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 ◽  
...  
2021 ◽  
Vol 38 (3) ◽  
pp. 269-273
Author(s):  
Mehmet Reşit Taysı ◽  
Muammer Kırıcı ◽  
Mahinur Kırıcı ◽  
Hasan Ulusal ◽  
Bünyamin Söğüt ◽  
...  

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.


1999 ◽  
Vol 163 (1) ◽  
pp. 87-97 ◽  
Author(s):  
J Chyb ◽  
T Mikolajczyk ◽  
B Breton

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.


2008 ◽  
Vol 157 (2) ◽  
pp. 116-124 ◽  
Author(s):  
Marta Codina ◽  
Daniel García de la serrana ◽  
Joan Sánchez-Gurmaches ◽  
Núria Montserrat ◽  
Oxana Chistyakova ◽  
...  

1997 ◽  
Vol 323 (1) ◽  
pp. 251-258 ◽  
Author(s):  
François FERRIERE ◽  
Naïm A. KHAN ◽  
Jean P. MEYNIEL ◽  
Pierre DESCHAUX

The present study was conducted on peripheral blood lympho-cytes of rainbow trout (Oncorhynchus mykiss) to assess the role of 5-hydroxytryptamine (5-HT; ‘serotonin’) in calcium signalling. 5-HT-induced increases in intracellular free calcium concentrations, [Ca2+]i, and its action was mediated by 5-HT receptor subtype 3 (5-HT3), but not by 5-HT receptor subtype 1A (5-HT1A) or subtype 2 (5-HT2) in these cells. In Ca2+-containing medium (1 mM CaCl2), 5-HT and 2-methyl-5-HT (5-HT3 receptor agonist) induced increases in [Ca2+]i, whereas in Ca2+-free medium (0 Ca2+, 1 mM EGTA), these two agents failed to evoke increases in [Ca2+]i in these cells, demonstrating that 5-HT mobilizes Ca2+ from the extracellular environment. Furthermore, 5-HT-induced increases in [Ca2+]i are not contributed to by the intracellular endoplasmic reticulum (ER) pool, as thapsigargin, an agent that recruits Ca2+ from ER stores, had additive effects on 5-HT-induced [Ca2+]i responses in fish peripheral lymphocytes. 5-HT-induced increases in [Ca2+]i were mediated by 5-HT3 receptors via gating the calcium through L-type, but not N-type, calcium channels in trout lymphocytes.


1991 ◽  
Vol 161 (1) ◽  
pp. 489-508 ◽  
Author(s):  
A. Pagnotta ◽  
C. L. Milligan

The role of blood-borne glucose in the restoration of white muscle glycogen following exhaustive exercise in the active, pelagic rainbow trout (Oncorhynchus mykiss) and the more sluggish, benthic winter flounder (Pseudopleuronectes americanus) were examined. During recovery from exhaustive exercise, the animals were injected with a bolus of universally labelled [14C]glucose via dorsal aortic (trout) or caudal artery (flounder) catheters. The bulk of the injected label (50–70%) remained as glucose in the extracellular fluid in both species. The major metabolic fates of the injected glucose were oxidation to CO2 (6–8%) and production of lactate (6–8%), the latter indicative of continued anaerobic metabolism post-exercise. Oxidation of labelled glucose could account for up to 40% and 15% of the post-exercise MO2 in trout and flounder, respectively. Exhaustive exercise resulted in a reduction of muscle glycogen stores and accumulation of muscle lactate. Glycogen restoration in trout began 2–4h after exercise, whereas in flounder, glycogen restoration began within 2h. Despite a significant labelling of the intramuscular glucose pool, less than 1% of the infused labelled glucose was incorporated into muscle glycogen. This suggests that blood-borne glucose does not contribute significantly to the restoration of muscle glycogen following exhaustive exercise in either trout or flounder and provides further evidence against a prominent role for the Cori cycle in these species.


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