Population Growth, Body Size, and Egg Size of Two Different Strains ofBrachionus calyciflorusPallas (Rotifera) Fed Different Algae

Abstract

Laboratory populations of two Brachionus calyciflorus strains (WH and GZ strains) collected respectively from Zhujiang River and Changjiang River basins of China were cultured on 0.3 mglml of Chlorella pyrenoidosa, Scenedesmus obliquus or on a 1 : 1 mixture (wet weight) of the two algal species. The population growth rates of the WH and GZ strains fed C. pyrenoidosa were markedly higher than those fed on S. obliquus, but the body size (lorica length) and the egg size (egg volume) of both strains fed C. pyrenoidosa were significantly smaller than those fed on S. obliquus. When fed the same type of alga, the population growth rate of the WH strain was significantly higher than that of the GZ strain. However, the body size and the egg size of the WH strain were markedly smaller than those of the GZ strain. These results indicated that both strains were capable of varying their reproductive patterns, according to the algal food type, to maximize their reproductive rates; and, under the same culture condition, different rotifer strains possessed different reproductive strategies.

Demographic parameters and mixis of three Brachionus angularis Gosse (Rotatoria) strains fed on different algae

“…Results have shown that rotifer strain significantly affected the population growth rate of B. plicatilis and B. calyciflorus (Snell & Carrillo, 1984;Xi, Liu, & Jin, 2002). The body size among different rotifer strains has also been confirmed to be significantly different in B. plicatilis (Snell & Carrillo, 1984;Yufera, 1982) and B. calyciflorus strains (Xi et al, 2002). In the present study, we found that the intrinsic rate of increase, generation time, and average lifespan of the three rotifer strains were all significantly different in the same culture condition.…”

“…Results have shown that rotifer strain significantly affected the population growth rate of B. plicatilis and B. calyciflorus (Snell & Carrillo, 1984;Xi, Liu, & Jin, 2002). The body size among different rotifer strains has also been confirmed to be significantly different in B. plicatilis (Snell & Carrillo, 1984;Yufera, 1982) and B. calyciflorus strains (Xi et al, 2002).…”

“…During the period, the rotifer populations were kept in log-phase growth. Algae were grown in semi-continuous culture with HB-4 medium and refreshed daily at 40% (Xi, Liu, & Jin, 2002). Algae in exponential growth was centrifuged and suspended in the rotifer medium.…”

“…Except for the population growth, the body size of rotifers is another factor that influences its application in aquaculture, for larva of different species and ages need corresponding amounts of food. Strain is an important endogenous factor affecting the population growth and body size of rotifers Snell & Carrillo, 1984;Xi, Liu, & Jin, 2002;Yufera, 1982). The culturing of different rotifer strains offered a better solution to obtain different rotifer sizes (Snell & Carrillo, 1984).…”

Diversity measures in macroinvertebrate and zooplankton communities related to the trophic status of subtropical reservoirs: Contradictory or complementary responses?

“…This is the case for rotifers which was usually the most abundant group found in eutrophic environments (Attayde and Bozelli, 1998;Sousa et al, 2008), as corroborated by the present study. Indeed, rotifers possess a wide trophic plasticity, and although they preferentially prey on the chlorophyta phytoplankton species, which are common in oligo-and mesotrophic environments as a preferential food resource, they are also able to grow and reproduce when they feed on cyanobacteria, which are frequent in eutrophic ecosystems (Xi et al, 2002;Claps et al, 2011).…”