Shape Of Spicules Research Articles

Morphobiological analysis of Trichuris vulpis (Nematoda, Trichuridae), obtained from domestic dogs

The parasitic nematode Trichuris vulpis Frölich, 1789 is the pathogen of trichuriasis in domestic and wild carnivores, and humans. This helminth species is distributed world-wide in populations of domestic dog (Canis lupus familiaris). The prevalence of T. vulpis in dogs depends to a large degree on the morphofunctional and biological adaptations of the parasite which support its high survivability in various environmental conditions. The present study considers the species-specific peculiarities of morphology, and metric parameters of the mature and embryonic stages of Trichuris nematodes parasitizing in C. lupus familiaris. We studied the periods of stages of development and infectious egg formation, and their survivability under optimal conditions for T. vulpis in laboratory culture. The differential characteristics of both female and male adult T. vulpis nematodes include the metric characteristics of cuticular protrusions at the surface of the anterior body part. The male T. vulpis nematodes can be distinguished from males of other species by the specifics of spicule sheath ornamentation, the shape and size of spicule, and the width of spicule sheath at different sections. In identification of the female nematodes of this species, it is necessary to consider the presence and size of papillary processes in the vulval area and metric parameters of vulva location. Nine metric characters of sexual dimorphism are described for T. vulpis nematodes. In laboratory conditions, five embryonic stages were observed for T. vulpis: protoplast, blastomere cleavage, and formation of bean-like embryo, larva and mobile larva. These stages are characterized by specific morphological features. The egg develops to the infectious stage at 27 °С in 18 days of culture, and their survivability is up to 76.6%. The egg development is associated with changes in their metric characters, such as decreasing egg length and width of egg shell, and increasing egg width and egg plug width.

Bursaphelenchus michalskii sp. n. (Nematoda: Aphelenchoididae), a nematode associate of the large elm bark beetle, Scolytus scolytus Fabr. (Coleoptera: Curculionidae), in Dutch elm disease-affected elm, Ulmus laevis Pall.

Summary Bursaphelenchus michalskii sp. n. is described from the bark of the European white elm, Ulmus laevis. All propagative stages of the nematode were found in larval galleries of the large elm bark beetle, Scolytus scolytus, and in overlapping gallery systems of this species and the small European elm bark beetle, S. multistriatus. Dauer juveniles of the new nematode are transmitted to new breeding trees under elytra of adult S. scolytus. Bursaphelenchus michalskii sp. n. is characterised by the female body length of 953 (838-1108) μm and male body length of 893 (811-971) μm, very slender body (a = 53.9 (46.1-58.5) and 60.9 (52.2-72.0) in female and male, respectively), lateral fields with three incisures (two bands), excretory pore usually located anterior to the median bulb, lack of vulval flap, long post-uterine sac, relatively small spicules 12.3 (10.8-13.3) μm long with no cucullus and with distinct, somewhat thorn-like, dorsally bent or reflexed condylus and a conical or digitate rostrum, and the arrangement of the seven male caudal papillae (i.e., a single precloacal ventromedian papilla (P1), one pair of adcloacal ventrosublateral papillae (P2) at or just anterior to cloacal slit, one ventrosublateral, postcloacal pair (P3) located at ca 60% of the tail length, posterior to cloacal slit, and one pair (P4) of ventrosublateral papillae located near the base of the bursa). The newly described species shares most of the key morphological characters with members of the eremus-group (sensu Braasch et al., 2009). However, B. michalskii sp. n. is unique amongst Bursaphelenchus species by a combination of female tail and spicule shape, excretory pore position, and other morphometric characters. These findings were confirmed by DNA sequencing and phylogenetic analysis of the 18S and 28S rDNA regions and by the unique molecular profile of the ITS region (ITS-RFLP).

