A NEW FRESHWATER CENTRIC DIATOM MICROSIPHONA POTAMOS GEN. ET SP. NOV.¹

Abstract

SUMMARY A new centric diatom, Microsiphona potamos gen. et sp. nov. (family Coscinodiscaceae), is described from the Little Miami River, Cincinnati, Ohio, where it occurred at cell densities ranging from 29 to 20,140/ml in surface grab samples during the period May 18–December 14, 1966, contributing an average of 11% and a maximum of 35% of the centric diatoms. This species has been observed in grab samples from rivers throughout the United States. The cells are 3–4 μ in diameter, 4–8 μ long, and contain 2 to several plate‐like chromatophores. They occur singly, or arc held together in short chains by the old girdle bands and by numerous apiculi that connect the opposing valves of adjacent daughter cells.

Taxonomic studies of centric diatoms (Diatomeae): unusual nanoplanktonic forms and new records for Brazil

“…The specific composition found was similar to those recorded by Weber (1970) in the Little Miami River, in the USA; by Sabater & Klee (1990) in the Ebro River, in Spain; and by Belcher & Swale (1978) in rivers in England and France. The species recorded are commonly found in plankton in high-nutrient environments (Sabater & Klee 1990).…”

Skeletonema potamos (Bacillariophyta) en la Laguna dos Patos, sur del Brasil: Taxonomía y distribución

“…These processes are tubular, with a cleft at the distal tip (Figs 8, 9). The morphology of the specimens agrees with the type, from the Little Miami River, Ohio, USA (Weber, 1970), except for the convexity and the pattern of granules on the valve face. The small granules of the specimens from the Patos Lagoon are limited to a middle area of the valve face.…”

“…Skeletonema potamos was first described as Microsiphona potamos by Weber (1970), from the Miami River, USA. The species was distinguished by its small "siphon" (strutted process) and by occurring in a lotic system.…”

“…This species is common in the rivers and lakes of North America, Europe (England, France, Spain, Germany, Poland, Finland, Hungary, Ukrany and Russia) and Australia (Weber 1970, Belcher & Swale 1978, Nicholls et al 1983, Chessman 1985, Kiss 1986, Chang & Steinberg 1988, Sabater & Klee 1990, Genkal & Ivanov 1990, Descy & Willems 1991, Kiss et al 1994, Turkia & Lepistö 1997, and its abundance is related to eutrophication. In Brazil the species was first reported by Torgan (1997) in Patos Lagoon (30°23'-32°07'S, 50°41'-52°12'W) on the Coastal Plain of the state of Rio Grande do Sul.…”

Centric diatoms of large rivers and tributaries in Hungary: morphology and biogeographic distribution

“…A second description was published from freshwater habitats by WEBER (1970) under the new genus and species name Microsiphona potamos Weber. HASLE and EVENSEN (1976) established the correct taxonomical position of the species with the new combination Skeletonema potamos.…”