Head Papillae Research Articles

A new species of Planipapillus (Onychophora: Peripatopsidae) that defies the original concept of its genus

Douch, J.K. and Reid, A.L. 2023. A new species of Planipapillus (Onychophora: Peripatopsidae) that defies the originalconcept of its genus. Memoirs of Museum Victoria 82: 257–262. Planipapillus Reid, 1996 (Onychophora: Peripatopsidae) is a genus of peripatus or velvet worms from south-eastern Australia, consisting of 12 nominal species, unique in having a patch of reduced papillae on the heads of males. Specimens from Mt Useful, Victoria, that lack this trait were identified as a species of Planipapillus on the basis of morphological and molecular analyses in 1999 and 2001, respectively. That species is herein described as P. absonus sp. nov., and an emended diagnosis for the genus is provided to accommodate this unusual addition. The relationship between modified head papillae and mating is discussed.

Identification of past and present gobies: distinguishing Gobius and Pomatoschistus (Teleostei: Gobioidei) species using characters of otoliths, meristics and body morphometry

Gobies (Gobiidae + Oxudercidae) are among the largest groups of extant marine fishes. Fossils of gobies are abundant since the Miocene, and many species have been reported so far. However, delimitation of fossil goby species is challenging because molecular markers and diagnostic traits such as the disposition of sensory head papillae are lost. This study provides, for the first time, an actualistic framework for the identification of fossil goby species. We focus on characters that can in principle be recognized in fossils, and evaluate their ability to discriminate between extant goby species based on statistical analyses. Using 14 extant species of Gobius and seven species of Pomatoschistus, we conducted otolith morphometry, elliptic Fourier shape analysis of otoliths using the package ‘Momocs’, conventional fish morphometry, and meristic counts. In addition, the otoliths of all species are depicted based on SEM images and briefly described. Otolith Fourier shape analysis proved to be most efficient in discrimination of species within both genera, Gobius and Pomatoschistus. Several characters used in the other approaches also worked well, but the results were variable, and the relative taxonomic significance of particular variables tended to change depending on the species under consideration. We propose otolith shape analysis as a powerful tool to explore ancient goby species diversity when samples with abundant fossil otoliths are present. Overall, the herein presented data will greatly facilitate delimitation of fossil goby species in future studies, and will consequently shed new light on the evolution of goby diversity and biogeography through time.

A New Species of Miniature Fish of the GenusMicrophilypnus(Gobioidei: Eleotridae) from the Upper Rio Negro Basin, Amazonas, Brazil

A new species of the eleotrid genus Microphilypus from the Upper Rio Negro basin is described herein. It differs from all congeners in the presence of 5–6 arched rows of melanophores on the abdominal region, posterior to the base of the pelvic fins, followed by six large irregularly oval black blotches, with the tips of the three posteriormost blotches visible in lateral view; a dark teardrop-shaped blotch on the caudal peduncle, extending to the base of the ventral caudal rays; five light brown blotches along the dorsal profile of the body, between the origin of the second dorsal fin and the caudal peduncle; and the poorly developed laterosensory system on the head, with horizontal rows of head papillae b and d absent. A key to the species of Microphilypnus is presented.

Hexamermis popilliae n. sp. (Nematoda: Mermithidae) parasitizing the Japanese beetle Popillia japonica Newman (Coleoptera: Scarabaeidae) in Italy.

A new species of mermithid nematode, Hexamermis popilliae n. sp. (Nematoda: Mermithidae) is described from the Japanese beetle Popillia japonica Newman in Italy, an area of new introduction for this invasive pest. The combination of the following characters separates H. popilliae from other members of the genus Hexamermis Steiner, 1924: adult head obtuse; amphidial pouches slightly posterior to lateral head papillae in female but adjacent to lateral head papillae in males; amphidial openings large, well developed; amphidial pouches elliptical in females and oblong in males; cuticular vulvar cone well developed, vulvar lips greatly reduced or lacking, vagina curved at tip where meeting uteri, without reverse bend (not S-shaped), spicules slightly curved, with a slight bend in the basal portion, approximately equal to body width at cloaca. This is the first record of a species of Hexamermis parasitizing the Japanese beetle Popillia japonica. The only previous mention of mermithid nematodes from P. japonica was an undescribed species of Psammomermis in North America. Hexamermis popilliae will be evaluated as a potential biological control agent in an integrated control program of the Japanese beetle in Italy.

