Nerve Ring Research Articles

A metameric origin for the annelid pygidium?

BackgroundSegmented body organizations are widely represented in the animal kingdom. Whether the last common bilaterian ancestor was already segmented is intensely debated. Annelids display broad morphological diversity but many species are among the most homonomous metameric animals. The front end (prostomium) and tail piece (pygidium) of annelids are classically described as non-segmental. However, the pygidium structure and development remain poorly studied.ResultsUsing different methods of microscopy, immunolabelling and a number of molecular markers, we describe the neural and mesodermal structures of the pygidium of Platynereis dumerilii. We establish that the pygidium possesses a complicated nervous system with a nerve ring and a pair of sensory ganglia, a complex intrinsic musculature, a large terminal circular blood sinus and an unusual unpaired torus-shaped coelomic cavity. We also describe some earlier steps of pygidial development and pygidial structure of mature animals after epitokous transformation.ConclusionsWe describe a much more complex organization of the pygidium of P. dumerilii than previously suggested. Many of the characteristics are strikingly similar to those found in the trunk segments, opening the debate on whether the pygidium and trunk segments derive from the same ancestral metameric unit. We analyze these scenarios in the context of two classical theories on the origin of segmentation: the cyclomeric/archicoelomate concept and the colonial theory. Both theories provide possible explanations for the partial or complete homology of trunk segments and pygidium.

Description of Sheraphelenchus parabrevigulonis n. sp. (Nematoda: Aphelenchoididae) in pine wood packaging from Italy and redescription of S. sucus in onion bulbs from South Korea, isolated at Ningbo, China

Two Sheraphelenchus populations were isolated from pine wood packaging from Italy and onion bulbs from South Korea at Ningbo Port, China, respectively. The former, on the basis of morphology and molecular sequencing, is described as S. parabrevigulonis n. sp., which is characterised by a stylet length of 11 μm, three lines in the lateral field, excretory pore at level with, or slightly posterior to, nerve ring, V = 93.1, and spicules with long condylus and membrane-like rostrum in a shallow triangular shape. The species from onion, also on the basis of morphology and sequence data, was identified as S. sucus, which is characterised by a stylet length of 13 μm (erroneously stated to be ca 6 μm in the type description), excretory pore at level of, or posterior to, median bulb, and V = 80.9. The phylogeny trees based on rDNA 18S, 28S D2-D3 and ITS1/2 sequences revealed that S. parabrevigulonis n. sp. and S. sucus clustered into a clear clade and grouped with Bursaphelenchus species. The study enriched the taxonomic information of Sheraphelenchus and confirmed its status as an independent genus.

Four new species of Iponematinae (Drilonematidae, Drilonematoidea, Cephalobomorpha) parasitic in earthworms: description and molecular affiliations

Three new species of Filiponema, Filiponema sp., and a new species of Iponema are described from earthworms. Filiponema champa sp. n., from the coelomic cavity of Pheretima sp. from Vietnam, is closest to F. cylindropharyngatum and F. javanicum but differs in having a wider body, longer spicules and more conspicuous excretory pore. Filiponema yaoense sp. n., from the coelomic cavity of Pheretima sp. from Vietnam, is differentiated from all valid species of Filiponema by its long, conspicuous excretory duct and a nerve ring situated more closely to the anterior extremity. It can be differentiated from F. champa sp. n. by a slimmer body, the more anterior position of amphids, circular vs transversely elliptical amphids and caudal organs, the wider tail tip, a shorter mail tail, longer eggs, smaller, straighter, spicules and a smaller gubernaculum. Filiponema suifunense sp. n., from the coelomic cavity of Drawida ghilarovi from Russia, is distinguished from all known species of the genus due to the presence of narrow, projecting lateral fields. Filiponema sp., from the coelomic cavity of Lumbricus friendi from France, is described but not named due to lack of material. Iponema visayanum sp. n., from the coelomic cavity of Megascolecidae gen. sp. from the Philippines, can be distinguished from I. tonkinense by its longer spicules and pharynx and its larger amphids situated further from the anterior extremity than in I. tonkinense. D2-D3 LSU sequences were obtained for I. visayanum sp. n. and F. suifunense sp. n. and compared with homologous sequences of other Drilonematoidea nematodes.

