Morphological and Molecular Characterization of Trichuris sp. (Nematoda: Trichuridae) in Crested Porcupines (Hystrix cristata; Rodentia: Hystricidae) from Italy

Adult specimens of Trichuris sp. collected from crested porcupines (Hystrix cristata) from Italy were characterized using an integrative taxonomic approach involving morphological and molecular tools. The morphological features of this Trichuris sp. were compared to data already available for Trichuris spp. from Hystrix sp., revealing diagnostic traits, such as spicule length in males or vulva shape in females, which distinguish this Trichuris sp. from the other species. Evidence from sequences analysis of the partial mitochondrial COX1 region indicated that the taxon under study is a distinct lineage. Biometrical and genetic data suggested this Trichuris sp. to be a valid and separated taxon. However, since molecular data from other Trichuris spp. infecting Hystrix, such as T. infundibulus, T. hystricis, T. javanica, T.landak and T. lenkorani, are missing in public repositories, the number and identity of distinct lineages able to infect porcupines remain only partially defined.

Two new insect-associated tylenchids, Sychnotylenchus hibisci n. sp. and Neoditylenchus xiphydriae n. sp. (Tylenchomorpha: Anguinidae), from Japan

Summary We isolated two tylenchid species belonging to the Sychnotylenchinae, Sychnotylenchus hibisci n. sp. and Neoditylenchus xiphydriae n. sp., from the bark beetle Ernoporus corpulentus and wood wasp Xiphydria ogasawarai, respectively. Sychnotylenchus hibisci n. sp. is characterised by its moderately stout body in both male and female, gubernaculum to spicule length ratio of one-third or less, crustaformeria structure composed of four columns with six large, rounded cells, and a broad female tail with a rounded terminus. The new species is closely related to S. ulmi, with which it shares body shape and gubernaculum to spicule length ratio, but is distinguished by the female tail shape and several morphometric values. Neoditylenchus xiphydriae n. sp. is characterised by its oval to leaf-shaped male bursa, male tail tip reaching the distal end of, and protruding beyond the bursa, a long post-vulval uterine sac (PUS), and a conical female tail with a narrowly rounded terminus. The species is typologically similar to N. pinophilus but is distinguished by its male spicule shape, gubernaculum to spicule length ratio, and longer PUS. Phylogenetically, the Sychnotylenchinae belongs under the Anguinidae (superfamily Sphaerularioidea) and is closely related to several Ditylenchus, Neotylenchus, Neomisticius, and Ficotylus species.

Description of Ironus telperionensis n. sp. (Nematoda: Ironidae) and two known species of Chronogaster (Nematoda: Chronogastridae) and Paraphanolaimus (Nematoda: Aphanolaimidae) from the Telperion Nature Reserve (Mpumalanga, South Africa)

Summary A nematode survey conducted in the Telperion Nature Reserve (Mpumalanga, South Africa) resulted in a new Ironus species being described as well as two known species reported for the first time from South Africa, viz., Chronogaster aspinata and Paraphanolaimus behningi. Ironus telperionensis n. sp. is characterised by a long (1724 (1456-1864) μm) and slender body (50 times longer than mid-body diam.), long stoma (116 (87-129) μm), and a 235 (212-257) μm long tail with a ventral curl at the tip. The new species is morphologically most similar to I. ignavus and I. paludicola. However, the new species can be separated from I. ignavus based on the lower ratio c (7.3 (6.5-8.0) vs 8.0-11.0) and longer stoma (116 (87-129) vs 76-90 μm). Ironus telperionensis n. sp. can be distinguished from I. paludicola by the lower ratio a (49.2 (37.4-53.0) vs 60.0-80.0) and lower ratio c (7.3 (6.5-8.0) vs 8.0-13.0). The 18S rDNA phylogenetic analysis of I. telperionensis n. sp. placed it close to I. elegans (KC133064), whereas the 28S rDNA phylogenetic analysis placed it close to I. tenuicaudatus. The phylogenetic analysis revealed that Ironus is a monophyletic group. Paraphanolaimus behningi was identified based on anteriorly bent vagina in the female, spicule length (106 or 110 μm) and number of supplements (13 or 14) in the male. Chronogaster aspinata was identified based on body length (1127 or 1203 μm), cephalic setae length (7 μm), finely rounded tail terminus without a mucron or additional spines, and no longitudinal ridges. It fits the known description of the species. Although various differences were observed between previously reported populations of these species, the morphometrics of the specimens found in Telperion widen the existing variation in these two species.