Description of peritoneal cavity dirofilariosis caused by Dirofilaria immitis (Filarioidea: Onchocercidae) in a dog: a case report

We describe Dirofilaria immitis occurring in the peritoneal cavity of a dog from Korea. Two worms were found in the fat of the umbrical cord area during operation for an umbrical cord hernia in a dog (four year old, female, Maltese). In gross findings, the worms were slander white and measured 132 mm (female), 111 mm (male). The tail of the male was spirally coiled. In light microscopy, the uterus was filled with not fully developed eggs. Scanning electron microscopy revealed that the cuticule was smooth on the head but those of the tail exhibited complex cuticular striation in the male. Head papillae were located in a cephalic plate forming a rectangular pattern dorsoventrally, with 4 inner labial papillae and four outer cephalic papillae. The mouth opening was very small and the bursal cavity was absent. Laterally there was a pair of amphids.  

A New Species ofMolinema(Nematoda: Onchocercidae) in Bolivian Rodents and Emended Description ofLitomosoides esslingeriBain, Petit, and Diagne, 1989

We report the distribution of 2 species of filarioid nematodes occurring in different hosts in the central region of South America. Molinema boliviensis n. sp. was recorded as a parasite of sigmodontine and echymyid rodents in Bolivia, and Litomosoides esslingeri was recorded in sigmodontine and ctenomyid rodents from Bolivia and Argentina. Molinema boliviensis n. sp. shares several similarities with other species reported in spiny rats; however, it can be easily differentiated by the presence of a flat anterior end, gradually tapering lappets and a tubercle present in posterior end, a short, uniform buccal capsule, an oval-shaped vagina vera, and a ratio of spicules of 1:1.44. An account for the morphological variability of L. esslingeri is presented that allows the identification of the buccal capsule, the tail tip in females, and the shape of spicules as reliable diagnostic traits. A complete set of head papillae is also described. The finding of these parasites in phylogenetically unrelated hosts suggests that host capture may be a frequent phenomenon in these filarioids. Researchers should focus efforts in surveying mammals within the same ecological guild to understand the distribution and host specificity of these nematodes.

Redescriptions of the Nematodes Litomosoides patersoni (Mazza, 1928) (Onchocercidae) and Stilestrongylus stilesi Freitas, Lent, And Almeida, 1937 (Heligmonellidae) Parasites of Holochilus chacarius (Rodentia, Cricetidae) From Salta, Argentina

Two nematode species are redescribed from the type host species Holochilus chacarius Thomas (Rodentia, Cricetidae, Sigmodontinae) and from the type locality of 1 of them, i.e., Ingenio San Martín de Tabacal, Salta Province, Argentina. Rodents were deposited at the Colección Mamíferos Lillo, Tucumán, Argentina. Litomosoides patersoni (Mazza, 1928) (Onchocercidae) possesses a buccal capsule with irregular external walls, a buccal cavity smooth, becoming thinner near the oral opening, a complete set of head papillae, 3-6 pairs of cloacal papillae, and the " sigmodontis " type of spicules. Filarioids were found in 3 of 17 examined hosts. Stilestrongylus stilesi Freitas, Lent, and Almeida, 1937 (Heligmonellidae), whose description was based on male specimens, was found in all 17 of the examined hosts. Here, we describe the female and the synlophe of both sexes. Females are characterized by a short uterus with less than 25 eggs, short ovejector, short and conical tail, and the posterior extremity strongly invaginated in a cuticular expansion usually harboring 1 to several eggs. The synlophe is characterized by 29-31 sub-equal cuticular ridges at the mid-body, with single (in males) or double (in females) axis of orientation of the ridges. The present work validates and enlarges the original descriptions of both species and assigns the specimens from L. patersoni, recovered from the type locality and the type host species, as neotypes.

