Tegumental ultrastructure of the juvenile and adult Himasthla alincia (Digenea: Echinostomatidae)

The tegumental ultrastructure of juvenile and adult Himasthla alincia (Digenea: Echinostomatidae) was observed by scanning electron microscopy. One-, 5- (juveniles) and 20-day-old worms (adults) were harvested from chicks experimentally fed metacercariae from a bivalve, Mactra veneriformis. The juvenile worms were elongated and curved ventrally. The head crown bore 31 collar spines, arranged in a single row. The lip of the oral sucker had 12 paired, and 3 single type I sensory papillae, and the ventral sucker had about 25 type II sensory papillae. The anterolateral surface between the two suckers was densely packed with tegumental spines with 4-7 pointed tips. The adult worms were more elongated and filamentous, and had severe transverse folds over the whole body surface. On the head crown and two suckers, type I and II sensory papillae were more densely distributed than in the juvenile worms. Retractile brush-like spines, with 8-10 digits, were seen on the anterolateral surface, whereas claw-shaped spines, with 2-5 digits, were sparsely distributed posteriorly to the ventral sucker. The cirrus characteristically protruded out, and was armed with small spines distally. The surface ultrastructure of H. alincia was shown to be unique among echinostomes, especially in the digitation of its tegumental spines, the distribution of sensory papillae and by severe folds of the tegument.     

A revision of the Mediterranean gobiid genus Chromogobius (Teleostei-Perciformes)

The Mediterranean gobiid genus Chromogobius (Teleostei-Perciformes) is redefined with additional information on lateral-line system and skeleton. The value of meristic features, colouration, squamation, and relative number of cephalic lateral-line papillae is shown for species and subspecies definition. Two species are recognized and described, the mediolittoral Ch. quadrivittatus (Steindachner, 1863) (type species) and the more offshore Ch. zebratus (Kolombatovic, 1891), with the latter being divided into the two subspecies Ch. z. zebratus (from Split, Adriatic Sea) and Ch. z. levanticus subsp. n . (Mediterranean coast of Israel; possibly Tyrrhenian Sea). Osteological confirmation for placing Chromogobius in the Gobiidae is provided, and Chromogobius shown to have affinity with certain South African species (Gobius nudiceps, G. caffer, G. natalensis, G. agulhensis, and Acentrogobius multi-fasciatus), as well as occupying an intermediate position between the Mediterranean Zebrus zebrus and Didogobius bentuvii.     

日本棘隙吸虫体被超微结构的研究

本文报道扫描电镜观察下日本棘隙吸虫皮式、体棘和3种感觉乳突的形态和分布。     

Tegumental ultrastructures of Echinoparyphium recurvatum according to developmental stages

The present study was performed to observe tegumental ultrastructure of Echinoparyphium recurvatum according to developmental stages. Worms (1, 3, 5 and 15-day old) were recovered from chicks experimentally infected with metacercariae from Radix auricularia coreana. One-day old worms were elongated and ventrally concave, and covered with peg-like tegumental spines except the adjacent areas of the head crown and excretory pore. Type I sensory papillae were distributed on the lip of the oral sucker, and grouped ciliated papillae were around the oral sucker. Peg-like tegumental spines were densely distributed on the anterior surface of the ventral sucker level. The ventral sucker had an aspinous tegument and no sensory papillae. Tegumental spines on the posterior surface of the ventral sucker level were sparsely distributed and disappeared posteriorly. In 3 and 5-day old worms, the tegument around the oral sucker was aspinose and wrinkled concentrically. The ventral sucker had a wrinkled tegument and many bulbous papillae. Type I sensory papillae were distributed between the bulbous papillae. Tegumental spines were spade-shaped with a terminal tip. A total of 45 collar spines including 4 end group ones on both ventral corners was alternately arranged in 2 rows. The 15-day old worms were very stout and their tegumental spines were tongue-shaped without a terminal tip. From the above results, it is confirmed that the surface ultrastructure of E. recurvatum was generally similar to that of other echinostomatid flukes. However, some features, i.e., morphological change of tegumental spines and appearance of sensory papillae on the ventral sucker according to development, and number, shape and arrangement of collar spines, were characteristic, which may be of taxonomic and bioecological significance.     