Micro‐computed tomography of spicule networks in three genera of dorid sea‐slugs (Gastropoda: Nudipleura: Doridina) shows patterns of phylogenetic significance

AbstractDorid nudibranchs (Gastropoda: Nudipleura) are a key taxon for studying the evolution and interaction of chemical defence, colour patterns and feeding specialization, but we lack a robust phylogeny for hypothesis testing. To provide new morphological characters, we investigated the extensive interior spicule networks of several dorid taxa. We compared traditional staining methods versus micro‐computed tomography (μCT) of 31 specimens representing 10 species ofAldisa,CadlinaandOnchidoris. We found that μCToffered a nondestructive view of sufficient resolution to study the gross morphology of networks, although images of fine structures were too grainy to allow robust comparisons. Network form did not vary within species and was consistent within genera. The three genera varied in several obvious characters, such as the presence of a pleural sinus channel, large dorsal spicules and multispicular tracts, as well as in relative size, shape and orientation of spicules. These characters, combined with those from the literature, supported recent molecular phylogenies that groupCadlinawithAldisa, and that question the monophyly of the Cryptobranchia. This suggests that these network forms will prove a fruitful source of phylogenetic characters with at least genus‐level resolution.

Steinernema taiwanensis n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from Taiwan.

A new isolate of the entomopathogenic nematode, Steinernema taiwanensis n. sp., was isolated from soil in Pingtung County, Taiwan. This new species could be characterized and distinguished from other related species by its morphological characters, morphometrics, and phylogenetic analysis. The body length and distance from anterior end to nerve ring of infective juveniles is 1012 (983-1045) µm and 124 (120-127) µm, lateral field formula 2, 6, 7, 8, 2, and the tail length 90 (79-96) µm without dorsal constriction in tail region. The first generation males of S. taiwanensis n. sp. are characterized by spicule shape, smooth blade tip, 23 genital papillae (11 pairs and 1 single papilla), spicule length of 94 (89-99) µm and gubernaculum length of 68 (65-70) µm. Females from the first generation of S. taiwanensis n. sp. have no epiptygmata and a slightly developed post-anal swelling. Phylogenetic analysis of ITS and D2D3 regions of rDNA showed that S. taiwanensis n. sp. belongs to the Longicaudum-clade and comprises a monophyletic group with S. guangdongense and S. longicaudum. The new isolate is described as a novel species according to morphological and phylogenetic analyses.

Pseudochromadora benepapillata (Timm 1961) comb. n. (Desmodoridae: Nematoda): revision of its taxonomic status and distribution.

Metachromadora (Bradylaimoides) benepapillata, was first discovered from the coastal mangroves of Bangladesh by Timm (1961). This species was later synonymised with Pseudochromadora cazca, which was described from the Brazilian coast by Gerlach (1956). The present paper proposes to update the taxonomic status of the Timm's species as Pseudochromadora benepapillata comb. n. along with its distribution and comparative morphology. The major differences between P. cazca and P. benepapillata are found in the characteristics of the head capsule; length of cephalic sensilla; length and position of somatic setae; shape of amphideal fovea; shape of spicules and gubernaculum; number and morphology of copulatory and postcloacal thorns. The present report on the occurrence of this species along the eastern most coast of India extends its distribution from the eastern part of Bay of Bengal to its western part.

Redescription of Bursaphelenchus eucarpus Rühm, 1956 (Nematoda: Aphelenchoididae) associated with the apple bark beetle, Scolytus mali Bechstein, and the shothole borer, S. rugulosus Müller

Summary New morphological, molecular and bionomic data are added to update the description of Bursaphelenchus eucarpus. The nematode was isolated from larval galleries and adults of the apple bark beetle, Scolytus mali, and the shothole borer, S. rugulosus, present under the bark of the bird cherry, Prunus padus, and the common European plum, P. domestica, in Poland. Detailed male, female and dispersal juvenile morphology and morphometrics are documented and compared with the original description. From partial 18S, ITS1/2 and partial 28S D2-D3 sequences and morphological features (three lateral lines, position of caudal papillae, shape of the delicate spicules with dorsally bent condylus, lack of vulval flap, a long post-uterine branch and a hyaline region at the female tail tip) it can be concluded that B. eucarpus belongs to the eremus group of Bursaphelenchus. The differentiation from related species of the eremus group is discussed.

