Cephalic Bulb Research Articles

Morphological and molecular characterization of larval Echinocephalus sp. (Spirurida: Gnathostomatidae), a parasite of the greater lizard fish (Saurida undosquamis) and red porgy or common seabream (Pagrus pagrus).

Larvae of an unidentified Echinocephalus species were obtained from two fish species: red porgy or common seabream (Pagrus pagrus) and greater lizard fish (Saurida undosquamis) from the Red Sea. The prevalence of Echinocephalus sp. larvae in P. pagrus was 4.92% and 4.98% in S. undosquamis. The length, width, cephalic bulb, and spine shape and pattern of the larvae resembled Echinocephalus overstreeti. SSU gene sequences of larvae from P. pagrus and S. undosquamis were identical. Comparison of the SSU sequence to those available in GenBank showed that the larvae from P. pagrus and S. undosquamis are diagnosably distinct. Based on sequence similarity and published phylogenetic analysis, these larvae are most similar to an unknown species of Echinocephalus from an Australian sea snake (Hydrophis peronii). Despite morphological similarities of the Red Sea larvae to E. overstreeti, the SSU sequence differences show that they are not the same species.

Advancing the knowledge of the nematode Echinocephalus pseudouncinatus (Gnathostomatidae, Spirurida): Morphological and molecular identification, new host, and host specificity in two coexisting pen shells (Bivalvia: Pinnidae)

The life cycle of Echinocephalus pseudouncinatus has not been described in detail to date, as is also the case of other species in the genus. This study contributes to the information available about the life history of the genus, particularly E. pseudouncinatus, by (1) using molecular techniques (small subunit rRNA gene [SSU rRNA] sequences) to identify larvae of this species; (2) describing the most conspicuous morphological characteristics that distinguish the species by scanning electron microscopy; (3) describing histological characteristics of the internal anatomy of larvae and the lesions caused by them in the gonads of hosts; (4) reporting new host and reporting evidence of host specificity of E. pseudouncinatus between two species of edible pen shells coexisting in the northern Pacific of Mexico; and (5) analyzing the frequency of infested gonads by host sex, size, and gonadal development stage. The molecular analysis confirmed the morphological and histological diagnosis of E. pseudouncinatus larvae infesting gonads of Atrina maura and Pinna rugosa in Ojo de Liebre and San Ignacio lagoons. The morphological characterization of larvae provides internal details of the cephalic bulb (including rows of hooks and ballonets), neural chord, and cell types of the body wall. Histopathological findings such as degenerated and atretic gametes and the displacement of gonadal tissue in hosts infested with E. pseudouncinatus larvae are discussed in terms of temperature anomalies caused by the “Godzilla El Niño”. The frequency of infestation increased with shell length and gonadal development in A. maura, with a higher infestation frequency in females versus males observed at both study sites. Our findings expand the list of hosts of E. pseudouncinatus, which was previously unknown as a parasite of P. rugosa. In P. rugosa, infestation frequencies are noticeably lower (<1 %) compared with those observed in A. maura (>30 %) at both study sites, suggesting host-specific requirements or preferences in E. pseudouncinatus larvae.

Echinocephalus caniculus n. sp. (Nematoda: Gnathostomatidae Railliet, 1895) from the lesser spotted dogfish Scyliorhinus canicula (L.) (Elasmobranchii: Scyliorhinidae Gill, 1862) off Tunisia, with a key to species of the genus Echinocephalus

Echinocephalus caniculusn. sp. (Nematoda, Gnathostomatidae Railliet, 1895) was isolated from the spiral valve of the lesser spotted dogfish Scyliorhinus canicula (L.) from the waters off Kalaat El Andalous, North East Tunisia. This new species is mainly characterized by a cephalic bulb armed with 31–39 transverse rows of uncinated hooks, a comparatively long oesophagus, short spicules and the presence of a gubernaculum. The new species differs from its congeners by having four cervical sacs of almost equal length, a higher oesophagus/body length ratio, the arrangement of the caudal papillae, the absence of a medioventral preanal organ and numerous scattered `pores´ limited to the lateral side of the posterior part of the body. This is the first report of a member of the genus Echinocephalus Molin, 1858 from the Tunisian coast, and a new host and locality record for the Gnathostomatidae. A key to the species of Echinocephalus is provided.

