An endoparasitic monogenean was identified for the first time from Indonesia. The oesophagus and anterior stomach of the croakers Nibea soldado (Lacépède) and Otolithes ruber (Bloch & Schneider) (n = 35 each) sampled from the South Java coast in May 2011 and Johnius amblycephalus (Bleeker) (n = 2) (all Sciaenidae) from Kedonganan fish market, South Bali coast, in November 2016, were infected with Pseudempleurosoma haywardi sp. nov. Prevalences in the first two croakers were 63% and 46%, respectively, and the two J. amblycephalus harboured three and five individuals. All three croakers represent new hosts for this monogenean genus. We provide infection rates, light microscopical observations, 3D confocal microscopical illustrations, and a morphometric comparison with all congeners. The new species differs in body size, the position and shape of the ovary and testes, and especially in the composition of the dorsal anchor complex, with the dorsal bar being anteriorly concave rather than planar or convex as in its congeners. The dorsal and ventral anchors of this new species are the longest in the genus, whereas the male copulatory organ is the smallest. The first DNA sequences for a member of this genus demonstrate the greatest similarity with endoparasitic freshwater monogeneans from African cichlid fishes. This suggests a freshwater origin for these marine endoparasitic monogeneans.

首次从印度尼西亚鉴定出一种内生寄生虫。2011年5月从南爪哇海岸采样的黄花鱼Nibea soldado（Lacépède）和Otolithes ruber（Bloch＆Schneider）（n = 35）的食道和前胃和Johnius amblycephalus（Bleeker）（n = 2）（所有S鱼科）于2016年11月从巴厘岛南部海岸的Kedonganan鱼市场上感染了Pseudempleurosoma haywardi sp。十一月 在头两个石首鱼患病率分别为63％和46％，并且两个Ĵ。弱脑窝藏了三个和五个人。这三个黄花鱼代表了这个单属的新宿主。我们提供感染率，光学显微镜观察，3D共聚焦显微镜插图以及所有同类物的形态计量比较。新物种的体型，卵巢和睾丸的位置和形状，尤其是背锚复合物的组成各不相同，其中背杆像其同类物一样是前凹的，而不是平面的或凸的。该新物种的背侧和腹侧锚在该属中最长，而雄性交配器官最小。该属成员的第一个DNA序列显示出与来自非洲丽鱼科鱼类的内寄生淡水单基因菌的最大相似性。