Successive reduction of the last instar larva of Loricifera, as evidenced by two new species of Pliciloricus from the Great Meteor Seamount (Atlantic Ocean)

Two new species of the genus Pliciloricus Higgins & Kristensen, 1986, are described from coarse sand at the plateau of the Great Meteor Seamount. Together with other species of the genus, Pliciloricus corvus sp. n. and Pliciloricus senicirrus sp. n., demonstrate that the last or seventh instar Higgins-larva can be more and more reduced.

Additionally, in the life cycle of P. corvus sp. n. a simplified adult is discovered which has a simplified body with persisting neck region and a sack-like trunk. The adult of P. corvus sp. n. is characterized, e.g., by 15 broad cross-walls in the clavoscalids, midventral spinoscalids of the second row transformed into a new type of double-organ, a secondary double-organ in the third row of scalids, type B spinoscalids of the fourth row ending in a grappling hook, a crescent-shaped ornamentation of the lorica margin with rounded gaps and protrusions, and a pair of longitudinal cuticular protrusions on the end cone. Distinguishing features of the first to sixth instar Higgins-larvae of P. corvus sp. n. are, e.g., setae of moderate length and long end spines of toes with double bulges. The seventh instar Higgins-larva of P. corvus sp. n. is not fully developed, e.g., the abdominal region is indistinct; the scalids, toes, and all five pairs of setae are clearly shorter than in the preceding instars of Higgins-larvae.

The adult of P. senicirrus sp. n. is characterized, e.g., by clavoscalids with many fine transversal striae, claw-like type B spinoscalids of the fourth row ventrally winged and with seven embedded needle-like teeth, edge of the lorica with 24 small protrusions, and 20 papillate flosculi at caudal end. The Higgins-larva of P. senicirrus sp. n. is characterized, e.g., by the wide and frill-like first section of the mouth cone, the second segment of spinoscalids with ventral serration and double tip, long anterosetae with strong spinules, and by the toes being nearly as long as the short lorica, to name a few. The most obvious feature is the extreme length of the three pairs of posterosetae. The posteroterminal setae are nearly as long as the whole body. The seventh instar Higgins-larva of P. senicirrus sp. n. is not reduced as in the case of P. corvus sp. n.     

Rugiloricus bacatus sp. nov. (Loricifera ‐Pliciloricidae) and a ghost‐larva with paedogenetic reproduction

Abstract

A new species of Loricifera, Rugiloricus bacatus sp. nov. is described together with the diagnoses of two other Rugiloricus species, Rugiloricus sp. nov. A and B, from the Faroe Bank (North Atlantic). Characteristic for all three species is the presence of a new type of reduced larva, a ghost‐larva. This type of reduced larva was discovered in 1986 by Jeanne Renaud‐Mornant, but it was with the Faroe Bank material that it was first discovered that the ghost‐larvae belonged to the phylum Loricifera. The ghost‐larvae are eitherfound inside late instar Higgins‐larvae, called penultimate Higgins‐larvae, or in the sediment. The three types of Higgins‐larvae from the Faroe Bank can be distinguished by characters such as anterior setae, posterior setae and toes. The adults of Rugiloricus bacatus sp. nov. are characterised by a prominent ruff resembling a pearl necklace; two of the eight clavoscalids are modified in the 1st row; the 2nd row of leg‐shaped scalids are very large and robust, and the 9th row with 30 beak‐like scalids alternating with 30 alternating plates. The postlarvae are free‐living and their scalids on the introvert are reduced to protoscalids. Postlarvae and adult stages have not been found for Rugiloricus sp. nov. A and B and therefore only diagnoses of these two species are presented here.     

