A novel male-associated marker for sex identification in Ussuri catfish Pseudobagrus ussuriensis

The Ussuri catfish Pseudobagrus ussuriensis is a promising aquaculture fish with sexual dimorphism that males grow 2–3 times faster than females. Therefore, all-male breeding could increase production of this fish, and sex-linked markers would be useful during the breeding process. In this study, a male-associated marker named PuGT54 was isolated in P. ussuriensis from a previously constructed microsatellite library. A total of 185 P. ussuriensis individuals containing 95 females and 90 males were used to test the usage of this maker. And results showed that sexes of all individuals were successfully identified, indicating the high reliability and accuracy of this marker for sex identifi cation. Furthermore, the male-specifi c fragment amplifi ed by this maker was cloned and sequenced, which was 118 base pairs in length. As homologous genes of this fragment was not found through BLASTn, detailed information of the male-specifi c fragment is unknown presently. Nevertheless, this marker would be helpful in conservation, breeding and ecological study of P. ussuriensis.

Protective Effect of Dietary Yeast Cultures on Lipopolysaccharide-induced Oxidative Stress,Immune and Inflammatory Responses in Pseudobagrus ussuriensis

This study aimed to evaluate the effects of dietary yeast culture(YC)on lipopolysaccharide(LPS)-induced oxidative stress,immune and inflammatory response in P.ussuriensis.The fish were randomly assigned into three groups as the control group,LPS group and YC+LPS group.The fish in the control were fed diet with no YC supplementation and no LPS challenge,and the fish in the LPS group or YC+LPS group were fed diet supplemented with no YC or 20 g·kg^(-1)YC,and with LPS challenge,respectively.The results showed that compared with the control group,intestinal total antioxidant capacity(T-AOC)level and superoxide dismutase(SOD)activity were significantly decreased,while intestinal malondialdehyde(MDA),plasma aspartate transaminase(AST)and alanine transaminase(ALT)levels were significantly increased in the LPS group(P<0.05).Besides,lower plasma alkaline phosphatase(ALP),alternative complement pathway(ACH50)activity and the albumin(ALB)level,as well as higher lysozyme(LZM)activity,were also found in the LPS group.However,dietary 20 g·kg^(-1)YC supplementation could relieve the above LPS-induced changes in Pseudobagrus ussuriensis.Furtherly,LPS challenge could significantly up-regulate gene expression of interleukin-8(IL-8),heat shock protein(HSP70)and NF-κBp65 except for toll-like receptors 2(TLR2),while dietary 20 g·kg^(-1)YC supplementation suppressed the increased expression of NF-κBp65 and IL-8 induced by LPS in P.ussuriensis.In summary,LPS challenge could induce immune impairment,oxidative stress and hepatic damage,and the protective effect of dietary 20 g·kg^(-1)YC supplementation on LPS-induced immune impairment and oxidative stress was observed in the present study,which was associated with the enhanced levels of antioxidant enzymes and immune parameters.Also,dietary 20 g·kg^(-1)YC supplementation could suppress LPS-induced inflammatory response by down-regulating NF-κBp65,HSP70 and IL-8 gene expression.

豆粕替代鱼粉对乌苏里拟鲿生长性能的影响

为了研究不同含量的豆粕替代鱼粉对乌苏里拟鲿(Pseudobagrus ussuriensis)生长性能的影响,选择同一批人工孵化的鱼苗,根据等氮、等能原则,试验共配置了5个豆粕替代鱼粉组,分别为0%、15%、30%、45%、60%。每个试验小组分3个重复,每个重复小组的乌苏里拟鲿饲养于规格为0.8 m×0.8 m×0.6 m的水族箱中。整个投喂试验维持64 d。试验结果显示,15%~30%替代组与对照组(0%)之间的乌苏里拟鲿的末期体重、增重率、成活率和特定生长率差异不显著(P>0.05),当豆粕替代量为45%和60%时,乌苏里拟鲿的末期体重、增重率、成活率均显著地低于对照组(P<0.05),其中45%的特定生长率显著地低于对照组(P<0.05),60%的特定生长率极显著地低于对照组(P<0.01)。研究表明,在鱼粉含量为50%等氮等能饲料中,豆粕替代鱼粉在30%以下,对乌苏里拟鲿的生长不会造成影响。

关于乌苏拟鲿和乌苏里拟鲿同物异名现象之商榷

Pseudobagrus ussuriensis作为一种名优水生经济动物,其养殖生产已在广东、四川、黑龙江等多个省市开展,并且具有蓬勃发展态势。但是,关于Pseudobagrus ussuriensis的中文名称作者通过查阅、浏览、比较《中国动物志》《中国鱼类系统检索》、《中国淡水鱼类原色图集》《黑龙江省鱼类志》等多个相关文献资料,发现Pseudobagrus ussuriensis存在“乌苏拟鲿”和“乌苏里拟鲿”两种命名现象,因此,作者对这一现象进行了初步整理并讨论商榷,以便相关研究人员对这一问题不产生混沌和困惑。