Role of Pre-transport Conditioning Density in Enhancing Transportation Success of Labeo rohita Fingerlings

Abstract

The present study was conducted during September, 2025 at the Fish Seed Production Centre and Instructional Fish Farm, College of Fisheries Science, Nagpur, Maharashtra, India, to evaluate the effects of different pre-transport conditioning densities on the physiological responses and transportation performance of Labeo rohita fingerlings. Fingerlings were conditioned for 24 h in a flow-through system at four stocking densities. Blood glucose, lactate, muscle glycogen, haemoglobin, haematocrit, water quality, gut evacuation time, and survival were assessed during conditioning and after manual simulated transportation for 12 and 24 h with 4 fingerlings l^-1. Glucose and lactate levels declined progressively during conditioning, while glycogen increased, indicating metabolic recovery. Haemoglobin and haematocrit decreased during conditioning but increased after transportation, reflecting adaptive responses to transport stress. Water quality remained suitable during conditioning, although ammonia increased and dissolved oxygen declined following transportation. Gut evacuation time decreased significantly with increasing stocking density, from 23.0±0.71 h in T₁ to 18.4±1.14 h in T₄. Survival declined with increasing conditioning density and transport duration, with the lowest values observed in T₄ (4 fingerlings l^-1). Although T₁ (1 fingerling l^-1) recorded the highest survival, T₃ provided comparable physiological stability, satisfactory post-conditioning and post-transport survival, and efficient conditioning density. Therefore, conditioning Labeo rohita at 3 fingerlings l^-1 for 19.80 h is recommended as the optimum strategy for improving transportation success and operational efficiency in commercial hatcheries.