International Journal of Aquatic Biology
Volume:2 Issue: 4, Aug 2014

This study was carried out to investigate the interaction of simultaneous use of fluoxetine (Flx), a selective serotonin reuptake inhibitor, and diclofenac (Dcf), a nonsteroidal anti-inflammatory drug, on food intake in goldfish, Carassius auratus. Treatments with different dosage of Flx including control, 0, 1, and 10 µg/g body weight (BW) were injected in the fish with mean weight of 30.16 ± 8.57 g every other day in total of 5 times. Then fish were exposed to 3 different levels of Dcf including 0, 10, and 100 mg/l for 5 days. Injection of fluoxetine significantly decreased food intake and consequently body weight. After 5 days exposure to Dcf, the amount of food intake in the Dcf receiving treatments of 1 mg/l and 10 mg/l was significantly larger than that of 0 mg/l Dcf recieving treatment in both the Flx dosage groups of 1 μg/g BW and 10 μg/g BW. Our results indicated that Dcf inhibits behavioral change effects of Flx showing the complex effects of pharmaceuticals on fish.

This study was carried out to clarify the feeding biology of the blood cockle (Anadara granosa). We collected blood cockles from 8 stations in the Matang mangrove estuary of Malaysia in July and August 2010. The digestive tube contents of the specimens were stained with Congo red and observed under a light microscope. The results showed blood cockles take in particles containing cellulose as well as phytoplankton such as diatoms. As blood cockles in estuaries are known to exhibit cellulolytic enzyme activity in their digestive gland, the present results indicate blood cockles in estuaries feed on litter supplied from mangrove forests and terrestrial plants.

Ecotoxicological studies that use histological techniques enjoy descriptive approach in explaining the damages to tissues. In the present study, a rank-based estimation for linear models was used to examine significant difference between levels of cypermethrin on histological changes of the liver in Aphanius sophiae. The toxicity of cypermethrin associated with certain environmental factors such as salinity and feeding frequency was studied in the Sophiae toothed carp (A. sophiae). Specimens were exposed to concentration of 0.02 μg L-1 cypermethrin, two levels of salinity (0 and 14 ppt) and feeding frequencies (two times a day and one time every three days) under laboratory conditions. After the end of 14 days period of the experiment, the liver tissues were removed and histological sections prepared. The results revealed that liver tissues alter significantly with the changes in salinity and diet frequency. The results also showed that sensitivity to cypermethrin increased with decreasing salinity and increasing feeding frequency. The results suggested using A. sophiae as an indicator for cypermethrin assessment in aquatic ecosystems and appropriateness of rank-based estimation for linear models, to evaluate the effect of toxins on histopathological alternations.

Use of nano-materials has increased in various aspects of human life. However, possible outbreak of nano-materials toxicity in humans and other organisms is one of the future challenges. Different chemical precursors which are used in chemical approaches for production of nano-materials may have secondary and sometimes toxic effects in living organisms. These secondary effects may be reduced in physical approaches due to not use of chemicals. To test this hypothesis, acute toxic effects of two types of silver nanoparticles (AgNPs) which were produced by physical (top-down) and chemical (bottom-up) methods on survival rate of Zebrafish (Danio rerio) were compared. According to the results, AgNPs produced by physical method were 38 times less toxic than ones generated by chemical method and therefore, the hypothesis was approved. The estimated 96 hr LC50 values of AgNPs produced by physical and chemical methods for zebra fish were 0.540 ± 0.032 and 0.014 ± 0.001 mg/L, respectively. According to these values and regarding the rules of European Union, both types of AgNPs are considered as highly toxic chemicals to aquatic organisms. Generally, AgNPs seems to have toxic effects on aquatic organisms regardless of the method used for their production, and so, their accidental or intentional entrance into the aquatic ecosystems should be inhibited.