New entodiniomorphid ciliates from the intestine of the wild African white rhinoceros belong to a new family, the Gilchristidae

Gilchristia artemis n.g., n.sp. and Digilchristia draconis n.g., n.sp. in the order Entodiniomorphida are described from the large intestine of the African white rhinoceros, and a new family Gilchristidae is proposed to contain them. These new species have a C-shaped adoral polybrachykinety, a slender vestibular polybrachykinety, and paralabial kineties along the ventral side of the adoral polybrachykinety in their retractable adoral ciliary zone, showing the same arrangement as in the rumen ciliates in the family Ophryoscolecidae. G. artemis has two skeletal plates and D. draconis one plate. In both species the dorsal skeletal plate is bow-shaped, folded in half longitudinally, twisting in the anterior part, and lying along the dorsal left side of the macronucleus. The second plate of G. artemis is slender and lies along the ventral side of the macronucleus. G. artemis has three ciliary arches and D. draconis has four arches along the dorsal and ventral sides of the body. Their arches are long and non-retractable, closely resembling those of ciliates in the families, Spirodiniidae and Cycloposthiidae, and are not analogous to the single retractable ciliary arch of the rumen ciliates in the family Ophryoscolecidae.     

Neotropical Monogenoidea. 33. Three new species of Ancistrohaptor n. g. (Dactylogyridae,Ancyrocephalinae) on Triportheus spp. (Teleostei,Characidae) from Brazil,with checklists of ancyrocephalines recorded from neotropical characiform fishes

Three new species of Ancistrohaptor n. g. are described from the gills of three species of Triportheus (Characidae) collected from the environs of Manaus, Amazonas, Brazil: A. falcatum n. sp. from T. elongatus; and A. falciferum n. sp. and A. falcunculum n. sp. from T. angulatus, T. albus and T. elongatus. Ancistrohaptor n. g. is proposed for species possessing overlapping gonads, a dextral or dextroventral vaginal aperture, a coiled (counter-clockwise) male copulatory organ, two accessory pieces in the copulatory complex, and a haptor armed with two pairs of anchors (ventral anchor with elongate shaft), dorsal and ventral bars and 14 hooks; hook pair 1 (ventral) anterior to ventral bar, pairs 2–4 (ventral) lying bilaterally anterior to ventral anchor bases, pair 5 (ventral) associated with distal end of ventral anchor shafts, and pairs 6 and 7 (dorsal) bilateral about midway along haptoral length. Parasite-host and host-parasite lists of the Ancyrocephalinae from neotropical Characiformes are provided.     

Mixacarus (Phyllolohmannia) pectinatus sp. n. (Acari,Oribatida, Lohmanniidae), a new species of oribatid mites from India

A new species of oribatid mites (adult and juvenile instars), Mixacarus (Phyllolohmannia) pectinatus sp. n., is described from India. The new species differs from the majority of species of the subgenus in the absence of distally dilated setae and narrower leaf-shaped setae on dorsal and ventral body sides.     

A phylogenetic study of Lepidapedoides Yamaguti, 1970 (Digenea) with a key and descriptions of two new species from Western Australia

Two new species of the genus Lepidapedoides are described from the aulopodid teleost Aulopus purpurissatus from south-western Australia. Both are distinguished from other Lepidapedoides spp. by their pedunculate ventral sucker. Lepidapedoides pistoris n. sp. and L. elongatrium n. sp. are distinguished by the possession of a narrow, elongate form, a long ventral sucker to ovary distance, the vitellarium reaching only to the posterior level of the cirrus-sac, the cirrus-sac length and the deep genital atrium with the metraterm entering distally to its base in L. elongatrium. A key to species of the genus is given. A character matrix is included for the genus. Poorly resolved phylogenetic trees indicate two main lineages in the genus. The two new species described here are resolved as sister taxa. The new combination Lepidapedoides freitasi (Kohn &; Fernandes, 1970) is formed for Acanthocolpoides freitasi.     