Morphometrical and Molecular Characterization of Oesophagostomum columbianum (Chabertiidae: Oesophagostominae) and Haemonchus contortus (Trichostrongylidae: Haemonchinae) Isolated from Goat (Capra hircus) in Sylhet, Bangladesh

This study was aimed at describing two (2) intestinal nematodes from naturally infected native breed of goats (Capra hircus) in Bangladesh, identified as Oesophagostomum columbianum (Curtice, 1890) Stossich 1899 and Haemonchus contortus (Rudolphi, 1803) Cobb, 1898. The identification was made based on morphometric features and was confirmed by amplifying internal transcribed spacer (ITS) and cytochrome c oxidase (cox1) gene. Well-developed lateral alae, distinct cervical papillae anteriorly to esophageal expansion, and male spicule length (0.73-0.79 mm, n = 2 ) were characteristically observed in O. columbianum. At the same time, male spicule length (0.40-0.46 mm, n = 2 ) and position of female vulvar flap (4.30-4.54 mm from posterior end, n = 3 ) were observed in H. contortus. DNA sequence homology of the ITS and cox1 gene of both specimens revealed the same results, showing similarity to the GenBank sequences of O. columbianum (GenBank No. KC715827; JX188470) and H. contortus (GenBank No. KJ724377; HQ389229). Phylogenetic analysis computed by maximum livelihood (ML) from the ITS nucleotide sequences revealed that the O. columbianum and H. contortus isolates identified in this study were clustered in the same clade with isolates from China and Iran, respectively. This study, for the first time, illustrates the characteristics of O. columbianum and H. contortus in Bangladesh, combining both morphological and molecular data. The universal primer-based polymerase chain reaction (PCR) protocol could be an economical and efficient option for researchers from poor resource settings for precise identification of nematodes. The information generated in this study may contribute to formulating effective control strategies against these nematodes.

The development of spicules in Heligmosomoides bakeri (Nematoda, Heligmosomidae)

The spicules of male parasitic nematodes are key morphological features, which vary between species in shape and length and are used often for species identification. However, little is known about spicules and particularly if/how their length varies during growth. We first assessed the degree of variation in spicule length of male Heligmosomoides bakeri 21 days post infection (PI), and then in two follow-up experiments measured spicule lengths at half daily/daily intervals between days 6 and 14 PI. Mean spicule length in 21-day worms was 0.518 mm with a range of 94 μm, and variation between the two spicules of individual worms from 2 to 32 μm. Spicules were first detectable on day 6–6.5, after which their lengths increased until day 7 PI (mean = 0.61 and 0.59). This was followed by significant contraction, initially relatively quickly over the following 48 h and then more slowly over a longer period, stabilizing by days 10–14, with only minor further reduction in length. We conclude that the length of spicules varies significantly over the first few days after they have formed, and, consequently, the age of worms is an important factor for consideration when spicule lengths are measured for experimental/diagnostic or taxonomical purposes.

The effect of conventional preservatives on spicule length of Heligmosomoides bakeri (Nematoda, Heligmosomidae)

Nematode spicules vary in shape and size even between closely related species and, therefore, constitute key characters in nematode taxonomy for distinguishing between species. Spicules are seldom measured on fresh specimens, but rather at some time after extraction from culled hosts and after a period of preservation of the worms in chemical fixatives or by freezing. We carried out two experiments to assess the effects of freezing in Hanks’ balanced salt solution, 70% or 80% ethanol and 10% formalin (both of the latter at room temperature and after storage at −80°C) on spicule length of Heligmosomoides bakeri at two time intervals after extraction from mice (Experiment 1, one and four weeks; Experiment 2, one and four months). In Experiment 1, no significant differences were detected, although there was some variation between treatments and over time. In Experiment 2, spicule length varied significantly between treatments and over time, the greatest shrinkage being in 80% ethanol and the least in 10% formalin. However, overall variation in spicule length was very limited, accounting for no more than 5.03% change in length over time and 4.95% between treatments at any of the periods of assessment. Therefore, while whole nematodes can shrivel and shrink in preservatives, making many measurements unreliable, our data indicated that spicule lengths are very little changed by preservation techniques over time, and so spicule length remains as a reliable taxonomic character.

