Physiological State as a Time-Determining Factor for Obtaining and Handling Mature Liza ramada During the Spawning Season

The physiological state of mature brood fish is a determining factor for achieving and stimulating a successful spawning process in captivity. In this 2- year investigation, the physiology of mature Liza ramada females was examined throughout the day at various times (24 hours) to ascertain the most suitable time for obtaining mature females raised in both saline water and fresh water in addition to handling them during the spawning season. In addition, blood concentrations of hormones involved in growth, acclimatization, and response to stress, as well as the levels of glucose, total protein, albumin, and the albumin: globulin ratio of L. ramada mature females were all investigated with respect to the factor of time during a period of 24hours. The highest levels of growth hormone, thyroxine, triiodothyronine, prolactin, cortisol, total protein and albumin were recorded at 12 midday and 6 in the morning for mature L. ramada females raised in both saline water and fresh water, respectively. These recorded levels were suitable for attaining a successful spawning and concurrently stimulating the process for L. ramada raised in captivity. Average levels of glucose were recorded for these fish at the aforementioned times. Low levels of the mentioned hormones, total protein, and albumin were observed at 6PM in fish raised in both saline and fresh waters. These hormones play a significant role in growth, acclimatization, stress response during handling, and stimulating spawning of L. ramada. In conclusion, it was proved that the optimal times for obtaining and handling mature L. ramada females during spawning induction are at 12PM for fish raised in saline water and 6AM for fish raised in fresh water.