Coccolithogenesis In Scyphosphaera apsteinii (Prymnesiophyceae)

Coccolithophores are the most significant producers of marine biogenic calcite, although the intracellular calcification process is poorly understood. In the case of Scyphosphaera apsteinii Lohmann 1902, flat ovoid muroliths and bulky, vase‐shaped lopadoliths with a range of intermediate morphologies may be produced by a single cell. This polymorphic species is within the Zygodiscales, a group that remains understudied with respect to ultrastructure and coccolith ontogeny. We therefore undertook an analysis of cell ultrastructure, morphology, and coccolithogenesis. The cell ultrastructure showed many typical haptophyte features, with calcification following a similar pattern to that described for other heterococcolith bearing species including Emiliania huxleyi. Of particular significance was the reticular body role in governing fine‐scale morphology, specifically the central pore formation of the coccolith. Our observations also highlighted the essential role of the inter‐ and intracrystalline organic matrix in growth and arrangement of the coccolith calcite. S. apsteinii secreted mature coccoliths that attached to the plasma membrane via fibrillar material. Time‐lapse light microscopy demonstrated secretion of lopadoliths occurred base first before being actively repositioned at the cell surface. Significantly, growth irradiance influenced the coccosphere composition with fewer lopadoliths being formed relative to muroliths at higher light intensities. Overall, our observations support dynamic metabolic (i.e., in response to growth irradiance), sensory and cytoskeletal control over the morphology and secretion of polymorphic heterococcoliths. With a basic understanding of calcification established, S. apsteinii could be a valuable model to further study coccolithophore calcification and cell physiological responses to ocean acidification.     

Reevaluation of the biological status of Juniperus Deppeana var. sperryi Correll

Foliage and bark samples were collected from the tree that provided the type specimen forJuniperus deppeana var.sperryi Correll, as well as from trees from populations ofJ. pinchotii Sudw.,J. flacida Schl., andJ. deppeana Steud. var.deppeana. These four taxa were compared using terpenoid and morphological characters. The terpenoid data suggest thatJ. deppeana var.sperryi is most closely related toJ. deppeana var.deppeana; no evidence of relict or present hybridization withJ. flaccida was detected. The morphological data showedJ. deppeana var.sperryi to be intermediate in several characters betweenJ. deppeana var.deppeana andJ. flacdda. The probability of a hybrid origin for this taxon is discussed. Due to the scattered occurrence of trees referable toJ. deppeana var.sperryi, it is proposed that this taxon be reduced in rank toJ. deppeana formasperryi.     

New species and combinations in Thelypteris subg. Goniopteris (Thelypteridaceae)

Three new species ofThelypteris are described and illustrated:T. littoralis andT. paranaensis, endemic to the rainforest of the southern Brazilian Atlantic coast, andT. multigemmifera, endemic to inland gallery forests of the São Paulo state. In addition, four new combinations are made:T. cutiataensis (Brade) Salino,T. iguapensis (C. Chr.) Salino. A new name is proposed forDryopteris lugubris var.quadrangularis:T. montana Salino. The species treated here belong toThelypteris subg.Goniopteris due to the indument of furcate and stellate trichomes.     

Further observations on the genus Pappomonas Manton et Oates with special reference to P. virgulosa sp. nov. from West Greenland

Electron microscopy of dried preparations of Arctic nanoplankton has permitted a second species of the recently erected genus Pappomonas Manton et Oates to be described and named. P. virgulosa sp. nov. is characterised by coccolith appendages composed of a central shaft ending in a cluster of four finger-like rods. There are also calcified plates of characteristic construction, without appendages. Detailed observations on the coccoliths, especially on the shapes and arrangement of component calcite crystallites and the presence of unmineralised components, have permitted further comparisons to be made with equivalent structures in Papposphaera lepida Tangen, recently investigated in the southern hemisphere, as well as with Pappomonas flabellifera Manton et Oates. As a working hypothesis, an interpretation of coccolith morphology in all three taxa has been formulated in terms of known structural components of uncalcified scales in Chrysochromulina spp. The need for fuller information on certain details, notably the coccolith bases in Pappomonas spp. is stressed.     