Review of the Indo-Pacific gobiid fish genus Lubricogobius, with description of a new species and a new genus for L. pumilus

The gobiid genus Lubricogobius Tanaka, distinctive in being scaleless, without sensory pores, but with sensory papillae on the head, consists of three small species (largest, 33.7 mm SL): the yellow L. exiguus Tanaka, type species, from Japan, with probable records from Taiwan and New Caledonia; L. ornatus Fourmanoir, orange with blue lines on the head, described from Vietnam, recorded from the Arafura Sea, and the range here extended to the Timor Sea and Northwest Shelf of Western Australia, Ryukyu Islands, and to New Caledonia; and L. dinah, a new species from Papua New Guinea and the Ryukyu Islands, white dorsally and abruptly orange-yellow ventrally, with 10–11 dorsal soft rays. L. pumilus Larson and Hoese, known from one 14.5-mm specimen from off Somalia, is referred to the new genus Larsonella. The new genus differs from Lubricogobius in having scales posteriorly on the body, a more slender body, depressed head, no pelvic frenum, the snout longer than orbit diameter, and a different pattern of sensory papillae on the head. Received: September 30, 1999 / Accepted: June 9, 2000     

Oral papillae of adults of the southern hemisphere lamprey Geotria australis

The morphology, cell types, and innervation of the several small papillae (x? = 17) and two larger papillae, which together form a ring just outside the fimbriae surrounding the suctorial disc of adult Geotria australis, have been studied using various histological stains, including silver impregnation, and scanning and transmission electron microscopy. The epithelium of all papillae consists almost entirely of mucigenic cells. The multivillous and oligovillous cells, which are found elsewhere in the lamprey epidermis, were not observed, and Merkel and polyvillous cells are rare. Free nerve endings are common, however, in the basal layers of the epidermis. Unlike the small papillae, the two large papillae contain a core of skeletal muscle and a prominent layer of dermal collagen. In the submucosa of these large papillae, the nerves form a dense, compact layer that contains many large and probably sensory axons. It is suggested that the oral disc papillae of adult G. australis are encapsulated mechanosensory structures that play a role in enabling the animal to locate and attach to a suitable point on host fishes or other surfaces.     

Tegumental ultrastructure of juvenile and adult Echinostoma cinetorchis]

The tegumental ultrastructure of juvenile and adult Echinostoma cinetorchis (Trematoda: Echinostomatidae) was observed by scanning electron microscopy. Three-day (juvenile) and 16-day (adult) worms were harvested from rats (Sprague-Dawley) experimentally fed the metacercariae from the laboratory-infected fresh water snail, Hippeutis cantori. The worms were fixed with 2.5% glutaraldehyde, processed routinely, and observed by an ISI Korea DS-130 scanning electron microscope. The 3-day old juvenile worms were elongated and ventrally curved, with their ventral sucker near the anterior two-fifths of the body. The head crown was bearing 37-38 collar spines arranged in a zigzag pattern. The lips of the oral and ventral suckers had 8 and 5 type II sensory papillae respectively, and between the spines, a few type III papillae were observed. Tongue or spade-shape spines were distributed anteriorly to the ventral sucker, whereas peg-like spines were distributed posteriorly and became sparse toward the posterior body. The spines of the dorsal surface were similar to those of the ventral surface. The 16-day old adults were leaf-like, and their oral and ventral suckers were located very closely. Aspinous head crown, oral and ventral suckers had type II and type III sensory papillae, and numerous type I papillae were distributed on the tegument anterior to the ventral sucker. Scale-like spines, with broad base and round tip, were distributed densely on the tegument anterior to the ventral sucker but they became sparse posteriorly. At the dorsal surface, spines were observed at times only at the anterior body. The results showed that the tegument of E. cinetorchis is similar to that of other echinostomes, but differs in the number and arrangement of collar spines, shape and distribution of tegumenal spines, and type and distribution of sensory papillae.     

