caa a22 4500 445894342 CHVBK 20180317145626.0 cr unu---uuuuu 170323e20110501xx s 000 0 eng 10.1007/s10750-010-0209-8 doi (NATIONALLICENCE)springer-10.1007/s10750-010-0209-8 Demographic characteristics of the copepod Acanthocyclops americanus (Sars, 1863) (Copepoda: Cyclopoida) fed mixed algal ( Scenedesmus acutus )-rotifer ( Brachionus havanaensis ) diet [Elektronische Daten] [Cecilia García, S. Nandini, S. Sarma] The predatory copepod Acanthocyclops americanus is commonly found in shallow ponds and lakes in Mexico. We tested the survivorship and reproduction-related variables of this copepod, isolated from Lake Huetzalin (Xochimilco, Mexico City), on four mixed diets comprising two algal concentrations (0.8×106 and 1.6×106 cells ml−1 of Scenedesmus acutus) and two rotifer densities (1 and 8ind.ml−1 of Brachionus havanaensis). Survivorship patterns of naupliar and adult stages of A. americanus were evaluated at 24±1°C. The demography experiments were initiated with five females and five males (1:1 ratio, 5th copepodites) into each of the 16 test [=4 diet combinations×4 replicates (cohorts)] jars containing 50ml medium and with one of the chosen algal-rotifer diets. Data on the survival of naupliar and copepodites (up to V) showed a high death rate (80%) in A. americanus by the time nauplii reached the adult stage. The duration of developmental time for nauplii and the copepodite V (C-V) was about 28days by which time A. americanus became adults. Food combination had a significant effect on both survival and duration of the naupliar and C-V but not on the development time in C-I, C-II, C-III, and C-IV. Naupliar stages showed highest life expectancy at low food levels (rotifers or alga). Adult male and female copepods showed better survival under higher availability of rotifers in the medium, while higher algal density resulted in steep mortality during the first days. Average adult lifespan and life expectancy of A. americanus varied from 19 to 23days, depending on the diet combination. Age-specific reproductive output (m x) of female A. americanus showed low reproduction (<10 offspring per female on any given day) when raised on low rotifer density, regardless of the algal concentration. On the other hand, enhanced offspring production (average of about 50 nauplii per female) was recorded when the rotifer density was higher (i.e., 8ind.ml−1). Gross and net reproductive rates varied from 48 to 438 and 27 to 318 offspring per female, respectively. In general, higher availability of rotifers in the medium resulted in higher (8-10 times as compared to those in low rotifer density) gross and net reproductive rates. There was no significant difference in the generation time (13-14days) in relation to the diet combination. The rate of population increase (r) (range: 0.29-0.69 per day) increased with greater abundance of B. havanaensis in the medium. Thus, our study showed that inclusion of animal protein in the diet is necessary for high population growth rates of A. americanus. Springer Science+Business Media B.V., 2010 Food quality nationallicence Copepoda nationallicence Survivorship nationallicence Reproduction nationallicence Acanthocyclops americanus nationallicence García Cecilia Programa de Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Edificio de Posgrado, Planta baja (Costado sur de la Torre II de Humanidades Circuito Interior), Cd. Universitaria, 04510, Coyoacán, Mexico City, Mexico aut Nandini S. Laboratorio de Zoología Acuática División de Investigación y Posgrado, Universidad Nacional Autónoma de México, Campus Iztacala, AP 314, CP 54090, Tlalnepantla, Edo. de México, Mexico aut Sarma S. Laboratorio de Zoología Acuática División de Investigación y Posgrado, Universidad Nacional Autónoma de México, Campus Iztacala, AP 314, CP 54090, Tlalnepantla, Edo. de México, Mexico aut Hydrobiologia Springer Netherlands 666/1(2011-05-01), 59-69 0018-8158 666:1<59 2011 666 10750 https://doi.org/10.1007/s10750-010-0209-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10750-010-0209-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- García Cecilia Programa de Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Edificio de Posgrado, Planta baja (Costado sur de la Torre II de Humanidades Circuito Interior), Cd. Universitaria, 04510, Coyoacán, Mexico City, Mexico aut NATIONALLICENCE 700 1- Nandini S. Laboratorio de Zoología Acuática División de Investigación y Posgrado, Universidad Nacional Autónoma de México, Campus Iztacala, AP 314, CP 54090, Tlalnepantla, Edo. de México, Mexico aut NATIONALLICENCE 700 1- Sarma S. Laboratorio de Zoología Acuática División de Investigación y Posgrado, Universidad Nacional Autónoma de México, Campus Iztacala, AP 314, CP 54090, Tlalnepantla, Edo. de México, Mexico aut NATIONALLICENCE 773 0- Hydrobiologia Springer Netherlands 666/1(2011-05-01), 59-69 0018-8158 666:1<59 2011 666 10750 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer