蓝裸甲藻有性生殖的初步观察

<正> 早在1879年,Joseph就描述了Peridinium stygium的配子融合现象。之后的近八十年中,对甲藻生活史中是否存在有性生殖一直存在着争论。直至Von Stosch(1964)报道了Ceratium horridium和C.cornutum有性生殖核配的详细过程后,甲藻的有性生殖才得到公认。迄今,至少已在15属30种甲藻的生活史中观察到有性阶段。 Andersoa等人经大量的研究,证明:Gonyaulax tamarensis的周期性赤潮起源于海底沉积物中的休眠合子。在Gonyaula

武汉东湖浮游植物的演变(1956-1975年)和富营养化问题

本文根据1956—1957、1962—1963和1973—1975年在湖北省武汉市东湖进行的三次调查资料,总结了过去二十年内在东湖两个代表性采样站上浮游植物群落生态学的主要变化(包括数量、种类组成、优势种类、多样性指数和初级生产力)。年平均总数在二十年内由每毫升几百个增为几千个。由甲藻和硅藻占优势逐步转变为以绿藻和蓝藻占优势,蓝藻中的大型种类明显增加。年数量变动曲线原来呈春季和秋季两个高峰,但60年代后,已变为夏、秋季的一个蓝藻高峰,而且数量大,延续时间长。浮游植物的年初级生产量和日最高初级生产量也有明显

Long-term (1956-1999) dynamics of phosphorus in a shallow, subtropical Chinese lake with the possible effects of cyanobacterial blooms

This paper describes the long-term dynamics of phosphorus concentrations in both the lake water and the sediment in a subtropical Chinese lake, Lake Donghu. The total phosphorus (TP) concentration in the lake water experienced an upward trend from the 1950s, and peaked in 1983/1984, but declined obviously afterwards. From the 1950s to the 1990s, TP content in the upper 10 cm sediment of the lake increased steadily from 0.307 to 1.68 mg Pg DW-1 at Station I and from 0.151 to 0.89 mg Pg DW-1 at Station II, respectively. The TP increase in the lake water before mid-1980s was mainly attributed to the massive input of sewage P. The outbreak of cyanobacterial blooms coincided with the peaks of TP and Orthophosphate (PO4-P) in the water in mid-1980s, and the maximum TP of the water reached as high as 1.349 mg/1 at Station I and 0.757 mg/l at Station II (in 1984), respectively. The declines of TP and PO4-P in the water after mid-1980s was coincident with the disappearance of cyanobacterial bloom. (C) 2001 Elsevier Science Ltd. All rights reserved.