Rhabdias(Nematoda: Rhabdiasidae) from Chamaeleonidae (Sauria): two new species fromTrioceros elliotiin east Africa and one fromBrookesia superciliarisin Madagascar

Rhabdias casiraghii n. sp. and R. kibiraensis n. sp. are described from Trioceros ellioti from Burundi and co-infection was observed in one of the host specimens. Distinctive characters between these species are, among others, the mouth and buccal capsule in front view, both of which are round in the former and laterally flattened in the latter species. Both species have a complete set of submedian head papillae (three in each submedian axis) as observed in the fourth stage larva of R. americanus from anurans. This primitive character opposes them to other species parasitic in Chamaeleonidae that have a single papilla per axis. The third species is the first described from the primitive chamaeleonid genus Brookesia; R. brygooi n. sp. from B. superciliaris from Madagascar can be distinguished from other Rhabdias in Chamaeleonidae by the small diameter of its mouth and buccal capsule. In this character, it resembles parasites from anurans. However, its infective larva has a rounded caudal extremity ornated with buds, as described in species of Rhabdias parasitic in Chamaeleonidae.

New species of Rhabdias (Nematoda: Rhabdiasidae) from Afrotropical anurans, including molecular evidence and notes on biology

Despite the small sample size the diversity of Rhabdias Stiles et Hassall, 1905 from anurans in the Afrotropical region was found to be high. Four species were collected from four localities, one in South Africa, two on Cameroonese mountains and one in Madagascar: Rhabdias picardiae sp. n. from the bufonid Amietophrynus gutturalis (Power); Rhabdias ohlerae sp. n. and Rhabdias tanyai sp. n. from the arthroleptids Leptopelis brevirostris (Werner) and Astylosternus rheophilus Amiet, respectively; and Rhabdias vencesi sp. n. from the mantellid Boophis madagascariensis (Peters). Distinctive characters between these species are numerous and obvious, based on body size, shape and size of the buccal capsule, arrangement of head papillae, and shape and size of the oesophagus and intestinal apex. Molecular data based on 500 bp of 12S rDNA and 600 bp of coxl of three of the four species are presented. Rhabdias vencesi resembles Rhabdias madagascariensis Chabaud, Brygoo et Petter, 1961 from an African ptychadenid introduced on Madagascar, but differs in body size and head morphology. The remaining new species are clearly distinct from those previously known from Afrotropical anurans. Outside the Afrotropics, some Rhabdias species present characters similar to those observed in the new species, but they all differ in various other characters. No clear correlation was seen between Rhabdias species and families of anuran hosts in this region. However, the narrow buccal capsule seen in Rhabdias species from Afrotropical lissamphibians opposes them to the majority of Rhabdias parasitic in chamaeleonids. Furthermore, the infective larva of R. vencesi has a conical pointed tail, while those of Rhabdias from chameleons have a rounded tail tip ornated with a few buds.

Morphological and biological study of Rhabdias spp. (Nematoda) from African chameleons with description of a new species.

