<b>Effect of Enriching Commercial Feed Enrichment with Marine Fish Oil on Morphometric Characteristic and Growth of Mahseer, </b><b>Tor douronensis</b><b> Fry.</b>

This study aimed to determine the effect of feeds supplemented with yellowfin tuna oil (TFO), sardine oil (BFO), squid oil (SFO), and a control feed (CFO), each at 5 g/100 g of feed, on the biometric performance, including morphometric characteristics, length-weight relationship (LWR), and condition factors of Tor douronensis fry. Additionally, it tested the effects of these supplements on the growth performance of the fry. A total of 600 fry (initial weight: 721 mg, length: 32.40 mm) were divided into four treatment groups, each with three replicates. The fry were reared in 12 aquariums (28 L volume, 50 fry per aquarium) for 30 days. The results showed that the addition of marine fish oils significantly affected (P &lt; 0.05) morphometric characteristics, growth patterns, condition factors, and the biometric performance of Tor douronensis fry. Morphometric analysis indicated that the TFO group had the highest average total length, head length, and body height, while the CFO group had the lowest. The LWR coefficient b ranged from 2.821 to 3.169, with Tor douronensis fed with CFO displaying negative allometric growth (-) and those fed with TFO, BFO, and SFO showing positive allometric growth (+). The Fulton condition factor (Kc) ranged from 1.09 ± 0.10 to 1.40 ± 0.18, indicating morphological variation among fry fed with different diets. Fry fed with TFO showed a final weight gain of 36.75%, a mortality rate of 2.66%, and a feed efficiency of 83.24%. Based on these findings, TFO supplementation resulted the highest biometric and growth performance, the highest feed conversion efficiency, and lowest mortality rate in Tor douronensis fry.本研究旨在探究添加比例为5g/100g饲料的黄鳍金枪鱼油（yellowfin tuna oil, TFO）、沙丁鱼油（sardine oil, BFO）、鱿鱼油（squid oil, SFO）与对照饲料（control feed, CFO），对似野结鱼（Tor douronensis）鱼苗的形态测量特征、体长-体重关系（length-weight relationship, LWR）及肥满度系数等生物性状表现的影响，同时验证上述油脂补充剂对鱼苗生长性能的作用。本实验共选取600尾初始体重721mg、体长32.40mm的似野结鱼鱼苗，随机分为4个处理组，每组设置3个生物学重复。将鱼苗饲养于12个体积为28L的水族箱中（每箱放养50尾鱼苗），饲养周期为30天。研究结果表明，海水鱼油的添加对似野结鱼鱼苗的形态学特征、生长模式、肥满度系数及生物性状表现均存在显著影响（P<0.05）。形态学分析显示，TFO组的平均总长度、头长与体高均为各组最高，而CFO组则为最低。体长-体重关系的系数b取值范围为2.821~3.169：投喂对照饲料的鱼苗呈现负异速生长（-），投喂TFO、BFO及SFO的鱼苗则呈现正异速生长（+）。富尔顿肥满度系数（Fulton condition factor, Kc）的取值区间为1.09±0.10~1.40±0.18，表明不同饲料组的鱼苗存在显著形态学差异。投喂TFO组的鱼苗终末体重相对增重率为36.75%，死亡率为2.66%，饲料效率为83.24%。基于上述实验结果，在似野结鱼鱼苗养殖中添加TFO，可使鱼苗获得最优的生物性状与生长表现、最高的饲料转化效率及最低的死亡率。