Distribution and Biomass of Tropocyclops prasinus mexicanus (Cyclopoida) in a Near-Thermally Constant Environment, Montezuma Well, Arizona

Patricia M Ellsworth, Dean W. Blinn

Research output: Contribution to journalArticle


We examined seasonal and spatial distribution of all life stages of the diminutive cyclopoid copepod Tropocyclops prasinus mexicanus in 2 years in the nearly thermally constant environment of Montezuma Well, Arizona, USA. Although annual temperatures remained relatively constant (21 ± 4°C), densities of T. prasinus mexicanus displayed a bimodal pattern, with highest densities during the summer and winter. Also, the vertical water column was nearly homeothermal, but all life stages avoided the top 2 m of the water column during clear summer days and utilized this stratum during the winter when light was reduced. Females within the population were egg-bearing throughout the entire year, which led to high annual mean densities (>200 animals/L). Mean annual biomass of T. prasinus mexicanus was estimated at ≥50 μg/L.

Original languageEnglish (US)
Pages (from-to)341-346
Number of pages6
JournalSouthwestern Naturalist
Issue number3
StatePublished - Sep 2003


ASJC Scopus subject areas

  • Ecology

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