Raquel Jiménez-Melero

Effect of temperature, food and individual variability on the embryonic development time and fecundity of Arctodiaptomus salinus (Copepoda: Calanoida) from a shallow saline pond

Organisms living in temporary and shallow wetlands are adapted to survive in very fluctuating and unpredictable conditions and might help us to understand life cycle strategies and plasticity in the context of global warming. Despite the importance of Arctodiaptomus salinus in these systems, little is known about the effect of temperature on its population dynamics. Through an individual-based experimental protocol, we studied the effect of this factor and food on its reproduction. This approach has revealed a large range of variability in reproductive parameters in all the experimental conditions. Temperature positively affected egg production and negatively longevity, but did not affect clutch size. Under unsuitable food conditions, the clutch size decreased and the inter-clutch period increased, and when the food conditions improved, the number of eggs increased gradually in every clutch. Eggs from the same clutch hatched synchronously. In contrast, there were significant differences between the hatching times of clutches from different females and between those of the same female. The observed individual variability increased when temperature moved away from the medium values. The thermal tolerance threshold for A. salinus development might be around 25–29°C. Since water pond is close to this thermal limit for long periods of time, an increment of temperature because of global warming might have dramatic consequences on this population. The individual-based experimental approach of this study provides useful information to construct realistic individual-based models, which will help us to better understand the population-level consequences of individual variability in A. salinus reproduction.

Selecting priority conservation areas based on zooplankton diversity: the case of Mediterranean wetlands

A set of Mediterranean wetlands has been studied in order to identify priority areas for conservation using zooplankton assemblages. We also measure the degree of nestedness to determine the best strategy for conservation of zooplankton diversity. The present study was conducted in 29 wetlands located in the south-east of the Iberian Peninsula (Spain). Two complementary approaches were used, cluster analysis and parsimony analysis of endemicity (PAE), with a presence–absence data matrix, in order to group wetlands as a function of zooplankton composition. To select conservation areas, four different criteria were used: species richness; exclusive species occurrences; the number of wetlands in which species appeared; and phylogenetic diversity. The results showed the existence of three different zones (subgroups of wetlands). Using the same method, a significant nestedness among wetlands was also observed independently of the method used to group them. The conservation proposal included 98% of the total species and 41.4% of the studied wetlands. This work confirms that zooplankton assemblages are essential for making wetland conservation decisions and for the identification of areas with connectivity (fluxes of species) in which efforts should be more intense to preserve their biodiversity.

Lipid Composition of Arctodiaptomus salinus (Copepoda: Calanoida)

ABSTRACT We analyzed the lipid and fatty acid composition in adult females and egg sacs of the calanoid copepod Arctodiaptomus salinus (Daday) to describe differences in composition due to fecundity status. The fatty acid composition varied between females carrying eggs and those without eggs, indicating differences in assimilation, catabolism, synthesis, or modification of fatty acids associated with physiological changes that occurs during reproduction.

Linking watershed land uses and crustacean assemblages in Mediterranean wetlands

The watershed land uses in Mediterranean wetlands are essential to understand the functioning of aquatic communities. This study was designed to assess the relationship between watershed land uses, wetland characteristics and zooplankton assemblages (branchiopods and copepods) in 24 Mediterranean wetlands of the southern Iberian Peninsula, which greatly differ in both wetland land uses (olive groves, pasture, scrublands, and forest) and in their morphometric and limnological features. Firstly, results from a Principal Component Analysis allowed us to classify wetlands in two categories: impacted and non-impacted. Then, one-way Analysis of Variance was performed to test differences in zooplankton species richness and a Permutational Analysis of Variance was performed to test differences in zooplankton assemblages between categories. Lastly, a Non-metric Multidimensional Scaling analysis was chosen for the lake-by-species ordination. The results support the hypothesis that zooplankton richness and composition were negatively affected by watershed land uses, mainly agriculture practices. Moreover, species zooplankton assemblages were clearly linked to the two different wetlands categories. The present study puts forward the important role of zooplankton community for testing land use effects in Mediterranean wetlands.

Zooplankton body size versus taxonomy in Mediterranean wetlands: implications for aquatic ecosystem evaluation

Intrinsic ecological characteristics of Mediterranean wetlands make them excellent sites for studying biodiversity, but these wetlands have been studied much less frequently than temperate lakes. The invertebrates that inhabit them, and zooplankton specifically, play important roles in these wetlands. We compared the ability of taxon- and size-based analyses of the zooplankton community to predict the influence of environmental variables. We sampled environmental variables and zooplankton at 7 Mediterranean wetlands in the Iberian Peninsula (southern Spain) monthly along 1 hydroperiod cycle (2009–2010). We used 3 arrays for classifying the zooplankton community: 1) species occurring in >5% of the samples, 2) coarse-level taxa easily identified by a nonexpert (large branchiopods, small branchiopods, calanoid copepods, cyclopoid copepods, and harpacticoid copepods), and 3) 4 body-size classes (<1, 1–2.5, 2.5–10, and >10 mm in length). We used permutational analysis of variance (PERMANOVA) and canonical correspondence analysis (CCA) to test our hypotheses. Communities differed significantly among wetlands, and body size (55.8% of explained variance) was more useful than taxonomic composition (common taxa: 24.4%, coarse-level taxa: 26.5% of explained variance) for rapid assessment of the influence of the environmental variables on zooplankton community in temporary wetlands.