Long-Term Changes in the Diet of Gymnogobius isaza from Lake Biwa, Japan: Effects of Body Size and Environmental Prey Availability

Prey are very important for the mass rearing of natural enemies and can affect the efficiency and quality of natural enemy products. Locomotion is important in dispersal of predatory mites on plants, and such activity is affected by body size and prey availability. The study evaluates the effects of prey (alternative prey: Tyrophagus putrescentiae Schrank and natural prey: Tetranychus turkestani Ugarov & Nikolskii) on the body size, locomotion and dispersal of the predatory mite Neoseiulus bicaudus Wainstein. When fed the alternative prey, the body size and locomotion of N. bicaudus were significantly lower than when fed the natural prey. However, the dispersal of N. bicaudus fed the two prey types was similar. The results suggest that long-term feeding on alternative prey could decrease the body size and locomotion of N. bicaudus. Nevertheless, the negative effects of alternative prey did not appear to affect the dispersal of N. bicaudus. The likely reason is that the type of prey does not affect the ability of the predatory mite to locate spider mites. In other words, when it fed alternative prey, N. bicaudus could still successfully disperse and locate spider mite-infested plants in the same way as when fed the natural prey.

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Long-term Changes in the Concentrations of Total Phosphorus and Nitrate in Some Quality Parameters of Water in Lake Biwa Using Integrated Analysis from Several Monitoring Data

Journal of Japan Society on Water Environment ◽

10.2965/jswe.35.89 ◽

2012 ◽

Vol 35 (6) ◽

pp. 89-100 ◽

Cited By ~ 3

Author(s):

Kazuhide HAYAKAWA ◽

Shigeo TSUJIMURA ◽

Toshiyuki ISHIKAWA ◽

Hiroki HAGA ◽

Takahiro OKAMOTO ◽

...

Keyword(s):

Total Phosphorus ◽

Lake Biwa ◽

Quality Parameters ◽

Monitoring Data ◽

Integrated Analysis ◽

Long Term Changes

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Reconstructing long-term changes in Daphnia's body size from subfossil remains in sediments of a small lake in the Himalayas

Journal of Paleolimnology ◽

10.1023/b:jopl.0000025295.04832.77 ◽

2004 ◽

Vol 32 (1) ◽

pp. 95-107 ◽

Cited By ~ 16

Author(s):

Marina Manca ◽

Patrizia Comoli

Keyword(s):

Body Size ◽

Small Lake ◽

Long Term Changes ◽

Subfossil Remains

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Biomass Spectra of Aquatic Ecosystems in Relation to Fisheries Yield

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f92-169 ◽

1992 ◽

Vol 49 (8) ◽

pp. 1528-1538 ◽

Cited By ~ 117

Author(s):

P. R. Boudreau ◽

L. M. Dickie

Keyword(s):

Body Size ◽

Aquatic Ecosystems ◽

Detailed Data ◽

Biomass Density ◽

Short Term ◽

The World ◽

Long Term Changes ◽

Biomass Spectra

The biomass density of aquatic ecosystems can be expressed as an allometric function of organism body size. The log–log plot of this relation, termed the biomass spectrum, is used to compare aquatic ecosystems in various parts of the world. We develop a standardized presentation for several example environments where detailed data on biomass density by body size in the trophic positions, phytoplankton, zooplankton, benthos, and fish, make it possible to establish overall or primary spectral slopes. The basic methodology is adapted for application to other ecosystems where less detailed data are available. Spectra from all the different environments exhibit a uniform low slope, but with different intercepts that appear to reflect ecosystem differences in nutrient circulation and availability. Detail on the secondary structuring at various positions in the trophic system appears to provide information useful for distinguishing between long-term changes in productivity and short-term perturbations in biomass or abundance.

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