# Effects of Dietary Tussah Immunoreactive Pupa Powder on Growth, Gonad Quality, Antioxidant Capacity, and Gut Microbiota of the Sea Urchin Strongylocentrotus intermedius

## TL;DR

Adding Tussah immunoreactive pupa powder to sea urchin feed improves growth, gonad quality, antioxidant levels, and gut health over 60 days.

## Contribution

Demonstrates the novel use of IPP in aquafeed to enhance sea urchin health and economic traits.

## Key findings

- 1.0% IPP significantly increased sea urchin weight gain compared to the control group.
- IPP improved gonad quality and growth compared to a kelp diet.
- IPP boosted antioxidant enzyme activities and altered gut microbiota for better digestive health.

## Abstract

Tussah immunoreactive pupa powder (IPP) is a novel aquafeed additive used in aquaculture, composed of various active substances. Therefore, we incorporated IPP into the feed and conducted a 60-day experiment. The results indicated that IPP had a positive effect on the growth, gonad quality, antioxidant capacity, and gut health of sea urchins. This study provides theoretical insights into the healthful farming of sea urchins and further extends the application of IPP in aquaculture.

Tussah immunoreactive pupa powder (IPP) is composed of various active substances. We speculated that it has the potential to improve key economic traits of sea urchins. Therefore, we conducted a 60-day experiment to examine the effects of IPP on growth, antioxidant capacity, gonad quality, and gut microbiota of sea urchins (Strongylocentrotus intermedius). The experiment involved the preparation of a kelp group and four types of feed containing 0% (the control group), 0.5%, 1.0%, and 1.5% IPP. The results indicated that IPP had no significant impact on the survival of sea urchins (p > 0.05). Firstly, adding IPP promoted the growth of sea urchins. The 1.0% IPP group showed the highest weight gain rate among the feed group, significantly higher than that of the control group (p < 0.05). Secondly, compared with the kelp group, the addition of IPP significantly improved the growth and quality of sea urchin gonads (p < 0.05), which demonstrated certain industrial value. Thirdly, following the addition of IPP, the activities of SOD, CAT, and POD significantly increased in comparison to the control group (p < 0.05). Lastly, added IPP increased the abundance of Firmicutes, Bacteroidetes, and Rhodobacteraceae, while reducing the abundance of Ralstonia and Vibrio. This indicates that added IPP may improve the digestive function and gut health of sea urchins. Overall, added IPP can improve certain economic traits and antioxidant capacity of sea urchins. This manuscript provides a theoretical reference for the healthful aquaculture of S. intermedius.