Presence Of Gubernaculum Research Articles

A new dracunculus species (Nematoda: Dracunculoidea) in neotropical otters (Lontra longicaudis) from Argentina: morphological and molecular characterization

A new species of Dracunculus is described in wild neotropical otters, Lontra longicaudis, occurring in Corrientes, Argentina, based on morphological and molecular characteristics. Worms were located in the subcutaneous tissue from two of five investigated otters. Dracunculus jaguape n. sp. is differentiated from the 14 species of Dracunculus described from mammals and reptiles by the prominent dorsal and ventral papillae on the head; deirids posterior to nerve ring; male with long needlelike spicules and presence of gubernaculum; and long first stage larva. Phylogenetic analysis using the 18S rRNA positioned Dracunculus jaguape n. sp. in an anterior position to the rest of Dracunculus sequences available and COI positioned it in a separated clade sister to Dracunculus lutrae sequences. This is the first report on the presence of this nematode in Lontra longicaudis in Argentina.

<i>Daptonema brzeskii</i> sp. n. and <i>D. rivale</i> sp. n. (Nematoda, Monhysterida, Xyalidae) from Mekong River Mouth, Vietnam

Two new nematode species of the genus Daptonema, D. brzeskii sp. n. and D. rivale sp. n., are described and illustrated based on the material collected from Mekong River Delta, Vietnam. Daptonema brzeskii sp. n. is close to D. lutosum Gagarin, 2021, D. dihystera Gagarin, Nguyen Vu Thanh, 2005 and D. hyalocella Aryuthaka, Kito, 2012 in the presence of postvulval uterus sac, and it is close to D. paraoxyuroides Nguyen Dinh Tu, Gagarin, Nguyen Vu Thanh, Nguyen Thi Xuan Phuong, Nguyen Thanh Hien, 2014 in the shape of spicular apparatus. From the former species it differs in the thinner body, slenderer tail, narrower labial region, shorter outer labial setae and spicules, larger pharyngostoma, and vulva located farther from the anterior body end. It differs from D. dihystera in the shorter body, narrowed labial region, shorter outer labial setae and spicules, and larger pharyngostoma. Daptonema brzeskii sp. n. differs from D. hyalocella in the thinner body, amphidial fovea located closer to the anterior body end, shorter outer labial setae, longer spicules, presence of gubernaculum, larger pharyngostoma, and vulva located farther from the anterior body end. From D. paraoxyuroides, D. brzeskii sp. n. differs in the presence of postvulval sac, longer body, slenderer tail, shorter outer labial setae and gubernaculum. Daptonema rivale sp. n. is similar to D. setihyalocella Aryuthaka, Kito, 2012 in shape of spicular apparatus and to D. brzeskii sp. n. in the shape of pharyngostoma. Daptonema rivale sp. n. differs from D. setihyalocella in the shorter and comparatively thinner body, shorter outer labial setae, spicules, and gubernaculum, bigger pharyngostoma, and vulva located farther from the anterior body end. Daptonema rivale sp. n. differs from D. brzeskii sp. n. in the longer body and outer labial setae, less slender tail, and vulva located farther from anterior body end.

New species of Parapharyngodon (Nematoda: Pharyngodonidae) parasite of Osteocephalus taurinus (Anura: Hylidae) from Northern Brazilian Amazon Region.

Parapharyngodon spp. are nematodes parasites of amphibian and reptiles worldwide distributed. Of 55 valid species, only 11 are known for the Neotropical realm, and six were found parasitizing hylid frogs in the world. In the present work, we describe a new species of Parapharyngodon from the large intestine of Osteocephalus taurinus from Reserva de Desenvolvimento Mamirauá, Amazonas, Brazil, using light and scanning electron microscopy. Parapharyngodon curupira n. sp. is allocated to the group of species with three pairs of cloacal papillae. However, it shows a set of different morphological characters compared to its congeners. In the new species, males have gubernaculum and smooth cloacal lip, females have pre-bulbar ovaries, and we also observed some morphometric differences. Among Parapharyngodon spp. from the Neotropical realm, the new taxon resembles P. alverangai and P. politoedi. The last species was described from the same host and biome (Amazon); however, they can be easily distinguished from new species by the presence of gubernaculum and v-shape structure at the lower caudal lip. Thus, we characterize and propose a new species of Parapharyngodon from the western amazon.

