Growth performance and stress responses of larval Mississippi Paddlefish Polyodon spathula to hypoxia under different diet treatments.

Ya Zhu,Chunfang Wang,Wen Lei,Qiliang Ding

doi:10.1155/2014/404595

Abstract

A growth trial was conducted to detect the effects of different diets on the growth performance and hypoxia adaptation capacity of Mississippi Paddlefish (Polyodon spathula) larvae. The larvae were fed with live food, formulated diets, and 1/2 live food with 1/2 formulated diets. After a 15-d growth trial, final body weight and total body length were measured, and five larvae from each dietary group were subjected to 1 h of hypoxia treatment. Serum total antioxidant capacity (T-AOC), serum superoxide dismutase (SOD), and liver malondialdehyde (MDA) were measured. Final body weight and weight gain of the fish fed live food were significantly higher than the values for the other two groups. Total body length of the fish fed live food and 1/2 live food with 1/2 formulated diets exhibited no significant difference. After hypoxia treatment, serum T-AOC and SOD activities of the fish fed formulated diets were significantly lower than those of the other two groups. Liver MDA content of the fish fed with live food was significantly higher than that of the other two groups. In conclusion, larval paddlefish fed with an appropriate proportion of live food and formulated diets exhibit improved adaptive capacity to hypoxia.

Highlights

The paddlefish, Polyodon spathula, is a freshwater chondrostean fish that belongs to the suborder Acipenseroidei [1]
The final body weight and weight gain of the fish fed with live food were significantly higher than those of the other two groups, whereas no significant difference existed between fish fed with formulated diets and those fed with 1/2 live food with 1/2 formulated diets
Serum total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activities of the fish fed with formulated diets were significantly lower than those of the other two groups, whereas no significant difference was observed between fish fed with live food and those fed with 1/2 live food with 1/2 formulated diets

Summary

Introduction

The paddlefish, Polyodon spathula, is a freshwater chondrostean fish that belongs to the suborder Acipenseroidei (order Acipenseriformes) [1]. This North American relict species is indigenous only to the waters of the MississippiMissouri River system and neighboring coastal drainages that flow into the Gulf of Mexico [2]. Paddlefish are ram suspension filter-feeders [4]. These features make appropriate food resource a bottleneck in the paddlefish aquaculture, especially in the early life stage. Diet items of larval and juvenile paddlefish include zooplankton and all stages of aquatic insects [3]. The survival and growth rates of such fish were significantly lower than those of fish fed with live zooplanktons

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Results

Conclusion