Relationship Between Bacterial Density and Hepatopancreas Histological Condition of the Pacific White Shrimp (Litopenaeus vannamei) Under Different Pond Management Systems (Traditional, Intensive, and Super-Intensive)

The health of the hepatopancreas Pacific white shrimp (Litopenaeus vannamei) is closely linked to microbial dynamics in culture systems; however, quantitative evidence linking bacterial load composition to organ histopathology across different pond intensification levels remains limited. This study addresses this gap by quantitatively examining the relationship between Total Plate Count (TPC) and Vibrio spp. abundance, and hepatopancreas histological condition in traditional, intensive, and super-intensive shrimp ponds. Shrimp samples were collected purposively at three growth phases (DOC-20, DOC-35, and DOC-50). Bacterial density was analyzed using the pour plate method for TPC and TCBS agar for Vibrio spp., while hepatopancreas condition was evaluated through Hematoxylin-Eosin (HE) staining. The results showed that the traditional system maintained low TPC levels (0.1307-0.2330 CFU/g) and a stable Vibrio/TPC ratio below 65%, allowing hepatopancreas tissue to recover from mild initial damage to near-normal structure by DOC-50. In contrast, the intensive system exhibited a sharp increase in the Vibrio/TPC ratio exceeding 100% at DOC-35, which coincided with severe histological alterations, including tubular disorganization and reduced digestive cell populations, with no full recovery observed by DOC-50. The super-intensive system showed a comparatively lower Vibrio/TPC ratio than the intensive system; however, persistently high TPC levels throughout the culture cycle induced metabolic stress and tissue damage, although partial recovery occurred at DOC-50. These findings demonstrate that not only pathogenic dominance but also averall bacterial load significantly influences hepatopancreas integraty. The novelty of this study lies in identifying the combined threshold effect of Vibrio/TPC ratio and total bacterial density as early indicators of hepatopancreas damage, highlighting the critical management window at DOC-20 to DOC-35. Effective control of microbial balance through water quality management, biosecurity measures, feed regulation, and probiotic application is therefore essential to sustain shrimp health and productivity.