How to increase productivity of the copepodAcartia tonsa(Dana): effects of population density and food concentration

Abstract

In this study, we analysed the effect of population density and food concentration on the fecundity of a Mediterranean strain of Acartia tonsa to maximize egg production. During 4-day feeding experiments, egg hatching success and faecal pellet production were also followed. The algae Rhinomonas reticulata was supplied at different concentrations corresponding to 250, 500, 1000, 1500, 2000 and 3000 lg C L À1 day À1 at the following adult copepod density: 40, 80 and 160 ind. L À1 . Our results show a positive relationship between algal concentration and egg production under all experimental conditions confirming that the quantity of food strongly limits A. tonsa fecundity. Maximum egg production (57 eggs per female) was reached at the lowest density and at the maximum food concentration. Percentage of egg hatching success was not dependent on the quantity of food used. At the same food concentration, an increase in population density from 40 to 80 ind. L À1 induced an increase in faecal pellet production per couple which did not correspond to an increase in egg production, suggesting that higher energetic costs were shifted to swimming activity. Productivity of the A. tonsa Mediterranean strain is mainly limited by the quantity of food rather than by crowding conditions.

Intraspecific variations in macronutrient, amino acid, and fatty acid composition of mass-cultured Teleaulax amphioxeia (Cryptophyceae) strains

“…Besides, rapid decay of TPG / RHO strains upon virus infection has been noted as a contributor to recycling of cellular nutrients (Nagasaki et al 2009). Thus, many strains of "RHO clade" cryptomonads have been used to rear the prey zooplankton for marine aquaculture owing to their high content of quality nutrients (Chu et al 2008, Seixas et al 2009, Zhang et al 2014, Boelen et al 2017, Peltomaa et al 2017.…”

The Copepod Acartia tonsa Dana in a Microtidal Mediterranean Lagoon: History of a Successful Invasion

“…dominant zooplankton species during summer [14], provided that high concentrations of particulate organic carbon and particulate organic matter are available. In fact, the life cycle of this copepod is strictly dependent on the quantity of the available food-the larger the trophic supplies are, the more accelerated its growth rate is [15][16][17].The Lagoon of Venice, a large Mediterranean lagoon located in the northwest coast of the Adriatic Sea, presents marked habitat heterogeneity, and the classification of its habitats is still a matter of debate [18,19]. The lagoon is considered the main hotspot for invasive species in the whole Italian coast with the presence of more than 60 NIS, including 29 invertebrates and 34 macrophyte species among which A. tonsa also appears [20][21][22][23][24][25].…”

“…dominant zooplankton species during summer [14], provided that high concentrations of particulate organic carbon and particulate organic matter are available. In fact, the life cycle of this copepod is strictly dependent on the quantity of the available food-the larger the trophic supplies are, the more accelerated its growth rate is [15][16][17].…”

The effects of temperature and photoperiod on egg hatching success, egg production and population growth of the calanoid copepod, Acartia grani (Calanoida: Acartiidae)

“…We speculate that several reasons may have contributed for these outcomes. Food quantity is known to affect egg production rate (Zhang et al., ), whereas food quality mainly affects hatching success (Guisande, Rivero & Maneiro, ). A. grani adults used in our experiments were fed Rhodomonas , an algal diet widely used as feed for copepod cultures (Vu et al., ) and normally high in EPA compared with DHA (Støttrup et al., ).…”