Pathogen Screening and Genetic Analysis of Brazilian Black Tiger Shrimp (Penaeus monodon) Populations for Enhancing Aquaculture Stocks

Abstract

Black tiger prawn (shrimp) (Penaeus monodon) populations that have established in the wild across the north of Brazil provide an alternative for shrimp aquaculture systems that are primarily based on pacific white-leg shrimp (Litopenaeus vannamei). A population of P. monodon that was sourced from the state of Ceará in Brazil, used to evaluate husbandry and breeding systems, and was assessed for pathogen incidence and genotyped to evaluate inbreeding, genetic diversity, and population structure after 10 generations of domestication. Ninety-six P. monodon were screened for 19 pathogens listed by WOAH, MAPA, and other significant pathogens. All 1133 qPCR/RT-PCR tests were negative, and the histopathology of 42 samples showed no significant morphological changes when inspected for general health status. Genotype data from other populations of P. monodon collected and genotyped with the same DNA marker panel were used to estimate inbreeding coefficients and population diversity estimates. The Brazilian population’s inbreeding coefficient estimate was low (0.03) compared to most comparison populations. Genetic distance estimates (F_st) showed Brazilian broodstock were genetically similar to both domesticated populations from Vietnam and wild populations from Australia, while being genetically different to populations originating from the Mozambique Channel region. The absence of pathogens and lack of inbreeding indicate that the population is well adapted to this region, making it suitable for the development of a structured breeding program to provide a reliable domestic source of genetically improved P. monodon. Such a program would contribute significantly to the long-term sustainability, resilience, and productivity of the shrimp industry in north/northeast of Brazil, reducing dependence on imported stocks and enhance local aquaculture development.