Benthic foraminifera contribution to fjord modern carbon pools: A seasonal study in Adventfjorden,Spitsbergen

The aim of this study was to determine the amount of organic and inorganic carbon in foraminifera specimens and to provide quantitative data on the contribution of foraminifera to the sedimentary carbon pool in Adventfjorden. The investigation was based on three calcareous species that occur commonly in Svalbard fjords: Cassidulina reniforme, Elphidium excavatum and Nonionellina labradorica. Our results show that the species investigated did not contribute substantially to the organic carbon pool in Adventfjorden, because they represented only 0.37% of the organic carbon in the sediment. However, foraminiferal biomass could have been underestimated as it did not include arenaceous or monothalamous taxa. Foraminiferal carbonate constituted up to 38% of the inorganic carbon in the sediment, which supports the assumption that in fjords where non‐calcifying organisms dominate the benthic fauna foraminifera are among the major producers of calcium carbonate and that they play crucial roles in the carbon burial process. The results presented in this study contribute to estimations of changes in foraminiferal carbon levels in contemporary environments and could be an important reference for palaeoceanographic studies.     

Pre-release evaluation of Heikertingerella sp. as a potential biocontrol agent for Tecoma stans in South Africa

Native to Central America, Tecoma stans (L.) Juss ex Kunth var. stans (Bignoniaceae) is a small tree that is invasive in South Africa and neighbouring countries. The plant was targeted for biological control in South Africa in 2003, with two insect agents released and established so far. The root-feeding flea beetle, Heikertingerella sp. (Coleoptera: Galerucinae: Alticini), was imported from Mexico as an additional biocontrol agent and its biology and host specificity was assessed under quarantine conditions. The beetle displayed a generation time (i.e. from adult to adult) of 49 to 67 days, ensuring four annual generations under laboratory conditions. The beetle's larval and adult stages inflicted high levels of damage on the root system and the leaves of T. stans, respectively. No-choice tests with 40 test-plant species revealed adult feeding on only two non-target species, Tecoma × alata and T. capensis (Thunb.) Spach, with feeding four times higher on T. stans. Larvae developed to adulthood on T. stans only. Multi-choice tests involving the three Tecoma species confirmed these trends, demonstrating that Heikertingerella sp. is host specific. Since T. × alata is a hybrid of T. stans with invasive tendencies, any unlikely attacks by Heikertingerella sp. would be inconsequential in South Africa. The native T. capensis, which suffered little leaf damage and produced no F1 adults, is also at minimal risk of attack. We conclude that Heikertingerella sp. is a suitable biocontrol agent for T. stans and that permission for its release in South Africa be sought.     

Stratigraphy of the Early Paleogene Muthaymimah Formation exposed on the western flank of the Northern Oman Mountains

Sixty-one species belonging to 32 foraminiferal genera are reported from the Paleocene to Early Eocene Muthaymimah Formation at different localities in the western flank of the Northern Oman Mountains of the United Arab Emirates (UAE) and Oman. Several of the discovered species provide precise ages for the Paleocene series (Bolivinoides curtus and Neoflabellina jarvisi). A prominent conglomerate bed marks the K–T boundary between the Late Cretaceous Simsima Formation and Muthaymimah Formation in the study area. Occurrences of planktonic foraminiferal Morozovella inconstans (Subbotina, 1947) and Morozovella trinidadensis (Bolli, 1957) of Early Paleocene age (P1–P2 zones) are recorded for the first time in some locations in the study area.

http://zoobank.org/2266E0F1-0C0F-428F-B18C-F8347F0CEE07     

Feeding and growth of native,invasive and non-invasive alien apple snails (Ampullariidae) in the United States: Invasives eat more and grow more

The United States hosts one native and five non-native species of aquatic apple snails (Ampullariidae). All are currently found in or around the Everglades in Florida. Two of these introduced species have devastated wetlands in Southeast Asia, but little is known about how they may impact the Everglades. To evaluate potential impacts of introduced apple snails relative to the native species, we investigated plant species preference, consumption rates, growth rates, and growth efficiencies in five introduced and the single native species across eight native macrophytes common in the Everglades. Three of the non-native snails are invasive, one has shown no tendency to expand, and one appears to have minimal direct impact on macrophytes due to its diet. All snails exhibited similar feeding preferences, with Utricularia sp. being the most preferred, Bacopa caroliniana, Sagittaria latifolia, and Nymphaea odorata being of intermediate preference, and Eleocharis cellulosa, Pontederia cordata, Panicum hemitomon and Typha sp. being least preferred (avoided as foods). Consumption and growth was minimal for P. diffusa on all macrophytes. On Utricularia sp. and Bacopa caroliniana, the invasive species Pomacea insularum and P. canaliculata tended to eat more, grow more, and have higher conversion efficiencies than the native P. paludosa or the non-invasive P. haustrum. These contrasts were more often significant for P. insularum than for P. canaliculata. The greater rates of expansion by the invasive species may derive from their enhanced feeding and growth rates.     

