Body size patterns in arctic and temperate zooplankton1

Crustacean zooplankton data were compiled from long-term observational studies at seven large shallow Florida lakes, to determine whether there are general characteristics in regard to species composition, body size, and biomass. In particular, we examined whether patterns in body size and species richness fit empirical models developed by Stanley Dodson. The lakes included range in size from 125 to 1730 km 2 and encompass mesotrophic to hyper-eutrophic conditions. We found that zooplankton biomass was strongly dominated by one species of calanoid copepod-Arctodiaptomus dorsalis. Large daphnids were absent, and Cladocera assemblages were dominated by small taxa such as Ceriodaphnia, Chydorus, and Eubosmina. The total number of species of pelagic cladocerans (8-12) was consistent with Dodson's predictions based on lake area. The average size of crustacean zooplankton in Florida lakes is small in comparison with temperate communities. A. dorsalis is the smallest calanoid copepod in North America, and the mean length of Cladocera (0.6 mm) is consistent with Dodson's results that size decreases from temperate to tropical zones. Total biomass of crustacean zooplankton was very low, ratios of zooplankton to phytoplankton biomass (0.01-0.1) are among the lowest reported in the literature, and the zooplankton displayed short-lasting early spring peaks in biomass. Cladocera were almost entirely absent in spring and summer. Factors known to occur in Florida lakes, which appear to explain these characteristics of biomass, include intense fish predation and high summer water temperature.

Section: Community Characteristicsmentioning

confidence: 98%

Composition, size, and biomass of zooplankton in large productive Florida lakes

Havens

Beaver²

2010

“…Size selective predation is a major factor that determines the composition of zooplankton species asso-0 (Brooks & Dodson, 1965 ;Dodson, 1979) . Plankton-eating fish tend to remove the larger species (Brooks & Dodson, 1965) .…”

Section: Species Associationsmentioning

confidence: 99%

“…Small species tend to occur either in lakes with intense fish predation and large species occur in lakes with little or no fish predation (Dodson, 1979) . We hypothesized that the same would be true in Aguascalientes .…”

Section: Introductionmentioning

confidence: 99%

Crustacean zooplankton species richness and associations in reservoirs and ponds of Aguascalientes State, Mexico

Dodson

Silva-Briano

1996

Self Cite

We report the species of crustacean zooplankton found in 19 resevoirs and ponds that were sampled at on at least two occasions in Aguascalientes State, Mexico, at a latitude of about 21°30' North Latitude . We collected a total of 33 cladoceran taxa, 15 calanoid and cyclopoid copepods, an Ergasilus copepod, 2 anostracans, one notostracan species and an amphipod . All these taxa had previously been reported in Mexico . As in more temperate areas, there was a significant correlation between the species richness and lake size . The species-area relationship for Aguascalientes was indistinguishable from that of more northerly lakes . The two most common associations of zooplankton species were (1) those small species that occurred with fish : Daphnia parvula, Diaphanosoma birgei, Leptodiaptomus siciloides, Mastigodiaptomus albuquerquensis, and Thermocyclops inversus, and (2) the large Daphnia schodleri that occurred with the predator Notonecta, in the absence of fish . With minor variations, these two associations also occur throughout temperate North America .

“…The zooplankton community in tundra ponds may be quite diverse (Dodson, 1979;Stross et al (1980). However, most ponds are frequently predominated by associations of only a few species.…”

Section: Effects Of Various Environmental Factors On Phytoplankton Sementioning

confidence: 99%

“…However, most ponds are frequently predominated by associations of only a few species. Generally they are characterized by relatively larger species, such as Daphnia middendorffiana Fischer and Heterocope septentrionalis Juday & Muttkowski or by smaller species, such as Daphnia pulex Leydig (Dodson, 1979). At Barrow, Alaska, Daphnia middendorffiana is the dominant species .…”

Section: Effects Of Various Environmental Factors On Phytoplankton Sementioning

confidence: 99%

Seasonality of phytoplankton in northern tundra ponds

Sheath

1986

Thermokarst ponds are the most abundant type of water body in the arctic tundra, with millions occurring in the coastal plains of Alaska, Northwest Territories and Siberia. Because ie covers of at least 2 m in thickness are formed at these latitudes, tundra ponds freeze solid every winter As a result, the growing season is shortened to a range of 60 to 100 days, during which time the photoperio-l is altered to a prolonged light phase. Tundra ponds are generally close to neutral in pH and low in ions, contain dissolved gases near saturation and are nutrient poor. In low arctic ponds there are two phytoplankton biomass and primary production peaks, whereas they may be only one in the high arctic. Nanoplanktonic flagellates of the Chrysophyceae and Cryptophyceae dominate the maxima. The mid-summer decline in phytoplankton in the low arctic can be attributed to a combination of phosphorus limitation and heavy grazing pressure. The cryptomonad Rhodomonas minuta Skuja is one of the most widespread phytoplankters in tundra ponds. Because of the altered photoperiods, many species do not form resting spores prior to ice formation but survive freezing in the vegetative state.