Multiple conducting systems in the cubomedusa Carybdea marsupialis.

Acute responses to mechanical, electrical, and photic stimuli were used to describe neural conducting systems in the cubomedusan jellyfish Carybdea marsupialis underlying three behaviors: contractile responses of single tentacles, protective crumple responses, and alterations of swimming activity by the visual system. Responses of single tentacles consisted of tentacular shortening and inward pedalial bending, and were accompanied by bursts of extracellularly recorded spike activity that were restricted to the stimulated tentacle. With nociceptive stimuli delivered to the subumbrella or margin, all four tentacles produced similar responses in a crumple response. The spike bursts in all four tentacles showed coordinated firing as long as the nerve ring was intact. Crumples were still produced following cuts through the nerve ring, but the activity in individual tentacles was no longer coordinated. Responses to light-on stimulation of a rhopalium, as recorded from the pacemaker region, were weak and inconsistent, but when present, resulted in a stimulation of swimming activity. In comparison, light-off responses were robust and resulted in temporary inhibition of swimming activity. Light-off responses were conducted in the nerve ring to unstimulated rhopalia. In conclusion, three conducting systems have been described as components of the rhopalia-nerve ring centralized system in Carybdea: the swim motor system, the crumple coordination system, and the light-off response system.

The nerve ring in cnidarians: its presence and structure in hydrozoan medusae

In our previous studies of the Hydra nerve ring, we proposed the following hypothesis: “The nerve ring in the hypostome of Hydra is a central nervous system (CNS)-like neuronal structure.” Related to this hypothesis, we have started to survey the nerve ring immunocytochemically using antibodies against neuropeptides throughout the whole phylum of cnidarians. In the present study, we describe nerve rings in hydrozoan medusae. We examined the medusae of five hydrozoan species belonging to three orders: Eirene sp. (order Leptomedusae), Craspedacusta sowerbyi (order Limnomedusae), Sarsia tubulosa, Turritopsis nutricula, and Cladonema radiatum (order Anthomedusae). We observed a well-developed nerve ring in all species. The nerve ring runs circumferentially around the margin of the bell. In all cases, the nerve ring was visualized by plural antibodies, suggesting that it contains different neural subpopulations. In C. radiatum, antibodies against four different neuropeptides labeled the nerve ring. We established clear (without undesirable cross-reactions) double-staining procedures with two rabbit primary antibodies. Using the double-staining method, three neural subsets visualized by three antibodies revealed completely separate neural populations. The results show that the nerve ring is a common feature in hydrozoan medusae and has a complex heterogeneous structure composed of different neural subsets.

Morphological and molecular characterization of two isolates of Paratrichodorus porosus from Shenzhen, China

Abstract Studies were conducted to characterize morphological and molecular profiles of two isolates of Paratrichodorus porosus (SZ1 and SZ2) which were recovered from Acacia mangium in Tianxinshan and Gleichenia linearis in Yangmeikeng environmental monitoring sites in Shenzhen, China, respectively. Analysis of morphometric, morphological and molecular characters revealed these two Shenzhen isolates are identical to P. porosus. Measurements of both study isolates lie within the ranges for P. porosus. It is typologically characterized by possessing a clearly swollen body cuticle after fixation, an onchiostyle ventrally curved, 46–58 μm long, a pharyngeal bulb usually with a well developed anterior-dorsal intestinal overlap, a secretoryexcretory pore opening between the nerve ring and anterior end of pharyngeal bulb, 90–110 μm from the anterior end, a reproductive system with didelphic, amphidelphic, without spermathecae, a pore-like vulva in ventral view and occupying 52.0 %–59.5 % of total body length from anterior end, a short and barrel-shaped vagina with small sclerotizations, a pair of ventromedian advulvar body pores located prevulvar and postvulvar, a rounded tail and a subterminal anus in females. The sequence analysis based on partial rDNA 18S gene and 28S D2/D3 expansion segment confirm its identity as P. porosus. This is the first report of P. porosus associated with A. mangium and G. linearis.

