Morphological and molecular characterisation of Heliconema hainanensis sp. nov. (Spirurina: Physalopteridae) from congers in the South China Sea,with a key to the species of Heliconema

Heliconema hainanensis sp. nov. collected from Uroconger lepturus (Richardson) (Anguilliformes: Congridae), Muraenesox cinereus (Forsskål) and Congresox talabonoides (Bleeker) (Anguilliformes: Muraenesocidae) in the South China Sea was described using light and scanning electron microscopy. The new species differs from its congeners by the following morphology: pseudolabia, the number and arrangement of caudal papillae (4 pairs of pedunculate precloacal papillae arranged in 2 groups of 2 and 2 pairs and 6 pairs of pedunculate postcloacal papillae arranged in 4 groups of 1, 2, 1 and 2 pairs), the length of spicules [left spicule 0.51-0.69 mm, right spicule 0.20-0.27 mm, spicule (right:left) ratio 1:2.20-2.69] and the morphology of the female tail tip. In addition, specimens of the new species collected from the three different hosts and specimens of an unidentified species of Heliconema collected from U. lepturus were characterised using molecular methods by sequencing the internal transcribed spacer (ITS) of ribosomal DNA. Analyses and comparison of the ITS sequence of H. hainanensis sp. nov. with Heliconema sp. support the validity of the new species based on morphological observations. An identification key to the species of Heliconema is also provided.     

Heliconema minnanensis n. sp. (Physalopteroidae: Physalopteridae) and Raphidascaris trichiuri (Yin and Zhang) n. comb. (Ascaridoidea: Anisakidae) in marine fishes.

Heliconema minnanensis n. sp. is described from the Chiloscyllium plagiosum south of the Minnan-Taiwan Bank Fishing Ground, Taiwan Strait. It is characterized by having the following combination of features. There are no longitudinal ridges in the posterior part of the body; the male has 4 pairs of precloacal papillae and 6-7 pairs of postcloacal papillae. The right spicule averages 0.2 mm long (1.1% of body length), and the left spicule averages 1.2 mm long (5.6% of body length), making an average spicule ratio of 1:5.2. The female has a vulva located on the left side of a thick membrane and 56-65% of the body length from the anterior end. Raphidascaris trichiuri (Yin and Zhang, 1983) comb. n., known previously from males only, is transferred from Cloeoascaris and redescribed, including material of both sexes from Muraenesox cinereus from the type locality.     

Diversity, relative abundance and metabolic potential of bacterial endosymbionts in three Bathymodiolus mussel species from cold seeps in the Gulf of Mexico

Cold seeps in the Gulf of Mexico are often dominated by mussels of the genus Bathymodiolus that harbour symbiotic bacteria in their gills. In this study, we analysed symbiont diversity, abundance and metabolic potential in three mussel species from the northern Gulf of Mexico: Bathymodiolus heckerae from the West Florida Escarpment, Bathymodiolus brooksi from Atwater Valley and Alaminos Canyon, and 'Bathymodiolus' childressi, which co-occurs with B. brooksi in Alaminos Canyon. Comparative 16S rRNA sequence analysis confirmed a single methanotroph-related symbiont in 'B.' childressi and a dual symbiosis with a methanotroph- and thiotroph-related symbiont in B. brooksi. A previously unknown diversity of four co-occurring symbionts was discovered in B. heckerae: a methanotroph, two phylogenetically distinct thiotrophs and a methylotroph-related phylotype not previously described from any marine invertebrate symbiosis. A gene characteristic of methane-oxidzing bacteria, pmoA, was identified in all three mussel species confirming the methanotrophic potential of their symbionts. Stable isotope analyses of lipids and whole tissue also confirmed the importance of methanotrophy in the carbon nutrition of all of the mussels. Analyses of absolute and relative symbiont abundance in B. heckerae and B. brooksi using fluorescence in situ hybridization (FISH) and rRNA slot blot hybridization indicated a clear dominance of methanotrophic over thiotrophic symbionts in their gill tissues. A site-dependent variability in total symbiont abundance was observed in B. brooksi, with specimens from Alaminos Canyon harbouring much lower densities than those from Atwater Valley. This shows that symbiont abundance is not species-specific but can vary considerably between populations.     

