Number Of Precloacal Supplements Research Articles

Two Species of the Family Cyatholaimidae (Nematoda: Chromadorida) from Korea

During a survey of the Wando-gun rockpool area in Korea, two species belonging to the family Cyatholaimidae were discovered within a sponge, Hymeniacidon sinapium, and are hereby reported. Despite the monophyletic nature of the family Cyatholaimidae, it has been a topic of discussion among nematologists due to its lack of synapomorphic characteristics and overlapping generic diagnoses. Many genus-defining features consist of a combination of non-unique characters, which may not hold significant taxonomic importance. Consequently, most genera within the family are non-monophyletic according to phylogenetic findings. The absence of molecular data complicates the identification of taxonomically important characteristics that may have been previously overlooked. While the pore complex and the lateral pore-like structure have been suggested as potentially important traits, these insights are lacking in most recorded species, along with molecular data to confirm their significance in topology. Given the considerable amount of work required from the ground up, this study provides both morphological information (including taxonomic description, morphometric measurements, tabular key comparing key features to all valid congeners, illustration, and microscope photographs) and molecular data (partial sequences of three molecular regions, K2P distance comparison, and phylogenetic trees) for the two species discovered in Korea. The study also offers insights on potentially significant traits, such as the pore complex and other pore structures. The Korean specimen of Acanthonchus (Seuratiella) tridentatus resembles the original description regarding aspects such as the number and type of precloacal supplements, as well as the shape of the spicules and gubernaculum. However, variations are observed in the following characteristics: body ratio, nerve ring location, pharynx length, and the presence or absence of the oscelli. Our partial molecular sequences of the specimens also match identically with a single existing entry on NCBI identified as A. (S.) tridentatus. The new species, Paracanthonchus spongius sp. nov., is most similar to P. kamui in terms of the general shape of the body and gubernaculum but can be distinguished by differences in the number of precloacal supplements, amphid position, and gubernaculum ratio. The phylogenetic tree constructed based on the 28S rRNA region shows both species grouped within the monophyletic clade of Cyatholaimidae with high bootstrap support. However, achieving generic resolution of these species will require more molecular sequences of congeners to accumulate in the future.

Miconchus prokini sp. nov. (Nematoda: Mononchida) from lake El'gygytgyn, Chukotka, Russia

A new nematode species in the order Mononchida, Miconchus prokini sp. nov., found in Lake El'gygytgyn (Chukotka, Russia) is described and illustrated. The new species is the largest member of the genus known to date. It is morphologically close to Miconchus rex in the big body size, vulva position in females, the number of precloacal supplements in males and in the relative length of the pharynx in both sexes, but it has a longer body (L = 7.7–13.1 mm in M. prokini vs. L = 6.5–7.0 mm in M. rex) and spicules (225–252 µm in M. prokini vs. 180 µm in M. rex), and a shorter tail (c = 9.3–15.2 in M. prokini vs. c = 5.3–7.1 in M. rex).

Sabatieria sinica sp. nov. (Comesomatidae, Nematoda) from Jiaozhou Bay, China

A new free-living marine nematode species of the genus Sabatieria was documented from the sediment of the Jiaozhou Bay, Qingdao, China, and it has been named Sabatieria sinica sp. nov. It is characterized by homogeneous cuticle without lateral differentiation, relatively short cephalic setae, spiral amphideal fovea with 2–2.25 turns; thick spicules with a mid constriction or joint, gubernaculum with a long straight dorso-caudal apophyses, and 6–7 prominent papillar precloacal supplements. This new species could be distinguished from other congener species by the combination of its characteristics: body size, length of cephalic setae, number of amphid turns, structures of spicules and gubernaculum, and type and number of precloacal supplements. An update dichotomous key is provided for nine species of pulchra group of Sabatieria including the new species.

