A descriptive study of some Antarctic notaspidean opisthobranchs (Gastropoda), with description of a new genus and species

During the expedition “ANTARTIDA 9101”, organized by the Spanish Oceanographic Institute to the South Orkney Islands, four specimens of notaspidean gastropods were collected. Three of them have been identified as Bathyberthella antarctica Willan and Bertsch, 1987. However, one specimen, although externally similar to B. antarctica, had an internal anatomy exhibiting features that have enabled us to consider it to be a new genus and species. This new taxon is characterized by the presence of jaws without mandibular elements, and a vaginal gland that partially surrounds the distal region of the vaginal duct. In this paper the new genus and species is described. Additional anatomical data of the specimens of B. antarctica collected during the expedition are also included.     

Larval development and metamorphosis in Pleurobranchaea maculata, with a review of development in the notaspidea (Opisthobranchia)

Pleurobranchaea maculata is a carnivorous notaspidean that is common in New Zealand. This species produces small eggs (diameter 100 microm) and planktotrophic veligers that hatch in 8 d and are planktonic for 3 weeks before settling on biofilmed surfaces (14 degrees C). Larval development is known in detail for only two other notaspidean species, P. japonica and Berthellina citrina. In all three species of pleurobranchids, mantle and shell growth show striking differences from veligers of other opisthobranch taxa. In young veligers of pleurobranchids, the shell is overgrown by the mantle, new shell is added by cells other than those of the mantle fold, and an operculum does not form. Thus some "adult" traits (e.g., notum differentiation, mechanism of shell growth, lack of operculum) are expressed early in larval development. This suggests that apomorphies characteristic of adult pleurobranchids evolved through heterochrony, with expression in larvae of traits typical of adults of other clades. The protoconch is dissolved post-settlement and not cast off as occurs in other opisthobranch orders, indicating that shell loss is apomorphic. P. maculata veligers are atypical of opisthobranchs in having a field of highly folded cells on the lower velar surface, a mouth that is posterior to the metatroch, and a richly glandular, possibly chemodefensive mantle. These data indicate that notaspidean larvae are highly derived in terms of the novel traits and the timing of morphogenic events. Phylogenetic analysis must consider embryological origins before assuming homology, as morphological similarities (e.g., shell loss) may have developed through distinct mechanisms.     

Duplaccessorius andinus n. gen., n. sp. (Dactylogyridae: Ancyrocephalinae) from the gills of Percichthys trucha (Perciformes: Percichthyidae) in Patagonia, Argentina

During a parasitological survey of Patagonian freshwater fishes, specimens of a new species of Monogenea were collected from the gills of Percichthys trucha (Perciformes: Percichthyidae). This species is described as the only member of a newly proposed genus of Ancyrocephalinae. Duplaccessorius n. gen. (Dactylogyridae, Ancyrocephalinae) is characterized by hooks with 2 subunits, gonads in tandem, a coiled male copulatory organ with counterclockwise rings, an accessory piece formed by 2 distinct parts, and a nonsclerotized sinistrolateral vagina with a funnel shape vestibule. Duplaccessorius andinus n. sp. infects the gills of P. trucha (Cuvier and Valenciennes, 1840) from Andean Patagonian lakes, being the first species of Ancyrocephalinae described from a South American percichthyid.     

Septesinus gibsoni n. g., n. sp. (Monocotylidae: Heterocotylinae), from the gills of Himantura walga (Dasyatidae) off Sarawak, Borneo

Septesinus gibsoni n. g., n. sp. (Monocotylidae: Heterocotylinae) is described from the gills of the dwarf whipray Himantura walga (Müller & Henle) collected in marine waters off Sarawak (Borneo), Malaysia. Septesinus n. g. is distinguished from other genera in the Monocotylidae by a combination of characters, including a haptor with one central and seven peripheral loculi, the presence of a highly sinuous ridge surmounting all haptoral septa, four rounded accessory structures on the dorsal surface of the haptor, and the anterior region with two pairs of anteromedian and three pairs of anterolateral gland-duct openings. Septesinus n. g. is accommodated in the Heterocotylinae. Septesinus gibsoni n. sp. is described and fully illustrated, and a key to the genera of Heterocotylinae is provided. The composition of the ridges surrounding the mouth of a number of heterocotyline species and their usefulness as a taxonomic character are examined. The identity of four specimens of Monocotyle Taschenberg, 1878, also recovered from the gills of this host species, is discussed.     

Three new species of the genus Peptostreptococcus isolated from humans: Peptostreptococcus vaginalis sp. nov., Peptostreptococcus lacrimalis sp. nov., and Peptostreptococcus lactolyticus sp. nov.