Lung-dwelling females of Rhabdias (Rhabdiasidae), and possible migrating ceolomic young females were searched for in 46 chameleons, belonging to seven species. Rhabdias chamaeleonis, the single species identified to date in Africa, was found in Chamaeleo (Trioceros) johnstoni and C. (T.) hoehnelii, and redescribed; the sizes of the buccal capsule and oesophagus were stable compared to the length of the female parasiles, which varied from 6 mm to 22 mm in length. A second species, R. jarki n. sp., was identified from one C. (T.) johnstoni; it differed from R. chamaeleonis in the shape of anterior region, the longer and slender oesophagus (ratio bulb diameter-body diameter at that level about 1/5 instead of 1/2), the arrangement of the head papillae, the shape of the buccal capsule, and the anatomy of the genital apparatus: one of the ovaries (the anterior or posterior one according to the specimen) had a band of small cells, among larger ovocytes of the synapsis zone, which were likely to generate the spermatozoa present in the oviducts, whereas these two elements were absent from R. chamaeleonis. The parasitic females of R. jarki thus appeared to be hermaphroditic, whereas those of R. chamaeleonis appeared to be parthenogenetic. The free living phase of these Rhabdias species was heterogonic. The infective larva of R. chamaeleonis was 360-590 microns long, unmolile and at third stage inside the maternal cuticle. The free-living male of R. jarki was described. The numerous infective larvae recovered from cultures of unidentified Rhabdias were all in maternal cuticle (one larva/female instead of two as in R. gemellipara from Calumma parsonii, from Madagascar) and two kinds of larvae were identified, R. chamaeleonis and larvae 700-900 microns long provisionally identified to R. jarki. The behaviour of infective larvae and a few successful infections of insects suggest that, in the field, insect transport hosts are involved in transmission and in preventing infective larvae from drying out.

Bisbalia vossi n. g., n. sp. (Nematoda: Onchocercidae), a filarial worm from a geomyoid rodent, Heteromys anomalus, in Venezuela.

Bisbalia vossi n. g., n. sp. is described from Heteromys anomalus (Rodentia: Geomyoidea: Heteromyidae) in northern Venezuela (Aragua). The filariae were found in a membranous pocket in the pleural cavity, and almost all had ingested red blood cells of their host. The morphology of this onchocercine species is highly evolved (advanced reduction of head and caudal papillae; short undivided oesophagus). Its very short microfilariae (60 microm) and the shape of the tail of the female (two terminal median pairs of bosses) suggest that this species could be derived from Ackertia Vaz, 1934, a South American genus parasitic in caviomorph rodents which is related to the Dipetalonema-line, but Ackertia has several pairs of precloacal papillae, which are absent in the new genus. In North America, where the geomyoid rodents originated and diversified, the two previously described filarial species differ from this new material and show affinities with Old World bat parasites (Litomosa van Beneden, 1871).

The eyes of suckermouth armoured catfish (Loricariidae, subfamily Hypostomus): pupil response, lenticular longitudinal spherical aberration and retinal topography.

The dilated, round pupils of a species of suckermouth armoured catfish (Liposarcus pardalis) constrict slowly on illumination (over 35-40 min) to form crescent-shaped apertures. Ray tracing of He-Ne laser beams shows that the lenses of a related species (Pterygoplichthys etentaculus), which also has a crescent-shaped pupil, are well corrected for longitudinal spherical aberration, suggesting that the primary purpose of the irregular pupil in armoured catfish is not to correct such aberration. It is suggested that the iris operculum may serve to camouflage the pupil of these substrate-dwelling species. An examination of the catfish retina shows the photoreceptors to be exclusively single cones interspersed with elongate rods and demonstrates the presence of multiple optic nerve head papillae. Two areas of high ganglion cell density, each side of a vertically oriented falciform process, provide increased spatial resolving power along the axes examining the substrate in front of and behind the animal.

Phylogenetics of Planipapillus, Lawn-Headed Onychophorans of the Australian Alps, Based on Nuclear and Mitochondrial Gene Sequences

We addressed phylogenetic relationships among species of Planipapillus, a clade of oviparous onychophorans from southeastern mainland Australia, to create a framework for understanding the evolution of the modified male head papillae used in mating in this clade. We sequenced fragments of two mitochondrial genes, COI and 12S rRNA, and a nuclear intron from the fushi tarazu gene, for individuals from 14 putative species of Planipapillus and six outgroups. We analyzed these data under both parsimony and likelihood criteria, incorporating heterogeneous parameter fitting guided by likelihood ratio tests. These analyses result in strong, congruent support for many clades. We infer multiple independent origins of spikes in Planipapillus male head structures.

