The Machaeridian Lepidocoleus Sarlei Clarke, 1896, from the Rochester Shale (Silurian) of New York State

Eight new specimens and the holotype of Lepidocoleus sarlei Clarke, 1896 from Lagersta¨tten deposits within the Rochester Shale (Silurian, Wenlock) of New York are described to elucidate the morphology, function and construction of the scleritome. The material exhibits an unusual type of dorsal hinge with a pronounced antero-posterior displacement between the two sides. Two specimens have an aberrant sclerite on the right side of segment eleven. One tightly enrolled specimen may demonstrate a method of defence with the stronger protected dorsal side oriented outwards. The presence of a segmented body plan is suggested, based on requirements for a functional spiral enrolment. Distinct anterior and posterior morphologies together with the pattern of rugae provide valuable help in reconstructing disarticulated lepidocoleids.     

A Curious Rusophycus (Arthropod Ichnofossil) Assemblage from the Upper Ordovician of Ontario,Canada

The ichnogenus Rusophycus includes a wide range of short bilobate excavations generally attributed to variable feeding behaviors of arthropods, especially trilobites. An unusual Rusophycus assemblage from Upper Ordovician Georgian Bay Formation in Ontario departs radically from previously described examples and presents new challenges for understanding the behavior represented by these traces. This specimen is unique in the arrangement of multiple Rusophycus burrows in a circular, lens-shaped array (as opposed to a linear or random arrangement typical of other Rusophycus assemblages). The size and shape of the individual Rusophycus components are consistent with traces attributed to the coeval trilobite Flexicalymene. Multiple Rusophycus assemblages likely reflect aggregations of trilobites in response to a local concentration of food. The topology of this particular Rusophycus assemblage suggests that the trilobites opportunistically exploited a rich and narrowly restricted food source, perhaps the decaying remains of a buried organism.     

Cumanensic acid, a new chromene isolated from Piper cf. cumanense Kunth. (Piperaceae)

A new chromene, cumanensic acid (1), together with eight known compounds have been isolated from the aerial part of Piper cf. cumanense Kunth (Piperaceae). Chromene structure was identified on the basis of spectroscopic analysis and comparison with literature data. The compound showed antifungal activity against Fusarium oxysporum f. sp. dianthi and Botrytis cinerea.     

Feeding of the Snailfish Careproctus cf. cyclocephalusin Pacific Waters of the Northern Kuril Islands

This paper describes the feeding habits of the snailfish Careproctus cf. cyclocephalus (Scorpaeniformes, Liparidae). The diet consisted mostly of crustaceans, among which decapods predominated comprising up to 69.3% of the mean biomass of food organisms. Small shrimp (Eualus biunguis and E. townsendi) dominated the diet making up over 40.9% of the total stomach fullness index.     

Morphology and ultrastructure of teratological forms of the diatoms Stephanodiscus niagarae and S. parvus (Bacillariophyceae) from Hamilton Harbour (Lake Ontario,Canada)

Teratological forms of Stephanodiscus niagarae Ehrenb. and S. parvus Stoermer & Håkansson were observed during a study of diatoms preserved in a radiometrically dated core from Hamilton Harbour (Lake Ontario, Canada). Morphological features and ultrastructures of both species were studied under the light and scanning electron microscope. The valve structure of abnormal forms of S. niagarae appears to be weakly silicified, especially in the central area. The shape of satellite pores are very irregular in comparison with the round shape of the normal specimen. The central fultoportulae are characterized as small tubes extending out of the external valve. Two types of abnormal frustules are present in the population of S. parvus studied. In one type valves are underdeveloped and only the siliceous layer and ribs are present, and in the other type the valves are strongly silicified and the areolae are almost completely occluded.The teratological forms of both species appeared in the core sediments after 1911, and both became the dominant components of diatom assemblages after 1970. Their occurrence and increased abundance coincides with records of heavy metal pollution in the harbour.     

Revision of Hyolitha from the Ordovician of Estonia

Topotype specimens of the Middle OrdovicianHyolithes acutus Eichwald, 1840, which is the type of the genus that lent its name to a family, order, class, and even phylum according to some, andH. latus Eichwald, 1860 allow that genus and those species to be firmly established on a sound, morphologic basis. In addition, preservation of the types ofHyolithes striatus Eichwald, 1860 is sufficiently good to warrant reassignment toDorsolinevitus Syssoiev, 1958. In contrast, the type ofH. insularis Eichwald, 1860 is incompletely preserved, and this species is not recognizable beyond the type material. The concept of the family Hyolithidae is revised to more closely conform to the morphology ofHyolithes, with authorship herein ascribed toSyssoiev (1958) rather than toNicholson (1872). The stratigraphic distribution of these taxa suggests thatHyolithes as defined herein first appears in the Middle Ordovician, but extends into at least the Lower Devonian, as suggested by two species from the Barrandian region of the Czech Republic. Their geographic distribution further re-enforces the notion of two distinct paleobiogeographic provinces based on hyoliths, a Mediterranean province and Baltic province, with almost no mixing of hyolith faunas during the Ordovician.      