Redescription of Heliconema africanum (Linstow, 1899) n. comb. (Nematoda: Physalopteridae), a nematode parasite of freshwater eels (Anguilla spp.) in South Africa

The little-known nematode species Heliconema africanum (Linstow, 1899) n. comb. (Physalopteridae) is redescribed based on light and scanning electron microscopical examinations of specimens collected from the stomach of the African longfin eel Anguilla mossambica (Peters) in the Nahoon River, Eastern Cape Province, South Africa. This species, previously misidentified as Heliconema longissimum (Ortlepp, 1922), is a common parasite of eels in South Africa. The systematic status of H. longissimum, a species originally described from unidentified Australian snakes, is unclear and probably several morphologically closely related species have been included under this name.     

Histopathology in Paulicea lutkeni (Pisces: Pimelodidae) resulting from infections with Megathylacus brooksi and Jauela glandicephalus (Cestoda: Proteocephalidae)

The histopathology in Paulicea lutkeni naturally infected with Megathylacus brooksi and Jauela glandicephalus is described. Megathylacus brooksi attaches to the epithelium of the anterior intestine by means of suckers, resulting in damage to the epithelium, haemorrhages and lymphocyte infiltration. Jauela glandicephalus penetrates through all layers of the intestine. This penetration elicits an intense host-response resulting in the hyperplasy of connective tissue and formation of a nodule surrounding the scolex of the parasite. Lymphocyte infiltration was observed. Concurrent infections were found in some specimens.     

Comparative scanning electron-microscopic study of the lingual papillae in two species of domestic mammals (Equus caballus and Bos taurus). 1. Gustatory Papillae

The morphological characteristics of bovine and equine gustatory lingual papillae are compared by scanning electron microscopy. The fungiform papillae in the cow have a shape that corresponds to their name, while in the horse, they almost do not emerge from the surface of the tongue. These papillae show taste pores in both species. The vallate papillae, four times larger in the horse than in the cow, show a complex organization of papillae and secondary grooves in the horse. In the cow, they occur single and are surrounded by a thick annular pad of lingual mucosa. Taste pores have been observed in the vallate papillae of both species, whereas in the foliate papillae, they are present only in the horse. A characteristic distribution of stratified scales and channeled tracts is observed on the surface of all gustatory papillae in both species. The possible functional importance of each type of gustatory papilla is discussed on the basis of their morphostructural features.     

Stephanofilaria thelazioides n. sp. (Nematoda: Filariidae) from a hippopotamus and its affinities with the species parasitic in the African black rhinoceros

Stephanofilaria thelazioides n. sp. (Filarioidea: Filariidae: Stephanofilariinae) is described from a hippopotamus Hippopotamus amphibius. This nematode is close to S. dinniki Round, 1964, a parasite of the black rhinoceros Diceros bicornis in Africa, but differs from it in the number of cuticular spines surrounding the mouth, the arrangement of the cloacal papillae and the measurements of the spicules, gubernaculum and microfilariae. Species of the genus Stephanofilaria possess spines on the head which have been derived by modification of the sensory papillae. S. thelazioides is the most primitive species of the genus and has the least modified arrangement of these papillae, with six bifid internal labial spines, four bifid external labial spines and four cephalic papillae. The genus appears to have diversified in various mammals which have in common a thick skin, such as rhinoceroses, elephants, buffaloes and now the hippopotamus. It appears to have become adapted secondarily to domestic bovines, initially in Asia and subsequently in North America.     

Morphology of floral papillae in Maxillaria Ruiz & Pav. (Orchidaceae)

BACKGROUND AND AIMS: The labellar papillae and trichomes of Maxillaria Ruiz & Pav. show great diversity. Although papillae also occur upon other parts of the flower (e.g. column and anther cap), these have not yet been studied. Labellar trichomes of Maxillaria are useful in taxonomy, but hitherto the taxonomic value of floral papillae has not been assessed. The aim of this paper is to describe the range of floral papillae found in Maxillaria and to determine whether papillae are useful as taxonomic characters. METHODS: Light microscopy, histochemistry, low-vacuum scanning and transmission electron microscopy. KEY RESULTS: A total of 75 taxa were studied. Conical papillae with rounded or pointed tips were the most common. The column and anther cap usually bear conical, obpyriform or villiform papillae, whereas those around the stigmatic surface and at the base of the anther are often larger and swollen. Labellar papillae show greater diversity, and may be conical, obpyriform, villiform, fusiform or clavate. Papillae may also occur on multiseriate trichomes that perhaps function as pseudostamens. Labellar papillae contain protein but most lack lipid. The occurrence of starch, however, is more variable. Many papillae contain pigment or act as osmophores, thereby attracting insects. Rewards such as nectar or a protein-rich, wax-like, lipoidal substance may be secreted by papillae onto the labellar surface. Some papillae may have a protective role in preventing desiccation. Species of diverse vegetative morphology may have identical floral papillae, whereas others of similar vegetative morphology may not. CONCLUSIONS: Generally, floral papillae in Maxillaria have little taxonomic value. Nevertheless, the absence of papillae from members of the M. cucullata alliance, the occurrence of clavate papillae with distended apices in the M. rufescens alliance and the presence of papillose trichomes in some species may yet prove to be useful.     