Description of the life-cycle stages of Brachylaima cribbi n. sp. (Digenea: Brachylaimidae) derived from eggs recovered from human faeces in Australia

The life-cycle of Brachylaima cribbi n. sp. was established in the laboratory. Asymmetrical brachylaimid eggs, measuring 26-32 microm (29.1 microm) long and 16 -17.5 microm (16.6 microm) wide, were recovered from human faeces and fed to the helicid land snail Theba pisana as the first intermediate host. Sporocysts and cercariae were recovered from the T. pisana eight weeks after infection. The cercariae were used to infect the helicid land snails Cernuella virgata and Helix aspersa as second intermediate hosts. Metacercariae were recovered from the kidneys of these snails and used to infect mice. Adults of Brachylaima cribbi n. sp. were recovered from the small intestine of the mice. The differential features of B. cribbi n. sp. are the specificity for helicid snails as first and second intermediate hosts; characteristic ventral sucker and body cercarial chaetotaxy; and a long slender adult worm with equal size suckers in the first quarter of the worm, the ventral sucker occupying 41% of the body width, the uterus extending anterior to the ventral sucker and the vitelline follicles falling short of the posterior margin of the ventral sucker. No other known Brachylaima species exhibits all of these features. B. cribbi n. sp. is the first brachylaimid known to have infected humans and is probably of European origin, as the intermediate host snails were all introduced into Australia from Europe.     

Morphology and life cycle of a new loriciferan from the Atlantic coast of Florida with an emended diagnosis and life cycle of Nanaloricidae (Loricifera)

Abstract. A new interstitial loriciferan, Nanaloricus gwenae sp. nov., is described from coarse-sand and shell-hash habitats ( Amphioxus sand), at 15–17 m depth, 6–7 miles off the coast of Fort Pierce, FL, USA. The new species is very closely related to the type species Nanaloricus mysticus found off the coast of Roscoff, France in nearly the same kind of sediment ( Dentalium sand). All life stages (Higgins larva, postlarva, and adult) in the life cycle of the new species were found through the 10-year investigation, leading to the conclusion that all species of Nanaloricidae have only a sexual reproductive cycle. The adult of the new species can be distinguished by the different body shape, the lorical spikes and sculpture, and the shape of the scalids. The postlarva has stronger longitudinal ridges on the lorical plates and the Higgins larva has toes with smaller mucrones than those of N. mysticus . An emended definition of the Nanaloricidae is provided based on the new formula of the number of rows and shape of the scalids on the introvert. The associated meiofauna found in the subtidal sand or shell hash is both abundant and diverse. Tardigrades, gastrotrichs, and kinorhynchs are among the most common associates. N . gwenae sp. nov. is represented by only eight specimens collected during a 10-year period of sampling this habitat.     

Introvert,mouth cone,and nervous system of Echinoderes capitatus (Kinorhyncha,Cyclorhagida) and implications for the phylogenetic relationships of Kinorhyncha

Summary The introvert, mouth cone, and nervous system of Echinoderes capitatus were examined by transmission and scanning electron microscopy. The introvert bears seven rings of primarily quincunxial sensory scalids, including type 1 and 2 spinoscalids as well as trichoscalids; the latter two types are additionally provided with glandular cells. The mouth cone bears one ring of decamerous sensory oral styles and three rings of quincunxial sensory pharyngeal styles. The intra- to basiepithelial, bilateral nervous system consists of a circumentric nerve ring in the introvert, a terminal and proximal nerve ring in the mouth cone, a ventral chain of ganglia, one in each trunk zonite, and a caudal ganglion. The introvert, the neck, and the trunk zonites are innervated from the forebrain; the mouth cone and the pharyngeal bulb are innervated from the hindbrain. The monophyly of the Kinorhyncha is based upon the following autapomorphic characters: (1) a mouth cone, (2) a neck with 16 placids, (3) a trunk with 11 zonites, (4) scalids of three types: type 1 and type 2 spinoscalids, and trichoscalids, (5) an anteriormost ring of ten type 1 spinoscalids (sensory organs divided into a basal and a terminal part), (6) a posteriormost ring of 14 trichoscalids (glandular sensory organs which are undivided), (7) rings in between the anteriormost and posteriormost are type 2 spinoscalids (glandular sensory organs divided into a basal and a terminal part), (8) a mouth cone with a terminal and a proximal nerve ring, (9) nine sensory oral styles with decamerous symmetry (the dorsal style is missing) and (10) three rings of sensory pharyngeal styles with, from anterior to posterior, ten, five, and five styles with quincunxial arrangement. The following characters are assumed to be autapomorphic for the taxon Nematoda+Gastrotricha+Kinorhyncha+Loricifera+Priapulida: (1) a basiepithelial circumentric brain and (2) a neuropileous nerve ring in a subterminal position. The following characters are assumed to be autapomorphic for the taxon Kinorhyncha+Loricifera+Priapulida: (1) a neuropileous nerve ring in a terminal position, (2) an introvert with scalids, (3) an eversible foregut and (4) tanycytes.The unpublished doctoral thesis of B. Neuhaus [1991 Zur Ultrastruktur, Postembryonalentwicklung und phylogenetischen Verwandtschaft der Kinorhyncha. PhD thesis. University of Götingen, Germany] was finished simultaneously with the completion of this study.     