Owing to reduction of sturgeon stocks in various water bodies, artificial propagation has become significantly important for stock restoration and appropriate broodstock selection is vital in this process. Selection of suitable broodstocks may influence the quality and quantity of obtained eggs and larva. The present study aimed to examine correlation between some morphometric and reproductive parameters to find suitable brood fish for artificial reproduction in Russian sturgeon, Acipenser gueldenstaedtii. Forty fish free of any external disease symptom and abnormality were selected for the study. Following biometric measurements including weight, total length, abdominal girth, PV (distance between pectoral and pelvic fins), LX (distance between anal and caudal fins), polarization index (PI), gonadosomatic index, absolute fecundity, and fertilization rate, correlations between these morphometric and biological characteristics with emphasis on breeding were calculated. There was higher correlation between weight-absolute fecundity and length-PV in fish responded to artificial breeding, while correlation between age-PV, length-PV and weight-abdominal girth were higher in those fish not responded to artificial breeding. The results suggests that it is quite possible to select suitable Russian sturgeon spawners for artificial propagation based on combination of body weight, LX, PV, age, abdominal girth and total length, however the most useful criteria for the selection seems to be precise measurement of the polarization index.

Mystus gulio is a euryhaline fish, occurring mostly in freshwater; it has also been found to thrive in backwaters of low salinity. It is a popular food fish due to its good taste and recently it has also been reported to be exported as indigenous ornamental fish from India. Number of workers earlier has studied morphology, age, growth pattern, food and feeding habit and reproductive biology of this fish species; but no such collective documentation on these aspects is available. With this view, the current review work has been made to document all available information along with noting down those which are lacking and will be beneficial for future fishery and management of this fish species.

Plant-based remediation (i.e. phytoremediation) is one of the most significant eco-sustainable techniques to cope with devastating consequences of pollutants. In the present study, the potential of a wetland macrophyt (i.e. Potamogeton crispus) for the phytoremediation of heavy metals (i.e. Cu, Cr, Pb, As and Cd) in the Anzali wetland was evaluated. The results showed that P. crispus tends to accumulate notable amounts of Cu, Cr, Pb, As and Cd according to their assayed concentrations as follows: 8.2 µg g-1 dw, 0.97 µg g-1 dw, 6.04 µg g-1 dw, 2.52 µg g-1 dw and 0.34 µg g-1 dw, respectively. Further accurate perception of the phytoremediation efficiency were conducted using both bioconcentration factor and translocation factor. The average of the highest bioconcentration factors was presented in a descending order as: 2.9×103, 1.9×103, 1.17×103, 0.68×103 and 0.46×103 for the Cu, Cr, Pb, Cd and As, respectively. Based on the results, P. crispus presents high potential to absorb all the alluded metals except for As and partly Cd. Correspondingly, the mean values of translocation factor were reported in the range of 0.41 to 2.24. Eventually, relying on the observed findings, the results support the idea that P. crispus species would be employed as the prospective candidate for the phytoremediation processes in Anzali wetland.

This study examined the spawning characteristics and distribution of Mullus barbatus and Upeneus moluccensis in Babadillimani Bight, in the northeastern Mediterranean (near Mersin, Turkey) between of May 1999 and April 2000. Sampling was carried out monthly at depths of 0-50 m, 50-100 m and >100 m using commercial trawl net mesh size 22 mm knot to knot. The results showed no difference between the length at first maturity of males and females (t-test, P>0.001) in either M. barbatus or U. moluccensis. This length for the combined sexes was calculated to be 11.7 cm and 10.9 cm in M. barbatus and U. moluccensis, respectively. When monthly changes in the Gonadosomatic Index (GSI) values were evaluated, the spawning period was determined as July-November for M. barbatus and May-August for U. moluccensis. The mean total lengths from the individuals belonging to M. barbatus from depth layers of 0-50 m, 50-100 m and >100 m were calculated as 8.65 cm, 8.70 cm and 12.70 cm, respectively. Total lengths for U. moluccensis were calculated as 8.40 cm, 11.66 cm and 13.32 cm, respectively. The mean total length of M. barbatus and U. moluccensis increased from coastal areas to deeper waters. Therefore bottom trawl fishing must be conducted in waters deeper than 100 m for both M. barbatus and U. moluccensis.