3D-microanatomy of the straight-shelled pteropodCreseis clava(Gastropoda: Heterobranchia: Euthecosomata)

The Thecosomata are pelagic euopisthobranch pteropods that are important for marine food chains, but threatened by ocean acidification. Members of the suborder Euthecosomata are either torted snails with a coiled, sinistral shell (Limacinidae) or are straight-shelled with a symmetrical body and an unusual ventral mantle cavity (Orthoconcha). The classification and taxonomy of euthecosomes still depends on shells, but is being challenged by initial molecular data. There is a large body of morphoanatomical information dating from the beginning of the last century, and only biological (rather than soft-part anatomical) detail has been added since. For our initial study on pteropod morphoanatomy we have selected the potentially basal orthoconch genus Creseis Rang, 1828. Supplementing Meisenheimer's (1905) monographic work, we redescribe the microanatomy of the Mediterranean C. clava (Rang, 1828) from serial semithin sections and present 3D-models of all major organ systems. In the absence of histological differences we interpret the head to be fused with the foot, forming the wings with reduced labial tentacles and rhinophores. The postpharyngeal nerve ring is strongly condensed, showing fused buccal ganglia and a short visceral loop with two discernable ganglia. The genital system is monaulic and hermaphroditic, with female glands and a potential allosperm receptacle of unclear homology. An open seminal groove connects with the frontal copulatory organ, which shows complex penial infoldings. We confirm the 180° longitudinal rotation of the visceral organs relative to the condition in limacinids. As an alternative to ontogenetic detorsion, progenesis may have skipped torsion. Other obvious paedomorphoses such as single, basally forked tentacular nerves, suggest that heterochrony has been a driving force in thecosome evolution. Retaining the mantle cavity in a ventral position, Creseis has its large mantle gland—necessary for creating a mucus web for feeding—close to the mouth. Further comparative microanatomical data on orthoconchs and limacinids are needed to corroborate our assumptions of homology, and for reconstructing pteropod evolution once reliable molecular phylogenetic hypotheses are available.

Taxonomic study on the molluscs collected during the Marion-Dufresne expedition (MD55) off SE Brazil: the Naticidae (Mollusca: Caenogastropoda)

ABSTRACT The deep-water Naticidae Guilding, 1834 collected in the expedition MD55 off SE Brazil are taxonomically studied; of the eleven species found, nine species and one genus are new. Microlinices n. gen., mainly characterized by its minute shell size (5–8 mm), thick unpigmented shell walls, weak callus, umbilicus wide lacking central fold, corneous operculum, absence of eyes, osphradium somewhat peduncular, penis at right of or ventral to right cephalic tentacle, nerve ring highly concentrated, and found in deepwater environment. The following taxa are studied here: Microlinices latiusculus n. gen., n. sp., the type species, off Rio de Janeiro (RJ), 430–450 m (anatomy included); M. ibitingus n. gen., n. sp., off Espirito Santo (ES) and RJ, 640–1575 m (anatomy included); M. benthovus n. gen., n. sp., same distribution, 607–1575 m (anatomy included); M. ombratus n. gen., n. sp., off ES, 1500–1575 m; M. apiculus n. gen., n. sp., off ES, 367 m; M. gaiophanis n. gen., n. sp., off RJ, 830 m; Natica jukyriu...

Enolase of Angiostrongylus cantonensis: more likely a structural component?

The cloned enolase gene of Angiostrongylus cantonensis (AcEno) comprised 1,667bp and encoded a peptide with 434 amino acid residues which lacked of a signal peptide but contained a transmembrane region, indicating that AcEno tends to be a structural component (intracellular or membrane protein). The real-time PCR revealed a meaningful difference in the expression level of AcEno in varied development stages. By immunolocalization, native AcEno was detected mainly in the cytoplasm in most tissues, such as parietal muscle, genital tracts, nerve ring, and alimentary canal where the energy consumption is high, but not as expected on the cuticle and hypodermis layer of the nematode. This suggests that the AcEno may be involved in a host of other biological functions, rather than a receptor of plasminogen or a component of excretory-secretory antigen. In addition, AcEno expressed alike in the nucleus, indicating that AcEno also involved in regulating the continuous growth and development of A. cantonensis in hosts. Despite of living in the vasculature at a certain stage of life cycle, AcEno was not localized in the outer surface of L3 and adults, indicating that A. cantonensis may have other virulence and immune evasion mechanisms.