Relationships between four novel ceratomyxid parasites from the gall bladders of labrid fishes from Heron Island, Queensland, Australia

Ceratomyxid parasites from the gall bladder of fishes from the family Labridae were examined for their taxonomic identity and their relatedness to other species of myxozoans. This paper describes four novel species Ceratomyxa choerodonae n. sp. from Choerodon cyanodus; Ceratomyxa cheilinae n. sp. from Cheilinus chlorourus; Ceratomyxa oxycheilinae n. sp. from Oxycheilinus digramma; and Ceratomyxa thalassomae n. sp. from Thalassoma lunare. Each species is characterised morphologically and small subunit (18 S) rDNA sequences were used in molecular phylogenetic analyses. Comparison of the small subunit rDNA sequences revealed four distinct species even though morphological differences indicated the presence of only two morphologically distinctive spore types. Phylogenetic analyses revealed that the ceratomyxids from labrid fishes did not form a clade to the exclusion of all other myxosporeans and provides evidence that host relatedness is not a good character to discriminate between species within the genus Ceratomyxa.     

Two new blood flukes (Digenea: Sanguinicolidae) from Epinephelinae (Perciformes: Serranidae) of the Pacific Ocean

Pearsonellum pygmaeus n. sp. is described from Cromileptes altivelis (Serranidae), the Barramundi Cod, from Heron Island (southern Great Barrier Reef) and Lizard Island (northern Great Barrier Reef). This new species differs from Pearsonellum corventum (type and only species) in the combination of smaller overall body size, the relative distance of the brain from the anterior end, the relative lengths of both the oesophagus and the testis, the degree to which the testis extends outside the intercaecal field, the shape of the testis, the shape and size of the ovary and the extent to which the uterus loops around the ovary. There are in addition, 20 base pair differences between the ITS2 rDNA sequence of P. pygmaeus n. sp. and that of P. corventum. Three new host records for P. corventum are reported. Adelomyllos teenae n. g., n. sp. is described from Epinephelus coioides (Serranidae), the Estuary Cod, from Moreton Bay, southeast Queensland. The new genus differs from the 22 other sanguinicolid genera in the combined possession of two testes, a cirrus-sac, separate genital pores, a post-ovarian uterus and an H-shaped intestine. A. teenae n. sp. is the third sanguinicolid described from the Epinephelinae. Sanguinicolids have now been reported from 11 species of Serranidae.     

