Tilapia are a commonly aquacultured fish yet little is known about their normal physiology and response to disease. In this study we determined the results of complete hematologic (n=40) and plasma biochemical profiles (n=63) in production tilapia (Oreochromis hybrids). The fish were raised in recirculating systems with a high stocking density (120 g/L), and were in the middle of a 15-month production cycle. Blood was analyzed using standard techniques, and reference intervals were determined using nonparametric methods. Non-production tilapia (n=15) from low-density tanks (4 g/L) also were sampled; the clinical chemistry results were compared to reference intervals from the fish raised in high-density tanks. Differences were noted in plasma protein, calcium and phosphorus concentrations, such that reference intervals for high-density production tilapia were not applicable to fish raised under different environmental and management conditions.

Reference values reported here will be useful for the early detection, identification, and monitoring of disease and sublethal conditions in cultured shortnose sturgeon.

Hybrid striped bass (Morone chrysops X Morone saxatilis ) are an important aquaculture species yet there are few diagnostic tools available to assess their health. Hematology and clinical chemistry analyses are not used extensively in fish medicine due to the lack of reference intervals for various fish species, and because factors such as age can affect blood values. There is little published information regarding age-related changes in blood values of juvenile fish. It is important to evaluate juvenile fish, as this is the time they are raised in aquaculture settings. Determining age-related changes in the blood values of fishes would further develop clinical pathology as a diagnostic tool, enhancing both fish medicine and the aquaculture industry. The results of standard hematology and clinical chemistry analysis were evaluated in juvenile hybrid striped bass at 4, 6, 9, 15, and 19 months of age. Values for PCV and RBC indices were significantly lower, and plasma protein concentration was significantly higher in younger fish. Total WBC and lymphocyte counts were significantly higher in fish at 6 and 9 months of age, while neutrophil and monocyte counts were higher at 6, 9, and 15 months. Eosinophil counts were significantly higher in 9-month-old fish. The majority of hematologic values fell within previously established reference intervals, indicating that only slight modification to the intervals is necessary for evaluating hematologic results of hybrid striped bass at different ages. The following analytes deviated sufficiently from adult reference intervals to warrant separate reference values: plasma protein concentration at 4 months, WBC and lymphocyte counts at 15 and 19 months, and thrombocyte-like-cells at 9 months of age. Values for most biochemical analytes were significantly different among age groups except for creatinine and potassium concentrations. Comparisons with reference intervals were not made for biochemical analytes, because established reference intervals were not available. Age-related changes in hematologic and biochemical values of striped bass were similar to those reported for rainbow trout and mammals.

Quaternary ammonium compounds (QACs) are antimicrobial disinfectants commonly used in commercial and household settings. Extensive use of QACs results in ubiquitous human exposure, yet reproductive toxicity has not been evaluated. Decreased reproductive performance in laboratory mice coincided with the introduction of a disinfectant containing both alkyl dimethyl benzyl ammonium chloride (ADBAC) and didecyl dimethyl ammonium chloride (DDAC). QACs were detected in caging material over a period of several months following cessation of disinfectant use. Breeding pairs exposed for six months to a QAC disinfectant exhibited decreases in fertility and fecundity: increased time to first litter, longer pregnancy intervals, fewer pups per litter and fewer pregnancies. Significant morbidity in near term dams was also observed. In summary, exposure to a common QAC disinfectant mixture significantly impaired reproductive health in mice. This study illustrates the importance of assessing mixture toxicity of commonly used products whose components have only been evaluated individually.

Graphical abstract

Alkyl dimethyl benzyl ammonium chloride (ADBAC) and didecyl dimethyl ammonium chloride (DDAC) are common ingredients in household bathroom and kitchen cleaning sprays. ADBAC+DDAC cause reproductive toxicity in mice. The aim of the present study was to investigate gender-specific reproductive effects from ADBAC+DDAC. Female reproduction was assessed through ovulation, oocyte implantation, and estrus cycling. Male reproductive function was assessed by sperm concentration, motility, and viability. Numbers of corpora lutea were not different after 2 weeks, but decreased after 8 weeks of ADBAC+DDAC exposure. Dams exposed for 5 weeks to ADBAC+DDAC spent significantly less time in estrus. ADBAC+DDAC exposed males exhibited declines in both sperm concentration and motility, but not sperm viability. Subfertility in mice from ADBAC+DDAC exposure is, therefore, mediated through reproductive disturbances in both females and males. While the effect of ADBAC+DDAC exposure on human health is unclear, widespread exposure necessitates further consideration of their potential reproductive toxicity.

