# Comparative analysis on survival and tissue damage of different environmental stress factors in Pacific white shrimp Litopenaeus vannamei

## TL;DR

This study compares how ammonia, nitrite, and sulfide affect the survival and tissue damage in Pacific white shrimp, finding that nitrite is the most harmful.

## Contribution

The study provides a comparative analysis of the specific effects of ammonia, nitrite, and sulfide on shrimp survival and tissue damage under varying concentrations.

## Key findings

- Nitrite caused more tissue damage and lower survival rates than ammonia and sulfide at increasing concentrations.
- All three chemicals progressively increased damage to hepatopancreas, midgut, muscles, and gills with higher concentrations.
- Muscle tissue showed severe dissociation at higher concentrations of ammonia and sulfide, and at all nitrite concentrations.

## Abstract

•Comparison of the effects of different environmental stress factors on the survival and tissue damage of Litopenaeus vannamei.•Damage to the hepatopancreas, midgut, muscles and gills progressively increased with increasing concentrations of ammonia, nitrite and sulfide.•Overall, nitrite (20 mg/L, 40 mg/L, 60 mg/L) caused more damage than ammonia (10 mg/L, 20 mg/L, 30 mg/L) and sulfide (2 mg/L, 3 mg/L, 4 mg/L).

Comparison of the effects of different environmental stress factors on the survival and tissue damage of Litopenaeus vannamei.

Damage to the hepatopancreas, midgut, muscles and gills progressively increased with increasing concentrations of ammonia, nitrite and sulfide.

Overall, nitrite (20 mg/L, 40 mg/L, 60 mg/L) caused more damage than ammonia (10 mg/L, 20 mg/L, 30 mg/L) and sulfide (2 mg/L, 3 mg/L, 4 mg/L).

Ammonia, nitrite and sulfide are aquatic systemic toxicants that threaten the health of aquatic animals. They directly affect aquatic animal survival and aquaculture productivity, and cause damage to aquatic animal tissues. This experiment investigated the effects of differences in concentrations and types of toxicants in aquatic systems on the survival rate of shrimp and the degree of damage to various tissues, which will provide a reference to the maintenance of the water quality conditions in shrimp aquaculture process. All the three chemicals affected shrimp survival compared to the control, and there was no significant difference between the effects of different concentrations of ammonia (10 mg/L, 20 mg/L and 30 mg/L ammonia-N) on survival at the end of stress, while both nitrite (20 mg/L, 40 mg/L and 60 mg/L nitrite-N) and sulfide (2 mg/L, 3 mg/L and 4 mg/L sulfide) gradually decreased the survival rate at the end of stress with increasing stress concentration. Ammonia and sulfide gradually increased the damage to the hepatopancreas with increasing stress concentrations, and all the three concentrations of nitrite caused severe damage to the hepatopancreas. The separation of the epithelial cells of the midgut from the basement membrane was more pronounced with increasing stress concentrations of all the three chemicals. Dissociation of muscle tissue was more severe at higher concentrations of ammonia and sulfide, and severe dissociation of muscle occurred at all the three concentrations of nitrite. All the three chemicals showed progressively more damage to gill with increasing stress concentrations. In summary, survival and tissue damage to Litopenaeus vannamei progressively increased with increasing concentrations of ammonia, nitrite, and sulfide, with nitrite overall being more damaging to survival and tissue than ammonia and sulfide.