Morphological Identification of Bolbosoma turbinella (Acanthocephala) in Sei Whale (Balaenoptera borealis) from Straits of Malacca, Malaysia

HighlightIdentification of Morphological characteristic of the Bolbosoma sp.Genetic confirmation of the specific species of Bolbosoma turbinella.The first report in Straits of Malacca.Health status of Sei Whale (Balaenoptera borealis).AbstractThe study of ectoparasite and endoparasites of marine mammals are not habitually done because some species are endangered and protected by law. A stranded Sei Whale, Balaenoptera borealis (Anderson, 1878) from the East Coast of Peninsular Malaysia was examined for endoparasites. The objective of this study is to identify the species of acanthocephalan in the intestine of the Sei Whale found in the straits of Malacca. A total of ten parasite specimens were collected from the fresh intestine, and were fixed in 10% buffered formalin for further histological procedures. The morphological features of this parasite viewed under Scanning Electron Microscope (SEM) are referred to as the proboscis armature and variations in the spination of the area between the anterior and posterior cephalic bulb. Genomic DNA extracted by using QIAGEN DNeasy Blood &amp; Tissue Kit DNA and sequenced with First Base Sequencer showed that this species belonged to Bolbosoma turbinella. This was the first record of a sei whale carrying the endoparasites Bolbosoma turbinella, in Malaysian waters.

SEM study of cephalic region of Tanqua tiara and Tanqua anomala (Nematoda: Gnathostomatidae) from Asansol coal-field area (W.B.) India

From the Asansol region of district Paschim Bardhaman of West Bengal, India two parasitic nematodes belonging to same genus, Tanqua tiara from the stomach of Water monitor lizard, Varanus flavescens and Tanqua anomala from the intesine of Asiatic water snake, Xenochropis piscator were recovered. The Surface structures of head region of both nematodes have been examined with Scanning electron microscope. The mouth region of both species is characterised by presence of two large pseudolabia followed by cephalic bulb. Each pseudolabium bears a pair of submedian cephalic papillae and a lateral amphid. T. tiara has four large cephalic bulbs whereas T. anomala has two large cephalic bulbs. Asansol industrial region is recorded as new geographical area for this parasite.

NEW HOST RECORD OF ECHINOCEPHALUS OVERSTREETI DEARDORFF AND KO (1983) (NEMATODA: GNATHOSTOMATIDAE) FROM THE COMMON SEA BREAM PAGRUS PAGRUS (SPARIDAE) OF THE RED SEA IN EGYPT

Several nematode species of family Gnathostomatidae are considered as fish-borne zoonotic parasites, although feral dogs and cats are the commonly identified definitive hosts of these species, humans may accidentally be part of the life cycle of these nematodes by eating undercooked fish infected by the fourth larval stages (L4). In the present study, thirtyfive fish specimens of the common sea bream Pagrus pagrus (Sparidae) were collected from a location along the Red Sea at Hurghada city, Cairo, Egypt. Twenty two fish were infected by the nematode parasite Echinocephalus overstreeti (family: Gnathostomatidae) isolated from the peritoneal cavity of infected fish attached externally to host viscera. Afterisolation and fixation, worms were examined by light and scanning electron microscopes. Morphologically, parasite possessed most of the features characterizing of Gnathostomatidae members. Body long with very narrow lateral alae, simple pseudolabia, 2 well-developed papillae and amphid, a cephalic bulb armed with six transverse rows of claw-shaped spines and a conical pointed tail equipped with anus.