One new species and one new combination of the family Xyalidae (Nematoda: Monhysterida) from the East China Sea

A new species and a new combination of the family Xyalidae are described from the East China Sea. Elzalia bifurcata sp. nov. is characterized by small body size, relatively long cephalic setae, elongated spicules with bifurcate or y-shaped distal end, simple tubular gubernaculum without apophyses. Elzalia bifurcata sp. nov. differs from the closely related species E. striatitenuis Zhang and Zhang, 2006 and E. mediterranea Vitiello, 1971 by the length of cephalic setae; presence or absence of cervical setae; shape, structure and length of spicules and gubernaculum. Daptonema macrostoma Huang & Xu, 2013 is redescribed and reclassified. The species agrees well with the characters of the genus Paragnomoxyala Jiang & Huang, 2015, such as large buccal cavity; outer labial sensilla papilliform, not setiform; spicules almost straight with slightly curved proximal ends, absence of gubernaculum. Therefore, it is transferred to the genus Paragnomoxyala. As a new combination, the species is named as Paragnomoxyala macrostoma (Huang & Xu, 2013) comb. nov. An emended key to valid species of Elzalia is provided.

Two new species of Oswaldocruzia (Nematoda, Molineidae) parasitising lizards in Ukraine

Two new species, Oswaldocruzia lisnykiensis sp. n. and Oswaldocruzia lacertica sp. n., are described from Anguis fragilis L. (Reptilia: Anquidae) and Lacerta agilis L. (Reptilia: Lacertidae) respectively. Both species belong to the Palaearctic group of species which have spicules divided in three main branches (blade, fork and shoe) with fork division above its distal third. The new species differs from all previously known Palaearctic species by several morphological characters: type of caudal bursa (type III in O. lisnykiensis and type I in O. lacertica), shape of spicules (blade distally divided into four tips and specific shape of shoe) and synlophe structure (narrow cervical alae consist of three crests in both species). Illustrated descriptions of O.lisnykiensis and O. lacertica based on 63 and 38 specimens respectively are presented. Host specificity and geographical distribution of the species are discussed. O.dispar is considered as a species inquirenda.

Spinitectus aguapeiensis n. sp. (Nematoda: Cystidicolidae) from Pimelodella avanhandavae Eigenmann (Siluriformes: Heptapteridae) in the River Aguapeí, Upper Paraná River Basin, Brazil.

Nematodes belonging to Spinitectus Fourment, 1883 (Nematoda: Cystidicolidae) were found in the intestine of Pimelodella avanhandavae Eigenmann (Siluriformes: Heptapteridae) from the Aguapeí River, Brazil. They represent a new species, Spinitectus aguapeiensis n. sp., which differs morphologically from its congeners in the body length, the number of spinose rings, the location of the excretory pore, the number of precloacal papillae and the length of the spicules. The new species is the first South American species within the genus with a remarkably spirally coiled posterior extremity in males and the largest spicules. It is also the second species with the highest number of precloacal papillae and has unique shape of the small spicule. Spinitectus aguapeiensis n. sp. is the first helminth species found in P. avanhandavae, the fourth species of this genus recorded in the River Paraná Basin and the sixth species of Spinitectus in South America.

Observations on the systematic position of the genus Gaigeria Railliet & Henry, 1910 (subfamily Necatorinae Lane, 1907: family Ancylostomidae Lane, 1907: Nematoda)

On the basis of the form and length of the dorsal lobe of the bursa and the shape of the spicules, as observed in Gaigeria pachyscelis and Bunostomum trigollocephalum , both genera are considered distinct and separate, and the former not a synonym of the latter.

A new species of Aplectana (Nematoda: Cosmocercidae) parasite of Pleurodema nebulosum (Anura: Leptodactylidae) from the Monte desert, Argentina, with a key to Neotropical species of the genus Aplectana.