On the fauna of bristletails of the genera <Emphasis Type="Italic">Petrobius</Emphasis> and <Emphasis Type="Italic">Trigoniophthalmus</Emphasis> (Thysanura,Machilidae) from the Caucasus

Five new species, Petrobius caucasicus sp. n., Trigoniophthalmus presimplex sp. n., T. divnogorski sp. n., T. kislovodski sp. n., and T. adigei sp. n. (Machilidae), are described from the Caucasus. A key to all the known species of the genus Trigoniophthalmus is given. Two subgenera (Trigoniophthalmus s. str., Trigoniocellus subgen. n.) in the genus Trigoniophthalmus are described. 2 + 2 retractile vesicles are present on abdominal segments II–IV in the species of Trigoniocellus subgen. n. and on II–V abdominal segments in Trigoniophthalmus s. str. Analysis of the evolution and phylogenetic relations between the species of the genus Trigoniophthalmus is performed for the first time. The formation of bristletails of the genus Trigoniophthalmus appears to occur in the Caucasian mountain province of the European area, from where they penetrated to the Central European mixed province and the Mediterranean subarea. Among the described species of the genus, T. kislovodski is distinguished by the greatest number of plesiomorphic states of morphological characters.     

Fine structure and formation of eggshells in marine Gastrotricha

Summary The fine structure of the gastrotrich eggshell in the hermaphroditic species Turbanella ocellata (Hummon 1974) and the parthenogenetic species Aspidiophorus sp. is described using transmission electron microscopy. The presented evidence strongly suggests that the shell is produced by the egg itself prior to oviposition in both species. The layed egg in Aspidiophorus sp. is provided with a special attachment stalk that is also preformed in the mother animal. Freshly layed eggs of T. ocellata are adhesive all around their surface and lack any specialized structures for attachment. Formation of the spiny eggshell of Aspidiophorus sp. appears to begin with a sudden release of special vesicles containing the preformed spines of the outer eggshell covering. Additional material appears to be secreted by the egg in a more gradual process after the initial vesicle release. The formation of the two fibrous layers in the eggshell of T. ocellata is less well understood and deposition of eggshell material could be seen either as a continuous process or as two separate steps, similar to the events observed for Aspidiophorus sp. For T. ocellata, Tetranchyroderma sp. and Aspidiophorus sp. it is demonstrated that formation of the cuticle occurs as an independent process from that of eggshell formation. This is significantly different from the basic mode of cuticle formation in the annelid line of evolution. The paper argues further that the data support earlier claims of a pronounced difference between the Gastrotricha-Macrodasyida and the Gastrotricha-Paucitubulatina and agree well with the postulated ties of the Gastrotricha and Nematoda. The phylogenetic importance of the eggshell fine-structure is discussed in the framework of present theories on aschelminth phylogeny.Abbreviations cus cuticular spines - cut cuticle - cov coated vesicles - cv cup-shaped vesicles - dp dense particles - ep epidermis - emb embryo - erl lacunae of smooth ER - fgb fibrous and granular bodies - fl fibrous layer - ga Golgi apparatus - gc gut cell - gv Golgi vesicles - im intercellular matrix - isp intercellular space - isl inner shell layer - ld lipid droplet - mdb medium-dense bodies - mvb multivesicular bodies - oc oocyte - od oviduct - osl outer shell layer - o egg - sv spiny vesicles - sh eggshell - st egg-stalk - sl spiny layer - sub substrate - trm trilaminate membrane - yb yolk bodies - yg yolk granule - yoc young oocyte This work was supported by NSF Grant # GB-42211 to R.M. Rieger     

Distribution of Antarctic benthic foraminifers settling on the pecten Adamussium colbecki

Summary Some benthic foraminifers in Explorers Cove, Antarctica, occur both in the sediment and on hard objects such as rocks and invertebrates. The abundances of four of these foraminiferal species have been measured from sediment samples and from the upper valve of the pecten Adamussium colbecki. The two calcareous species, Cibicides refulgens and Rosalina globularis were more abundant on the pecten shells than the sediment: the agglutinated species, Trochammina ochracea and T. malovensis were more abundant in the sediment. A zone of low foraminiferal density was observed around the outer margin of each shell, but no evidence of an influence of pecten feeding currents on the foraminiferal distributions was found. The size of the pecten shell influenced the density of epizoic foraminifers colonizing it; large shells (area >43 cm²) supported much higher densities than smaller ones.     