We describe three new species of the genus Peptostreptococcus which were isolated from human specimens and were tentatively identified as Peptostreptococcus prevotii. These three organisms were not homologous with previously described type strains of the genus Peptostreptococcus. A total of 12 strains that were identified biochemically as P. prevotii were divided into five independent DNA similarity groups; 10 of these strains were divided into three similarity groups which exhibited significant phenotypic differences from previously described species. Therefore, we propose the following new species: Peptostreptococcus vaginalis for group 1 strains, Peptostreptococcus lacrimalis for group 2 strains, and Peptostreptococcus lactolyticus for group 3 strains. The type strain of P. vaginalis is strain GIFU 12669 (= JCM 8138), the type strain of P. lacrimalis is strain GIFU 7667 (= JCM 8139), and the type strain of P. lactolyticus is strain GIFU 8586 (= JCM 8140).     

Diclidophora embiotocae sp. n. (Monogenea, Diclidophoridae), a parasite of embiotocid fishes of Oregon.

Diclidophora embiotocae sp. n. is described from adult specimens obtained from the gills of three species of embiotocid fishes from the central coast of Oregon. It differs from all other members of the genus in hosts, geographic location, and in possessing pre- and para-ovarian, as well as post-ovarian testes. Diagnosis of Diclidophora (Yamaguti 1963) is emended.     

Dendromonocotyle lasti n. sp. from the skin and Monocotyle caseyae n. sp. (Monogenea: Monocotylidae) from the gills of Himantura sp. (Dasyatidae) in Moreton Bay, Queensland, Australia

Seven specimens of rays of the genus Himantura which could not be identified to species were collected from waters near Dunwich, Stradbroke Island, Moreton Bay, Queensland, Australia. The five smallest specimens of Himanturasp. (disc width 218-302 mm; four female, one male) had a banded tail and the dorsal surface was uniformly grey/brown. The two largest individuals of Himantura sp. (disc widths 460, 533 mm; female and male, respectively) also had a banded tail but the grey/brown dorsal surface had white spots. Two new monogenean species (Monocotylidae: Monocotylinae) are described from both the plain and white-spotted specimens of Himantura. Dendromonocotyle lastin. sp. is distinguished from other species in the genus by the number of papillae on the haptor, by the morphology of the male copulatory organ and by the morphology of the proximal portion of the vagina. The muscular sheath which surrounds the male copulatory organ is also unique having sclerotised spines at the distal end. Dendromonocotyle species are skin parasites, but a total of five juvenile specimens of D. lasti were found on the gills of four rays. Monocotyle caseyae n. sp. from the gills is characterised by the morphology of the male copulatory organ and its accessory piece. One specimen of M. spiremae Measures, Beverley-Burton & Williams, 1990, originally described from the gills of Himantura fai Jordan & Seale off Heron Island, Great Barrier Reef, Queensland, Australia, was also found on the gills of one Himantura specimen. The site and host-specificity of the parasites and the identity of the hosts are discussed.     

Dysgonomonas mossii sp. nov., from human sources

Phenotypic and phylogenetic studies were performed on seven unidentified gram-negative, facultatively anaerobic, coccobacillus-shaped organisms isolated from human clinical specimens. Comparative 16S rRNA gene sequencing demonstrated that four of the strains corresponded to Dysgonomonas capnocytophagoides whereas the remaining three isolates represent a new sub-line within the genus Dysgonomonas, displaying greater than 5% sequence divergence with Dysgonomonas capnocytophagoides and Dysgonomonas gadei. The three novel isolates were readily distinguished from D.capnocytophagoides and D. gadei by biochemical tests. The DNA base composition of the novel species was consistent with its assignment to the genus Dysgonomonas. Based on phylogenetic and phenotypic evidence it is proposed that the unknown species, be classified as Dysgonomonas mossii sp. nov. The type strain of Dysgonomonas mossii is CCUG 43457T (= CIP 107079T).     

Ichthyobodo hippoglossi n. sp. (Kinetoplastea: Prokinetoplastida: Ichthyobodonidae fam. nov.), an ectoparasitic flagellate infecting farmed Atlantic halibut Hippoglossus hippoglossus