First Report of Aphelenchoides besseyi Causing White Tip Disease of Rice in Jilin Province, China.

White tip disease of rice caused by the plant-parasitic nematode Aphelenchoides besseyi is an important domestic quarantine issue causing heavy yield losses of rice. During a survey for rice diseases in 2013, suspect white tip disease of rice was observed in the cities of Changchun and Gongzhuling, Jinlin Province, China. Leaf tips of susceptible rice varieties were white or yellow, becoming brown or black as necrosis set in. Tips of developing leaves were twisted and wrinkled. The flag leaf became twisted above the panicle until development was inhibited. General stunting of the plant accompanied leaf injury. Panicles were severely reduced and produced small deformed kernels while spikelets were reduced in number. Maturity of panicles was delayed, and secondary panicles arising from the lower nodes of the panicle were sterile. Nematodes were isolated from rice grains of diseased panicles. Key morphological features were determined for females and males. Measurements of females (n = 15) were: body length 612.50 to 735.00 μm (mean 673.75 μm), body width 17.37 to 22.21 μm (mean 19.79 μm), esophagus to gland 64.44 to 68.07 μm (mean 66.26 μm), and tail 34.41 to 41.29 μm (mean 37.85 μm). Females had a relatively short ovary with oocytes arranged in several lines; posterior uterine branch two to four times as long as body width; and tail tapering, conoid, with terminus bearing a mucro with four processes arranged in a shape somewhat that of a star. Measurements of males (n = 22) were: body length 483.39 to 580.00 μm (mean 531.70 μm), body width 14.46 to 17.12 μm (mean 15.79 μm), esophagus to gland 63.97 to 66.42 μm (mean 65.20 μm), and tail 30.38 to 36.45 μm (mean 33.41 μm). Males had a curved tail about 180° when relaxed, three pairs of ventrosubmedian papillae with the first one adanal, spicula curved with a slight basal process, and terminus bearing four mucrones arranged variably. Both males and females had lateral field occupying one fourth of the body width, marked by four incisures; delicate cephalic framework; small spear with moderate-size basal knobs; excretory pore was anterior to nerve ring; and intestine joined to esophagus immediately behind median bulb (3). All morphological data and characters were consistent with A. besseyi. Molecular diagnosis as A. besseyi was confirmed after DNA was extracted from nematodes (n = 16) and the templates were used in PCR analysis. The internal transcribed spacer region (ITS) of rDNA was amplified with primers TW81 and AB28 (2). The size of PCR product was 842 bp, and this sequence (KJ009342) was submitted to GenBank and was 98% similar with that of A. besseyi isolates from India (JF826519, JF93390, JF826517, JF826518) and Russia (EU186069). Molecular identification was further confirmed by amplifying part of the ITS region and part of the 5.8 gene of rDNA using the A. besseyi-specific primers BSF and BSR (1). The amplification yielded a 312-bp product specific to A. besseyi. Morphological and molecular data confirmed that the pathogen responsible for white tip disease in Changchun and Gongzhuling was A. besseyi. While this nematode has been reported from many rice-producing areas in China, this is the first detection of A. besseyi in Jilin Province, China.

Swedish Plectida (Nematoda). Part 6. Neocamacolaimus parasiticus gen. n., sp. n.

A new genus Neocamacolaimus gen. n., with one new species N. parasiticus gen. n., sp. n. is described from the benthic polychaete Sphaerosyllis cf. hystrix collected in the Skagerrak off the west coast of Sweden. Neocamacolaimus gen. n. is placed in the family Camacolaimidae and is particularly characterised by having annulated cuticle with lateral alae; setiform cephalic sensilla located at level with amphids; amphidial fovea ventrally spiral; buccal cavity without armament; pharynx muscular; nerve ring located at base of pharynx; male reproductive system diorchic with outstretched testes; spicules weakly arcuate with straight manubrium; gubernaculum absent; alveolar supplements located in the pharyngeal region; tubular supplements absent; tail conoid; caudal glands and spinneret present. Juveniles of this genus are particularly characterised by their parasitic lifestyle and the following unique morphological features: lips form a dorso-ventrally elongated perioral disc with internal sclerotizations: one midventral and two dorsosublateral (right and left); cephalic sensilla setiform, subventral sensilla are noticeably longer than the subdorsal ones; intestine extends posterior to rectum and anal opening, forming a post-anal pouch.