Benthic foraminifera associated with the invasive ascidian, Didemnum sp. A

The invasive ascidian, Didemnum sp. A, first appeared in New England bays and harbors in the early 1990s, and in the waters around Cape Cod in 1993. While ship traffic was the likely vector introducing the species, its origin and precise date and location of its introduction are presently unknown. Colony surfaces of Didemnum sp. A appear very clean and not favorable substrates for epibiota settlement, but closer inspection revealed the presence of benthic foraminifera. During 2003 and 2004, 52 samples of Didemnum sp. A and other ascidians were collected to determine whether or not the foraminiferal assemblages might also be non-native and thus provide a potential clue to the place of origin of Didemnum sp. A. Sample locations included the New England coast from Connecticut to Maine (with a concentration in the Cape Cod area), northern California, Zeeland, The Netherlands, and Shakespeare Bay, New Zealand. From New England samples, 18 species of benthic foraminifera were identified. The most common species represented were Cornuspira involvens, C. planorbis, Elphidium galvestonense, E. margaritaceum, Glabratellina lauriei, Miliolinella subrotunda, Quinqueloculina bicornis, and Rosalina floridana. Foraminiferal assemblages on Didemnum sp. A from other regions sampled were composed of the same cosmopolitan species found in New England, plus other species which were indigenous to each region. Because no exotic foraminifera species were found it is concluded that Didemnum sp. A likely did not introduce non-native foraminifera originating from their native habitats into the New England region.     

Riboflavin content of six species of microalgae used in mariculture

Concentrations of riboflavin — a vitamin essential for maricultured animals—were measured in six species of microalgae commonly used in mariculture. These were two diatoms (Chaetoceros gracilis, Thalassiosira pseudonana); two prymnesiophytes (Isochrysis sp. (clone T.ISO),Pavlova lutheri); one chlorophyte (Nannochloris atomus) and one eustigmatophyte (Nannochloropsis oculata). Cultures were analysed during both logarithmic and stationary growth phase.The proportions of riboflavin (µg g^-1 dry weight) during logarithmic growth-phase ranged from 20 (T. pseudonana) to 40 µg g^-1 (Isochrysis sp. T.ISO). With the onset of stationary phase, the proportion of riboflavin increased in all species; the increase was most dramatic in cultures ofC. gracilis, T. pseudonana andN. atomus (2- to 3-fold).Chaetoceros gracilis contained more riboflavin (106 µg g^-1) than all other species (48 to 61 µ g^-1).Despite the differences in the composition of the different microalgae, across both logarithmic and stationary growth-phases, all species should provide a rich source of riboflavin for maricultured animals.Author for correspondence     

Antagonistic effect of two isolates of Trichoderma harzianum against postharvest pathogens of tomato (Lycopersicon esculentum)

Pathogenicity test of all fungi (14 different isolates) isolated from both infected tomato fruits and the surface wash of other healthy fruits had different pathogenicity rates. The genus Rhizopus sp. was the most pathogenic one followed by Fusarium sp. Trichoderma harzianum isolates (T3 and T4) had a different pattern of antagonism against the tested pathogens. In dual plate test of the antagonistic action of T3 and T24 against the postharvest pathogens, clear zone size ranged between 1 and 4 and 3 and 6 mm by T3 and T24, respectively. The antagonists (T3 and T24) didn't show inhibition zone against Rhizopus sp., but they could overgrow it by 100% after 9 days of incubation. Mostly, all the other postharvest isolates showed high degree of overgrowth by T3 than T24. The two antagonists failed to overgrow Aspergillus species except for A. niger (3) which was overgrown by T3. Volatile and non-volatile metabolite tests indicated that mycelial growth of Penicillium stekii was significantly inhibited by T3 and T24 more than the other tested pathogens. The inhibition of A. niger (1) was 12% by non-volatile metabolites of T24 produced after 1 day incubation, and reached to 97% inhibition by the metabolites of 3 days. Interestingly, inhibition of Aspergillus sp. by volatile compounds of T3 and T24 was 2% and 20%, respectively, whereas the inhibition of the same pathogen by non-volatile compounds reached 75% and 87%, respectively. The results of slice assay clearly indicate that T. harzianum (T3 and T24) could provide a complete protection to tomato slices from the infection of the tested pathogens. After 3 days of incubation, Trichoderma suppressed the linear growth of these pathogens on tomato slices and the percentage of suppression was significant and ranged between 80 and 100%, except with Rhizopus sp. the suppression reached 33% only.     