Description of a new marine predatory nematode Latronema dyngi sp. nov. (Nematoda, Chromadorida, Selachinematidae) from the west coast of Sweden and an updated phylogeny of Chromadoria

A new nematode species, Latronema dyngi sp. nov., is described from Skagerrak off the west coast of Sweden with the type locality near Dyngö island. Latronema dyngi sp. nov. is characterized by multispiral amphideal fovea with circular outline, 0.2–0.3 corresponding body diameters wide in males and 0.1–0.2 corresponding body diameters wide in females, 12 cuticular longitudinal ridges and 18–27 precloacal supplements in males. Latronema dyngi sp. nov. most closely resembles L. orcinum in terms of body length; demanian ratios a, b, c and c′; number of amphid turns in males; and the ratio of spicule length to cloacal body diameter. The two species can be differentiated by the number longitudinal ridges on the cuticle (12 for Latronema dyngi sp. nov. vs 20–22 for L. orcinum) and spicule length (65–78 μm for L. dyngi vs 60 for L. orcinum) and shape (weakly arcuate for L. dyngi sp. nov. vs strongly arcuate for L. orcinum). We also performed a maximum likelihood phylogenetic analysis on over 250 nematodes of the subclass Chromadoria based on their nearly full-length 18S rDNA sequences. In agreement with previous studies, our analysis supported Selachinematidae as a monophyletic group and placed Richtersia Steiner, 1916 within Desmodoridae Filipjev, 1922 or just outside of the main Desmodorida clade with the latter placement not well supported.

A new species of Hastospiculum Skrjabin (Spirurida: Diplotriaenidae) parasite of Xenodon merremii (Walger in Spix) (Serpentes: Dipsadidae) from Northeastern Brazil

A new nematode species of the Diplotriaenidae is described from the Neotropical region. The species was found infecting the body cavity of the snake Xenodon merremii (Wagler in Spix) collected in the municipality of Barbalha, Ceará State, Northeastern Brazil. Hastospiculum nordestinum n. sp. differs from the congeners by combining the following characters: caudal end ornamented with lateral alae not surrounding the tail end and not connected, supported by eight pairs of pedunculated papillae (three precloacal, one paracloacal, and four postcloacal pairs) and three adcloacal sessile papillae, and left spicule length 719.6–902.4 µm. Besides the description of Hastospiculum nordestinum n. sp., a species list and a dichotomous key to Hastospiculum are provided.

A detailed taxonomic study on two new and one known species of Anaplectus De Coninck & Schuurmans Stekhoven, 1933 (Nematoda: Plectidae)

This paper provides descriptions of two new and one known species of the genus Anaplectus De Coninck & Schuurmans Stekhoven, 1933. Anaplectus sudhausi sp. nov. is characterised by leaf-shaped lips interspersed with interlabial liplets; bifid apices of the lateral lips; cheilostom with non-cuticularised walls; gymnostom with cuticularised arcuate walls; 120–132 sublateral hypodermal glands on each body side with an additional 5–8 smaller subdorsal hypodermal glands; female tail with three caudal setae; males with arcuate spicules having manubrium slightly wider than calomus or blade, last median tubulus or supplement about half the spicule length and tail terminus with a weakly cuticularised spinneret. A. labiosulcus sp. nov. is characterised by 115–123 sublateral hypodermal glands on each side of the body with those on the dorsal side usually larger than the ventrals; the 5–6 anteriormost glands are unpaired and arranged linearly; lips with cuticularised interlabial grooves; gymnostom arched, occasionally double-arched and caudal glands grouped and opening through a cuticularised spinneret. A. granulosus (Bastian, 1865) De Coninck & Schuurmans Stekhoven, 1933 has been redescribed with some minor differences from previous descriptions.

Phasmarhabditis zhejiangensis sp. nov. (Nematoda: Rhabditidae), a new rhabditid nematode from Zhejiang, China

A new nematode species of the genus Phasmarhabditis was isolated from the body surface of a slug (Philomycus bilineatus Benson, PB). Morphological and molecular analyses confirmed this nematode as a new species. The nematode was named Phasmarhabditis zhejiangensis sp. nov. (Nematoda: Rhabditidae) and is dioecious. In males, the open bursa with genital papillae is characterized by the formula 1-1-1-2-1-3, and the spicule length is 58μm. In female, the vulva is located approximately in the middle of the body. The nematode belongs to papillosa group because of its tail shape pointed with filiform tip. The phasmids are rod-shaped. The posterior anus is slightly swollen. P. zhejiangensis was further characterized by internal transcribed spacer (ITS), 18S rDNA and 28S rDNA sequences. After the sequencing results were compared with sequences available from the National Center for Biotechnology Information (NCBI), the maximum similarities of ITS, 18S and 28S sequences were 89.81%, 96.22% and 95.28%, respectively. Phylogenetic analyses placed Phasmarhabditis zhejiangensis sp. nov. in the genus Phasmarhabditis.