New and Rare Chrysophytes From Wyoming and Colorado Lakes

Abstract

Colorado and Wyoming lakes with high pH values generally ranging from 8 to 10 are dominated by phytoplankton belonging to the chrysophytes, diatoms and cryptomonads. Our studies on phytoplankton diversity in Dowdy, South Delaney Buttes and Cowdrey Lakes in Colorado and Diamond and Twin Buttes Lakes in Wyoming have yielded several isolates of rare or new chrysophytes. These isolates were examined with light microscopy, SEM, TEM, and novel information regarding their structure is presented. Proposed new species belong to the genera Saccochrysis, Prymnesium and Chrysochromulina. Chrysophytes that were examined for the first time include Monochrysis aphanaster, Uroglenopsis, and a mixotrophic species of Ochromonas, which ingests small diatoms. Probable new species are the following: Saccochrysis sp. nov. differs in chloroplast structure, cell shape and cell number/colony, and absence of a posterior vacuole; Prymnesium sp. nov. is the first freshwater form examined with EM and differs in scale morphology; and Chrysochromulina sp. nov. is similar to Chrysochromulina parva but lacks scales. The ultrastructure of M. aphanaster is unique and appears to be a member of the Chrysophyceae. It has two flagella, one of which is emergent, while the other is hidden within an invagination of the cytoplasm. Diacronema and Sarcinochrysis spp. from these lakes also were isolated and reinvestigated, and some unique cellular features will be discussed.

Changes in gene expression of Prymnesium parvum induced by nitrogen and phosphorus limitation

“…Recurrent Ecosystem Disruptive Algal Blooms (EDABs) formed by P. parvum have resulted in significant economic losses in the aquaculture industry (Moestrup, 1994 ; Edvardsen and Paasche, 1998 ; Sunda et al, 2006 ), and these events appear to be increasing in frequency and geographical range. In recent years, P. parvum has spread throughout the northeast coast of the United States and into southwestern states, most notably Texas and Oklahoma (Aguiar and Kugrens, 2000 ; Watson, 2001 ; Hargraves and Maranda, 2002 ; Baker et al, 2009 ; Hambright et al, 2010 ). Blooms of P. parvum sufficient to result in fish kills tend to occur in environments characterized by high levels of macronutrients (Lindholm et al, 1999 ; Graneli and Salomon, 2010 ).…”

Haptophyte Algae

“…1-23; non figs. Aguiar (2000) and Aguiar and Kugrans (2000) described, from five Colorado lakes, a new species of Chrysochromulina (C. asquamosa Aguiar et Kugrans) that differs from C. parva mainly in its lack of scales and other details relating to its flagella, haptonema, and cell size. P. laurentiana (Kling) Nicholls, comb.…”