Direct and indirect impact of two common rotifer species (Keratella spp.) on two abundant ciliate species (Urotricha furcata, Balanion planctonicum)

1. We investigated the potential competition and feeding impact of the common rotifer species, Keratella cochlearis and K. quadrata , on the abundant prostomatid ciliates, Urotricha furcata and Balanion planctonicum, in laboratory batch culture experiments. All four species have similar feeding preferences, co-occur in many freshwater environments, and are thus potential competitors for the same algal food.
2. Two small Cryptomonas species served as food for the ciliates and the rotifers in the experiments. Growth rates of each ciliate species were measured when they grew alone and when they were paired with one of the rotifer species.
3. Both rotifer species reduced the growth rate of U. furcata , probably primarily by direct feeding on the ciliates. Growth rate of B. planctonicum was unaffected by K. cochlearis , but was drastically reduced by grazing and/or mechanical interference of K. quadrata .
4. These results suggest niche partitioning of the sympatric ciliates with respect to their rotifer competitors/predators.     

Enumeration of small ciliates in culture by flow cytometry and nucleic acid staining

We developed a fast and simple protocol for accurate quantification of small freshwater ciliates by flow cytometry (FCM). The ciliates were stained with several nucleic acid stains such as TO-PRO-1, YO-YO-1 and PicoGreen, and analysed by a commercially available flow cytometer. The method was tested with cultures of the prostomatid species Urotricha farcta and Balanion planctonicum, including the small cryptophyte Cryptomonas sp. as food. Of the dyes tested, TO-PRO-1 gave the best results. Flow cytometric results agreed well with microscopic counts. Due to its greater speed and accuracy, FCM was superior to light microscopy. FCM was also superior to electronical particle counting and sizing (EPCS). Of particular importance, FCM in combination with TO-PRO-1 staining allowed unequivocal discrimination in cases of overlapping size distributions between the target population (i.e., the ciliate predators) and other particles (the cryptophyte prey, detritus).     

Balanion masanensis n. sp. (ciliophora: prostomatea) from the coastal waters of Korea: morphology and small subunit ribosomal RNA gene sequence

The planktonic ciliate Balanion masanensis n. sp. is described from living cells, from cells prepared by quantitative protargol staining (QPS), scanning electron microscopy (SEM), and transmitted electron microscopy (TEM) preparations, and the sequence of its nuclear small subunit rDNA (SSU rDNA) is reported. This species is almost ovoid with a flattened anterior oral region when the cells are alive and stained. The flattened anterior region of a living cell often forms a dome with the perimeter receded in a groove, and this region is easily inflated or depressed. In SEM photos, a brosse of six to nine monokinetids (or possibly three to five dikinetids) was observed inside the circumoral dikinetids. In TEM photos, circumoral microtubular ribbons were observed below the oral cilia, which along with the oral flaps were 8-16 microm in length. The cytostome is a slight funnel-like central depression on the flattened anterior end. The morphological characteristics of this ciliate are identical to those of the genus Balanion (Order Prorodontida). The ranges (and mean+/-standard deviation) of cell length, cell width, and oral diameter of living cells (n=23-26) were 27-43 microm (35.2+/-4.6), 25-32 microm (28.6+/-2.3), and 25-30 microm (27.6+/-1.3), respectively, while those of the QPS-stained specimens (n=70) were 23-37 microm (30.6+/-3.5), 26-35 microm (30.7+/-2.2), and 26-33 microm (29.5+/-1.5), respectively. Forty-six to 55 somatic kineties (SKs) were equally spaced around the cell body and extended from the oral to near the posterior regions with 24-50 monokinetids per kinety. Each kinetid bore a cilium 2.8-7.2 microm long. A caudal cilium (ca 14 microm long) arose on the posterior end. The single ellipsoid macronucleus is 6.8-13.4 x 6.8-10.5 microm, accompanied by a single micronucleus (2.0-2.8 x 1.5-2.5 microm) visible only in QPS specimens. Because, the cell size, the number of SKs, and the number of kinetosomes per SK of this ciliate were much greater than those of Balanion comatum and Balanion planctonicum, the only two Balanion species so far reported, we have established B. masanensis n. sp. When properly aligned, the sequence of the SSU rDNA of B. masanensis n. sp. (GenBank Accession No. AM412525) was approximately 9% different from that of Coleps hirtus (Colepidae, Prorodontida) and 12% different from that of Prorodon teres (Prorodontidae, Prorodontida).     

