Showing papers in "Transactions of the American Microscopical Society in 1973"

Acridine orange-epifluorescence technique for counting bacteria in natural waters.

Abstract: FRANCISCO, D. E., MAH, R. A. & RABIN, A. C. 1973. Acridine orange-epifluorescence technique for counting bacteria in natural waters. Trans. Amer. Micros. Soc., 92: 416-421. Total direct counts of aquatic bacteria from natural samples were estimated by epifluorescence microscopy after acridine orange staining. Cells were concentrated by membrane filtration on black membrane filters and counted directly. Using this method, bacterial counts of pure cultures corresponded to those obtained by the Petroff-Hauser and Coulter counter methods. Epifluorescence counting is the method of choice for ecological studies of the natural distribution of bacteria in aquatic environments since it permits ready discrimination of bacteria from detritus and does not rely on the adequacy of culture methods to elicit growth of all viable organisms. Total counts obtained in this way were related to glucose and acetate uptake by resident microbial populations of lake water sample. Viable counts of the same samples were not related.

Free-living marine nematodes from biscayne bay, florida v. stilbonematinae: contributions to the taxonomy and morphology of the genus eubostrichus greeff and related genera1

Abstract: HOPPER, B. E. & CEFALU, R. C. 1973. Free-living marine nematodes from Biscayne Bay, Florida V. Stilbonematinae: contributions to the taxonomy and morphology of the genus Eubostrichus Greeff and related genera. Trans. Amer. Micros. Soc., 92: 578-591. Four species of stilbonematid nematodes are recorded from Florida waters, two of which are described as new to science, Eubostrichus dianeae n. sp. and Catanema porosum n. sp. Cobb's term, the "porid" is reintroduced in its original context of being "tubular setae serving as outlets for glands. .. ." Unique cervical and caudal porids are described for males of Eubostrichus. The association of the pleiomorphic blue-green alga Schizothrix calcicola with Eubostrichus species is discussed. It is speculated that the alga's differential growth habits are related to specific substances emanated from the hypodermal gland complexes via the porids (or pores).

The utilization of bacteria as food for Paramecium bursaria.

Abstract: BARNA, I. & WEIS, D. S. 1973. The utilization of bacteria as food for Paramecium bursaria. Trans. Amer. Micros. Soc., 92: 434-440. This study was undertaken to compare the nutritional value of bacterial food organisms for Paramecium bursaria. Several bacterial species isolated from nature were tested as potential food for six stocks of Paramecium bursaria. Among the bacterial food organisms tested, those yielding the best growth are gram-negative rods. Among these, Enterobacter cloacae produced the best growth of P. bursaria. Gram-positive bacilli such as Bacillus polymyxa proved to be poor food organisms. The gram-positive coccus Micrococcus liquefaciens is toxic to all stocks of P. bursaria tested. A mixed bacterial flora yields a growth index (no. of animals at time t/no. of animals at time 0) which is intermediate to the growth indices on the single bacterial species tested separately.

Some Species of Lecithaster Lühe, 1901 (Digenea: Hemiuridae) and Related Genera from Fishes in the Northern Gulf of Mexico

Abstract: OVERSTREET, R. M. 1973. Some species of Lecithaster Liihe, 1901 (Digenea: Hemiuridae) and related genera from fishes in the northern Gulf of Mexico. Trans. Amer. Micros. Soc., 92: 231-240. Lecithaster helodes n. sp. is described from Mugil curema and M. cephalus. It differs from the closely related L. mugilis Yamaguti, 1970 by having four rather than three ovarian lobes and other minor differences. Discussions and measurements are presented for L. confusus Odhner, 1905, L. leiostomi Overstreet, 1970, Hysterolecitha elongata Manter, 1931, Aponurus pyriformis (Linton, 1910) n. comb., and A. elongatus Siddiqi & Cable, 1960. Branchadena Linton, 1910 is considered a synonym of Aponurus Looss, 1907. New host records are listed for some of the above hemiurid trematodes. Leurodera ocyri Travassos, Frietas & Bihrnheim, 1965 and L. inaequalis Travassos, Freitas & Biihrnheim, 1965 are considered synonyms of A. pyriformis.