Three new species of the genus Oswaldocruzia Travassos, 1917 (Nematoda, Trichostrongylina, Molineoidea) parasites of Enyalius spp. (Iguanidae) from Brazil

Three new species of the genus Oswaldocruzia Travassos, 1917 belonging to the sub-family Molineinae are described from the stomach and/or the small intestine of Enyalius spp. from Brazil. They belong to group 6 of Ben Slimane, Chabaud & Durette-Desset (1996). In this group they share along with O. peruensis Ben Slimane, Verhaag & Durette-Desset, 1995, a parasite of Iguanidae from Peru the followings linked characters: (i) a caudal bursa of type II; (ii) cervical alae present; (iii) undulated cuticular ridges. The Peruvian species differs from the Brasilian species by the absence of a strut in the cervical alae, by a small number of cuticular ridges at mid-body and by a spicular fork with a ramified inner twig. Oswaldocruzio fredi n. sp., a parasite of the stomach and the small intestine of Enyalius iheringii, mainly differs from the two other species by the absence of the oesophageal ventral cuticular ridges. Oswaldocruzia benslimanei n. sp., a parasite of the small intestine of Enyalius bilineatus, differs from Oswoldocruzia burseyi n. sp., a parasite of the stomach of Enyalius perditus, by the division of the fork at 23.4 % of spicule length (versus 32 %), and the length of the blade longer than the fork. Oswoldocruzia subauricularis sensu Freitas, 1955 nec Rudolphi, 1819 and O. mazzai sensu Vicente, 1981 nec Travassos, 1935 should be considered as species inquirendae.     

Scientific Report on the Belgian Expedition to the Great Barrier Reef in 1967. Nematodes IX Four new species of Quadricoma Filipjev (Nematoda, Desmoscolecida)

The following species are described: Q. papillata sp.n., characterized by its head-shape with broad truncated anterior end and in males by the possession of 2 single short, stout ventral genital papillae situated anterior to the middle of the body; Q. lizardiensis sp.n., closely related to Q. papillata but distinguished from the latter by its head-shape with a pronounced distally widened anterior border and the absence of genital papillae in the male; Q. freudenhammeri sp.n., characterized by its head-shape with an anteriorly tapering naked front part with thickened, sclerotized cuticle and a rounded posterior part covered with thin cuticle and by the stoma with cheilorhabdia; Q. noffsingerae sp.n., characterized by its head-shape with widened truncated anterior border surrounding 6 sometimes protruding lips, each with a tube-like papilla and by the position of the ocelli situated along the posterior half of the long cylindrical oesophagus.     

Description of two new interstitial species of Psammodrilidae (Annelida) from Bermuda

The family Psammodrilidae (Annelida) is a group of small polychaetes hitherto containing three nominal species in Psammodriloides and Psammodrilus. Psammodrilus swedmarki, n. sp. and P. moebjergi, n. sp. are described from subtidal coarse sand in Bermuda. Both new species are interstitial, as is the monotypic Psammodriloides fauveli Swedmark, 1958, which they resemble by their small size and lack of a muscular collar region. However, studies with scanning electron microscopy show that the larger, hermaphroditic P. moebjergi possesses a pair of peristomial dorsolateral non-ciliated areas with hexagonal cells representing those of the characteristic collar region of Psammodrilus. The uncini of both species resemble those of Psammodrilus balanoglossoides Swedmark, 1952. The systematically contradicting characters support a synonymization of the two genera. An emended diagnosis of Psammodrilus and a key to the species are presented.     

Symmetry of priapulids (Priapulida). 2. Symmetry of larvae

Larvae of priapulids are characterized by radial symmetry evident from both external and internal characters of the introvert and lorica. The bilaterality appears as a result of a combination of several radial symmetries: pentaradial symmetry of the teeth, octaradial symmetry of the primary scalids, 25-radial symmetry of scalids, biradial symmetry of the neck, and biradial and decaradial symmetry of the trunk. Internal radiality is exhibited by musculature and the circumpharyngeal nerve ring. Internal bilaterality is evident from the position of the ventral nerve cord and excretory elements. Externally, the bilaterality is determined by the position of the anal tubulus and two shortened midventral rows of scalids bordering the ventral nerve cord. The lorical elements define the biradial symmetry that is missing in adult priapulids. The radial symmetry of larvae is a secondary appearance considered an evolutionary adaptation to a lifestyle within the three-dimensional environment of the benthic sediment.     