Observations of herbivore attack on garlic mustard (Alliaria petiolata) in Southwestern Ontario, Canada

We have observed what appears to be the first significant report of herbivory of a population of Alliaria petiolata (M. Bieb.) Cavara & Grande (Garlic Mustard) in Canada. Ceutorhynchus erysimi Fabr., Plutella xylostella L. (Diamondback Moth), and Philaenus spumarius (Meadow Spittlebug) were identified attacking, and successfully proceeding through different stages of development on A. petiolata. From the field observations, we hypothesize that these species have recognized A. petiolata as a host and therefore may be candidates for the management of the invasive species.     

Effect of temperature,humidity and photoperiod on mortality of Mononychellus tanajoa (Acari: Tetranychidae) infected by Neozygites cf. floridana (Zygomycetes: Entomophthorales)

The effect of temperature, humidity and photoperiod on the development of Neozygites cf. floridana (Weiser and Muma) in the cassava green mite, Mononychellus tanajoa (Bondar) was studied in the laboratory. Dead infected mites began to appear 2.5 days after inoculation. At 33 and 28°C peak mortalities were higher and occurred earlier (after 2.5 days), than at 23 and 18°C. Mean LT₅₀ (time for half the infected mites to die) decreased with increasing temperature as follows: 3.9, 3.0, 2.9 and 2.5 days at 18, 23, 28 and 33°C, respectively. When placed under conditions of high relative humidity for a period of 24 h, the percentage of dead infected mites from which the fungus sporulated was highest at 28°C (51.4%) and lowest at 33°C (6.5%). The development of the fungus inside the mite was not significantly affected by ambient humidity or photoperiod. No significant interactions between tested factors were found.     

AnOistodus venustus-like conodont species from the Middle Ordovician of Baltoscandia

Ordovician conodont specimens resemblingOistodus venustus Stauffer, 1935 have been reported from many areas. There is increasing evidence, however, that several lineages with homeomorphic conodont elements have erroneously been referred to one and the same species. I have investigated Baltoscandian conodont elements of this kind in order to find out about their origins and phylogenetic relationships with morphologically comparable elements from other areas. A natural grouping of finds from the Middle and lower Upper Ordovician of Baltoscandia is here described as belonging to a new species of a new genus,Venoistodus balticus n. gen., n. sp. The new species probably evolved paedomorphically fromDrepanoistodus forceps (Lindström, 1955) in the Early Ordovician.     

Survival of Neozygites cf. floridana (Zygomycetes: Entomophthorales) in mummified cassava green mites and the viability of its primary conidia

The survival of Neozygites cf. floridana (Weiser and Muma) as dry hyphal bodies in mummified cassava green mites, Mononychellus tanajoa (Bondar), at 5.0% RH in the dark was affected by storage temperature. Survival of the fungus in mummies kept at 24±1.0°C could be demonstrated for 6–7 months. When stored at 4°C, the fungus sporulated from 90% of the mummies liberating an average of 186.9 primary conidia per mummy even after a storage period of 16 months, when the experiment was terminated. The temperature, humidity and light condition significantly affected the viability of primary conidia. The percent viability across all factors dropped from 98.4% after 0 h (beginning of the experiment) to 23.4% after a 1 h exposure to the conditions tested. Lower temperatures maintained higher viabilities with 86.3% of the conidia surviving after 18 h at 18°C, whereas almost all conidia died after 12 h at 33°C. Conidia survived less than 1 h when exposed to SDs (saturation deficit) of 2.0 mm Hg or higher at any tested temperature.     

Life history responses of the cladoceran Ceriodaphnia cf. dubia to variation in food concentration

The effect of five different food concentrations on the life history of Ceriodaphnia cf. dubia was examined by following cohorts of 25 individuals from <24 hours until the death of all individuals. The food concentrations used in the study were chosen to reflect densities found in lentic freshwater systems and those commonly used in toxicity testing, and ranged from 1 × 10⁴ cells mL^-1 to 15 × 10⁴ cells mL^-1. Food concentration was found to have a significant effect (p<0.05) on several life history parameters, with a decrease in food concentration leading to a decrease in brood sizes and population growth rate, and an increase in longevity. Population growth rates varied from approximately 0.39 neonates d^-1 to 0.54 neonates d^-1, while mean lifespan ranged from 16.7 days to 42.9 days. A decrease in food concentration also led to an increase in the mean generation time.     

Cyclocarya cf. paliurus （Batal.） Iljinskaja （Juglandaceae） from the Hunchun Formation （Eocene）, Jilin Province, China

The leaflet architecture of Cyclocarya cf. paliurus （Batal.） Iljinskaja from the Hunchun Formation （Middle Eocene） shows similarity to that of modem C. paliurus （Batal.） Iljinskaja and the specimen is the oldest fossil record in Europe and Asia. The distributions of C. cf. paliurus and other fossil records, such as Glyptostrobus, Metasequoia, Nyssa, and Liquidambar, in Hunchun flora show that it would have been a warmer-temperature to subtropical climate in Hunchun District during the Eocene period.     