Utriculimermis microcaudata n. gen., n. sp., a new genus and species of Mermithidae (Nematoda) of the rivers Lafnitz and Teigitsch in the southeastern Austrian Alps

AbstractUtriculimermis microcaudata n. gen., n. sp. (Nematoda: Mermithidae) is described from the hyporheic biotope of two running waters in southeastern Austria. The mermithids were sampled by pumping and with a modified 'Hess'-sampler. The characteristics of this new genus are: long body length, a very long pharynx which attains about 95% of the body length, six head papillae, mouth opening terminal, six hypodermal chords at midbody level, excretory pore present near the nerve ring, small cupshaped amphids, cuticula lacking cross fibres under light microscope, males with long slightly curved spiculum, very large number of genital papillae, vulva slightly curved to barrel-shaped with vulval flap, postparasitic juveniles with very short tail appendage often only present as a button-like nipple.

Description of Madathamugadia hiepei n. sp. (nematoda: Splendidofilariinae), a parasite of a South African gecko, and its development in laboratory bred Phlebotomus dubosqi (Diptera: Psychodidae).

Madathamugadia hiepei n. sp., Splendidofilariinae, a parasite of a South African gecko Pachydactylus turneri is described together with its development obtained experimentally in Phlebotomus duboscqi (Diptera: Psychodidae: Phlebotominae). This new species differs from the two small, more highly evolved groups with a short tail and atrophied postcloacal papillae, the first group consisting of two Madagascan species, M. zonosauri and M. hopluri, parasites of the Gerrhosauridae and Iguanidae, and the second containing three species from the Ethiopian Region, M. huambensis, M. versterae and M. bissani, parasites of the Scincidae. It also differs from M. ineichi, the most primitive species of the genus (cuticularised buccal capsule, no atrophy of head papillae and largest number of precloacal papillae), a parasite of the Cordylidae in South Africa. M. hiepei is close to the two species parasitic in the Gekkonidae of the Mediterranean subregion, M. ivaschkini and M. wanjii, all three of which have a post-oesophageal vulva. However, the new species can be distinguished from the Mediterranean parasites by (a) the shorter oesophagus, (b) the number and position of the cloacal papillae and (c) the microfilaria. The three filariae of this group and M. ineichi, the only ones of which aspects of the life-cycles are known, experimentally develop in phlebotomine sand flies.

Two new species ofThaumastoderma(Gastrotricha, Macrodasyida) from Korea

Abstract Two new marine gastrotrichs of the genus Thaumastoderma are described from South Korea T. coronarium sp. nov. was collected from the intertidal zones of Manripo beach and Sopori, Tokchok Island in the Yellow Sea. This species seems to be most closely related to T. bifurcatum CLAUSEN, 1991 or T. truncatum CLAUSEN, 1991 in that they share the following characteristics: one pair of simple, spatulate tentacles; six pairs of dorsal cirri; and absence of eye spots. It differs from these species in having four conspicuous head papillae and a different arrangement of dorsal cirri. T. appendiculatum sp. nov. was collected from the intertidal and shallow sublittoral zones of Pong po beach, Sokcho in the East Sea of Korea, and is easily distinguished from its congeners in having a pair of stout adhesive tubes on the posterior trunk margin, and in that it frequently possesses accessory dorsal cirri. This is the first report on marine gastrotrichs from Korea, and the first record of the genus Thaumastoderma in East Asia.

The ultrastructure of the anterior end of male Onchocerca volvulus: papillae, amphids, nerve ring and first indication of an excretory system in the adult filarial worm.