Here we describe a new cosmocercid nematode, Aplectana nebulosa sp. nov., from the small and large intestines of Pleurodema nebulosum (Anura: Leptodactylidae), from the Monte desert of San Juan, Argentina. The new species belongs to the Aplectana group that possesses a gubernaculum and unpaired adcloacal papilla anteriorly to cloaca. It resembles A. membranosa, A. paraelenae and A. travassosi by the presence of four adcloacal papillae, but differs from those species by the following characters: number and arrangement of precloacal papillae; number and arrangement of postcloacal papillae; shape and size of spicules and gubernaculum, and by the presence of lateral alae in caudal region of males. The description of the new species is based on light microscopy and scanning electron microscopy (SEM) and we also provide a key to Neotropical species of Aplectana.

Deep-sea chitons of the genus <i>Stenosemus</i> (Mollusca: Polyplacophora) from Fiji and Solomon Islands

Three new species of the genus Stenosemus collected near Fiji and Solomon Islands of the central Pacific are described here. Stenosemus fijiensis sp. nov. from Fiji differs from the congeneric species by a unique sculpture of the central areas of tegmentum, consisting of triangular pits and light brown spots on valves. S. philippei sp. nov. and S. solomonensis sp. nov., both from the Solomon Islands, differ from other the species of the genus by having a head of major lateral tooth of radula bicuspidate with small outer denticle, shape and sculpture of dorsal spicules and sculpture of tegmentum.

Integrative taxonomy reveals the first record and a new species for the previously monotypic genus Tethytimea (Tethyida: Tethyidae) in the Gulf of Mexico.

The first record of the previous monotypic genus Tethytimea and the description of a new species from cryptic habitats of Gulf of Mexico are presented. Tethytimea carmelita sp. nov., is a red orange cushion shaped sponge (about 5 mm thick) with a tuberculate to granular surface. The spicular complement is formed by tylostyles (200-1120 µm length), smooth spheres (12.5-55 µm in diameter); megasters-spheroxyasters (12.5-90 µm in diameter); and micrasters in two categories: oxy-strongylasters (12.5-27.5 µm in diameter) and spherotylasters (2.5-25 µm in diameter). The new species differs from the only species known T. tylota (Hentschel, 1912) mainly by differences in the size and shape of spicules. T. tylota possesses tylostyles in two size categories; megasters include giant oxyspherasters up 250 µm and micrasters in a single category. Additionally, to the morphological characteristics, we integrated partial sequences of a large sub-unit ribosomal 28S rDNA gene region (D1-D2 domains), in order to establish the molecular taxonomic position of our new species (and genus). Tree topologies (Maximum Likelihood and Bayesian Inference) were congruent in phylogenetic hypothesis, retrieving the Order Tethyida as monophyletic. In this clade, the family Timeidae was separated from the other families Tethyidae + Hemiastrellidae. Inside this latter group and according to the taxonomic hypothesis based on morphology, Tethytimea carmelita sp. nov. was included in Tethyidae clade, together with a sequence of Tethya sp. (AY626300), forming a sister group with representatives of genera Xenospongia and Thectitethya. Our new species constitutes the second valid known species for the genus Tethytimea and the first record of genus for the Atlantic Ocean.

Description of Bursaphelenchus taphrorychi sp. n. (Nematoda: Parasitaphelenchidae), the second Bursaphelenchus species from larval galleries of the beech bark beetle, Taphrorychus bicolor (Herbst.) (Coleoptera: Curculionidae: Scolytinae), in European beech, Fagus sylvatica L.