Redescription of Tanqua tiara (von Linstow, 1879) Blanchard, 1904 (Nematoda: Gnathostomatidae) from Varanus flavescens (Hardwicke and Gray, 1827) (Reptilia: Varanidae) from Birbhum district, West Bengal, India.

Tanqua tiara (von Linstow, 1879) Blanchard, 1904, recovered from the stomach of water monitor lizard, Varanus flavescens (Hardwicke and Gray, 1827), collected from the Dubrajpur town, Birbhum district of West Bengal, India, is redescribed with light as well as scanning electron microscopy. This species is characterised by presence of two large lateral pseudolabia followed by massive cephalic bulb. The inner surface of each pseudolabium is folded into five rounded tooth-like formations which fit into corresponding folds on adjacent pseudolabium. Spicules are equal and similar. Gubernaculum is absent. Caudal papillae are sessile and five pairs in number. Present nematode differs from earlier descriptions of T. tiara in having five pairs of caudal papillae and an unpaired median precloacal papilla. Position of phasmids has also been reported in present study. Actual structure of cervical papillae and cuticular striations have been shown in present SEM studies which are also different from earlier descriptions. Dubrajpur is recorded as new geographical area for this parasite.

Morphological Identification Nematodes Tanqua tiara Found on Gastric Varanus salvator at East Java

Tanqua tiara (T. tiara) is the gastric nematode of Varanus salvator (V. salvator) [1-4], this study was conducted to identification morphology of T. tiara. Although there are no reports of human and animal infection T.tiara but still have the potential to transmit the disease to humans through direct contact or indirectly. Isolation of adult worms T. tiara from the digestive tract of V. salvator and then will make to dry preparat.Some 20 V.alvator's gastrointestinal tract at autopsy and gained as much as 321 nematode worms, nematode worms were obtained from the stomach V. salvator, result identification from dry preparat show : Male (mm) (Total length of body 9.4-32, Wide body 0,26-1,77, Diameter of head-bulb 0,17-0,32, The length of the head 0,23-0,33, Distance from the head-end to the end of the esophagus 2,8-5,7, Distance from the head-end to cervical sac 0,22-0,81, The thickness of the cuticle 0,008-0,036, Long tail 0,13-0,42, Long spikula0,3-1,1) and female (mm) (Total length of body 6,8-22, Wide body 0,14-2,33, Diameter of head-bulb 0,15-0,34, The length of the head 0,1-0,28, Distance from the head-end to the end of the esophagus 2,3-4,58, Distance from the head-end to cervical sac 0,18-0,88, The thickness of the cuticle 0,007-0,031, Long tail 0,12-0,28, Distance vulva from the tail end 3,02-3,61, Long uterus 13,1-21,4, size of egg 0,04-0,052X0,03-0,049). Identification of morphological Tanqua tiara indicate worms vary in size, but the specimen is dominated by small-sized worms. Keywords: Varanus salvator; Tanqua tiara; Cephalic bulb.

Gnathostomatidae nematode parasite of Colomesus psittacus (Osteichthyes, Tetraodontiformes) in the Ilha de Marajó, Brazilian Amazon.

The genus Gnathostoma comprises 17 species, whose adult specimens are found in the stomach serosa of animals that consume raw fish; some species of the genus are zoonotic agents. The present study describes the presence of a nematode (Gnathostomatidae) parasitizing the digestive tract of Colomesus psittacus in the Ilha de Marajó in the eastern Brazilian Amazon. Thirty specimens of C. psittacus were collected in the municipality of Soure, Ilha de Marajó, state of Pará, Brazil, transported to the laboratory, necropsied and the helminths were collected and fixed. Of the 30 fish that were studied, 16.67% were parasitized with nematodes. The nematode larvae found encysted in the intestinal serosa have anterior region with two lips, each with a pair of papillae; a cephalic bulb armed with six rows of discontinuous spines; four cervical sacs; a claviform esophagus; cuticular striations along the body; a simple excretory pore; and a short tail ending in a mucron. These morphological structures are diagnostic characters of the genus Gnathostoma, whose adults parasitize the stomach of carnivorous mammals and, rarely, the stomach of fish. However, fish, amphibians, reptiles, and birds are intermediate hosts of the third-stage larvae (L3), and humans may act as accidental hosts.