Life history and taxonomy ofCricosphaera roscoffensis var.haptonemofera,var. nov. (class prymnesiophyceae) from the pacific

A new coccolithophoridCricosphaera roscoffensis var.haptonemofera is described by means of electron microscopy and with the aid of laboratory culture. The living specimens, which were in the motile phase, were collected in Okinawa, a subtropical region in Japan, and a unialgal culture was established in the laboratory. The life history was observed, starting from the motile cells. The life history consists of two phases: the motile phase and the benthic filamentous phase. The former is unicellular and presumably a diploid sporophyte, whereas the latter is similar to an alga previously known as “Apistonema submarinum” described by Dangeard (1934), and probably a haploid gametophyte. The motile cells bear two acronematic flagella and one short haptonema. The scales attached on the surface of the motile cells are of two kinds: one is an organic thin scale, and the other is a cricolith, a kind of coccolith, the latter being structurally almost identical with that ofCricosphaera roscoffensis studied by Gayral and Fresnel (1976). Because this species has neither haptonema nor a benthic filamentous phase, we propose, at present, to treat this alga as a new taxon at the rank of infraspecies, naming itCricosphaera roscoffensis var.haptonemofera Inouye et Chihara.     

Calcareous nannoplankton in surface sediments of the East China Sea

Twenty-eight species of coccoliths were identified in surface sediments of the East China Sea. The species composition of the coccolith assemblages is similar to that of the North Pacific Water Mass, but differs from the latter by a greater dominance ofEmiliania huxleyi andGephyrocapsa oceanica (together making up over 90% specimens). The coccolith species composition shows considerable differences between the continental shelf and the Okinawa Trough areas, reflecting different water masses. On the other hand, the coccolith content in sediments is apparently controlled largely by the deposition rate of terrigenous material.     

LIGHT AND ELECTRON MICROSCOPE OBSERVATIONS OF ALGIROSPHAERA ROBUSTA (PRYMNESIOPHYCEAE)1

The coccolithophore Algirosphaera robusta (Lohmann) R. E. Norris was isolated into laboratory culture for the first time. This species is of particular interest as the first deep photic coccolithophore to be cultured, the only member of the Rhabdosphaeraceae to have been successfully isolated, and the first coccolithophore with a coccolith structure including a complex disjunct central area to have been studied in detail. Observations on the culture strain supported the previous inference that the commonly recognized species A. robusta, A. oryza Schlauder, and A. quadricornu (J. Schiller) R. E. Norris are conspecific. However, A. meteora (Müller) R. E. Norris and A. cucullata (Lecal‐Schlauder) J. R. Young, Probert et Kleijne were recognized as discrete species. Coccolith rim formation in A. robusta follows the pattern of biomineralization documented in other heterococcoliths and was suggested to be universal. However, the prominent central hood had a unique ultrastructure and appeared to be formed by a distinctively different biomineralization mode. We suggest that this can provide a key to reinterpreting homology in coccolith structure and that this species is a promising target for comparative biochemical and genomic studies of biomineralization. In terms of cell ultrastructure, A. robusta exhibited marked similarities to Syracosphaera pulchra Lohmann, and a close evolutionary relationship between the families Rhabdosphaeraceae and Syracosphaeraceae is suggested.     

THE GENUSFULGENSIAA. MASSAL. & De NOT., A DIVERSE GROUP IN THE TELOSCHISTACEAE

The morphology and the anatomy of the 13 species presently included in the genusFulgensiawere surveyed.Caloplaca aureaandC. paulii, two species regarded as closely related toFulgensiaby earlier authors, were also included in the study.Fulgensiawas found to exhibit a great variation in both morphology and anatomy. The differences in size, shape and septation of the spores, in the anatomy of cortex and exciple, and in the gross morphology, will presumably motivate a different taxonomic treatment in the future. A tentative separation of the species into four different groups is proposed here. Group A comprisesF. australisandF. chanousiae, which appear close to species inCaloplacasect.Gasparrinia.Groups B and C, each comprises one species,F. schistidiiandF. canariensisrespectively and group D comprises the remaining nine species, including the type speciesF. fulgens. The last group may be further split by a more detailed investigation. The present separation ofFulgensiainto two subgenera cannot be regarded as taxonomically sound. The genus is probably polyphyletic and the different groups are probably related to different groups within the large genusCaloplaca.     

