Influence of environmental factors on the life cycle and morphology of Artemia salina (Crustacea: Anostraca) in Sabkhet El Adhibet (SE Tunisia)

Abstract

This study was aimed to examine in greater detail the influence of selected environmental factors on the life cycle and morphological characteristics of the brine shrimp Artemia salina (Linnaeus, 1758). During this follow-up, from November 2005 to April 2006 and from November 2006 to April 2007, Sabkhet El Adhibet (southeast Tunisia: 33°07'7.58"N, 11°24'8.69"E) was surveyed monthly to determine the impact of water salinity, temperature, pH, dissolved oxygen, and phytoplankton density and community structure on Artemia density, population structure, reproductive mode, and total offspring. Strong correlations were found between physicochemical parameters of water and Artemia reproduction characteristics. In contrast, no significant relationship was detected between physicochemical variables and Artemia population structure and density. Further, there were no correlations between phytoplankton density and the Artemia life cycle. Moreover, we observed relationships between physicochemical parameters and all morphological characteristics, especially between the width of 3 rd abdominal segment and salinity (r xy = 0.96), temperature (r xy = 0.73), pH (r xy = -0.77) and oxygen (r xy = -0.92) for male specimens, and between the length of the furca and both salinity (r xy = -0.76) and dissolved oxygen (r xy = 0.74), and between the maximal diameter of compound eyes and temperature (r xy = -0.56) for female specimens. Principal component analysis (PCA) shows that male and female specimens collected at different environmental conditions converge, which explains the morphological similarity between them according to salinity, temperature, and dissolved oxygen concentration as well as total phytoplankton, diatom, cryptophyte, and dinophyte density.

Phytoplankton variability with relationships to environmental factors in a temporary salt lake

“…The mean values of water temperature, salinity, pH and dissolved oxygen as well as nutrients concentrations measured in all stations have been reported earlier by Ben Naceur et al (2009). Figure 1 The mean values of minimum and maximum surface water temperatures obtained were 12.1 °C (March 2006) and25.4 °C (April 2006).…”

“…However, the saltern is generally filled by rain-water from December to February. For more information about Sabkhet El Adhibet see Ben Naceur et al (2009Naceur et al ( , 2011.…”

Do environmental factors influence the morphotypes in Artemia franciscana Kellogg, 1906 (Crustacea: Anostraca)?

“…It may occur due to the environmental pressures and adaptations of different geographical areas [41]. Interestingly, different morphotypes were encountered in A. franciscana and their occurrence was recorded in all sampling sites [42][43][44][45]. In general, the morphotype was categorized based on structure of second antenna in male and ovisac shapes in females [20].…”

Egg banks in dryland wetlands provide information on the diversity and vulnerability of branchiopod communities along a longitudinal aridity gradient

“…; pH increase). This effect of pH is not surprising, as it is known to influence branchiopod reproductive strategies, even at very small variations (Korhola and Rautio 2001;Scho ¨nbrunner and Eder 2006;Naceur et al 2012). Although more research is needed to understand the processes behind the variation in pH values it seems to be an important variable to consider when monitoring temporary wetland communities.…”