Surface ultrastructure of the advanced third-stage larvae of Gnathostoma nipponicum

The surface ultrastructure of advanced third-stage larvae (AL3) of Gnathostoma nipponicum was studied using scanning electron microscopy. The larvae were recovered from the grass snake Rhabdophis tigrina in the Republic of Korea. Parasites had a globular head bulb with a pair of lips at the anterior end and 2 labial papillae and an amphid on each lip. The head bulb was characteristically armed with 3 transverse rows of hooklets, averaging 36, 38, and 43 in number, increasing posteriorly. A total of 213-232 minute unidentate cuticular spines were present along the entire length of the larvae, forming the transverse striations. Two pairs of cervical papillae were located between the 8th and 12th transverse striations, and a pair of body papillae was seen laterally on the posterior third of the body. A pair of caudal phasmids was recognized near the posterior extremity. The surface ultrastructure of AL3 of G. nipponicum is unique compared with that of other species.     

The lateral-line system of Caspiosoma caspium (Kessler, 1877) and the systematic status of Asra turcomanus Iljin, 1941

The lateral-line system of the Ponto-Caspian gobiid Caspiosoma caspium (Kessler, 1877) is described, with new data on the arrangement of sensory papillae over the head. The systematic status of related forms, especially Asra turcomanus Iljin, 1941, is briefly discussed.     

Fasciola gigantica: surface topography of the adult tegument

Adult Fasciola gigantica are leaf-shaped with tapered anterior and posterior ends and measure about 35 mm in length and 15 mm in width across the mid section. Under the scanning electron microscope its surface appears rough due to the presence of numerous spines and surface foldings. Both oral and ventral suckers have thick rims covered with transverse folds and appear spineless. On the anterior part of the ventral surface of the body, the spines are small and closely-spaced. Each spine has a serrated edge with 16 to 20 sharp points, and measures about 20 microm in width and 30 microm in height. In the mid-region the spines increase in size (up to 54 microm in width and 58 microm in height) and number, especially towards the lateral aspect of the body. Towards the posterior end the spines progressively decrease in both size and number. The tegumental surface between the spines appears highly corrugated with transverse folds alternating with grooves. At higher magnifications the surface of each fold is further increased with a meshwork of small ridges separated by variable-sized pits or slits. There are three types of sensory papillae on the surface. Types 1 and 2 are bulbous, measuring 4-6 microm in diameter at the base with nipple-like tips, and the type 2 also have short cilia. Type 3 papillae are also bulbous and of similar size but with a smooth surface. These sensory papillae usually occur in clusters, each having between 2 and 15 units depending on the region of the body. Clusters of papillae on the lateral aspect (usually types 1 and 2) and around the suckers (type 3) tend to be more numerous and larger in size. The dorsal side of the body exhibits similar surface features, but the spines and papillae appear less numerous and are smaller. Corrugation and invaginations of the surface are also less extensive than on the ventral side of the body.     

纤细背孔吸虫体被超微结构的研究

本文对人工感染获得的纤细背孔吸虫Notocotylus attenuatus(Rud.,1809)成虫的体被进行了扫描电镜观察。发现虫体不同部位的体被有着不同的被式。口吸盘处为放射状条索;虫体腹面口吸盘后至中列第一腹腺前为无棘区,呈石板条块状,其余部分均为银杏叶和尖叶形体棘所覆盖。虫体背面边缘一圈为有棘区,其圈内为珠状突起结构。     

Scanning Electron Microscope Studies of Steinernema anomali Kozodoi, 1984

This paper presents SEM micrographs of portions of the male, female, and infective-stage juvenile of Steinernema anomali. Included are micrographs of the cephalic and caudal region, spicules, and gubernaculum of the male, the cephalic and vulval region of the female, and the cephalic region of the infective-stage juvenile. Males have six labial and four prominent cephalic papillae and small amphids. There are 11-14 pairs and one single genital papillae; of these, 6-9 pairs are preanal and subventral, one pair preanal, lateral, one pair adanal, and three pairs postanal. Spicules have a short head, a long blade, and a reduced shaft. The distal end is enlarged and bears a dorsal aperture. Gubernaculum much shorter than spicules; cuneus of gubernaculum short and bifurcate anteriorly. Females have six labial and four cephalic papillae and small amphids. Vulva with a thickened posterior lip. Infective juveniles have a smooth head, prominent amphids, and four cephalic papillae. Labial papillae, if present, are not evident.     

