Search

Di-(2-ethylhexyl) phthalate (DEHP) is extensively used in plastic, which results in DEHP to appear in numerous environmental media worldwide. There is a lack of sufficient studies on the longterm transgenerational effect of DEHP exposure on the growth and reproduction of M. macrocopa. While non-fatal effects of DEHP exposure in M. macrocopa have been reported earlier, this study elucidates that DEHP exposure to parental water fleas had no adverse effects on offspring development or capacity for reproduction. The exposure for the parental generation through F2 progeny did not result in a concentration-dependent growing deleterious effect in subsequent generations, even with long-term exposure. These findings imply that DEHP exposure can cause oxidative stress, and that water flea (M. macrocopa) growth and reproduction were not significantly different from blank control and solvent control. The results of the present study aid in the understanding of DEHP risk assessment in aquatic systems. Moreover, the findings can be applied as baseline data to carry out future research on ecotoxicological risk assessment of DEHP. [ABSTRACT FROM AUTHOR]

During a tributyltin (TBT)-exposure experiment, the ultrastructural features of oogenesis have been examined in TBT-induced imposex females of Babylonia areolata and compared with those of the normal female. The results obtained from such experiment demonstrates that B. areolata exhibits a low to moderate intensity of imposex because all VDSI values are never higher than 3. Ultrastructures of germ cell development including oogonia, pre-vitellogenic, early vitellogenic, late vitellogenic and mature oocytes show that oogenesis in imposex female is similar to that of normal females except for the presence of numerous lipid droplets in the cytoplasm of the oocytes and the follicle cells in imposex females, indicating the degeneration of their oocytes. Vitellogenesis in B. areolata involves both auto- and heterosynthetic processes that resemble those of the basal gastropods and the pulmonates. In addition, the presence of cortical granules and microvilli are unique structures of this species. [ABSTRACT FROM AUTHOR]

Di (2-ethylhexyl) phthalate (DEHP) is used as a plasticizer in plastics. The effects of DEHP on terrestrial vertebrates have been extensively reported but the effects of DEHP contamination on aquatic ecosystems have not been thoroughly studied. Since water bodies are one of the main mediums through which DEHP is released worldwide, the impacts of DEHP contamination should be manifested in water fleas. Therefore, maternal Moina macrocopa were exposed to 1, 10, 100, and 1000 μg/L concentrations of DEHP. Changes in growth and reproduction were evaluated. The findings demonstrated that DEHP exposure did not have a negative impact on growth or the ability to reproduce. An analysis of the ovary yolk body (YB) demonstrated that the average size and number of yolk bodies (YBs) produced by M. macrocopa exposed to 1000 μg/L DEHP were not significantly different to the average size and number of YBs produced in blank control and solvent control conditions. These outcomes support the cellular pathology data gathered by other researchers. Nevertheless, when M. macrocopa was exposed to 1000 μg/L DEHP for five days, a significant increase in YB numbers was observed with changes in YB morphology. The critical cellular pathology of YB showed morphological abnormalities, including rod-shaped YBs, and YB density was higher than in the blank and solvent controls. Even though these results suggest that antioxidative stress can be induced by DEHP exposure, growth, and reproduction were not significantly different among exposed water fleas compared to fleas in the blank and solvent controls. The result was attributed to the antioxidant response of the water flea. In conclusion, the present study enhances our understanding of previous findings from risk assessments of DEHP contamination in aquatic ecosystems., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Amornrat Chaikritsadakarn (Ph.D. student) reports financial support was provided by the Research Program of Municipal Solid Waste and Hazardous Waste Management under the grant of Center of Excellence on Hazardous Substance Management (HSM), Bangkok, Thailand with grant number HSM-PJ-CT-17-02. Asst. Prof. Dr. Chutchawan Muenpo reports equipment, drugs, or supplies and writing assistance were provided by Prince of Songkla University, Thailand. Asst. Prof. Dr. Dudsadee Muenhor reports administrative support, article publishing charges, and statistical analysis were provided by Prince of Songkla University, Thailand. Associate Prof. Dr. Banchong Witthayawirasak reports administrative support, equipment, drugs, or supplies, and statistical analysis were provided by Prince of Songkla University, Thailand. Professor Ronald D. DeLaune reports writing assistance was provided by Louisiana State University, Baton Rouge, LA 70803, USA. Asst. Prof. Chutchawan Muenpo reports a relationship with Prince of Songkla University, Thailand that includes: employment. Dr. Chutchawan Muenpo has patent No patent issued to No patent. 1. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. 2. We do not have patent in this experiment., (© 2024 The Authors. Published by Elsevier Ltd.)

The optimal protein replacement of fish meal (FM) by fish condensate (FC) was investigated in striped snakehead, Channa striata (Bloch) (1.78 ± 0.02 g initial weight). The FM-based diet (0FC) was replaced by substituting protein from FC for 100 (100FC), 200 (200FC), 300 (300FC), 400 (400FC), 500 (500FC) or 600 (600FC) g kg -1 of the FM, and a commercial diet (CD) for carnivorous fish was included for comparison. The experiment was conducted indoors under completely randomized design (8 treatments × 3 replications × 60 fish per pond) over a 6-month trial. There were no significant differences in water quality during the experiment. The fish fed with 500FC had superior growth performance and feed utilization. This dietary treatment gave similar levels to all observed specific activities of digestive enzymes as did baseline 0FC. Survival, carcass composition, hematological parameters and liver histopathology were not negatively impacted by this protein replacement level. Economic analysis also supports the use of this by-product as a potent protein replacer in striped snakehead diet. Findings from the current study indicate that a 500 g kg -1 protein replacement of FM by FC is near optimal for striped snakehead, and similar use of it in the aquafeed of other species appears worth further studies.