Loss of Symbiodinium from bleached soft corals Sarcophyton ehrenbergi, Sinularia sp. and Xenia sp.

The deleterious effects of temperature-induced coral bleaching, a process by which corals lose their endosymbiotic algae (zooxanthellae; genus Symbiodinium) primarily at temperatures above mean yearly maximums, has not been well described for alcyonacean soft corals (Coelenterata, Octocorallia). The study of Symbiodinium cells lost from Sarcophyton ehrenbergi, Sinularia sp., and Xenia sp., which have not been compared in bleaching studies, indicate that the soft coral S. ehrenbergi released the greatest number of symbiont cells, however, it was less susceptible to heat stress surviving temperatures of 34 °C for >39 h. Sinularia sp. showed intermediate levels of bleaching tolerance to elevated temperatures, surviving prolonged exposures at 32 °C, but dying within 24 h at 34 °C. Xenia sp., however, was the most vulnerable to high heat stress maximally releasing Symbiodinium at temperatures ≤30 °C. This evidence indicates that Xenia sp. is even more susceptible to elevated temperatures than Acropora spp., previously reported to be the most vulnerable coral species to elevated temperature-induced bleaching.

Molecular analysis showed that the more resistant soft coral species (S. ehrenbergi) had the same type of Symbiodinium (clade C) as less resistant soft corals (Xenia sp.). In comparison to scleractinian corals collected from the same region that show similar bleaching resistance to high temperatures (e.g. Porities solida—more robust; Favites complanata—moderate resistance; Acropora hyacinthus—less robust), all scleractinian corals were symbiotic with Symbiodinium from clade C. A. hyacinthus, however, was found to possess multiple symbionts (clades B and C), and this represents a first report of Clade B in any Acropora species.     

Neotropical Monogenoidea. 46. Three new species from the gills of introduced aquarium fishes in India,the proposal of Heterotylus n. g. and Diaphorocleidus n. g., and the reassignment of some previously described species of Urocleidoides Mizelle & Price, 1964 (Polyonchoinea: Dactylogyridae)

Three new species of the Dactylogyridae are described from aquarium fishes collected in India and two new genera are proposed: Heterotylus heterotylus n. g., n. sp. from Hypostomus sp. (Loricariidae), Diaphorocleidus armillatus n. g., n. sp. from Gymnocorymbus ternetzi (Characidae) and Urocleidoides vaginoclaustrum n. sp. from Xiphophorus helleri (Poeciliidae). Heterotylus n. g. is characterised by species having overlapping gonads (testis posterodorsal to the ovary), a mid-ventral vaginal aperture, a copulatory complex consisting of a relatively straight copulatory organ unarticulated to a complex accessory piece, erect acute hook thumbs, unexpanded hook shanks, dorsal and ventral anchor/bar complexes and absence of well-defined basal roots of the ventral anchors. Diaphorocleidus n. g. includes species with overlapping gonads (testis posterodorsal to the ovary), submarginal sinistral vaginal pore, a copulatory complex comprising a coiled (counterclockwise) copulatory organ unarticulated to an accessory piece, protruding depressed hook thumb, hook shank with two subunits (proximal subunit expanded), dorsal and ventral anchor/bar complexes and V-shaped bars. The following new combinations are proposed: D. affinis (Mizelle, Kritsky & Crane, 1968) n. comb. (syn. U. affinis Mizelle, Kritsky & Crane, 1968), D. kabatai (Molnar, Hanek & Fernando, 1974) n. comb. (syn. U. kabatai Molnar, Hanek & Fernando, 1974) and D. microstomus (Mizelle, Kritsky & Crane, 1968) n. comb. (syn. U. microstomus Mizelle, Kritsky & Crane, 1968).