Three new species of the free-living marine nematode Metoncholaimus Filipjev, 1918 (Enoplida, Oncholaimidae) from Argentinean coasts.

Three new species of free-living marine nematodes of the genus Metoncholaimus are described from San Matías gulf (Río Negro, Argentina). Metoncholaimus sanmatiensis sp. n. is characterized by large body size, long spicules, small gubernaculum, presence of long setose pre- and postcloacal genital sensilla and presence of precloacal pores. Metoncholaimus perdisus sp. n. is characterized by small-sized body, short spicules, small gubernaculum, presence of long setose pre- and postcloacal genital sensilla and presence of pre- and postcloacal pores. Metoncholaimus paracavatus sp. n. is closely related to Oncholaimus cavatus but can be considered as a new Metoncholaimus species based on the presence of gubernaculum and the morphology of the demanian system. A compendium of all valid species, including new species, is given.

Durettenema guangdongense gen. et sp. nov. (Nematoda: Molineoidea) from Hipposideros larvatus (Horsfield) (Chiroptera: Rhinolophidae) with discussion of the taxonomic status of Macielia rhinolophi Yin, 1980.

Durettenema guangdongense gen. et sp. nov. is described from Hipposideros larvatus (Horsfield) (Chiroptera: Rhinolophidae) in Guangdong Province, China. The new genus differs from the other genera of subfamily Molineinae in the structure of the synlophe, the absence of lateral alae, the arrangement of the bursa rays, the shape of the spicules, the female tail and the presence of gubernaculum. Meanwhile, considering the morphological characters of Macielia rhinolophi Yin, 1980, including the pattern of the bursa ray, the shape of the spicules, and the female tail, this species should be transferred to the genus Durettenema, as D. rhinolophi (Yin, 1980) comb. nov., which can be distinguished from D. guangdongense in the shape of the ovejector. In addition, the ITS-1 sequences of D. guangdongense were also analysed, these sequence added new data for the molecular diagnosis of trichostrongylid nematodes.

Morphological description of Cosmocerca sp. (Nematoda: Cosmocerdidae) from the Mascarene grass frog Ptychadena cf. mascareniensis (Amphibia: Ptychadenidae). A light and scanning electron microscopic studies

The Mascarene grass frog Ptychadena cf. mascareniensis is a species of frog with a vast area of distribution in Africa. A total of 300 frog specimens were collected from different localities at El-Giza province, Egypt; then dissected and examined for the presence of parasitic infection. Only eighty six (28.66%) specimens were found to be naturally infected with nematode parasite. Seasonally, the prevalence of infection was reached its maximum value of 74.66% during summer and minimum values of 26.66% (20/75), 13.33% (10/75) during spring and autumn, respectively; while no records were observed during winter season. The morphology of the recovered parasite was studied by using light and scanning electron microscopy. The adult worm characterized by anterior extremity with small mouth opening being surrounded by three lips provided with four sub-median cephalic papillae and one pair of lateral amphids. Body measurements showed that male worms were smaller than females measuring 1.22-2.43 (2.21 ± 0.1) mm in length and 0.21-0.34 (0.29 ± 0.01) mm in width. Females measured 1.9-3.7 (2.8 ± 0.1) mm in length and 0.24-0.42 (0.38 ± 0.01) mm in width. Comparing the present parasite with other species of the same genus described previously, several similarities were observed. However, peculiar new characteristics such as the arrangement of plectanes and somatic papillae, the presence of gubernaculum, the position of nerve ring, excretory pore, and vulval opening make it reasonable belongs to the family Cosmocercidae and identified as Cosmocerca sp. In addition, the present study was the first report for occurrence of cosmocercid species from the Mascarene grass frog in Egypt.

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.

