An April 1996 to March 1997 comparative study on the abundance and secondary production of Branchiura sowerbyi Beddard, 1892 in two typical shallow lakes showed that in Houhu, an algae dominated lake, the worm density (68 ind·m -2 ) peaked in July, biomass (1.930 g·m -2 ) peaked in June, while in Biandantang, a macrophyte dominated lake, standing stock (density:60 ind·m - 2 ; biomass:1.019 g·m -2 in wet weight) peaked in December. Secondary production of the animal in Houhu Lake was 3.413 g wet wt m -2 a -1 , a little more than that (2.675 g wet wt m -2 a -1 ) in Biandantang Lake. Their turnover rates (P/B ratios) were 4.0 and 5.0, respectively.