Surface ultrastructure of Metagonimus miyatai metacercariae and adults

A scanning electron microscopic study was performed to observe surface ultrastructures of excysted metacercariae and adults of Metagonimus miyatai. Metacercariae were collected from the scale of the pale chub (Zacco platypus), and adult flukes were harvested 1-4 weeks after infection to rats. In excysted metacercariae, the oral sucker was devoid of tegumental spines and had type I and type II sensory papillae. Anteriorly to the ventral sucker, spines were dense and digitated into 5-7 points, whereas near the posterior end of the body spines were sparse and digitated into 2-3 points. In one-week adults, 7 type II sensory papillae were arranged around the lip of the oral sucker, and at inner side of the lip one pair of small and two pairs of large type 1 sensory papillae were seen on each side. The distribution of tegumental spines was similar to that of metacercariae, but they were more differentiated with 9-11 pointed tips. In two- to four-week old adults, the surface ultrastructure was nearly the same as in one-week old adults, however, sperms were frequently seen entering into the Laurer''s canal. Conclusively, the surface ultrastructure of M. miyatai was generally similar to that of M. yokogawai, however, differentiation of tegumental spines and distribution of sensory papillae around the oral sucker were different between the two species, which may be of taxonomic significance.     

Morphology of sensory papillae on the feeding proboscis of cone snails (Mollusca,Gastropoda)

Cone snails, predatory marine gastropods, have developed a specialized prey capture method in which a long, distensible proboscis is used to identify prey and inject venom via a hydraulically propelled hollow radular tooth. Using brightfield, epifluorescence, confocal, and transmission and scanning electron microscopy, we describe the morphology of ciliated sensory structures concentrated on the tip of the proboscis. The number and morphology of these sensory papillae are linked to the type of preferred prey: cone snails feeding on worms and mollusks have short, cone or finger‐shaped papillae, whereas fish‐hunting cone snails have long tubular papillae in addition to short conical papillae. Sensory papillae are well positioned to provide information necessary to locate, identify, and dispatch prey. Proboscis tips and their sensory papillae regenerated within 10 d following experimental ablation, and snails with regenerated proboscis tips were able to locate and envenomate prey. The remarkable intrageneric variation found in the morphology of these sensory structures is probably linked to the specialized prey that cone snail species have evolved to hunt.     

Surface ultrastructure of the tegument of Clonorchis sinensis newly excysted juveniles and adult worms.

The tegumental structures of newly excysted juveniles and adult worms of Clonorchis sinensis were studied using scanning and transmission electron microscopy. After excystation the juvenile's tegumental surface is characterized by knoblike protuberances and is armed almost entirely with numerous rows of small spines encircling the body. These spines are double- or triple-pointed on the anterior portion of the body and become single-pointed posteriorly. Four types of presumed sensory structures were observed as follow: A) ciliated knoblike papillae and B) nonciliated platelike papillae, both of which are arranged in rougly a bilaterally symmetrical pattern dorsally, ventrally, and laterally; C) rounded swellings of nonciliated papillae on the lips of the ventral and oral suckers, which are characterized in the transmission electron microscope by a rounded dense body in the apical bulb; and D) a sensory receptor with a bulbous projection having the appearance of a modified cilium, which was not found with SEM likely owing to its being enclosed by an extension of the tegument. In full-grown adult worms, the tegumental surface is knobbed or lobulated in various forms without surface spines. The tegumental structures in the adults appear to be clearly differentiated from those in the juveniles. Upraised, buttonlike papillae, each topped by a short cilium, which are similar to the Type A papillae in the juveniles, are distributed thickly around the oral and ventral suckers, and are rather randomly scattered over the remainder of the body. Some nonciliated swollen papillae were found on the lip of the ventral sucker.     

A new West Balkanian sand-goby (Teleostei: Gobiidae)

A new species of West Balkanian freshwater sand-goby Pomatoschistus montenegrensis sp. nov. (Teleostei: Gobiidae) is described from the Morača River, southern Montenegro, and shown to be related to the euryhaline Adriatic Pomatoschistus canestrinii . The generic status of these two species is discussed with reference to the limits of Pomatoschistus (type Gobius minutus ) and the status of a subgenus [ Ninnigobius (type-species Gobius canestrini )]. The habitat and the local distribution of the new species are described.