Structure, distribution, and seasonal dynamics of the benthic community in the upper Newport Bay, California

The benthic community in the Upper Newport Bay was sampled at two intertidal and two subtidal depths at three stations during five assessment periods between October 1977 and January 1979. Heavy sediment deposition occurred during the 1977-1978 winter period, and the sedimentary environment was transformed from one characterized by fine sands (January 1978) to one dominated by silts (January 1979). Total density, species richness, and species diversity were generally lowest at the uppermost station (Ski Zone) and highest at the lowermost station (Shellmaker Island). Immediately following the 1977-1978 winter rainy period, total faunal density was extremely low, particularly at the Ski Zone station. However, heavy recruitment after April 1978 resulted in maximal total density values at all stations in August 1978. Species richness was highest during October 1977 and lowest in April 1978 following the heavy rainfall period. The benthic community was dominated in October 1977 by three polychaetes, Fabricia limnicola, Streblospio benedicti, and Capitella capitata. By August 1978, F. limnicola had not recruited back into the community and three additiona1 polychaete species (Polydora ligni, Pseudopolydora paucibranchiata, and Scolelepis acuta) shared community dominance with C. capitata and S. benedicti. The crustaceans showed strong seasonal oscillations, being abundant in the October and August samples and occurring sparsely in the January and April samples. (76pp.

Atlantid Heteropods as Living Substrata for Eggs of Halobates sericeus (Heteroptera: Gerridae)

Atlantid heteropods are collected occasionally in Hawaiian waters with yellow, narrowly elliptical objects attached to their shells. Examination of 139 of these objects from 72 atlantids showed that they consisted of an outer, clear capsule whose contents were usually yellow, although 16 were empty and four contained brown insects at an advanced stage of development. The latter were identified as preemergent nymphs of the Pacific pelagic seaskater or ocean strider, Halobates sericeus Eschscholtz. The maximal number of attached capsules was four, although most shells (79%) had one or two. Capsules averaged 0.93 mm long and 0.36 mm wide and were deposited on either the right, left, or both sides of the shell. All 72 atlantids with egg capsules were adult males. Exclusive usage of males by H sericeus is suggested to result from swarming behavior by male atlantids at the water surface. Although egg capsules were recorded from eight species of atlantids, most (86%) were on Atlanta turriculata d'Orbigny and A. fusca Souleyet, two of the most strongly pigmented species. Hypothetically, these two species would be the most visually conspicuous to H sericeus at the ocean surface

Antifungal Activity from Leaves of Acacia Nilotica against Pythium Aphanidermatum

Gallic acid and methyl ester of gallic acid has been identified as antifungal compounds against the mycelial growth of Pythium aphanidermatum from acetone-water extracts of Acacia nilotica leaves. The growth of fungus was completely ceased by gallic acid and its methyl ester at 1000 ppm and 750 ppm, respectively. Antifungal properties of both compounds were found to be higher in combination than alone. The minimum inhibitory concentration for both compounds was 1000 ppm. No phytotoxic effect of the compounds was observed on watermelon seed germination. The growth of roots and shoots of watermelon seedlings was promoted by gallic acid but decreased with methyl ester of gallic acid. Nitrate reductase activity of the fungus was significantly inhibited by both compounds