scholarly journals The role of branchial carbonic anhydrase in acid-base regulation in rainbow trout (Oncorhynchus mykiss)

2006 ◽  
Vol 209 (3) ◽  
pp. 518-530 ◽  
Author(s):  
T. Georgalis
Keyword(s):  
Rainbow Trout ◽  
Carbonic Anhydrase ◽  
Oncorhynchus Mykiss ◽  
Acid Base ◽  
Rainbow Trout Oncorhynchus Mykiss

scholarly journals The role of nitrosative and oxidative stress in rainbow trout (Oncorhynchus mykiss) liver tissue applied mercury chloride (HgCl2)

2021 ◽  
Vol 38 (3) ◽  
pp. 269-273
Author(s):  
Mehmet Reşit Taysı ◽  
Muammer Kırıcı ◽  
Mahinur Kırıcı ◽  
Hasan Ulusal ◽  
Bünyamin Söğüt ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Liver Tissue ◽  
Stress Index ◽  
Mercury Chloride ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Total Antioxidant ◽  
Ld50 Value

The aim of this study was to determine oxidative stress caused by mercury chloride (HgCl2) in rainbow trout (Oncorhynchus mykiss) liver tissue. For this purpose, the LD50 value of HgCl2 on rainbow trout was determined as 551 μg/L. In the study, 40 fish in four groups were exposed to 25% and 50% (138 and 276 µg/L) of the two subletal doses of HgCl2 for 2 and 7 days, with 10 fish (n=10) in each group. To determine oxidative stress; peroxynitrite (ONOO−), total oxidant level (TOS), total antioxidant level (TAS), oxidative stress index (OSI) and malondialdehyde (MDA) were analyzed. In the study, it was observed that the differences between the groups in terms of ONOO−, TOS, TAS and OSI levels in the liver tissues was significant (P<0.05), however, this difference was not significant (P>0.05) in terms of MDA values. As a result, it can be concluded that HgCl2 increases ONOO−, TOS, TAS, OSI and MDA levels in liver tissue and even small doses of mercury are toxic to fish.

scholarly journals Post-ovulatory secretion of pituitary gonadotropins GtH I and GtH II in the rainbow trout (Oncorhynchus mykiss): regulation by steroids and possible role of non-steroidal gonadal factors

1999 ◽  
Vol 163 (1) ◽  
pp. 87-97 ◽  
Author(s):  
J Chyb ◽  
T Mikolajczyk ◽  
B Breton
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Body Cavity ◽  
The Body ◽  
Ovarian Fluid ◽  
Multiple Injections ◽  
Rainbow Trout Oncorhynchus Mykiss

In order to determine the factors of ovarian origin which can modulate the postovulatory secretion of the FSH-like gonadotropin (GtH I) and the LH-like gonadotropin (GtH II), freshly ovulated female rainbow trout were divided into two groups. In the first group the fish were stripped in order to eliminate the eggs and ovarian fluid from the body cavity, while in the second group the eggs were kept in the body cavity. Subsequently, fish from both groups were implanted with testosterone (10 mg/kg), 17beta-estradiol (10 mg/kg) or 17,20beta-ddihydroxy-4-regnen-3-one (17,20betaP) (1 mg/kg) or injected every 2 days with desteroidized ovarian fluid (1.5 ml/kg). The secretion of GtH I dramatically increased in stripped fish, reaching its maximum levels 2 weeks after ovulation. The preservation of eggs in the body cavity led to the suppression of this increase. The profiles of GtH II secretion were opposite to those encountered for GtH I because the increase of GtH II was observed only in unstripped fish. The administration of steroids showed that testosterone is able to inhibit GtH I release and stimulate that of GtH II in stripped fish, having no effect on the release of these gonadotropins in non-stripped animals. 17beta-Estradiol failed to modify GtH I secretion, however it decreased the release of GtH II in fish containing retained eggs in the body cavity. 17,20betaP had a delayed stimulating influence on GtH I release in unstripped fish. Finally, multiple injections of desteroidized ovarian fluid into stripped fish led to a significant decrease of GtH I release and to an increase of GtH II secretion. This study demonstrates that factors, which are present in ovarian fluid, modulate the post-ovulatory secretion of both gonadotropins--their net action is negative on GtH I and positive on GtH II. Among the steroids, testosterone is of major importance, being able to inhibit GtH I release and to stimulate that of GtH II. We also show that non-steroidal factors present in the ovarian fluid can influence the release of both gonadotropins, which indirectly supports the previous findings about the existence of inhibin/activin-like factors in fish.

The role of live fish trade in the translocation of parasites: the case of Cystidicola farionis in farmed rainbow trout (Oncorhynchus mykiss)

2019 ◽  
Vol 27 (6) ◽  
pp. 1667-1671 ◽  
Author(s):  
Vasco Menconi ◽  
Paolo Pastorino ◽  
Giulia Cavazza ◽  
Morena Santi ◽  
Davide Mugetti ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Live Fish ◽  
Cystidicola Farionis ◽  
Fish Trade
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