Two new Myristicaceae from Ecuador

Compsoneura lapidißora is described as a new species. It differs from other species of Compsoneura in having dendritic hairs with articulated, flat branches, and many more (19–22 vs. up to 14) secondary veins in the leaves; it also has bracteoles which are otherwise not known in the genus and hairs on the inner surface of the perianth that surround the base of the androecium, a character unknown in other Neotropical Myristicaceae. Otoba cyclobasis is also described as a new species. It is related to Otoba acuminata with which it shares the apparently derived feature of having a swollen ring that surrounds the filament column, but O. acuminata differs from O. cyclobasis in having fewer secondary veins (5–9 vs. 14–17), and a bottleshaped (not slender) filament column.     

The Dutch representatives of the Staurastrum manfeldtii complex (Desmidiaceae, Chlorophyta): a taxonomic revision

The taxonomy and local distribution within The Netherlands of a group of closely related species belonging to the Staurastrum manfeldtii cluster have been investigated. S. manfeldtii is a benthic species, distributed in mesotrophic, circum neutral water bodies. S. planctonicum and S. pingue are common plankters in eutrophic. alkaline lakes. S. productum stat. nov., and S. bulbosum stat. nov., confined to the benthos of acid, oligo-mesotrophic pools, occurred scarcely in the beginning of this century but are without any record after the twenties. S. bicorne and S. simplicius stat. nov only very incidcntally encountered, might be mere biradiate forms of S. productum and S. planctonicum respectively.     

Biochemical composition of algivorous freshwater ciliates: you are not what you eat

The focus of our study was to determine whether the biochemical composition of two algivorous ciliates, both fed the same alga, resembles that of their diet. By comparing both ciliated protozoa we intended to identify species-specific differences in the metabolic features of these ciliates. Carbon- and cell-specific concentrations of fatty acids and essential amino acids were investigated for the ciliates Balanion planctonicum and Urotricha farcta grown on the cryptomonad Cryptomonas phaseolus. Stepwise discriminant analyses (SDA) indicated differences in the biochemical composition between ciliates and their diet and between the two ciliated protozoa. Carbon-specific fatty acid concentrations were usually higher in the ciliates than in their diet, especially concentrations of monounsaturated and some polyunsaturated fatty acids. Except for tryptophan, valine, and lysine, amino acid concentrations were higher in the ciliates than in C. phaseolus. Furthermore, differences in the polyunsaturated fatty acids accounted for the largest discrepancies between the two ciliated protozoa. The higher concentrations in the ciliates compared to their diet suggest that these species are capable of efficiently ingesting, assimilating or possibly synthesizing some fatty acids and amino acids. We conclude that dietary fatty acid and amino acid composition influences the composition of the two ciliated protozoa to a minor extent, and that species-specific differences in fatty acid and amino acid metabolism may be more important determinants of the biochemical composition of the studied ciliates. Moreover, the metabolism of polyunsaturated fatty acids seems to differ more profoundly between the two ciliated protozoa than the metabolism of other fatty acid classes or amino acids.     

A new species, Polydactylus siamensis, from Thailand and redescription of P. plebeius (Broussonet, 1782) with designation of a neotype (Perciformes: Polynemidae)

A new species, Polydactylus siamensis, is described on the basis of eight specimens from Thailand. The species is similar to P. plebeius (Broussonet, 1782) in having five pectoral filaments and several dark stripes along the scale rows above and below the lateral line, but differs from the latter in having lower counts of pectoral fin rays (15 vs. 16–18 in P. plebeius), pored lateral line scales (54–58 vs. 60–68), scale rows above and below the lateral line (7 and 10 or 11, respectively vs. 8 or 9 and 12 or 13, respectively) and gill rakers (9 or 10 upper series, 13 or 14 lower and 22–24 total vs. 9–14, 13–18 and 24–32, respectively), and a longer upper jaw (mean 17% [range 16–17%] of standard length vs. 15% [13–16%]). Polydactylus siamensis is currently known only from Bangkok and Songkhla, Gulf of Thailand, and Phuket Island, Andaman Sea, whereas P. plebeius is widely distributed in the Indo-Pacific. Received: January 12, 2000 / Revised: September 15, 2000 / Accepted: January 12, 2001     