Residual effects of 3,4-dichloroaniline on offspring born to Ceriodaphnia cf. dubia exposed for multiple generations

One of the acknowledged limitations ofconventional toxicity tests is their inabilityto evaluate the impact of toxicants onsubsequent generations. Given their relativelyshort lifespan, cladocerans in the field may beexposed to toxicants for several generations.However, it is unclear what effect such anexposure regime could have on the cladoceranfitness after removal of the toxicant. Thispaper aimed to determine the offspring fitnessof juveniles produced by adult Ceriodaphnia cf. dubia exposed toresidual levels of 3,4-dichloroaniline overfour generations. Mass cultures of Ceriodaphnia cf. dubia were maintainedfor several generations in variousconcentrations of 3,4-dichoroaniline (0, 2.5,5, 10, 15 and 20 µg/L). The mass cultureswere re-established every generation using4th brood neonates <24 h old. Eachgeneration, 4th brood neonates <24 h oldwere also transferred individually intotoxicant-free water and examined until theproduction of their 3rd brood. F1offspring of mothers exposed to 15 and20 µg/L 3,4-dichloroaniline showedsignificantly (p < 0.05) reducedreproduction compared to the controls. Nosignificant (p > 0.05) changes inreproduction due to 3,4-dichloroaniline wereobserved for the F2 and F3 offspring. However,F4 offspring of mothers exposed to all3,4-dichloroaniline concentrations showedsignificantly (p < 0.05) increasedreproduction compared to the controls. Possibleexplanations for the varying influence ofmaternal 3,4-dichloroaniline exposure on thereproductive output of the offspring arediscussed.     

Cyclocarya cf. paliurus (Batal.) Iljinskaja (Juglandaceae) from the Hunchun Formation (Eocene), Jilin Province, China

The leaflet architecture of Cyclocarya cf. paliurus (Batal.) Iljinskaja from the Hunchun Formation (Middle Eocene) shows similarity to that of modern C. paliurus (Batal.) Iljinskaja and the specimen is the oldest fossil record in Europe and Asia. The distributions of C. cf. paliurus and other fossil records,such as Glyptostrobus, Metasequoia, Nyssa, and Liquidambar, in Hunchun flora show that it would have been a warmer-temperature to subtropical climate in Hunchun District during the Eocene period.     

Gracilaria conferta and its epiphytes: (2) Interrelationship between the red seaweed and Ulva cf. lactuca

Ulva cf. lactuca has been a disturbing competitor of experimental Gracilaria conferta outdoor cultures in Israel. The effect of environmental conditions on the competitive ability of Ulva versus Gracilaria, and the main limiting factors for which these seaweeds compete, were studied here. Single and biculture experiments of both seaweeds showed that Ulva outgrew and damaged Gracilaria under all irradiance and temperature combinations. The higher competitive ability of Ulva cf. lactuca in bicultures was not a result of responses to shading or nitrogen shortage, but rather to a shortage of available inorganic carbon, an increase in pH and apparent excretions of Ulva which inhibited the growth of Gracilaria.     

Influence of migrant tundra swans (Cygnus columbianus) and Canada geese (Branta canadensis) on aquatic vegetation at Long Point, Lake Erie, Ontario

Numerous studies have shown that large, herbivorous waterfowl can reduce quantity of aquatic plants during the breeding or wintering season, but relatively few document herbivory effects at staging areas. This study was done to determine if feeding activities of tundra swans (Cygnus columbianus columbianus) and Canada geese (Branta canadensis) had a measurable additive influence on the amount of aquatic plants, primarily muskgrass (Chara vulgaris), wild celery (Vallisneria americana), and sago pondweed (Potamogeton pectinatus), removed during the fall migration period at Long Point, Lake Erie, Ontario. Exclosure experiments done in fall 1998 and 1999 showed that, as compared to ducks and abiotic factors, these two large herbivorous waterfowl did not have any additional impact on above or below ground biomass of those aquatic plants. As expected, however, there were substantial seasonal reductions in above-ground and below-ground biomass of aquatic plants in wetlands that were heavily used by all waterfowl. We suggest that differences in large- and small-scale habitat use, feeding activity, and food preferences between tundra swans and other smaller waterfowl as well as compensatory herbivory contributed to our main finding that large waterfowl did not increase fall reductions of Chara spp, V. Americana, and P. pectinatus biomass.     

Simplicissin,a New Pollen Growth Inhibitor Produced by the Fungus,Penicillium cf. simplidssimum (Oudemans) Thorn No. 410

A new pollen growth inhibitor, named simplicissin, was isolated from Penicillium cf. simplicissimum (Oudemans) Thorn No. 410, and its structure was established by spectroscopic methods including 2D NMR. The biological activities of the compound were examined by the bioassay methods involving tea pollen together with lettuce seedlings. The compound inhibited the growth of the tea pollen tube by 45% at a concentration of 3 mg/liter and showed complete inhibition at 10mg/liter.