Two new species of free-living nematodes of the family Dorylaimidae (Nematoda, Dorylaimida) from small freshwater bodies of Vietnam

Illustrated descriptions of two new species of free-living nematodes found in sediments of small water bodies of Vietnam are presented. Laimydorus propinquus sp. n. is morphologically similar to L. papillatus Ahmad, Ahmad, 2002, but it is distinguished from it by a relatively longer and thicker body, a longer tail in females, a more anterior position of vulva, a longer prerectum in females, longer spicules, and large number of precloacal supplements in males. Ischiodorylaimus paracognatus sp. n. differs from the similar species I. cognatus Andrassy, 1983 by a longer body, relatively short pharynx, thicker cuticle, wider lip area, and shorter spicules.

Ethmolaimus riparius sp. n. and Paramononchus major sp. n. (Nematoda) from Lake Baikal, Russia.

Two new nematode species found in Lake Baikal (Russia) are described and illustrated. Ethmolaimus riparius sp. n. is morphologically close to E. pilosus Shoshin, 1998 and E. lanatus Shoshin, 1998. The new species differs from E. pilosus by the longer and thinner body (L = 1228-1501 µm, a = 26-34 vs L = 720-1070 µm, a = 19-23), larger stoma (26-32 µm long vs 19-24 µm long), longer spicules and gubernaculum (45-50 µm long and 21-25 µm long vs accordingly 32-37 µm long and 8 µm long). E. riparius sp. n. differs from E. lanatus by the longer body (L = 1228-1501 µm vs L = 680-1180), shorter cephalic setae (its length is equal 1.1-1.4 labial region diameter vs 1.6-2.1 labial region diameter) and longer spicules and gubernaculum (45-50 µm long and 21-25 µm long vs accordingly 25-30 µm long and 7-8 µm long). Paramononchus major sp. n is close to P. orientalis Gagarin & Naumova, 2012, but differs from it by the longer body (L = 5926-7820 µm vs L = 3081-3778 µm), longer spicules (410-475 µm long vs 208-238 µm long) and larger number of precloacal supplements (52-61 vs 21-24). Keys for the identification of valid species of the genera Ethmolaimus and Paramononchus are given.

A new species of the genusMarylynnia(Nematoda: Chromadorida: Cyatholaimidae) from Gwangyang Bay, Korea

Abstract A new species of the family Cyatholaimidae Filipjev, 1918 was collected from Gwangyang Bay, Korea. The new species belongs to the genus Marylynnia Hopper, 1977 on the basis of the following morphological characters: 1) two types of cuticular pores, 2) dorsal tooth with a pair of small subventral teeth, 3) cup shaped precloacal supplements, and 4) conico-cylindrical tail. Marylynnia denticulata n. sp. is closely related to Marylynnia malsa (Hopper, 1972) by virtue of body length, the number of cervical setae, spicule length, the presence of denticles lining the distal portion of the gubernaculum, and gubernaculum length. However, the new species differs from M. malsa by the location of the cervical setae, the shape of the spicule and gubernaculum, and the number of precloacal supplements. This is the first description of the family in the study area.

New records and species of Enchelidiidae (Nematoda): Symplocostoma brasiliensis sp. nov. and a first description of the female of Calyptronema pigmentatum Gerlach, 1957

This contribution presents a new species of Symplocostoma, the first member of this genus identified for the coast of Brazil, and a dichotomous key for species of the genus. There is also a redescription of the male and the first description of the female of Calyptronema pigmentatum. Samples were collected on the continental shelf of the Potiguar Basin, northeastern Brazil. Symplocostoma brasiliensis sp. nov. has several distinguishing characteristics: the position of the secretory–excretory pore, tail length, the presence of denticles in the buccal cavity (female) and the number of precloacal supplements (male). The male of C. pigmentatum showed most morphological and morphometric characters of the original description, except for the size of the amphidial fovea and the number of precloacal supplements. The male differs from C. maxweberi in the spicular apparatus, gubernaculum shape, number of precloacal papillae and tail length. The female of the species has a buccal cavity similar to that of C. mawsoni, but differs in the position of the secretory–excretory pore and the shape of the amphidial fovea and tail.

