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Maca tuber meal is used in ¢sh diet formulations in Andean trout culture and knowledge of its e¡ects on ¢sh growth is paramount to healthy human food production. In the ¢rst experiment with rainbow trout alevins (0.096 AE 0.002 g), starter diets were o¡ered from ¢rst feeding until 15 weeks.We formulated high protein content ($60%) semi-puri¢ed starter diets supplemented with 0%, 5%, 10%, or 15% maca tuber meal (control, M-5, M-10, and M-15 respectively). The second feeding trial was conducted with juveniles (1.56 AE 0.02 g) fed one of three diets (control, M-15, and commercial) for 8 weeks. In the ¢rst experiment, ¢sh fed M-10 and M-15 diets exhibited signi¢cantly higher growth rates than the other dietary groups. Survival was signi¢cantly improved in the groups fed diets supplemented with maca tuber meal (60.06 9.2%) in comparison with the group fed a control diet (21.7%). The second experiment showed a higher growth rate in the M-15 group compared with the control and a commercial diet fed group. Leucocyte numbers were increased by dietary supplementation of maca tuber meal. The ¢ndings of the present study suggest that a maca tuber meal inclusion at least 5% improves growth rate, feed utilization, immunity by increased leucocyte number, and survival of rainbow trout alevins and juveniles. Aquaculture Research, 2004, 35, 215^223 r 2004 Blackwell Publishing Ltd 215 Ã Values (AE SD) having di¡erent superscripts are signi¢cantly di¡erent (Po0.05).wWeight gain (%) 5 [(¢nal weight À initial weight) Â 100]/initial weight. zFeed conversion ratio 5 dry feed intake (g)/wet body weight gain (g). ‰Protein e⁄ciency ratio 5 body weight gain (g)/protein intake (g). zSpeci¢c growth rate (%) 5 [(ln ¢nal weight À ln initial weight) Â 100]/days. kInstantaneous feed intake (%) 5 [dry feed intake (g) Â 100]/body weight (g).Aquaculture Research, 2004, 35, 215^223 Supplementation of maca meal in rainbow trout diet K-J Lee et al.

The growth of fish is directly dependent on feed composition and quality. Medicinal plants can be added to fish feed as adjuvant therapy for the prevention of fish diseases. The purple coneflower (Echinacea purpurea (L.) Moench.) has been reported to have multiple biological effects, including immunomodulatory and antioxidant activity. The most active compounds of E. purpurea are polyphenols - caffeic acid derivatives: caftaric acid, chlorogenic acid, cynarin, echinacoside and cichoric acid.Due to a relatively limited number of studies on the use of the purple coneflower as a nutritional supplement for fish feeding, extruded fish feed with addition of Echinacea roots was produced. In the feed total phenolic content, selected polyphenol contents, the energetic value, nutrient contents and antioxidant capacity were examined.The results indicate that fish feed with addition of the Echinacea has a great potential to be a good source of natural radical scavengers, for example polyphenols, and nutritive ingredients. Antioxidant properties of feed were well correlated with the coneflower content. The study findings confirmed that high-temperature extrusion-cooking process does not deactivate phenolic antioxidant compounds, which are present both in the Echinacea roots and in the final product. Fish feed with addition of E. purpurea can be used as a nutritional supplement in the prevention of fish diseases caused by oxidative stress.

IntroductionOrnamental fish can suffer from different bacterial diseases. Among them the most prevalent are infections caused by Aeromonas, Shewanella, Citrobacter, Plesiomonas, Edwardsiella, and Pseudomonas. But there is a broad spectrum of rarely identified bacteria which may be causative agents of diseases. The aim of the study was to determine the species of bacteria pathogenic for fish which are prevalent in aquariums.Material and MethodsBacteria were isolated from infected ornamental fish from pet shops and private aquariums in the Lublin region in 2015 and classified to species using MALDI-TOF MS.ResultsA total of 182 isolates from ornamental fish were identified. The most frequent bacteria found in diseased fish were Aeromonas veronii (30.8% of total number of strains), A. hydrophila (18.7%), Shewanella putrefaciens (7.1%), Citrobacter freundii (7.1%), Pseudomonas spp. (7.1%), Shewanella baltica (4.9%), and Plesiomonas shigelloides (3.3%).ConclusionIsolated bacterial species are facultative pathogens for fish and humans and may be isolated from fish without apparent symptoms of the disease.

Rodents are known to play a significant role as reservoir hosts for TBEV. During three sequential expeditions at 4-year intervals to three ecologically similar study sites in NE Poland, we trapped bank voles (Myodes glareolus) and then tested their blood for the presence of specific antiviral antibodies to TBEV. The strongest effects on seroprevalence were the extrinsic factors, site of capture of voles and year of sampling. Seroprevalence increased markedly with increasing host age, and our analysis revealed significant interactions among these three factors. Seroprevalence did not differ between the sexes. Therefore, based on the seroprevalence results, the dynamics of TBEV infection differ significantly in time, between local sub-populations of bank voles and with increasing host age. To fully understand the circulation of the virus among these reservoir hosts and in the environment, long-term monitoring is required and should employ a multi-site approach, such as the one adopted in the current study.

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The effects of Echinacea purpurea supplementation on growth performance, nutrient utilization, body composition and disease resistance were studied in the ornamental fish Poecilia reticulata. Five diets were used, each differing in Echinacea content (0 g kg )1 diet -control, 5 g kg )1 dietgroup 1, 10 g kg )1 diet -group 2, 20 g kg )1 diet -group 3, 30 g kg )1 diet -group 4 and 60 g kg )1 diet -group 5), and the fish were fed twice daily at a rate of 30 g kg )1 body weight per day for 67 days. The gain in the body weight and the condition factor were significantly increased in groups 2-5, whereas specific growth rate and feed conversion ratio were significantly increased in the supplemented groups (P < 0.05). Cumulative mortalities after challenge infection with the fish pathogen Aeromonas bestiarum were the lowest in the groups supplemented with Echinacea. Log-rank tests showed significant differences between the supplemented groups 1, 2, 3, 4 and 5 and the control group (P = 0.0074, P = 0.0075, P = 0.00507, P = 0.00001 and P = 0.00001, respectively). The results of this study indicate that Echinacea improves body weight gain and resistance against challenge infection in fish.

Detection of Mycobacterium marinum, M. peregrinum, M. fortuitum and M. abscessus in aquarium fish