Experimental study of reliable iris parameters and their relationships with temperament, character, and heart rate variability

IntroductionWhile many studies have indicated that iris parameters are not a valid tool for disease diagnosis, it is still uncertain whether these parameters are more closely related to inherited characteristics or overall functional parameters. The aim of this study was to examine the relationship between the iris, overall functional parameters, and inherited characteristics of individuals. MethodsA total of 117 healthy volunteers (42 men, 75 women) participated in our study. After photographing each subject's iris, we graded six iris parameters: iris density, pigment dots, nerve ring, toxic radii, autonomic nerve wreath ratio, and pupil area ratio. We randomly selected 30 samples and conducted intra- and inter-rater reliability tests. To measure inherited characteristics, each subject completed a temperament and character inventory (TCI). To measure functional markers, we calculated frequency domain (TP, VLF, LF, and HF) parameters of heart rate variability (HRV) using 5-min ECG recordings. Finally, we examined the relationships between iris characteristics, HRV parameters and TCI measurements. ResultsIntra- and inter-rater reliabilities of the six iris parameters were high, with intra-class correlation coefficients ranging from 0.868 to 1.000. Among the iris parameters, nerve ring, iris density, and pupil area ratio parameters were related to novelty seeking, persistence, harm avoidance, and self-directedness subscales of the TCI. The relationships between iris characteristics and HRV parameters were weaker. These relationships were more prominent in men than in women. ConclusionsWe concluded that iris parameters are more likely to be determined by inherited characteristics than functional changes and were more prominent in men than women.

On the life cycle and morphology of development stages of Paraspiralatus sakeri Gibbons et al., 2004 (Nematoda: Spiroidea, Spirocercidae), a heteroxenic stomach parasite of falcons

Pitted darkling beetles (Adesmia cancellata) were infected with nematode eggs found in the alimentary tract of a gyrfalcon (Falco rusticolus) naturally infected with Paraspiralatus sakeri. Third-stage larvae in numbers between 1 and 84 were removed from the beetles 5weeks postinfection and were used for morphological studies as well as to infect domestic chicken, yellow-bellied geckos (Hemidactylus flaviviridis) and fringe-toed lizards (Acanthodactylus schmidti). All experimental animals, necropsied 4-38weeks later, were positive for spirally coiled nematode larvae located under the skin and in the interstitium of skeletal muscles. Despite similarities in general morphology, larvae from beetles and reptiles and chicken differed strikingly in the total body length and body width. Differences in length of the muscular oesophagus and distances of cervical papillae, nerve ring and excretory pore from the anterior end were less distinct. Morphology of these larvae matched with larvae found in subcutaneous cysts in naturally infected houbara bustards (Chlamydotis macqueeni) from Pakistan and UAE as well as with those detected in the muscles of an ocellated skink (Chalcides ocellatus).

Caenorhabditis elegans glia modulate neuronal activity and behavior

Glial cells of Caenorhabditis elegans can modulate neuronal activity and behavior, which is the focus of this review. Initially, we provide an overview of neuroglial evolution, making a comparison between C. elegans glia and their genealogical counterparts. What follows is a brief discussion on C. elegans glia characteristics in terms of their exact numbers, germ layers origin, their necessity for proper development of sensory organs, and lack of their need for neuronal survival. The more specific roles that various glial cells have on neuron-based activity/behavior are succinctly presented. The cephalic sheath glia are important for development, maintenance and activity of central synapses, whereas the amphid glia seem to set the tone of sensory synapses; these glial cell types are ectoderm-derived. Mesoderm-derived Glial-Like cells in the nerve Ring (GLRs) appear to be a part of the circuit for production of motor movement of the worm anterior. Finally, we discuss tools and approaches utilized in studying C. elegans glia, which are assets available for this animal, making it an appealing model, not only in neurosciences, but in biology in general.