Mesodorylaimus dolichurus sp. nov. (Nematoda, Dorylaimida) from freshwater body of Vietnam

A new species of Mesodorylaimus Andrássy, 1959 is described and illustrated from Vietnam. Mesodorylaimus dolichurus sp. nov. is similar to M. flagellifer Andrássy, 2002 and M. derni Loof, 1969 and differs from both by longer odontostyle, longer tail in females, longer spicules and larger number of precloacal supplements in males.

New species of Antomicron and Leptolaimus (Nematoda: Leptolaimidae) and record of Procamacolaimus (Nematoda: Camacolaimidae) from Patagonia coast, Chubut and Santa Cruz, Argentina

This paper focuses on Antomicron, Leptolaimus and Procamacolaimus, three genera inhabiting coastal water systems of the Patagonian, Chubut and Santa Cruz provinces of Argentina, providing a review of their taxonomy for a new identification key. One new species belonging to the genus Antomicron and one new species belonging to the genus Leptolaimus of the family Leptolaimidae are described from Puerto San Julián, Santa Cruz province: Antomicron alveolatum sp. nov. has 35 alveoli and three precloacal supplements and Leptolaimus gabinoi sp. nov. is characterized by the structure and number of precloacal supplements (three) with hamate distal end with two hooks. Another species belonging to the genus Procamacolaimus of the family Camacolaimidae is described and recorded from Puerto Madryn, Chubut province of Argentina: Procamacolaimus dorylaimus.

Two new species of dorylaimids (Nematoda and Dorylaimida) from Lake Baikal

Illustrated descriptions are given of two species of free-living nematodes new to science, Arctidorylaimus parvulus and Eudorylaimus sedatus, found in the littoral zone of southwestern Lake Baikal. A. parvulus, sp. n., differs from A. kurenkovi Gagarin, 2002, in its shorter body, absence of longitudinal cuticular ridges, shorter spicules, smaller number of precloacal supplements, and relatively short prerectum. E. sedates sp. n. is morphologically similar to E. spongiophilus Batalova, 1983, but smaller, has shorter odontostyle and odontophore, and longer tail and prerectum. An identification key to the valid species of the genus Arctidorylaimus is given.

First Report of Trichodorus variopapillatus (Nematoda: Trichodoridae) from the Czech Republic.

Members of the Trichodoridae can cause substantial crop losses directly by feeding on plant roots and indirectly as vectors of tobraviruses; both vector and virus are polyphagous. In April of 2008, soil samples from the rhizosphere of Ulmus minor Mill in a deciduous broadleaf forest at Krivoklat yielded a population of Trichodorus variopapillatus Hooper, 1972. Nematodes were identified by morphological and morphometric characters as well as by molecular analysis. For classical identification, specimens were extracted from soil by a decanting-sieving method, heat killed and fixed in triethanolamine formalin, and processed and mounted in anhydrous glycerin. For molecular analysis, specimens were stored at -20°C in 1 M NaCl. Specimens largely agreed with T. variopapillatus (1,3). Average morphometric data of five male specimens are: body length 766 μm; body width 33 μm; onchiostyle length 55 μm; and spicule length 43 μm. Number of anterior ventromedian cervical papillae and number of precloacal supplements was three each. Spicules are regularly curved and the manubrium is knob-like. Morphometric data of two female specimens are: body length 663 and 858 μm; body width 29 and 38 μm; onchiostyle length 52 and 53 μm; V 54 and 57%. Refractive thickenings at the vulva are very large and quandrangular in shape in the lateral optical section. Identification of these nematodes was further verified by sequencing two regions of rDNA (18S gene and D2/D3 expansion segments of the 28S gene). Single female and male specimens from NaCl storage were transferred to 0.5-ml Eppendorf tubes containing 0.25M NaOH. Total genomic DNA was prepared by a rapid technique (4). The 18S gene was amplified in three fragments using the primer SSU_F_04 + SSU_R_09 (first fragment), SSU_F_22 + SSU_R_13 (second fragment), and SSU_F_23 + SSU_R_81 (third fragment). D2/D3 expansion segments of the large subunit of rDNA were amplified using the forward primer D2A and the reverse primer D3B (2). The regions were sequenced in both directions after purification of PCR products. The sequences of female and male specimens were identical. The sequences were deposited in GenBank with Accession Nos. GQ148719 (28S) and GQ148719 (18S). The length of 18S was 1,760 bp and D2/D3 was 786 bp. The obtained sequences were compared by BLAST in NCBI. The D2/D3 sequence is not available in GenBank for T. variopapillatus. The best BLAST hits were obtained with Trichodorus species. BLAST results of 18S sequence showed 5% divergence (76 substitutions) after trimming unequal ends with published sequence of T. variopapillatus Accession No. AY284841. All substitutions were confirmed from the chromatographs. To our knowledge, this is the first report of T. variopapillatus associated with U. minor in the Czech Republic.