Activity patterns in moose and roe deer in a north boreal forest

The activity patterns of a coarse browser, the moose. Alces alces , and a selective browser, the roe deer, Capreolus capreolus . in a north boreal forest, central Sweden, were compared with respect to time allocated for foraging and processing (ruminating) in different seasons. Data were quantified by measuring 24 h activity patterns which included both the duration and frequency of active and inactive periods. Activity patterns were measured from 9 female moose and 9 roe deer that were radiomarked during April 1974–May 1978 (roe deer) and February 1982–December 1984 (moose). In total, data were available from 4345 h for roe deer and 14745 h for moose. Roe deer differed from moose in having active bouts more evenly distributed over the day. Generally, both species were most active during sunrise and sunset. Total daily active time varied with season, reaching the highest value in late May – early June among roe deer (56.7% of the day) and a month later among moose (51.9%). Both species were least active in February (30–40%). Average length of active bouts did not differ significantly between the species but changed with season (roe deer 48.6–99.2 min, moose 61.6–88.7 min). Average length of inactive bouts varied significantly with season, with moose having consistently longer bouts (89.3–156.3 min) than roe deer (55.8–107.0 min). The number of activity bouts per day were also higher among roe deer. During midsummer, they changed activity nearly twice as many times as moose (26 times d⁻¹ vs 16 times d⁻¹).     

Snail faunas in the early stages of a chalk grassland succession

Snail faunas from 10 sites in chalk grassland on the South Downs are described. The sites represent a range of early stages in the succession of grazed chalk grassland to scrub. The faunas of the later stages sampled, with vegetation 12–45 cm high, are substantially different from those of the earlier stages (2.5–10 cm high), lacking most xerophil species, and having much higher proportions of species typical of woods and hedgerows.
The results are discussed in relation both to those from other studies of existing faunas, and also to the environmental interpretation of buried faunas from geological and archeologtcal studies.     

Liopropoma dorsoluteum sp. nov., a new serranid fish from Okinawa, Japan

A new serranid fish,Liopropoma dorsoluteum sp. nov., is described on the basis of two specimens from Yaeyama Is., Okinawa, Japan. The new species is most similar toL. erythaeum Randall & Taylor, 1988, in having the following characters: Dorsal fin rays VIII, 12; anal fin rays III, 9; pored lateral line scales 52–53; anterior nostril situated midway between posterior nostril and anterior tip of snout; slightly forked caudal fin with both lobes rounded. It differs from the latter species in having a shorter pectoral fin (23.4–23.8% SL vs. 26.9–29.0% SL), greater preanus length (65.6–68.0% SL vs. 63.3–65.1% SL), fewer gill rakers (6+12 vs. 6–7+14–15) and yellow coloration on the back (vs. light red on head and body) in fresh specimens.     

An early Ordovician patelliform gastropod, Palaelophacmaea, reinterpreted as a coelenterate

Yochelson, Ellis L. & Stanley, George D., Jr. 1981 12 15: An early Ordovician patelliform gastropod, Palaelophacmaea , reinterpreted as a coelenterate. Lethaia , Vol. 15, pp. 323–330. Oslo. ISSN W24–1164.
The fossil Palaelophacmaea criola Donaldson, from the early Ordovician Stonehenge Formation of central Pennsylvania, was described as a patelliform gastropod. A reinterpretation of the type lot and study of a few additional specimens provide the basis for an alternative placement. Palaelophacmaea is here assigned to the Hydrozoa, as a possible chondrophore. It has an exceptionally thin shell or test and concentric but irregular corrugations. Cambrian univalve genera having a more or less circular outline that are currently assigned to the Gastropoda or Monoplacophora should be reexamined to see whether they have the features of fossil chondrophore coelenterates rather than those of molluscs. The late Cambrian Palaeoacmaea Hall & Whitfield is removed from the monoplacophoran Mollusca and left unassigned as to phylum. We judge that at least some early Cambrian species of Scenella are probably coelenterate remains. * Early Ordovician , Palaelophacmaea, Gastropoda, Monoplacophora, Hydrozoa .     