Organization of the Ectodermal Nervous Structures in Medusae: Cubomedusae

At least two conducting systems are well documented in cubomedusae. A variably diffuse network of large neurons innervates the swim musculature and can be visualized immunohistochemically using antibodies against α- or β-tubulin. Despite the non-specificity of these antibodies, multiple lines of evidence suggest that staining highlights the primary motor networks. These networks exhibit unique neurite distributions among the muscle sheets in that network density is greatest in the perradial frenula, where neurites are oriented in parallel with radial muscle fibers. This highly innervated, buttress-like muscle sheet may serve a critical role in the cubomedusan mechanism of turning. In scyphomedusae, a second subumbrellar network immunoreactive to antibodies against the neuropeptide FMRFamide innervates the swim musculature, but it is absent in cubomedusae. Immunoreactivity to FMRFamide in cubomedusae is mostly limited to a small network of neurons in the pacemaker region of the rhopalia, the pedalial apex at the nerve ring junction, and a few neuron tracts in the nerve ring. However, FMRFamide-immunoreactive networks, as well as tubulin-immunoreactive networks, are nearly ubiquitous outside of the swim muscle sheets in the perradial smooth muscle bands, manubrium, pedalia, and tentacles. Here we describe in detail the peripheral nerve nets of box jellyfish on the basis of immunoreactivity to the antibodies above. Our results offer insight into how the peripheral nerve nets are organized to produce the complex swimming, feeding, and defensive behaviors observed in cubomedusae.

A new sensory organ in “primitive” molluscs (Polyplacophora: Lepidopleurida), and its context in the nervous system of chitons

IntroductionChitons (Polyplacophora) are molluscs considered to have a simple nervous system without cephalisation. The position of the class within Mollusca is the topic of extensive debate and neuroanatomical characters can provide new sources of phylogenetic data as well as insights into the fundamental biology of the organisms. We report a new discrete anterior sensory structure in chitons, occurring throughout Lepidopleurida, the order of living chitons that retains plesiomorphic characteristics.ResultsThe novel “Schwabe organ” is clearly visible on living animals as a pair of streaks of brown or purplish pigment on the roof of the pallial cavity, lateral to or partly covered by the mouth lappets. We describe the histology and ultrastructure of the anterior nervous system, including the Schwabe organ, in two lepidopleuran chitons using light and electron microscopy. The oesophageal nerve ring is greatly enlarged and displays ganglionic structure, with the neuropil surrounded by neural somata. The Schwabe organ is innervated by the lateral nerve cord, and dense bundles of nerve fibres running through the Schwabe organ epithelium are frequently surrounded by the pigment granules which characterise the organ. Basal cells projecting to the epithelial surface and cells bearing a large number of ciliary structures may be indicative of sensory function. The Schwabe organ is present in all genera within Lepidopleurida (and absent throughout Chitonida) and represents a novel anatomical synapomorphy of the clade.ConclusionsThe Schwabe organ is a pigmented sensory organ, found on the ventral surface of deep-sea and shallow water chitons; although its anatomy is well understood, its function remains unknown. The anterior commissure of the chiton oesophagial nerve ring can be considered a brain. Our thorough review of the chiton central nervous system, and particularly the sensory organs of the pallial cavity, provides a context to interpret neuroanatomical homology and assess this new sense organ.

Two new species of free-living marine nematodes of Adoncholaimus Filipjev, 1918 (Oncholaimida: Oncholaimidae: Adoncholaiminae) from Hokkaido, northern Japan, with a key to species and discussion of the genus

Two new species of free-living marine nematodes,Adoncholaimus daikokuensissp. nov. andA. pseudofervidussp. nov., from the coastal area of northern Japan, are described and illustrated.Adoncholaimus daikokuensissp. nov. is similar to five congeners,A. derjugini,A. punctatus,A. oxyuroides,A. squaluscomb. nov. andA. filicaudacomb. nov. in the absence of a gubernaculum, but differs in the absence of a ventral swelling on tail, spicule length and buccal cavity length.Adoncholaimus pseudofervidussp. nov. is similar toA. fervidusin having large body size, short tail, similar positions of the excretory pore and nerve ring, short spicules, arrangement of subventral setae in posterior region of body in males, and a single pair of terminal pores of the Demanian system surrounded by small gland cells in females.Adoncholaimus pseudofervidussp. nov. differs fromA. fervidusin having smaller, more anteriorly located amphids, longer buccal cavity, absence of gubernaculum in the male, and a different position of the terminal pores in the female. Partial sequences of the mitochondrial cytochromecoxidase subunit I gene (309-337 bp) of the new species are provided for identification based on the DNA barcoding method.Metoncholaimoidesis proposed as a junior synonym ofAdoncholaimus. The new diagnosis ofAdoncholaimusand a key to species are provided.Adoncholaimus squaluscomb. nov.,Adoncholaimus filicaudacomb. nov., andAdmirandus papillatuscomb. nov. are proposed.