Bursaphelenchus taphrorychi sp. n. is described from the bark of European beech, Fagus sylvatica. All propagative stages of the nematode are numerous in larval galleries of the beech bark beetle, Taphrorychus bicolor, while dauer juveniles are transmitted to new breeding trees under the elytra of adult beetles. The new species is characterised by the body length of 782 (717-858) μm in female and 638 (475-789) μm in male, moderately slender body (a = 35.0 (31.7-36.5) and 35.5 (31.4-37.1) in female and male, respectively), spicules 12.0-16.0 μm long, lateral fields with four incisures (i.e., three bands), and the arrangement of the seven male caudal papillae (i.e., a single precloacal ventromedian papilla (P1), one pair of adcloacal ventrosublateral papillae (P2), one postcloacal pair (P3) located at ca 60% of the tail length, posterior to the cloacal aperture, and one pair (P4) of subventral papillae of a similar size as the previous pair, but with somewhat sunken tips, located near base of bursa). In the number and arrangement of caudal papillae, stout and curved spicules with prominent rostrum and condylus, small vulval flap, body narrowed posterior to vulva, four incisures in the lateral fields, and long post-uterine sac, B. taphrorychi sp. n. shares most of the key morphological characters with members of the sexdentati-group. However, the newly described species is unique amongst Bursaphelenchus species of this group by the combination of shape of female tail, shape of spicules, and some other morphometric characters. The close relation of B. taphrorychi sp. n. with members of the sexdentati-group has been confirmed by DNA sequencing and phylogenetic analysis of the 28S rDNA region. The taxonomic separation of the new species is also confirmed by the unique molecular profile of the ITS region (ITS-RFLP). In laboratory rearing, B. taphrorychi sp. n. can develop and reproduce on Botrytis cinerea cultures.

Four new species and five morphospecies of Ficophagus Davies & Bartholomaeus, 2015 (Nematoda: Aphelenchoididae) from Ficus subgenus Urostigma sect. Americana (Moraceae) in Central America

Four new species ofFicophaguswere recovered from the sycones ofFicusspp. from the SubgenusUrostigmasectionAmericanafrom Central America. The species are described here asFicophagus bulleneisp. n.,F. costaricanussp. n.,F. paraensissp. n. andF. kayaisp. n. The new species are differentiated from other species of the genus by a combination of morphological characters including body length, position of the excretory pore, spicule shape, stylet form, length of the post-uterine sac, tail shape, sequence data of the ribosomal DNA 18S, 28S D2-D3 and mitochondrial DNA cytochrome oxidase subunit I, biogeographical range, and host wasp andFicusspecies affiliations. In addition, five morphospecies are described fromFicus cahuitensis,F. citrifolia,F. dugandii,F. obtusifolia, andF. trigonata, respectively. The morphospecies are not formally named due to a lack of pertinent data/molecular sequences.

Steinernema goweni n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from Zulia State, Venezuela.

A nematode from the genus Steinernema was isolated in Zulia state (North-western, Venezuela). Morphological, morphometric and molecular studies indicated that this nematode belongs to the "bicornutum" group and is described herein as Steinernema goweni n. sp. Steinernema goweni n. sp. is characterised by morphometrics of its infective juveniles, with body length 640 (531-719) µm, pharynx length of 119 (109-126) µm, tail of 67 (59-89) µm, c ratio = 9 (6-11) and E% = 77 (48-94). First generation male specimens can be recognised by the shape and size of spicules (55 (50-57) µm long) and gubernaculum (35 (30-40) µm long), and %D value 42 (28-59), which is at the lower limit within the "bicornutum" group. The number of genital papillae in males is also distinctive for S. goweni n. sp. presenting up to 27 (13 pairs + 1) papillae in 15% of specimens. The phasmids can be seen in scanning electron microscopy in all stages, characters not previously reported within the "bicornutum" group. Phylogenetic analyses of the "bicornutum" group based on both ITS and D2D3 regions showed a clear separation of S. goweni n. sp. from the other species. In both analyses S. goweni n. sp. formed a strongly supported group of American species.

Three new and two known free-living marine nematode species of the family Ironidae from the East China Sea.