Attributes of the seed bank after a century of primary succession on islands in Lake Hjälmaren, Sweden

1 A large number of islands was created when the water table of Lake Hjälmaren, south central Sweden, was lowered between 1882 and 1886. We have complete lists of vascular plant species for 40 of these islands from 1886, 1892, 1903–04, 1927–28 and 1984–85.
2 We have investigated the seed bank on nine of these islands and compared species composition at different soil depths with the species lists from the islands in 1886–1985, and with the present vegetation in the area of seed bank sampling. We have also investigated the distribution in the soil of seeds from species with different ecological attributes, including seed longevity, successional status, seed weight, seed form and species longevity.
3 Seeds in soil samples were allowed to germinate over the course of two summers with an intermediate cold storage. We found 1944 seeds representing 65 taxa. The mean seed density was 84 seeds dm ^–2 .
4 The similarity between the surface soil (0–3 cm) seed bank and the vegetation at the different vegetation analyses increased from 1886 to 1993. The similarity between the present vegetation and the seed bank decreased with increasing soil depth, and the soil at 12–15 cm had no species in common with the present vegetation. Several species now absent from the vegetation were found in the seed bank.
5 Deeply buried seeds came from early successional, annual species with long-term persistent and low-weight seeds, as expected from seed bank theories, but were slightly elongated, which was in contrast to theories. Spherical seeds were associated with the surface soil, as were short-lived and high-weight seeds from late successional, perennial species.     

Temporal and spatial distribution of planktic cyanobacteria in Lake Kastoria, Greece, a shallow, urban lake

The temporal and spatial distribution of planktic cyanobacteria and some environmental parameters were studied in the shallow, urban Lake Kastoria, Greece from June 1996 to June 1997. Water temperature varied from 6–27 °C, pH from 7.5–8.9 and dissolved O₂ concentration from 0.7–12 mg m^-3 10^-3. The mean annual Chl a concentration was 83 mg Chl a m^-3 indicative of the eutrophic-hypertrophic state of the lake. Cyanobacterial biomass ranged from 11–238 g FW m^-3, constituting about 90% of the total phytoplankton biomass throughout the year. Cyanobacterial biomass was non-uniformly distributed both vertically and horizontally from August to November 1996 and resulted mainly from the distribution of Microcystis. Seven cyanobacterial taxa were reported for the first time in Lake Kastoria. Six taxa were dominant: Microcystis aeruginosa, M. flos-aquae, M. novacekii. Limnothrix redekei, Anabaena sp. and Cylindrospermopsis raciborskii. The dominant cyanobacterial taxa can be grouped on the basis of their distribution patterns (1) Microcystis species: maximum biomass occurring at pH > 8, temperature 12–17 °C, depth < 0.2 m; (2) Anabaena sp. and Cylindrospermopsis raciborskii : maximum biomass at temperatures 23–26 °C; (3) Limnothrix redekei : maximum biomass at temperatures 6–27 °C. Usually, non-uniform, vertical distributions of cyanobacterial biomass were associated with the formation of temperature, pH and O₂ gradients. L. redekei was considered to be a key lake organism since it contributed up to 59% of the cyanobacterial biomass. Interestingly, three of the dominant cyanobacteria Microcystis aeruginosa, Anabaena sp. and Cylindrospermopsis raciborskii belong to genera that include toxin-producing species.     

A comparative study on morphology, growth rate and reproduction of Clarias gariepinus (Burchell, 1822), Heterobranchus longifilis Valenciennes, 1840, and their reciprocal hybrids (Pisces, Clariidae)

A detailed study on reproduction indicated that female C. gariepinus mature earlier (5–7 months) than female H. longifilis (12–14 months). In the reciprocal hybrids, female first sexual maturity was attained at 20–21 months. Both reciprocal hybrids and parental species displayed an equilibrated sex ratio. Macroscopical and microscopical observations revealed numerous abnormalities in gonadal development of the hybrids. GSI and fecundity in female hybrids were considerably lower than those found in the parental species. Moreover, intra-ovarian tumors occurred in 20% of the hybrids. In hybrid males, GSIs were generally higher than those found in the parental species, but the spermatozoa concentration in the semen was about 100 times less. Despite these abnormalities, viable larvae, resulting from F2 and backcross fertilizations, were obtained.     

Tiron bellairsi sp. n. (Amphipoda, Synopiidae) from Coral Sand in Barbados, with Notes on Behaviour

Tiron bellairsi sp. n. is described and illustrated. The species, of less than 3 mm in length, was quite common on shallow-water coral sand with a fine layer of detritus. It has a hitherto undescribed behaviour in that the animals move around on top of the sand carrying, with pereopods 3–7, two flat slabs of coral or shell debris for protection. The species belongs to a group of Tiron having stubby, pincerlike dactyls on pereopods 3–7, and is compared with other stubby-legged species of the genus. Metatiron Rabindranath, 1972 is here included in Tiron Lilljeborg, 1865.     