New species of Bakeria (Nematoda; Strongylida; Molineidae), new species of Falcaustra (Nematoda; Ascaridida; Kathlaniidae) and other helminths in Cnemaspis mcguirei (Sauria; Gekkonidae) from Peninsular Malaysia.

Two new nematode species, Bakeria schadi sp. nov. and Falcaustra malaysiaia sp. nov. from the gastrointestinal tract of McGuire's rock gecko, Cnemaspis mcguirei (Sauria: Gekkonidae) collected in Peninsular Malaysia are described. The two species now assigned to Bakeria are separated on the bases of male bursa type and location of the excretory pore: type II in B. schadi sp. nov. and type I in B. bakeri; location of excretory pore, anterior to nerve ring in B. schadi sp. nov. and posterior to nerve ring in B. bakeri. Falcaustra malaysiaia sp. nov. is most similar to F. chabaudi, F. concinnae, F. condorcanquii, F. barbi, F. dubia, and F. tchadi in that these 7 species possess 1 pseudosucker, 1 median papilla plus 10 pairs caudal papillae, and spicules with lengths between 1 and 2 mm. F. barbi and F. tchadi lack adcloacal papillae; the remaining 5 species possess 1 pair of adcloacal papillae. Falcaustra chabaudi is known from Nearctic salamanders; F. concinnae from Nearctic turtles; F. condorcanquii from Neotropical frogs, F. dubia from Oriental frogs, and F. malaysiaia sp. nov. from Oriental geckos. Two additional species of Nematoda were found, Cosmocerca ornata and Meteterakis singaporensis. Cnemaspis mcguirei represents a new host record for Cosmocerca ornata and Meteterakis singaporensis.

Description of Aphelenchoides stellatus n. sp. (Nematoda: Aphelenchoididae) found in packaging wood from Japan

Aphelenchoides stellatusn. sp. is described and figured. The new species was isolated from packaging wood from Japan imported to Ningbo harbour, China. The new species has a body length of 485-533 μm (males) and 547-699 μm (females). The cuticle is weakly annulated and there are four lines in the lateral field. The stylet is 9-11 μm long and has small basal swellings. The excretory pore is located posterior to the nerve ring. Spicules smoothly curved, rose-thorn shaped. Apex and rostrum round, only slightly offset, dorsal limb 19-21 μm long. Male tail bearing six (2 + 2 + 2) caudal papillae. The female spermatheca is axial and oblong with round sperm present in multiple rows. Both male and female tail pegs have 3-4 processes, appearing star-like under SEM. The new species belongs to the Group 3 category ofAphelenchoidesspecies. Phylogenetic analyses based on full length ITS and 28S D2/D3 region of rDNA confirmed its morphological status as a new species.

New Species of Parasitic Nematodes of the Genus Cloacina (Nematoda: Strongyloidea) from the Banded Hare Wallaby, Lagostrophus Fasciatus(Marsupialia: Macropodidae)

Two new species of Cloacina von Linstow, 1898, C. ridei sp. nov. and C. biscoei sp. nov. are described from the stomach of the banded hare wallaby, Lagostrophus fasciatus (Péron & Lesueur, 1807) from Western Australia. The two species differ from all congeners in having the excretory pore at the level of the nerve ring and the externodorsal ray arising from the dorsal ray. In spite of the relatively poor state of preservation of the nematodes, the two species are distinguishable from one another by the shape of the oesophagus, which is elongate and has combs in the bulb in C. ridei and in the shape of the buccal capsule, that of C. biscoei having an undulating anterior margin and in the shape of the cephalic papillae, with C. ridei having an enlarged distal segment and C. biscoei having a tiny distal segment.