Anatomical and neurohistological observations on the tongue of the India goat, Capra aegagrus.

The anatomy and neurohistology of the tongue of the Indian goat, Capra aegagrus, have been described. The apex linguae is notched in the centre. The foramen caecum is found to be absent. The sublingua could not be traced. The filiform papillae are the most common and divided into three types: the simple, giant, and true filiform papillae. The true filiform papillae are the most developed of the three types. The foliate papillae are absent. There are 13--14 circumvallate papillae arranged in two rows in a V-shaped pattern. The fungiform papillae are large and could easily be seen with the naked eye. They are scattered over the entire dorsum, being in abundance at the tip. The tongue of the goat is richly innervated. On the dorsum, the lamina propria is innervated by thick nerve fibres. In the fungiform papillae quite a large number of nerve fibres could be seen. The circumvallate papillae are also abundantly provided with nerves. A few ganglion cells are found below the circumvallate papillae. Thick nerve fibres are seen across the numerous glands and their ducts. Muscle fibres and connective tissue are also richly innervated.     

Development of mechanical papillae of the tongue in the domestic goose (<Emphasis Type="Italic">Anser anser f. domestica</Emphasis>) during the embryonic period

Three types of mechanical papillae, i.e., conical, filiform, and hair-like papillae, are present on the tongue in the domestic goose. Within conical papillae, we distinguish three categories: large and small conical papillae on the body and conical papillae on the lingual prominence. The arrangement of mechanical papillae on the tongue in Anseriformes is connected functionally with different feeding mechanisms such as grazing and filter-feeding. The present work aims to determine whether morphology of three types of mechanical papillae in goose at the time of hatching is the same as in an adult bird and if the tongue is prepared to fulfill feeding function. Our results revealed that the primordia of the large conical papillae start to develop during the differentiation stage. The primordia of the small conical papillae and conical papillae of the lingual papillae start to develop during the growth stage. At the end of the growth stage, only large conical papillae, three pairs of small conical papillae, and conical papillae of the lingual prominence have similar arrangement as in an adult bird. The shape and arrangement of the remaining small conical papillae probably will be changed after hatching. During embryonic period, the filiform papillae and hair-like papillae are not formed. The embryonic epithelium that covered the mechanical papillae undergoes transformation leading to the formation of multilayered epithelium. During prehatching stage, epithelium becomes orthokeratinized epithelium. In conclusion, the tongue of the domestic goose after hatching is well prepared only for grazing. The filtration of food from water is limited due to the lack of filiform papillae.     

The ultrastructural characterization of the tegument of Clonorchis sinensis (Cobbold, 1875) cercaria.

The tegumental ultrastructure of the cercaria of the liver fluke, Clonorchis sinensis (Cobbold, 1875), was studied by scanning and transmission electron microscopy. The body surface is almost encircled by many rows of regularly arranged spines. The tegumental syncytium of the body contains many rod-shaped dense granules and central electron-lucent bodies, neither of which are present in the tail tegument. There are four rows of hooked teeth and modified spines on the oral cone. These teeth are differentiated morphologically and probably functionally from the other body spines. Disc-shaped papillae with long or short cilia are distributed on the body in a bilaterally symmetrical pattern dorsally and ventrally. There are 30 to 37 papillae with much longer cilia laterally. Four pairs of papillae were found on the tail. From their structure and location these papillae appear to have a mainly tango- or rheoreceptive function. Another type of sheathed papillae is situated around the oral sucker. The cuticular tegument is expanded laterally at the base of the tail, forming a characteristic sac-like structure.     

