Daphnia in Lake Washington1

D . lumholtzi in Lake Samsonvale, Queensland, Australia, is a small species (max. size approx . 7 tgC) that occurs in low abundance (max . abundance 6400 m -3 ), with an average daily biomass of 3.32 mgC m -3 . Its annual rates of carbon assimilation, production and respiration, are 166, 110, and 56 mgC m -3 y -' respectively . Annual biomass turnover (annual production/average daily biomass) is 33 and production efficiency is 50-66% . The population may consume 1 .65-2 .20 mgC m -3 daily, equivalent to about 1 ° of the average daily standing crop of phytoplankton . Clutch size is small, 2 eggs, but represents 30-80% of a female's weight . A female may only produce 8-10 offspring in a full lifespan, nevertheless egg production may account for 56% of total production . The population shows autumn and spring peaks in abundance, and is believed to oversummer (4 months) as ephippia .

Section: Discussionmentioning

confidence: 99%

The productivity and carbon budget of a natural population of Daphnia lumholtzi Sars

King

Greenwood

1992

“…Another explanation of the replacement of large Daphnia by small ones could have been the intensification of the role of bluegreens interfering with the filtration process in large Daphnia, thereby preventing the growth of their populations (Gliwicz, 1977). In Lake Washington, for instance, the disappearance and then the reappearance of large Daphnia were explained by Edmondson & Litt (1982) partly by the influence of Oscillatoria. However, there are no grounds to believe that blue-greens (e.g.…”

Section: Discussionmentioning

confidence: 99%

History of the community of planktonic Cladocera in Lake Glubokoe (Moscow Region)

Matveev

1986

A 128-centimeter sediment core of a forest lake in the Moscow Region, for which the recent zooplankton has been well studied, was analysed. The changes in the density and size of organisms in the core points to an important role of fish and interspecific competition in Cladocera and to a minor role of invertebrate predators in the historical development of the plankton. No substantial shifts in the lake trophy seem to have occurred during the last 600 years. A widely used technique of heating the sediment in a 10°7o KOH solution may account for 5-13-fold losses of planktonic cladocerans' remains.

“…De Bernardi & Guissani (1975) failed to detect any influence of L. kindti in Lago Maggiore with the density of L. kindti being 0.03 ind. 1 -, nor did Edmondson & Litt (1982) in Lake Washington, with the density of L. kinti being 0.08 ind. 1 -l .…”

Section: Invertebrate Predatorsmentioning

confidence: 99%

Long-term changes in the community of planktonic crustaceans in Lake Glubokoe in relation to predation and competition

Matveev

1986

Studies on the planktonic Crustacea in Lake Glubokoe (Moscow region) from 1897 to 1982 have been reviewed. After 1965, when most of the swamp water inflow was diverted from the lake, certain populations have penetrated into deeper layers, while the average overlap in the community has dropped. The summer dominant Mesocyclops leuckarti disappeared and Chydorus sphaericus appeared in mass quantities; this development was not associated with biomass changes of blue-greens. The Cladocera/Calanoida ratio and the relative abundance of certain species showed no considerable changes. The effect of Chaoborus, Cyclops and Leptodora in the 70's on the crustacean populations was insignificant in spite of the increasing abundance of these genera after 1965. Analysis of the dynamics of the clutch size and the density of lake populations in the 1970's and 1980's revealed food limitation and competition in herbivorous Cladocera. In laboratory experiments with lake water they always competed, though the intensity of their interaction varied depending on the species combinations.