Journal of Environmental Biology

Elaphoidella grandidieri (Harpacticoida: Copepoda): Demographic

characteristics and possible use as live prey in aquaculture

Author Details

S. Nandini

(Corresponding author)

Laboratorio de Zoolog?a Acu?tica, Divisi?n de Investigaci?n y Posgrado, Universidad Nacional

Aut?noma de M?xico, Campus Iztacala, Av. de Los Barrios No. 1, Los Reyes Iztacala, AP 314, CP

54090, Tlalnepantla, Edo. de M?xico, M?xico

e-mail: nandini@servidor.unam.mx

Alma Rosa Nunez Ortiz

Laboratorio de Zoolog?a Acu?tica, Divisi?n de Investigaci?n y Posgrado, Universidad Nacional

Aut?noma de M?xico, Campus Iztacala, Av. de Los Barrios No. 1, Los Reyes Iztacala, AP 314, CP

54090, Tlalnepantla, Edo. de M?xico, M?xico

S.S.S. Sarma

Laboratorio de Zoolog?a Acu?tica, Divisi?n de Investigacion y Posgrado, Universidad Nacional

Aut?noma de M?xico, Campus Iztacala, Av. de Los Barrios No. 1, Los Reyes Iztacala, AP 314, CP

54090, Tlalnepantla, Edo. de M?xico, M?xico

Publication Data

Paper received:

28 February 2010

Revised received:

22 May 2010

Accepted:

24 September 2010

Abstract

In freshwater ecosystems, rotifers and cladocerans are ideal prey for fish larvae whereas copepods, due to their purported low growth rate and predatory tendency, are not. We recently isolated the parthenogenetic Elaphoidella grandidieri (Guerne et Richard, 1893) a benthic freshwater harpacticoid, from a fish farm in the State of Morelos, central Mexico and tested its potential as a live prey organism for larval vertebrates. Population growth and life table demography experiments were conducted, in 100 ml recipients with 50 ml of test medium on a diet of Scenedesmus acutus at a density of 1.0 X 10⁶cell ml^-1; the former on live algae alone while the latter on live algae as well as detritus. We also conducted experiments to document the prey preference for this copepod by the larval Ameca splendens (Pisces: Goodeidae) and Ambystoma mexicanum (Amphibia: Ambystomatidae), fed the rotifer Plationus patulus, the ostracod Heterocypris incongruens, and the cladocerans Moina macrocopa and Daphnia pulex. Elaphoidella grandidieri is relatively easy to maintain under laboratory conditions, reaching densities (copepodites and adults) of more than 10,000 l^-1. The generation time ranged between 30-45 days, depending on the diet. The net reproductive rate was as high as 60 nauplii female ^-1 day ^-1. Population growth rates ranged between 0.03 and 0.11 d^-1, live algae being the superior diet compared to detritus. Both predators showed no preference for E. grandidieri, but in the absence of alternate prey they consumed 80% of the harpacticoids offered. The data have been discussed in relation to the potential of E. grandidieri as live food for aquaculture.

Key words

Aquaculture, Copepods, Population density, Fish food, Mass culture

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