Host size- and habitat-dependent intensity of Heliconema longissimum (Nematoda: Physalopteridae) in the Japanese eel (Anguilla japonica)

Heliconema longissimum (Ortlepp, 1923) is an ecologically poorly known nematode found in the stomach of Japanese eels, Anguilla japonica Temminck and Schlegel. The occurrence of this nematode in Japanese eels was surveyed in 2 contiguous brackish-water areas (Misho Cove and the lower Renjoji River) of Ehime Prefecture, western Japan, during April 2008 to March 2009. The factors associated with the nematode intensity were also assessed by applying generalized additive models (GAM). Heliconema longissimum exhibited nearly 100% prevalence in both areas, but its intensity differed. The heavier infection in the cove eels indicates that H. longissimum is mainly distributed in the cove, which supports the past speculation for this nematode as a brackish-water parasite. The intensity also increased with the body size of eels. This tendency suggests that the eels inhabiting the cove consume, as they grow, a greater quantity of crustaceans that presumably serve as the nematode's intermediate hosts.     

Torquatoides trogoni n. sp. and Excisa ramphastina n. sp. (Nematoda: Habronematoidea: Habronematidae) in birds from the area de Conservacion Guanacaste, Costa Rica

Two new species of habronematid nematodes are described in birds from the Area de Conservacion Guanacaste, Costa Rica. Torquatoides trogoni n. sp., in Trogon massena, can be distinguished from T. torquata, T. bengalensis, and T. crotophaga in lacking lateral alae. Among species lacking lateral alae, the new species differs from T. balanocephala in having 14 versus 8-10 cephalic cuticular plaques, 21-22 versus 13-17 pairs of preanal papillae, and a beak-shaped versus U-shaped gubernaculum. The new species differs from T. singhi in body length, in having 21-22 versus 10 pairs of precloacal papillae, longer spicules, and larger eggs. The new species differs from T. crotophaga, the only other species known from Central America, in lacking lateral alae, and having 14 versus 6 cephalic cuticular plaques, 21-22 versus 17 pairs of precloacal and 3 versus 2 pairs of postcloacal papillae, and a gubernaculum. Excisa ramphastina n. sp., in Ramphastos sulfuratus, can be distinguished from E. excisa, E. biloba, E. buckleyi, E. dentifera, and E. khalili in having 1 lateral ala versus none, cervical papillae anterior versus posterior to the nerve ring, and asymmetrical caudal alae. Excisa ramphastina is similar to E. curvata in having cervical papillae anterior to the nerve ring but differs in having 1 lateral ala versus none, asymmetrical caudal alae, an average spicule ratio of 1:4.4 versus 1:3.3, and 4 versus 2 pairs of sessile papillae. The new species differs from E. columbi in having 1 versus 2 lateral alae, in the length of the spicules, in having a different spicule ratio, and in the numbers of sessile papillae.     

Physalopteroides arnoensis n. sp. (Nematoda: Physalopteroidea) and other intestinal helminths of the mourning gecko, Lepidodactylus lugubris (Sauria: Gekkonidae), from Arno Atoll, Republic of the Marshall Islands, Oceania

Physalopteroides arnoensis n. sp. (Nematoda: Physalopteroidea) from the intestinal tract of the gecko Lepidodactylus lugubris is described and illustrated. Physalopteroides arnoensis is the 18th species to be assigned to the genus and is distinguished from other oriental species by the distribution pattern of caudal papillae of the male: 22 posterior subventral pedunculated papillae; 8 precloacal papillae in symmetrical pairs; 14 postcloacal papillae, 6 papillae immediately postcloacal in symmetrial pairs and remaining 8 papillae asymmetrically placed, 3 on right, 5 on left. Other helminths found include Pharyngodon lepidodactylus, Hedruris hanleyae, Maxvachonia chabaudi, and larvae of Ascarops sp. Our review of Physalopteroides removes all subspecies designations; Physalopteroides minor Caballero, 1969 n. comb is proposed.     

The skeleton of the eye: II. Overlap of the scleral ossicles of the domestic fowl

The scleral ossicles, a ring of overlapping membrane bones, lie just outside the corneal margin in the eyes of domestic fowl. Eighty percent of the bony rings contain 14 bones; less than 1% have 13 bones; 19% have 15 bones; about 1% have 16 bones. Each bone is foreshadowed during development by a transient papilliform thickening in the overlying conjunctival epithelium. These conjunctival papillae appear on the eighth day of incubation and disappear on the twelfth day, when the corresponding preosseous membranes begin to ossify. Observations, and experiments involving the removal of specific papillae early or late in their maturation (in order to delete, or to reduce the size of, individual bones), demonstrated the following constraints on the morphogenesis of the scleral ossicular ring. (1) The number of ossicles is a function, not only of the number of papillae, but also of the distance between adjacent papillae; when two papillae lie close together, a single ossicle may arise beneath the pair. (2) There are three regions in the ring: nasal, dorsal (in both of which the bones overlap in one direction) and temporal (in which the bones overlap in the opposite direction). (3) The determinants of the direction of overlap between adjacent bones are extrinsic to the ossicles themselves and are distributed throughout each region, rather than confined to the discrete locations within each region where overlap normally occurs. (4) The three places in the ring where these regions meet are characterized by the loss (in 13-membered rings) or the addition (in 15- and 16-membered rings) of papillae and of their corresponding bones, and by transitions in the direction of overlap between the bones.     

Margolisianum bulbosum n. gen., n. sp. (Nematoda: Philometridae) from the southern flounder, Paralichthys lethostigma (Pisces: Bothidae), in Mississippi Sound, USA

A new species of a philometrid nematode, Margolisianum bulbosum, is described from the subcutaneous tissue in the mouth (larvigerous females), head (males, ovigerous, and larvigerous females), and eye (preovigerous females) of the southern flounder, Paralichthys lethostigma, from Mississippi Sound. It is placed in a new genus diagnosed by the combination of 8 large, paired but separate cephalic papillae; no inner cephalic papillae; an esophagus with a separate, muscular anterior bulb; a prominent mononuclear esophageal gland; and variable, irregularly distributed cuticular bosses in the females, as well as a vestigial rectum, particularly in larvigerous females. Some female specimens exhibit rows of lateral grooves and longitudinal ridges near the posterior end. Males have 2 small slightly subequal spicules, a barbed gubernaculum, 4 pairs of small cephalic papillae, and a bipartite hypodermal extension within a membranous cuticle on the posterior end. Males, ovigerous females, and larvigerous females appear to be present year round in this sporadic infection in Mississippi.     

Paradollfusnema telfordi n. sp. (Nematoda: Cosmocercidae) from the worm lizard,Rhineura floridana (Amphisbaenia), of Florida

Paradollfusnema telfordi n. sp. (Nematoda: Cosmocercidae) from the large intestine of a worm lizard, Rhineura floridana, collected in Florida is described and illustrated. Paradollfusnema telfordi n. sp. represents the second species assigned to the genus and is distinguished from the other species on the basis of caudal papillae patterns in the male: P. telfordi n. sp. with 8 pairs of precloacal papillae, second pair from anterior much larger than others; Paradollfusnema amphisbaenia with 4 or 5 pairs of precloacal papillae, all of equal size.     

Fine structure of the dorsal lingual epithelium of the Japanese monkey Macaca fuscata fuscata.

Filiform papillae, which were densely distributed all over the dorsal surface of the lingual body, were crown-shaped, with a central, circular area that sloped in the anterior direction and several branches that surrounded it in a semicircle from the back of the central area. Dome-shaped, fungiform papillae were scattered among these filiform papillae. At the posterior end of the lingual body, there were four circumvallate papillae. Prominent microridges and elevated intercellular borders were widely distributed in the central area of the filiform papillae and the interpapillar region. On the surface of the branches of the filiform papillae, microridges were rarely seen. On the surface of the fungiform papillae, indistinct microridges were observed. Histologically, the dorsal lingual epithelium revealed three different regions: the epithelium on the anterior side of the filiform papillae, the epithelium on the posterior side of the filiform papillae and the interpapillar epithelium. Whereas the basal and suprabasal cells are similar throughout, differences characterize the intermediate and surface layers. Keratohyalin granules appear predominantly in the intermediate layer in the epithelium on the anterior side of filiform papillae. In the epithelium on the posterior side of the filiform papillae, no keratohyalin granules occur and, instead, tonofibrils are prominent. The cells become significantly flattened. In the interpapillar epithelium, no keratohyalin granules are visible, and the tonofilaments occupy almost the entire cytoplasm of most cells in the intermediate and surface layers. The cells are larger in volume in these layers.