Ultrastructure of Phasmid Development in Meloidodera floridensis and M. charis (Heteroderinae)

Phylogenetic characters for Heteroderinae Luc. et al., 1988 are evaluated in Meloidodera which is believed to have primarily ancestral characters. Phasmid ultrastructure is observed in second-stage juveniles (J2), third-stage juvenile males, fourth-stage juvenile males, and fifth-stage males of Meloidodera floridensis and M. charis. Phasmid secretion occurs inside the egg before the J1-J2 molt. Before J2 hatch, concentric lamellar membranes occur within the sheath and socket cells. Some membranes become lamellae of the sheath cell plasma membrane; others become multilamellar bodies. During early molting, plasma membrane lamellae disappear and a distal dendrite segment appears in a rudimentary canal. After the molt, the distal dendrite is not present within the canal. The phylogenetic utility of phasmid features is discussed. In both species the ampulla shape and size between molts are stable features in juveniles and males. The posthatch J2 sheath cell receptor cavity may vary in a species specific manner, but comparative morphology requires precise timing after hatch.     

A MOLECULAR APPROACH TO THE CIRCUMSCRIPTION AND EVALUATION OF SOME GENERA SEGREGATED FROMPARMELIAS. LAT.

New sequences have been produced of the ITS rDNA region of twenty-nine species ofParmeliaceae, and analysed by neighbour-joining maximum likelihood distance analysis, and maximum parsimony analysis. Twelve monophyletic groups have been identified, most of which correspond to proposed generic segregated fromParmelias. lat.ParmeliaandParmelina,Melanelia, andPuncteliaappear as independent monophyletic groups; the type species of the two latter genera were, however, not included in the analysis. The parsimony analysis does not supportXanthoparmeliaas a monophyletic group separate fromNeofuscelia, andRimelia reticulatais nested withinParmotrema. Parmelinopsis horrescensis more closely related toHypotrachyna revolutathan toParmelina. Genetic distance values suggest thatFlavoparmelia caperatais closer toParmotremathan to other taxa included, and thatPlatismatia glaucaandHypogymnia tubulosaare closer toParmelias. lat. than to thePhysciaceae. However, there is no conclusive support for any of the latter groupings in the parsimony analysis. We conclude that the ITS region contains valuable information for studying generic delimitations within the familyParmeliaceae, but our study suggests that this region will not conclusively resolve within-family relationships in this group.     

Ultrastructure of nuclear inclusions and the separation ofVerbenaceae andOleaceae (incl.Nyctanthes)

TEM observations were carried out on 40 taxa of the familyVerbenaceae and 35 taxa of the familyOleaceae, in order to ascertain distribution, ultrastructure and morphology of the intranuclear proteinic inclusions in the mesophyll parenchymatic cells. The investigated genera amount to some 25% and 60% respectively of the genera of the two families. Inside theVerbenaceae, lamellar inclusions (L-type) occur in 6 out of 23 investigated genera: they are mostly present inside the tribesCitharexyleae andVerbeneae (both belonging toVerbenoideae), while they are absent in other subfamilies. All of the investigatedOleaceae genera show intranuclear crystalline inclusions (C 1-type) of three different shapes. Among theAsteridae this is a character peculiar toOleaceae. They appear to be a well defined natural group, including the controversial genusNyctanthes.     