Aosa sigmoidea, a new species of the genus Aosa (Loasaceae) from Brazil

A new species of Aosa (Loasaceae) is described from Minas Gerais in Brazil. A. sigmoidea clearly is a close relative of Aosa rostrata from the same area. The plant differs in being very much taller (2 m in A. sigmoidea in comparsion to 0.05–0.30 m in A. rostrata ) and in having capsules with a clavate inferior portion which is 7–10 mm long while the inferior capsule portion in A. rostrata is hemisphaerical and only 1.5–2 mm in diameter.     

A new species, Gazza squamiventralis, from the East Coast of Africa (Perciformes: Leiognathidae)

Gazza squamiventralis sp. nov. is described as the fifth species of the genus, based on the holotype and eight paratypes, 42–96 mm in standard length, collected along the east coast of Africa, from Kenya to Mozambique. The species is similar to other congeners in general appearance, differing clearly from them in having the ventrolateral surface of the body scaled anterior to a line from the pectoral fin base to the pelvic fin origin (vs naked) and a smooth supraorbital ridge (vs finely serrated). Additionally, the species differs from G. dentex, G. rhombea, and G. achlamys in having the dorsolateral surface of the body scaled anterior to a vertical through the tip of the posterior branch of the supratemporal canal (vs corresponding region naked), and from G. minuta in having the first dorsal fin pterygiophore narrowly expanded anteriorly, with a concave margin (vs broadly expanded, with a convex or linear margin), and a short antrorse extension of the first anal fin pterygiophore (vs long). A key to the five species of the genus Gazza is provided. Received: May 30, 2000 / Revised: September 16, 2000 / Accepted: January 16, 2001     

A new species of Magnolia sect. Tulipastrum (Magnoliaceae) from Fujian, China

Magnolia polytepala Law, R.Z. Zhou & R.J. Zhang sp. nov. (Magnoliaceae) a new species from Fujian, south-east China, is described and illustrated. The species was found growing only in the evergreen broad-leaved forests of Mount Wuyishan at altitudes of 500–1200 m. Notes are also presented on the phenology and conservation status of the new species. It is closely related to Magnolia liliiflora Desr., but differs from the latter in its stunted habit (less than 2 m tall) and tepals, which are more numerous (12–16) and not contorted at the base.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 289–292.     

Diversity, flower visitation frequency and generalism of pollinators in temperate rain forests of Chiloé Island, Chile

Species richness and taxonomic composition of pollinator assemblages are documented for 26 plant species from temperate rain forests of northern Chiloé Island, southern Chile (42°30'S). We investigated the patterns of generalism and specialization among plants and animal pollinators by comparing the flower visit frequency by different pollen vectors during the spring and summer months of three consecutive years (2000–2002). Species studied exhibited a range of floral morphologies (radial vs. zygomorphic, open vs. tubular) and rewards (nectar and/or pollen). Overall, we recorded 172 pollinator species, with an average of 6.6 species of pollen vectors/plant species. Pollinators visited an average of 15.2 plant species/pollen vector. Pollinator assemblages were dominated by Coleoptera (75 species), Diptera (56 species) and Hymenoptera (30 species), but passerine birds and hummingbirds were also important. The most specialized plants were vines, including the bee-pollinated genus Luzuriaga (Philesiaceae) and two endemic species of hummingbird-pollinated Gesneriaceae. Hymenoptera contributed 41.2% of all visits, with the bumblebee Bombus dalhbomii accounting for 22.5% of these. Plants with unspecialized flower morphology supported a higher species richness of pollinators, but visiting rates did not differ from specialized flowers.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 399–416.     

Record of a larval Parataeniophorus brevis from Hawaii

A 7.2 mm notochordal-length larva of Parataeniophorus brevis is described and illustrated from the fifth and the smallest specimen, collected near Hawaii. This larva is compared to all other described species of the family Mirapinnatidae, and is unique in having the unpaired fin rays developing in the finfold. The three species of Parataeniophorus can be distinguished on the basis of the number of dorsal-fin and anal-fin rays: bertelseni , 18–20 and 16–18; brevis , 13–16 and 13–15; gulosus 28–33 and 23–29, respectively.