Diseased Atlantic halibut Hippoglossus hippoglossus juveniles from a hatchery in western Norway showed gill and skin infections with an Ichthyobodo species. Genus Ichthyobodo contains a single valid species, I. necator, a parasite originally described from the skin and fins of a salmonid fish in freshwater. Many studies have identified this species from other hosts, but recent molecular evidence suggests that many Ichthyobodo spp. occur in both fresh- and seawater. We redescribe I. necator from Atlantic salmon Salmo salar skin infections in Norway and compare the morphology of I. necator with the form from halibut. A scheme to standardise the measurements of Ichthyobodo cells is presented. Morphologically, the Ichthyobodo species from the skin and gills of halibut differs from I. necator from salmon skin by shape (in air dried stained smears), by a low number of variably sized kinetoplasts and by a long flagellar pocket. There is also a clear increase in the number of kinetoplasts in L necator with increasing cell size (area), a pattern absent from Ichthyobodo sp. from halibut. The 2 forms are also clearly separated by their small subunit (ssu) rDNA sequences; alignments of partial ssu sequences showed 93.5 % similarity. Consequently, Ichthyobodo sp. from halibut is considered a new species, and is named I. hippoglossi n. sp. Its closest relative is Ichthyobodo sp. IV from another marine fish, the Atlantic cod Gadus morhua. A family, Ichthyobodonidae fam. nov. in the order Prokinetoplastida Vickerman, 2004, is erected to encompass Ichthyobodo spp.     

On the description of Tisochrysis lutea gen. nov. sp. nov. and Isochrysis nuda sp. nov. in the Isochrysidales, and the transfer of Dicrateria to the Prymnesiales (Haptophyta)

The Isochrysidaceae is a family of non-calcifying organisms within the haptophyte order Isochrysidales. Isochrysis galbana, a species widely used as a food source in aquaculture, is the best-known representative of this family that contains three genera but only six described species. We sequenced partial nuclear small subunit (SSU) and large subunit rDNA and mitochondrial cytochrome oxidase 1 genes of 34 isochrysidacean culture strains (including authentic strains when available) and compared molecular phylogenetic inferences with cytological and ultrastructural observations. The isochrysidaceaen culture strain Isochrysis affinis galbana (Tahiti isolate), widely used in aquaculture and commonly known as T-Iso, is clearly genetically distinct from Isochrysis galbana, despite seemingly being morphologically identical. A strain with a similar ultrastructure to that of Isochrysis galbana except for the lack of body scales had sequences that were more similar to but still distinct from those of Isochrysis galbana. Dicrateria inornata, a species that lacks body scales, is classified within the Isochrysidaceae, but the SSU rDNA sequence of the authentic strain of this species matches that of Imantonia rotunda within another haptophye order, the Prymnesiales. D. inornata and Imantonia rotunda have similar ultrastructure except for the respective absence/presence of scales. These results lead us to propose the erection of one new genus (Tisochrysis gen. nov.) and two new species (Tisochrysis lutea sp. nov. and Isochrysis nuda sp. nov.). D. inornata is reclassified within the Prymnesiales, and Imantonia rotunda is transferred to this genus (Dicrateria rotunda comb. nov.).     

Microfungi on the Pandanaceae:Polytretophora macrospora sp. nov.

Polytretophora macrospora is introduced based on specimens from two species ofPandanus in Seychelles. The new species is compared with currently accepted species. A key and a comparative synopsis toPolytetophora species are provided. Numerous specimens ofP. calcarata, collected on members of the Pandanaceae from Australia, Fiji, Hong Kong, Malaysia, New Caledonia, Palau, Philippines, Seychelles and Solomon Islands are also reported, along withP. dendroidea onPandanus sp. from Malaysia.     

Enteromius pinnimaculatus sp. nov. (Cypriniformes: Cyprinidae) from southern Gabon

We present and describe a new species of Enteromius, adding to the 16 species of Enteromius currently recorded from Gabon, West Africa. This new species is distinguished from all other Gabonese Enteromius by the presence of several distinct spots on the dorsal fin in combination with three or four round spots on the flanks. In Africa, it is superficially similar to Enteromius walkeri and with which it shares an unusual allometry in that the proportional length of the barbels decreases as the fish grows. Nevertheless, one can distinguish these species by vertebral number, maximum standard length, the length of the anterior barbels, the length of the caudal peduncle and in most specimens, the number of lateral-line and circumpeduncular scales. These two species also inhabit widely separated drainages, with E. walkeri occurring in coastal drainages of Ghana including the Pra and Ankobra Rivers and the new species occurring in tributaries of the Louetsi and Bibaka Rivers of Gabon, which are part of the Ogowe and Nyanga drainages, respectively. Despite extensive collections in those drainages the new species is known from only two localities, suggesting the importance of conservation of its known habitat.     

A molecular evaluation of the Liagoraceae sensu lato (Nemaliales,Rhodophyta) in Bermuda including Liagora nesophila sp. nov. and Yamadaella grassyi sp. nov.