Revisional notes on the genus Toxopoda Macquart (Diptera,Sepsidae) in the Oriental and Australasian regions

I herein revise the genus Toxopoda Macquart of the Oriental and Australasian regions. A total of 16 species is discussed. Six new species are described: T. cavata sp. nov., T. angulata sp. nov., T. elephantina sp. nov., T. zuskai sp. nov., T. malayana sp. nov., and T. ozerovi sp. nov. The species T. contracta (Walker), T. viduata (Thomson) and T. simplex Iwasa, which can be easily confused with other species, are correctly redescribed and illustrated. Distributional notes and a key to the species of the Oriental and Australasian regions are provided.     

Species composition and distribution patterns of baetid nymphs (Baetidae: Ephemeroptera) in a Japanese stream

Species composition and distributional patterns among nymphs of five baetid genera (Ephemeroptera), Baetis, Tenuibaetis, Labiobaetis, Nigrobaetis and Alainites were investigated in Yura Stream, Kyoto Prefecture. I collected 13 species: B. sahoensis, B. thermicus, B. sp. F, B. sp. J, B. sp. M1, B. sp. S1, T. sp. E, T. sp. H, L. sp. G, N. chocoratus, N. sp. D, N. sp. I and A. yoshinensis, among which B. thermicus, B. sp. S1 and T. sp. E were dominant, whereas B. sahoensis, B. sp. F, B. sp. M1 and N.sp. I were scarce. Based on their longitudinal distribution patterns, the 13 species were classified into upper species, upper-middle species, middle species, middle-lower species and lower species. Baetis thermicusand A. yoshinensis showed long downstream tails. Baetis sp. J and N. sp. D extended their longitudinal distribution upstream in summer. With regard to habitat preference, Alainites and Labiobaetis were restricted to riffle and vegetated zones, respectively. Tenuibaetis consisted of riffle-vegetated zone species, whereas Baetis and Nigrobaetiscontained both riffle species and ubiquitous species. Habitat partitioning (`sumiwake') along the watercourse (macro-sumiwake) was evident in Tenuibaetis, and that between habitat types (micro-sumiwake) in Labiobaetis vs. Baetis (rhodanigroup species) and Labiobaetis vs. Alainites.     

Trichodinid parasites (Ciliophora: Peritricha) from the gills of some Australian marine fishes

Three species of the genus Trichodina are reported from the gills of marine fishes in south-eastern Tasmania, Australia. Two of these species are new: T. australis n. sp. from five atherinid fish species, Atherinosoma microstoma, Leptatherina presbyteroides, Kestratherina brevirostris, K. esox and K. hepsetoides; and T. nesogobii n. sp. from Nesogobius sp. 1. One previously reported species, T. jadranica Raabe, 1958, was also found on Nesogobius sp. 1.     

CYTOMORPHOLOGICAL CHARACTERIZATION OF THE PLANKTONIC DIAZOTROPHIC CYANOBACTERIA TRICHODESMIUM SPP. FROM THE INDIAN OCEAN AND CARIBBEAN AND SARGASSO SEAS1

Trichodesmium Ehrenberg species were collected in the Caribbean Sea, Sargasso Sea, and coastal areas of Tanzania (Indian Ocean). The specimens were divided into five species on the basis of morphometric characters such as cell dimensions and colony formation: T. tenue Wille, T. erythraeum Ehrenberg, T. thiebautii Gomont, T. hildebrandtii Gomont, and T. contortum Wille. In addition, Trichodesmium sp., a spherical colony of uncertain taxonomic position was examined. The cell structure of each species was investigated by means of light, scanning electron, and transvnission electron microscopy. Particular attention was paid to the presence and ultrastructural arrangement of gas vacuoles and glycogen fiber clusters (GFCs). This resulted in identification of two major groups of species: 1) T. tenue, Trichodesmium sp. with spherical-shaped colonies, and T. erythraeum with GFCs and more or less localized gas vacuoles; and 2) T. thiebautii, T. hildebrandtii, and T. contortum lacking GFCs and with gas vacuoles spread at random. The species within each group were further characterized with respect to the dimension of the gas vesicles, cylindrical bodies, scroll bodies, and a new cellular inclusion body, Differences in colony formation and cell dimensions correlated with specific ultrastructural characters in five of the six forms. This is the first ultrastructural study comparing different forms of Trichodesmium sampled at geographically remote areas and shows that one species appears identical regardless of the sampling site. Some of the species had not been investigated earlier, and probably more species are to be identified and analyzed.     