New species of free-living marine nematodes from the Yellow Sea, China

Three new species of free-living marine nematodes: Oncholaimus multisetosus sp. nov., Sabatieria stenocephalus sp. nov. and Setosabatieria coomansi sp. nov. from the Yellow Sea, China are described and illustrated. The male of Oncholaimus multisetosus sp. nov. is characterized by a tail sharply constricted at the junction of the conical and cylindrical sections; two circles of 12–15 pairs of circumcloacal setae each. In the female, the conical section of the tail gradually tapers in a cylindrical section. Sabatieria stenocephalus sp. nov. is characterized by the pronounced sharp-pointed anterior body, sclerotized tooth-like front edge of buccal cavity and 15 tubular-shaped precloacal supplements with the posterior five more closely spaced. Setosabatieriacoomansi sp. nov. can be separated from the other species of the genus by the number (6–8) of cervical setae per file, the number of precloacal supplements (15) and the absence of central strips in spicules and leaf-like extensions of the cuticle lateral to the cloaca. Types are deposited in the College of Marine Life Sciences, Ocean University of China.

Three new species of free-living nematodes from the Bohai Sea, China

Three new species of free-living marine nematode, Setosabatieria jingjingae sp. nov., Amphimonhystera circula sp. nov. and Belbolla zhangi sp. nov., from the Bohai Sea, China, are described and illustrated. Setosabatieria jingjingae can be separated from the other two species in the genus by the number of amphid turns, the structure of the spicules and the number of pre-cloacal supplements. A pictorial key and tabular information are provided to facilitate species identification in this genus. Amphimonhystera circula is characterized by circular amphids, a simple gubernaculum and the shape of the tail. Belbolla zhangi is characterized by the number of oesophageal bulbs, the shape of the spicules and gubernacular apophysis, and the size of the two pre-cloacal supplements. The types are deposited in the Natural History Museum (London).

Morphologic Variability and Value of the Characters Used for Species Identification in Paratrichodorus Siddiqi, 1974 (Nematoda: Trichodoridae)

The variability of characters used for species identification in Paratrichodorus Siddiqi, 1974 are studied and their taxonomic value discussed. The thirteen characters considered valid for the genus database and conforming to the NEMAID identification computer program are: onchiostyle length, spicule length, number of precloacal supplements, presence of spermatheca, number of ventromedian cervical papillae, cloacal opening with bilobed lip, shape of vulva in ventral view, sperm structure, pharyngo-intestinal junction, presence of males, shape of vaginal sclerotizations, shape of spicules and geographical distribution. Additionally, three very specific characters included in the species identification system, although restricted to few species, are: a conoid tail shape with acute tip, the presence of medioventral body pores in female and the presence of two postcloacal papillae in the male.