Leptographium pini-densiflorae sp. nov. from Japanese red pine

ALeptographium species was isolated from deadPinus densiflora at six sites in Japan. The fungus is morphologically most similar toL. lundbergii but could be distinguished from that species by its short stipes, primary branches of conidiophores, and conidia with a rounded to sub-truncate base. In addition, the colony morphology, growth rate and tolerance to the antibiotic cycloheximide of theLeptographium species andL. lundbergii differed markedly. Here we describe the fungus as a new species,Leptographium pini-densiflorae. Contribution No. 144, Laboratory of Plant Pathology and Mycology, Institute of Agriculture and Forestry, University of Tsukuba.     

Spatial distribution of cpDNA and mtDNA haplotypes in a hybrid zone betweenPinus pumila andP. parviflora var.pentaphylla (Pinaceae)

Pinus species exhibit paternal chloroplast inheritance and maternal mitochondrial inheritance. This independent inheritance of two cytoplasmic genomes provides an exceptional environment for discriminating female (seeds) and male (pollen) components of gene flow across hybridizing species. We obtained mitochondrial genetic markers diagnostic toP. parviflora var.pentaphylla andP. pumila by PCR amplification of the intron ofnad1 on mtDNA, and examined the spatial-distribution pattern of the mtDNA haplotypes in a hybrid zone betweenP. parviflora var.pentaphylla andP. pumila in the Tanigawa Mountains of Japan. These data, in conjunction with previous information on cpDNA haplotypes and needle morphology, revealed contrastive patterns of introgression of two cytoplasmic genomes. CpDNA introgression has occurred uni-directionally fromP. parviflora var.pentaphylla toP. pumila. Conversely, mtDNA introgression has occurred in the opposite direction, fromP. pumila toP. parviflora var.pentaphylla. Levels of introgression are roughly equivalent for cpDNA and mtDNA. The contrastive spatial distribution pattern of cpDNA and mtDNA haplotypes could be caused by differential movement of seeds and pollen for interspecific genetic exchange.     

Biological and ecological studies of the parasitoidChelonus inanitus [Hym.: Braconidae] in Israel

Only one species ofChelonus Panzer,Chelonus inanitus (L.), was found to be widespread in all areas of Israel. The parasitoid was particularly widespread in alfalfa fields but also was present in cotton, sugar beet, artichoke and corn. Spodoptera littoralis (Boisd) andS. exigua (Hbn.) were the main hosts ofC. inanitus although it might develop in other Lepidoptera species. A study of its population showed that adults were present in the spring, summer and autumn but not during the winter. In most cases the population density of the parasitoid appeared to be related to that of the hosts. Parasitism and sex ratio ofC. inanitus in alfalfa fields were studied. The number of males (average of 75%) was higher than that of the females. Percentage of parasitism in larvae ofS. littoralis andS. exigua reached up to 39.8% and 13.5% respectively. The parasitism values in eggs ofS. littoralis were up to 71%.     

Revision of Jaegeria (Compositae-Heliantheae)

The genusJaegeria consists of a diploid-polyploid complex of eight species found in moist habitats from Mexico to South America. The distributions, habitats, generic affinities, and tribal placement are discussed. Chromosome numbers were determined for all species exceptJ. axillaris, which is known only from Colombia.J. glabra andJ. pedunculata are diploid (2n = 18) ;J. hirta, J. macrocephala, J. gracilis, andJ. crassa are tetraploid (2n = 36) ;J. bellidiflora is octoploid (2n = 72). One Galápagos Island endemic,J. gracilis, is quite similar to the common mainland species,J. hirta, but the other endemic,J. crassa, is quite distinct from any other species.J. bellidijlora is most similar morphologically toJ. glabra;J. macrocephala is allied toJ. pedunculata. J. axillaris is somewhat distinct from the other species.     

Chloroplast DNA typing by PCR-SSCP in thePinus pumila-P. parviflora var.pentaphylla complex (Pinaceae)

Pinus hakkodensis has been considered as a hybrid betweenP. pumila andP. parviflora var.pentaphylla. Chloroplast DNA typing of this putative hybrid and hypothesized parental species in the Tanigawa Mountains, Japan, was conducted by PCR and single-strand conformation polymorphism (SSCP) of the intergenic spacer betweentrnL(UAA)3′ exon andtrnF(GAA) of cpDNA. Each of the hypothesized parental species collected from other mountain regions displayed a diagnostic SSCP pattern, whereas all morphological intermediates sampled in the Tanigawa Mountains had the SSCP pattern ofP. parviflora var.pentaphylla. Furthermore, some individuals classified on the basis of needle morphology as belonging toP. pumila in this mountain region showed the SSCP pattern ofP. parviflora var.pentaphylla. This may suggest that pollen-mediated uni-directional introgression fromP. parviflora var.pentaphylla toP. pumila occurs in the Tanigawa Mountains.     

