Study links nitrite tolerance in shrimp to two gill enzymes

Nitrite tolerance in whiteleg shrimp may hinge on two gill enzymes, according to a new study in Animals that compared nitrite-tolerant and nitrite-sensitive Penaeus vannamei families. The researchers used survival testing, transcriptomics, qPCR, physiological assays, and RNA interference, and concluded that carbonic anhydrase 2 and Na+/K+-ATPase help explain why some selectively bred families handle nitrite exposure better than others. The work points to branchial ion transport and acid–base balance, rather than a single generalized stress response, as central to family-level differences in tolerance. That fits with broader crustacean physiology research showing gills are the main site of ion regulation, and that carbonic anhydrase and Na+/K+-ATPase are core components of NaCl uptake and acid–base control. (frontiersin.org)

Why it matters: For veterinary and aquatic animal health professionals working with shrimp systems, the study adds mechanistic support for breeding and management strategies aimed at reducing nitrite losses in intensive production. Nitrite is a well-established hazard in shrimp aquaculture, especially in intensive or low-salinity settings, where it can impair oxygen transport, disrupt osmotic balance, and reduce survival. Industry guidance and prior literature also indicate that higher salinity can improve nitrite tolerance, likely because chloride competes with nitrite at branchial uptake sites. In practice, that means genetics, water chemistry, and system design should be viewed together, not as separate levers. (mdpi.com)

What to watch: Watch for follow-up work translating these molecular findings into usable breeding markers, screening tools, or water-management recommendations for commercial shrimp production. (pubmed.ncbi.nlm.nih.gov)