the specimens examined. Sensory papillae surrounding the oral aperture were ruptured, while those at the acetabular region appeared to be sunken due to tegumental swelling. The tegumental disruption became more pronounced and both oral sucker and acetabulum were severely distorted, on increasing the concentration to 20 microg ml(-1). With higher concentration of 30 microg ml(-1), gross swellings of the body of the fluke, clearly visible to the naked eye, were observed, and damage to both oral sucker and acetabulum was so extreme that little recognizable structure remained.

Surface ultrastructure of Plagiorchis muris growth and developmental stages in rats, the final host

In the excysted metacercaria, the whole fluke surface was covered with peg-shaped tegumental spines. Ciliated sensory papillae (type I) were concentrated around the oral sucker, and non-ciliated sensory papillae (type II) were aligned on the lip of oral and ventral suckers. Several type II papillae were aligned laterally with linear symmetry between the oral and ventral suckers. In juvenile flukes, cytoplasmic processes were band-shaped on the anterior half of the body surface and velvety on the posterior half. In adult flukes, cytoplasmic processes were differentiated into velvety processes, and densities of tegumental spines were reduced on the posterior half of the body. Flukes grew to be elongated and leaf-like as adults and retained a surface ultrastructure that was similar to that of juveniles in terms of the distribution of tegumental spines and sensory papillae. From the above results, the authors suppose that the marked differentiation of cystoplasmic processes and the reduced density of tegumental spines observed on the posterior half of the body surface are closely related to the development of reproductive organs therein.

Comparative in vitro effect of artemether and albendazole on adult Toxocara canis

Since the integrity of Toxocara canis cuticle is essential for the nutritive and protective functions, light and scanning electron microscopic studies were undertaken to assess, for the first time, whether artemether had any effect on the cuticle including lips and sensory organs following 24 and 48 h incubation in vitro. The results were compared with those observed in the worm cuticle following incubation in albendazole, as it was 100% effective against adult nematode. The body cover changes seen after in vitro administration of artemether were similar to that induced by albendazole sulfoxide, active form, (ABZ-SO). However, the earlier onset of those changes was recorded with the former. The swollen appearance of the anterior end of T. canis, including the lips, distortion of some sensory papillae, and appearance of a number of lesions on the lips, were observed during in vitro action of artemether. Cuticular disruption had also been observed in adult T canis exposed to ABZ-SO. The surface changes were more severe than those observed following incubation in artemether, with which limited loss of the cuticle occurred in the lips of nematode but was not as widespread as that seen with ABZ-SO. However, the cuticular swelling of the anterior end of T canis was more pronounced than that with ABZ-SO. In the present study, artemether presented itself as a drug that might become important in nematode chemotherapy, besides its broad spectrum of activity against various trematodes.