Two new fossil woods ofAcer and a new combination ofPrunus from the Tertiary of Japan

Two new species ofAcer fossil woods,A. momijiyamense andA. Watarianum, are described and a short review of fossil wood of this genus from the Tertiary of Japan is given. In the course of a study on three fossil wood species which have been described asAcer andAcernium from Japan, it is noticed thatAcernium iwatense Watari does not belong toAcer but toPrunus of the Rosaceae, and is therafore transferred intoPrunus asPrunus iwatense comb. nov.     

DISTRIBUTION OF TWO TYPES OF EMILIANIA HUXLEYI (PRYMNESIOPHYCEAE) IN THE NORTHEAST ATLANTIC REGION AS DETERMINED BY IMMUNOFLUORESCENCE AND COCCOLITH MORPHOLOGY1

Culture strains of Emiliania huxleyi (Lohmann 1902) Hay et al. 1967 were placed into two groups designated E. huxleyi type A and type B on the basis of coccolith morphology and immunological properties of the coccolith polysaccharide. We studied the distribution of these types in the North Atlantic region using an indirect immunofluorescence assay with antisera directed against the coccolith polysaccharide of E. huxleyi type A and type B and epifluorescence microscopy. In field samples taken in the Northeast Atlantic Ocean, E. huxleyi type A was found exclusively. In contrast, type B was dominant in the North Sea. Scanning electron microscopy of the samples revealed the same unequal distribution of the two types as found with the immunofluorescent-labelling assay.     

The Effect of cytoskeleton inhibitors on coccolith morphology in Coccolithus braarudii and Scyphosphaera apsteinii

The calcite platelets of coccolithophores (Haptophyta), the coccoliths, are among the most elaborate biomineral structures. How these unicellular algae accomplish the complex morphogenesis of coccoliths is still largely unknown. It has long been proposed that the cytoskeleton plays a central role in shaping the growing coccoliths. Previous studies have indicated that disruption of the microtubule network led to defects in coccolith morphogenesis in Emiliania huxleyi and Coccolithus braarudii. Disruption of the actin network also led to defects in coccolith morphology in E. huxleyi, but its impact on coccolith morphology in C. braarudii was unclear, as coccolith secretion was largely inhibited under the conditions used. A more detailed examination of the role of actin and microtubule networks is therefore required to address the wider role of the cytoskeleton in coccolith morphogenesis. In this study, we have examined coccolith morphology in C. braarudii and Scyphosphaera apsteinii following treatment with the microtubule inhibitors vinblastine and colchicine (S. apsteinii only) and the actin inhibitor cytochalasin B. We found that all cytoskeleton inhibitors induced coccolith malformations, strongly suggesting that both microtubules and actin filaments are instrumental in morphogenesis. By demonstrating the requirement for the microtubule and actin networks in coccolith morphogenesis in diverse species, our results suggest that both of these cytoskeletal elements are likely to play conserved roles in defining coccolith morphology.     

A new aulopodid species,Hime microps,from the eastern South Pacific,with comments on geographic variations ofH. japonica

A new aulopodid fish,Hime microps, is described after two specimens from the Nazca submarine ridge (25°43′S, 85°29′W at 160–165 m; 25°42′S, 85°24′W at 162–168 m). This species is related toH. japonica andH. curtirostris but differs in having no pyloric caeca and smaller eyes with the horizontal diameter shorter than the snout length. Specimens ofH. japonica from off Japan, the Hawaiian submarine ridge and the Tasman Sea are compared and found to be morphologically identical.