Fish Health Section, Marine Biotechnology Division, ICAR-Central Marine Fisheries Research Institute, Kochi, Kerala, 682018, India.
Acta Parasitol. 2023 Mar;68(1):42-50. doi: 10.1007/s11686-022-00637-y. Epub 2022 Nov 8.
Myxobolus planilizae n. sp. is described from the intestinal muscles of the largescale mullet Planiliza macrolepis from Cochin backwaters, Kerala, India.
Host fishes inhabiting Cochin backwaters were collected using Chinese nets/gill nets. The morphometry and morphological studies were carried out using Nomarski differential interference contrast (DIC) optics, followed by molecular and phylogenetic analyses of the small subunit ribosomal DNA gene (SSU rDNA).
Plasmodia small, pale white, and infect the muscles of the intestine; measured 0.13-0.22 (0.17) × 0.09-0.14 (0.13) mm. Mature myxospores pyriform in valvular view, and biconvex in sutural and apical views with a short anterior extension, and measured 7.45-8.75 (8.40) × 6.04-6.86 (6.25) µm. Shell valves with sutural ornamentations. Polar capsules two, equal, pyriform, measured 3.96-4.54 (4.45) × 2.22-2.94 (2.52) µm. Polar filament arranged in five coils, measured 24.41-34.44 (28.52) µm when extruded. In morphological and morphometric analysis, the present species exhibit remarkable variations from other species of the genus Myxobolus. In molecular analysis, the present species revealed the highest identity of 91.85% and divergence of 9.95% with related species, underlining its molecular uniqueness. In phylogenetic analysis, species of Myxobolus infecting mullets appeared as a separate clade and the present species was positioned distinctly with a high bootstrap value.
Based on morphology, morphometry, and molecular and phylogenetic analyses, along with tissue/host specificities and geographic location, the present parasite is treated as new and is reported here as M. planilizae n. sp.
从印度喀拉拉邦科钦泻湖的大型马鲛 Planiliza macrolepis 的肠肌中描述了新种 Myxobolus planilizae n. sp。
使用中国式网/刺网收集栖息在科钦泻湖的宿主鱼类。使用诺玛斯基微分干涉对比（DIC）光学进行形态测量和形态学研究，随后对小亚基核糖体 DNA 基因（SSU rDNA）进行分子和系统发育分析。
原生动物小，苍白，感染肠肌；测量值为 0.13-0.22（0.17）×0.09-0.14（0.13）mm。成熟的粘孢子虫在瓣膜视图中呈梨形，在缝合和顶点视图中呈双凸形，具有短的前延伸，测量值为 7.45-8.75（8.40）×6.04-6.86（6.25）µm。壳瓣具有缝合装饰。极囊两个，相等，梨形，测量值为 3.96-4.54（4.45）×2.22-2.94（2.52）µm。极丝排列成五圈，挤出时测量值为 24.41-34.44（28.52）µm。在形态和形态测量分析中，本种与属中的其他种表现出显著的变化。在分子分析中，本种与相关种的同源性最高为 91.85%，分化度最高为 9.95%，突出了其分子独特性。在系统发育分析中，感染马鲛的粘孢子虫种作为一个单独的分支出现，而本种则以高置信度值明显定位。
基于形态、形态测量、分子和系统发育分析以及组织/宿主特异性和地理位置，本寄生虫被视为新种，并在此报告为 M. planilizae n. sp。