Morphological and phylogenetic analysis of Echinocephalus carpiae n. sp. (Nematoda: Gnathostomatidae) infecting the common carp Cyprinus carpio inhabiting Burullus Lake—a new host record in Egypt

The present study described a new species of the genus Echinocephalus that was isolated from the intestine of the common carp Cyprinus carpio inhabiting Burullus Lake, Kafr el-Sheikh Governorate, Egypt. Thirty-two out of 70 examined specimens (45.71%) were found to be naturally infected. The adult male worms were elongated and measured 0.79-0.85mm (0.81 ± 0.02) in length and 0.21-0.32mm (0.28 ± 0.002) in width, while females reached 0.89-0.98mm (0.9 ± 0.02) long and 0.25-0.38mm (0.28 ± 0.002) wide. The reported species are investigated microscopically, genetically, and compared with previous related ones. The present study recorded this new nematode parasite as Echinocephalus carpiae with accession no. KC493258, inhabiting new host and locality records in Egypt. It is especially characterized by short body length, cephalic bulb with few (six to eight) multiple rows of spines, clear annulated cuticle, and new genetic sequences, which identify the paraphyly of Gnathostomatinae.

Description of advanced third-stage larvae of Gnathostoma lamothei Bertoni-Ruiz et al. 2005 (Nematoda: Gnathostomatidae) from experimental hosts and contributions to its life cycle

The advanced third-stage larvae (AdvL(3)) of Gnathostoma lamothei was obtained from experimental hosts. Frogs Lithobates heckscheri and snakes Nerodia fasciata pictiventris were compatible hosts allowing optimal larval development. AdvL(3) are 4,487.94 μm long, have two lateral cervical papillae between rows 10 and 16 and an excretory pore at row 23. The average counts of the cephalic bulb hooklets from the four rows are 39.3, 43.3, 44.2, and 47.3. Larvae show an esophagus that represents 40% of the body width. These findings indicate that amphibians and reptiles could be involved as G. lamothei natural hosts; nevertheless, their role as etiological agents of human gnathostomiasis is uncertain. This paper reports for the first time the taxonomic description of G. lamothei AdvL(3) obtained from experimental hosts and contributes to the understanding of its life cycle.

Abnormalities on cephalic hooklets of advanced third-stage larvae from Gnathostoma Owen, 1836 (Nematoda: Gnathostomidae) collected from Mexican rivulus Millerichthys robustus Costa, 1995 (Ciprinodontiformes: Rivulidae) in Tlacotalpan, Veracruz, Mexico

Morphological abnormalities were observed on the cephalic bulb hooklets of advanced third-stage larvae (AdvL(3)) of genus Gnathostoma. The larvae were obtained from the fish "Mexican rivulus" Millerichthys robustus collected from a seasonal pond near Tlacotalpan, Veracruz, Mexico. The abnormalities involved (1) extra rudimentary hooklets, located between the four rows and after the fourth row, (2) branched or lobulated hooklets, and (3) fragmented hooklets not uniformly disposed in rows. The alterations observed on the cephalic bulb hooklets do not represent intraspecific variations, and they may be considered as a potential tool for assessing the presence of pollutants or stressors located within the ecosystem.