A new entomopathogenic nematode, Steinernema bifurcatum n. sp. (Rhabditida: Steinernematidae) from Punjab, Pakistan

A new species of Steinernema is described herein as S. bifurcatum n. sp. It is characterised by the presence of a male gubernaculum that is bifurcate at both proximal and distal ends, a key diagnostic feature. Steinernema bifurcatum n. sp. belongs to the bicornutum group by having two horn-like structures on the labial region of the infective juvenile (IJ). It can be recognised by IJ body diam. = 22 (20-24) μm, pharynx = 114 (102-134) μm, ratio a = 24 (22-25) and D% = 39.7 (33-47). The new species can be further recognised by the male characters of D% = 48 (42-58), and genital papillae = 23 (22 + 1) in number and, for the first generation female, excretory pore = 75.7 (60-108) μm, pharynx = 174 (158-200) μm and tail length = 43.2 (38-60) μm. Steinernema bifurcatum n. sp. is distinguished from all other members of the bicornutum group by the presence of a gubernaculum which is bifurcated at both proximal and distal ends in first generation males. On the basis of genital papillae number (22 + 1) it is close to S. abbasi, S. ceratophorum and S. pakistanense, but can be distinguished by morphometrics of IJ and adults. IJ of S. bifurcatum n. sp. can be differentiated from those of S. ceratophorum and S. pakistanense by the smaller body length of 460-590 μm. Steinernema bifurcatum n. sp. differs from S. abbasi by morphological characters of IJ, male and female stages. The IJ can be distinguished by D% (33-47), body diam. (20-24) μm, b value (3.8-5.6) and pharynx length (102-134) μm. The second generation male differs by GS ratio (0.29-0.45) and the mucronate tail. The first generation female is distinguished by a protruding vulva and no postanal swelling. Analysis of ITS rDNA (824 bp), D2-D3 (880 bp) and mt DNA region (507 bp) sequences confirm that the studied nematode isolate represents a valid new species, the combination of molecular and morphological features indicating that it belongs to Clade IV, the bicornutum group.

New species ofEpacanthion(Nematoda: Thoracostomopsidae) from Patagonia coast, Río Negro and Chubut, Argentina

Two new free-living marine nematodes belonging to the family Thoracostomopsidae, subfamily Enoplolaiminae and the generaEpacanthionare described from Patagonian coastal areas, Río Negro and Chubut provinces of Argentina. InEpacanthion bicuspidatumsp. nov. the main features are: two cusps on distal mandible end; presence of two rings of eight setae in the cervical region; and eight crown-shaped setae along the body, presence of one supplement distant two cloacal body diameter (cbd) from cloacae, gubernaculum and short spicule.Epacanthion ampullatumsp. nov. is characterized by having a tubular and long pre-cloacal supplement, short spicule, presence of gubernaculum, presence of three long setae on the tip of the tail, the presence of one supplement distant three cbd from cloacae and the presence of two small cusps on the distal end of the mandible.

On a new species of the genus Cobboldina (Nematoda: Atractidae) from Hippopotamus (Hippopotamus amphibius Linnaeus, 1758) captivated at the Alipore Zoological Garden, Kolkata, West Bengal, India

The specimens of the genus Cobboldina Leiper, 1911 and family Atractidae (Railliet, 1917) Travassos, 1919 recovered from the faecal matter of Hippopotamus (Hippopotamus amphibius Linnaeus, 1758) from the Alipore Zoological Garden, Kolkata, India recognized as a new species after careful observation. The collected nematode differs from the only valid species Cobboldina vivipara Leiper, 1911, in the presence of gubernaculum (13.2-29.7μm in length) and the number of caudal papillae (10 pairs) and named as Cobboldina gubernacularia sp. n., This is the second species of the genus Cobboldina recorded from the host Hippopotamus amphibius Linnaeus, 1758 remaining captive in the Alipore Zoological Garden, Kolkata, India.

A new species of Meteterakis Karve, 1930 (Nematoda: Heterakoidea) from Indotestudo elongata (Blyth) in China with a key to the species of Meteterakis

Meteterakis wangi sp. nov. was collected from the intestine of Indotestudo elongata (Blyth) from Shijiazhuang, Hebei Province, China by anthelminthic treatment. The new species differs from congeners by the shape and length of spicules, the number and arrangement of caudal papillae, and presence of gubernaculum. The name of M. bufonis Gambhir, Tarnita, Chinglenkhomba, Gyaneswori & Indranich, 2006 was preoccupied and is thus a junior secondary homonym of M. bufonis (Biswas & Charkavarty, 1963) Baker, 1984. We propose to rename the species as M. gambhiri nom. nov. A key to the species of the genus Meteterakis is also given.