Three new and two known species of free-living marine nematodes of the family Ironidae from the East China Sea are described and illustrated. Conilia sinensis sp. nov. is identified by the relatively large body size (1883-2399 µm); the well developed lips; the number, shape and length of spicule (single and striated, length 87-100 µm as arc); the shape of telamon; the number of supplements (1). Pheronous donghaiensis sp. nov. is characterized by its sharp tail point; caudal gland absent; buccal cavity armed with four big solid teeth and rows of minute denticles; spicules stout, with central septum at proximal end, male caudal region with two rows of small conical subventral papillae. Trissonchulus latispiculum sp. nov. can be distinguished by its head not set off from remaining body, tail short and blunt, buccal cavity with minute denticles, spinneret opening slightly ventrally, spicule broad and alate with central septum and head on proximal end. Trissonchulus benepapillosus (Schulz, 1935) and Trissonchulus oceanus Cobb 1920 which are first reported from China, are redescribed in detail with emphasis on new or hitherto poorly described morphological features. Types are deposited in the Institute of Oceanology, Chinese Academy of Sciences.

Nematodes of amphibians from Java, Indonesia, with a description of new species, Meteterakis wonosoboensis n. sp. (Nematoda : Heterakoidea).

During a survey on the parasites of amphibians of Indonesia, toads (30 Bufo melanostictus) and 246 frogs (213 Fejervarya cancrivora, 11 F. limnocharis, 22 Rana macrodon from West Java and 68 F. cancrivora from Central Java) were examined for parasitic nematodes. Three species of nematodes were found and described, i.e. Meteterakis wonosoboensis n. sp. from Fejervaria cancrivora; Meteterakis japonica from Bufo melanostictus, F. cancrivora and F. limnocharis; and Chabaudus sp. from F. cancrivora, F. limnocharis and Rana macrodon. Meteterakis wonosoboensis n. sp. is distinguished from other species of the genus by the length and shape of spicules, the number of caudal papillae, the presence of gubernaculum in male and the presence of vulval flap in female. Bufo melanostictus and Java are recorded as new host and locality for M. japonica, respectively.

Redescription of Paraleptus chiloscyllii Yin et Zhang, 1983 (Nematoda: Physalopteridae) from the Arabian carpetshark Chiloscyllium arabicum (Chondrichthyes: Hemiscylliidae) off Iraq.

The nematode Paraleptus chiloscyllii Yin et Zhang, 1983 (Physalopteridae) is redescribed on the basis of new material collected from the stomach of the Arabian carpetshark Chiloscyllium arabicum Gubanov (Hemiscylliidae) from marine waters off Iraq. Originally, P. chiloscyllii was found in C. plagiosum (Anonymous [Bennett]) from Fujian, China, but its description was rather poor and some important morphological features, such as deirids, shape and number of structures surrounding mouth, ventral unpaired papilla on the anterior cloacal lip, among others, were overlooked. It differs from its congeners in the shape of spicules and body length, although is very similar to the type species, P. scyllii Wu, 1927, only differing in the inequality of spicules. The generic diagnosis of Paraleptus was amended. Paraleptus minnanensis (Damin et Heqing, 2001) is considered a junior synonym of P. chiloscyllii and some morphological details of the posterior end of a male of P. australis Johnston et Mawson, 1943 are provided. The present finding of P. chiloscyllii in C. arabicum from off Iraq represents new host and geographical records.

Parasitodiplogaster salicifoliae n. sp. (Nematoda: Diplogastridae) from Ficus ingens and F. salicifolia in South Africa

Parasitodiplogaster salicifoliae n. sp. was isolated from Ficus salicifolia and F. ingens from South Africa and is described and depicted herein. Molecular sequence (D2-D3 expansion segments of the large subunit (LSU) ribosomal DNA and a fragment of mtCOI) and morphological comparisons with P. australis from F. virens from Australia support a monophyletic lineage of fig wasp-associated diplogastrids within what is currently accepted as Parasitodiplogaster from figs in the subgenus Urostigma, section Urostigma, subsection Urostigma. This ranking within Parasitodiplogaster is conditional upon examination of more material from figs from the subsection Urostigma from its putative centre of origin (Indo-Australasia) because the morphology (presence of one prodelphic ovary vs two amphidelphic ovaries and several other autapomorphic features) and molecular data are suggestive of a potentially well-defined radiation of nematode species. Parasitodiplogaster salicifoliae n. sp. can be typologically distinguished from its nearest known relative, P. australis, by the male genital papillae number and arrangement, as well as spicule shape.