A detailed morphological investigation of the anterior sensory organs, the nerve ring and a glomerulus-like structure in male Onchocerca volvulus was performed by means of electron microscopy. The 8 head papillae are arranged in the common 4 + 4 pattern of most filarial worms in circles around the mouth opening. The amphidial openings are found between the circles of inner and outer papillae on both sides of the mouth. Inside, several additional nerve axons are seen in the tissue of the anterior tip not related to one of the identified papillar structures. The inner and outer papillae exhibit a remarkably different fine structure, and are part of a complex system of at least 2 different receptor cell types at the anterior tip of the worm. The amphidial channel contains 8 modified cilia; accessory axons are associated with the cytoplasm of the sheath cell. The anterior nerve ring of male worms is located about 150 micrometers posterior from the outermost tip of the head region. It consists of several fibres coiled around the oesophagus. The comparison of the fine structure of the central nervous system did not show the expected morphological differences associated with the heterogeneous age distribution in the natural worm population. This was in contrast to previous findings with respect to tissues in different parts of the worm. The study also provides the first evidence that suggests the existence of an excretory organ in a filarial worm in the region of the anterior nerve ring. Paired glomerulus-like structures in the lateral chords and a canal formed by a projection of the basal zone of the cuticles were identified.

Two New Species of Larvicidal Nematodes (Mermithidae) from Larvae of Chironomus plumosus (Diptera: Chironomidae) in Minnesota, U.S.A.

Telomermis amphiorchis n. gen., n. sp. and Gastromermis plumosus n. sp. are described from the larvae of Chironomus plumosus in the north arm of Lake Itasca, Clearwater County, Minnesota. Telomermis is distinguished from other mermithid genera in having a terminal mouth, four head papillae, a short S-shaped vagina, no visible cuticular cross-fibers, amphidal opening posterior to head papillae, two simple spicules, and a rounded posterior terminus. The post-parasitic juvenile lacks a larval horn. Gastromermis plumosus is distinguishable from most species of the genus by the mouth opening, amphidal opening and head papillae being at the same level. Four other adequately described species of Gastromermis have those characteristics. The length and shape of the spicule, amphids, and vagina is used to separate G. plumosus from the four species. Octomyomermis itascensis heavily infected the larvae of Chironomus plumosus from 1959 through 1962. In 1969-1970, it was replaced by the two new species. The 1969-1970 condition also existed

Morphologically distinct populations of the shorthead sculpin, Cottus confusus, and mottled sculpin, Cottus bairdi (Pisces, Cottidae), near the western border of Canada and the United States

Previously known within Canada from the Flathead River, nominal Cottus confusus also occur in the Kettle, Columbia, and Slocan rivers of British Columbia. The latter populations are similar to those from Washington, and possess a post-maxillary pore, lower numbers of pectoral rays, prickles behind the pectoral fin, and a smooth head. They are sympatric with nominal Cottus bairdi, with some individuals morphologically intermediate between the two species. Flathead River samples of nominal C. confusus differ from Columbia River populations in absence of the pore and prickles, higher fin ray counts, and larger head papillae. Specimens of nominal C. bairdi previously reported from the St. Mary River (Saskatchewan and Nelson drainages) and Milk River (Missouri River drainage) of Alberta are similar to Flathead River C. confusus, with others intermediate between Flathead River C. confusus and Columbia River populations of C. bairdi and C. confusus. Differences between Flathead River and Columbia River samples suggest that these populations require separate status in Canada. Similkameen River samples of C. bairdi are morphologically variable, individuals from upstream populations having some characters similar to those of C. confusus. A thorough study of C. bairdi and C. confusus in the United States is needed to redefine species limits.

Head and Cuticular Structures of Some Species in the Family Steinernematidae (Nematoda)

Head and cuticular structures of the Steinernematidae: Steinernema kraussei, Neoaplectana glaseri, N. carpocapsae and N. bibionis were compared by scanning electron microscopy. In both genera and all species studied one ring of six labial papillae and one of four cephalic papillae were clearly visible, which shows that Steinernema and Neoaplectana cannot be separated on the number of head papillae alone. Details of the morphology of the lips, openings of secretory organs and of the surface of the cuticle are given. Invasive juveniles have only one ring of four cephalic papillae.