经济动物学报

为研究投喂频率对东北林蛙(Rana dybowskii)蝌蚪生长、存活和肠道菌群的影响，选取600尾初重为（0.04±0.012）g 的健康蝌蚪，随机分为4个投喂频率组（1-4 餐/d），分别命名为T1组、T2组、T3 组和T4组，每组3个重复，每个重复50尾，在室温条件下开展试验（初始平均室温19±1.5℃)，试验期50d。试验期间室温随环境呈上升趋势，通过每日更换1/3养殖用水、定期清理残饵与粪便维持水质。定期观察蝌蚪后肢形态发育状态，待各组蝌蚪分别达到Gosner发育37期（后肢五趾完全分化）时采集样本，采用称重法测定增长率（单位：倍）、存活率等生长指标，通过高通量测序技术分析肠道菌群结构特征。结果显示，T3组的增重率和存活率显著高于其他组（p＜0.05），而T1组显著低于其它组（P＜0.05）。东北林蛙蝌蚪的肠道菌群中，梭杆菌门、变形菌门和放线菌门为优势菌门，合计占比超90%，其中T4组梭杆菌门占比最高（58.59%），T1组变形菌门占比最高（44.74%）；属水平上，T4组鲸杆菌属占比最高（57.08%），T1组最低（27.27%）。各组Alpha多样性无显著差异（p＞0.05)。在Beta多样性分析中，T1组与其他三组在PCo1轴上分离较明显，意味着一天头喂1次时肠道菌群组成和一天投喂2-4次差异大。T3组和T4组有益菌属鲸杆菌属（梭杆菌门）相对丰度高于其他两组，一定程度改善了肠道微生物结构。研究表明，以生长性能和肠道菌群健康度为指标，东北林蛙蝌蚪适宜的日投喂频率为3餐/d。

To investigate the effects of feeding frequency on the growth， survival， and gut microbiota of Rana dybowskii tadpoles， 600 healthy tadpoles with an initial weight of (0.04 ± 0.012) g were selected and randomly divided into four feeding frequency groups (1-4 meals/d)， named T1 group， T2 group， T3 group， and T4 group， with 3 replicates in each group and 50 tadpoles in each replicate. The experiment was conducted at room temperature (initial average room temperature of 19 ± 1.5 ℃) for 50 days. During the experiment， the room temperature showed an upward trend with the environment， and the water quality was maintained by changing 1/3 of the breeding water daily， regularly cleaning residual bait and feces. Regularly observe the morphological and developmental status of tadpoles' hind limbs， and collect samples when each group of tadpoles reaches Gosner development stage 37 (complete differentiation of hind limbs and five toes). Use weighing method to determine growth rate (unit: fold)， survival rate and other growth indicators， and analyze the structural characteristics of intestinal microbiota through high-throughput sequencing technology. The results showed that the weight gain rate and survival rate of the T3 group were significantly higher than those of the other groups (p<0.05)， while the T1 group was significantly lower than the other groups (P<0.05). In the gut microbiota of Rana dybowskii tadpoles， the dominant phyla are Fusobacteria， Proteobacteria and Actinobacteria accounting for over 90% of the total. Among them， the T4 group had the highest proportion of Fusobacteria (58.59%) and the T1 group had the highest proportion of Proteobacteria (44.74%); At the genus level， the T4 group had the highest proportion of Cetobacterium somerae genus (57.08%)， while the T1 group had the lowest proportion (27.27%). There was no significant difference in alpha diversity among the groups (p>0.05). In the Beta diversity analysis， the T1 group showed significant separation from the other three groups along the PCo1 axis， indicating a significant difference in gut microbiota composition when fed once a day compared to 2-4 times a day. The relative abundance of beneficial bacteria belonging to the genus Cetobacterium somerae (Fusobacteria) in the T3 and T4 groups was higher than the other two groups， which improved the gut microbiota structure to a certain extent. The study indicated that， based on growth performance and gut microbiota health as indicators， the appropriate daily feeding frequency for Rana dybowskii tadpoles is 3 meals/d.