Background: Quaternary ammonium compounds are a large class of chemicals used for their antimicrobial and antistatic properties. Two common quaternary ammonium compounds, alkyldimethylbenzyl ammonium chloride (ADBAC) and didecyldimethyl ammonium chloride (DDAC), are combined in common cleaners and disinfectants. Introduction of a cleaner containing ADBAC1DDAC in the vivarium caused neural tube defects (NTDs) in mice and rats. Methods: To further evaluate this finding, male and female mice were dosed in the feed at 60 or 120 mg/kg/day, or by oral gavage at 7.5, 15, or 30 mg/kg ADBAC1DDAC. Mice also received ambient exposure to ADBAC1DDAC from the disinfectant used in the mouse room. Embryos were evaluated on gestational day 10 for NTDs, and fetuses were evaluated on gestational day 18 for gross and skeletal malformations. Results: We found increased NTDs with exposure to ADBAC1DDAC in both rats and mice. The NTDs persisted for two generations after cessation of exposure. Notably, male exposure alone was sufficient to cause NTDs. Equally significant, ambient exposure from disinfectant use in the vivarium, influenced the levels of NTDs to a greater extent than oral dosing. No gross or significant axial skeletal malformations were observed in late gestation fetuses. Placental abnormalities and late gestation fetal deaths were increased at 120 mg/kg/day, which might explain the lack of malformations observed in late gestation fetuses.Conclusion: These results demonstrate that ADBAC1DDAC in combination are teratogenic to rodents. Given the increased use of these disinfectants, further evaluation of their safety in humans and their contribution to health and disease is essential.

During the period of most active leaf expansion, the foliar dark respiration rate of soybeans (Glycine max cv Williams), grown for 2 weeks in 1000 microliters CO2 per liter air, was 1.45 milligrams CO2 evolved per hour leaf density thickness, and this was twice the rate displayed by leaves of control plants (350 microliters CO2 per liter air). There was a higher foliar nonstructural carbohydrate level (eg. sucrose and starch) in the CO2 enriched compared with CO2 normal plants. For leaves. These increases, however, are due to an increase in the volume and water content of the cells, and not an increase in the actual number of cells (15). Recently, attention has been given to the role of carbohydrate status in regulating carbon metabolism (9). It has been suggested that high carbohydrate levels inhibit photosynthesis (3, 25). Azcon-Bieto (3) postulates that above a certain critical level of carbohydrate, CO2 assimilation would decrease due to carbohydrate accumulation impairing the production or consumption of ATP/NADPH in photosynthesis. However, Robinson (22) has reported higher photosynthetic activities associated with high starch and sucrose levels.Carbohydrate status may also have an effect on dark respiration. A high carbohydrate status has been associated with elevated respiration rates in a number of studies (1,2,5,20,26). Dark respiration is thought to have two components, growth and maintenance. Growth respiration occurs in those parts of a plant which are actively dividing or expanding (21). The rate ofgrowth respiration is thought to be related to the rate of photosynthesis. Maintenance respiration occurs throughout the life of the plant and is proportional to the Dw ofthe plant (18, 21). During plant growth both types of respiration occur, but growth respiration would decrease as the leaf matures. Both are thought to involve carbohydrate oxidation through glycolysis, the pentose phosphate pathway and the tricarboxylic acid cycle (2).In this study, long-term CO2 enrichment was used to increase carbohydrate levels in order to investigate the relationship between dark respiration and carbohydrate status. The effect of increased carbohydrate status on dark respiration was studied by monitoring dark CO2 release from whole leaves. Subcellular fractionation of enriched and control leaves was performed to determine if there were increases in the activity or number of mitochondria as a consequence of a high CO2 level. MATERIALS AND METHODSPlant Material. Soybeans (Glycine max cv Williams) were planted in 15-cm pots containing vermiculite and were grown in Environmental Growth Chambers No. M-2 at 25°C, with a 12-h photoperiod. The plants were illuminated with a mixture of fluorescent and incandescent bulbs at 600 uE/m2 at pot height. They were flushed daily with a nutrient solution described previously (22