<Emphasis Type="Italic">Actinostola callosa</Emphasis> (Verrill, 1882) (Actinostolidae,Anthozoa), a medusivorous sea anemone and its mass occurrence in the Lurefjord,Norway

The seafloor of two Norwegian fjords (Lurefjord and Sognefjord) was studied using a remotely operated vehicle (ROV). Two large sea anemone species, Actinostola callosa and Bolocera tuediae, are part of the benthic fauna of these fjords. The first species is the most abundant in the Lurefjord north of Bergen. A special linear model to calculate the distances between specimens was constructed using the Geographic Information System data from the ROV. A. callosa was found to be medusivorous. Its biomass and high abundance seem to be correlated with a mass occurrence of its important local prey, the coronate medusa Periphylla periphylla.Communicated by H.-D. Franke     

Tracer Experiments in Feeding Littoral Foraminifera*†‡

SYNOPSIS. Tracer technic has proved to be an excellent tool in the study of predator-prey relationships among the foraminifera. More than fifty axenic species of protists including diatoms, dinoflagellates, chlorophytes, chrysophytes, cyanophytes, bacteria and yeasts were tested as potential food for Allogromia sp (NF), A. laticollaris, Am. monia beccarii, Quinqueloculina spp, Rosalina floridana, Anomalina sp, Elphidium sp, Spiroloculina hyalina, Globigerina bulloides, and Globorotalia truncatulinoides. Although many types of potential food are present in the environment, foraminifera select only certain organisms. The yeasts, cyanophytes, dinoflagellates, chrysophytes and most bacteria tested were not eaten. Selected species of diatoms, chlorophytes and bacteria were eaten in large quantity. Three additional factors affect feeding: the “age” of the food organism, the “age” of the foraminifer or its position in the life cycle, and the concentration of the food. Feeding by foraminifera on most food is erratic below a concentration of 10³ organisms and is approximately directly proportional to concentration within a range of 10³-10⁶ organisms per 10 ml experimental tube. A natural bloom of Protelphidium tisburyensis was analyzed. A high concentration of 6 species of diatoms characterized the community. A “bloom”-feeder hypothesis for foraminiferal nutrition is presented.     

Genetic response to human‐induced habitat changes in the marine environment: A century of evolution of European sprat in Landvikvannet,Norway

Habitat changes represent one of the five most pervasive threats to biodiversity. However, anthropogenic activities also have the capacity to create novel niche spaces to which species respond differently. In 1880, one such habitat alterations occurred in Landvikvannet, a freshwater lake on the Norwegian coast of Skagerrak, which became brackish after being artificially connected to the sea. This lake is now home to the European sprat, a pelagic marine fish that managed to develop a self‐recruiting population in barely few decades. Landvikvannet sprat proved to be genetically isolated from the three main populations described for this species; that is, Norwegian fjords, Baltic Sea, and the combination of North Sea, Kattegat, and Skagerrak. This distinctness was depicted by an accuracy self‐assignment of 89% and a highly significant F _ST between the lake sprat and each of the remaining samples (average of ≈0.105). The correlation between genetic and environmental variation indicated that salinity could be an important environmental driver of selection (3.3% of the 91 SNPs showed strong associations). Likewise, Isolation by Environment was detected for salinity, although not for temperature, in samples not adhering to an Isolation by Distance pattern. Neighbor‐joining tree analysis suggested that the source of the lake sprat is in the Norwegian fjords, rather than in the Baltic Sea despite a similar salinity profile. Strongly drifted allele frequencies and lower genetic diversity in Landvikvannet compared with the Norwegian fjords concur with a founder effect potentially associated with local adaptation to low salinity. Genetic differentiation (F _ST) between marine and brackish sprat is larger in the comparison Norway‐Landvikvannet than in Norway‐Baltic, which suggests that the observed divergence was achieved in Landvikvannet in some 65 generations, that is, 132 years, rather than gradually over thousands of years (the age of the Baltic Sea), thus highlighting the pace at which human‐driven evolution can happen.