We have undertaken a comprehensive, molecular‐assisted alpha‐taxonomic examination of the rhodophyte family Liagoraceae sensu lato, a group that has not previously been targeted for molecular studies in the western Atlantic. Sequence data from three molecular markers indicate that in Bermuda alone there are 10 species in nine different genera. These include the addition of three genera to the flora — Hommersandiophycus, Trichogloeopsis, and Yamadaella. Liagora pectinata, a species with a type locality in Bermuda, is phylogenetically allied with Indo‐Pacific species of Hommersandiophycus, and the species historically reported as L. ceranoides for the islands is morphologically and genetically distinct from that taxon, and is herein described as L. nesophila sp. nov. Molecular sequence data have also uncovered the Indo‐Pacific L. mannarensis in Bermuda, a long‐distance new western Atlantic record. DNA sequences of Trichogloeopsis pedicellata from the type locality (Bahamas) match with local specimens demonstrating its presence in Bermuda. We described Yamadaella grassyi sp. nov. from Bermuda, a species phylogenetically and morphologically distinct from the generitype, Y. caenomyce of the Indo‐Pacific. Our data also indicated a single species each of Ganonema, Gloiocallis, Helminthocladia, Titanophycus, and Trichogloea in the flora.     

Caligus tunisiensis n. sp. (Copepoda: Caligidae) parasitic on the painted comber Serranus scriba (L.) (Perciformes: Serranidae) from the Mediterranean Sea,off the Tunisian coast

Systematic Parasitology - A new species of parasitic copepod, Caligus tunisiensis n. sp. (Caligidae), is described based on two female specimens collected from the gills of the painted comber,...     

Molecular and phenotypic characterization of Leptospira johnsonii sp. nov., Leptospira ellinghausenii sp. nov. and Leptospira ryugenii sp. nov. isolated from soil and water in Japan

In a previous study, 50 of 132 soil samples collected throughout Japan were found to be Leptospira‐positive. In the present study, three strains identified in the collected specimens, three, E8, E18 and YH101, were found to be divergent from previously described Leptospira species according to 16S ribosomal RNA gene sequence analysis. These three strains have a helical shape similar to that of typical Leptospira and were not re‐isolated from experimental mice inoculated with the cultured strains. Upon 16S ribosomal RNA gene sequence analysis, E8 was found to belong to the intermediate Leptospira species clade and E18 and YH101 to belong to the saprophytic Leptospira species clade. Based on analyses of genome‐to‐genome distances and average nucleotide identity in silico using whole genome sequences and DNA–DNA hybridization in vitro, these isolates were found to be distinct from previously described Leptospira species. Therefore, these three isolates represent novel species of the genus Leptospira for which the names Leptospira johnsonii sp. nov., (type strain E8 ^T, = JCM 32515 ^T = CIP111620 ^T), Leptospira ellinghausenii sp. nov., (type strain E18 ^T, = JCM 32516 ^T = CIP111618 ^T) and Leptospira ryugenii sp. nov., (type strain YH101 ^T, = JCM 32518 ^T = CIP111617 ^T) are proposed.     

Morphological and biochemical variations in the gills of 12 aquatic air-breathing anabantoid fish

All fish species in the Anabantoidei suborder are aquatic air-breathing fish. These species have an accessory air-breathing organ, called the labyrinth organ, in the branchial cavity and can engulf air at the surface of the water to assist in gas exchange. It is therefore necessary to examine the extent of gill modification among anabantoid fish species and the potential trade-offs in their function. The experimental hypothesis that we aimed to test is whether anabantoid fishes have both morphological and functional variations in the gills among different species. We examined the gills of 12 species from three families and nine genera of Anabantoidei. Though the sizes of the fourth gill arch in three species of Trichogaster were reduced significantly, not all anabantoid species had morphological and functional variations in the gills. In these three species, the specific enzyme activity and relative protein abundance of Na(+)/K(+)-ATPase were significantly higher in the anterior gills as compared with the posterior gills and the labyrinth organ. The relative abundance of cytosolic carbonic anhydrase, an indicator of gas exchange, was found to be highest in the labyrinth organ. The phylogenetic distribution of the fourth gill's morphological differentiation suggests that these variations are lineage specific, which may imply a phylogenetic influence on gill morphology in anabantoid species.     

The morphology and anatomy of the Antarctic gastropod Bathyberthella antarctica (Opisthobranchia, Notaspidea, Pleurobranchidae)

The external morphology, anatomy and histology of the Antarctic notaspidean Bathyberthella antarctica Willan & Bertsch, 1987 is described and the intraspecific variability presented. The species is compared with the only other known pleurobranch from the high Antarctic zone, Tomthompsonia antarctica (Thiele, 1912).