Three nematode species from elasmobranchs off New Caledonia

Nematode specimens of three species, Terranova scoliodontis (Baylis, 1931) (Ascaridida, Anisakidae), Echinocephalus sinensis Ko, 1975 and E. overstreeti Deardorff & Ko, 1983 (both Spirurida, Gnathostomatidae) were collected from the tiger shark Galeocerdo cuvier, the ray Aetobatus cf. narinari and the blotched fantail ray Taeniura meyeni, respectively, from the coastal waters of New Caledonia, South Pacific. Their examination, including scanning electron microscopy (SEM), made it possible to obtain some new data on their morphology, e.g. in relation to the number and arrangement of male caudal papillae in T. scoliodontis and both Echinocephalus spp., the presence of ventral cuticular ornamentations in T. scoliodontis and the number of transverse spines on the cephalic bulb in Echinocephalus spp. All these species are reported for the first time from New Caledonian waters and G. cuvier is a new host species for T. scoliodontis. SEM examination of the fourth-stage larvae of E. overstreeti from the type-host showed the presence of anterior dorsal and ventral groups of minute spines on the cephalic bulb to be an important taxonomic feature for the interspecific distinction of Echinocephalus larvae and questions previous data on the occurrence of E. overstreeti larvae in many elasmobranch fishes and molluscs in Australian waters.

Durettechina beveridgei n. g., n. sp. (Nematoda: Seuratidae) from Antechinus spp. (Dasyuridae: Marsupialia) from Australia.

Durettechina beveridgei n. g., n. sp. (Nematoda: Seuratidae) is described from Antechinus flavipes (Dasyuridae) from Victoria and New South Wales. A single female from A. bellus from the Northern Territory may also be D. beveridgei. This new genus is compared with other genera of the Echinonematinae, to which it has been assigned. The genus has a unique body armature and most closely resembles Chabaudechina, in the armature of the cephalic bulb, but has four rather than five rows of hooks, and Linstowinema, in having body hooks on the cuticle of the anterior region, but has 18-22 hooks in each row rather than 14-16. The hooks of Durettechinca are also smaller and have a less complex root morphology than those of Linstowinemna. Durettechina resembles Seurechinac and Chabaudechina in having caudal alae into which papillae extend, but differs from both these genera in the number and arrangement of the caudal papillae, as well as in the body armature. Durettechina, is most different from Bainechina, which has neither hooks on a cephalic bulb nor body hooks on the anterior region nor caudal alae.

A New Species of Echinocephalus (Nematoda: Gnathostomidae) from Neotropical Stingrays with Comments on E. diazi

Echinocephalus daileyi sp. n. is described from the freshwater stingrays Potamotrygon circularis and P. hystrix in South America. It is most similar to E. diazi by virtue of possessing a gubernaculum and six postanal papillae, but may be distinguished from E. diazi and other members of the genus by possessing 30 to 34 rows of spines on the cephalic bulb, three preanal papillae, and a body 55 to 85 mm long. Specimens of E. diazi were collected from Himantura schmardae, the type host, from Cienaga Grande, Colombia, a new locality record. Based on numerical phylogenetic analysis, E. daileyi is a member of a monophyletic group including E. sinensis, E. diazi, and E. pseudouncinatus. Examination of marine and freshwater stingrays in northern South America during 1975 to 1978 revealed the presence of two species of Echinocephalus Molin, 1858. One of those species is described herein as new, and a new locality record is reported for the other. Specimens were removed from hosts, fixed in 10% formalin or in glacial acetic acid, stored in a solution of five parts glycerin and 95 parts 70% ethanol, then examined in glycerin after evaporation of the alcohol. All measurements are in micrometers unless otherwise stated, and figures were drawn with the aid of a drawing tube. Echinocephalus daileyi sp. n. (Figs. 1-12)

Gnathostoma Spinigerum from the Cervix of a Woman in Jakarta

A male Gnathostoma spinigerum was removed from the cervix of a 29-year-old Jakarta resident who suffered from chronic cervicitis. The worm was 6.7 mm in length and had eight rows of spines on the cephalic bulb. This is the third case of gnathostomiasis reported from Indonesia.