Petrov Anatoly A, Dmitrieva Evgenija V, Popyuk Maryana P, Gerasev Pavel I, Petrov Sergey A
Zoological Institute of the Russian Academy of Sciences, Saint Petersburg, Russia.
A.O. Kovalevsky Institute of Marine Biological Research, Sevastopol, Crimea.
Folia Parasitol (Praha). 2017 Jul 11;64:2017.022. doi: 10.14411/fp.2017.022.
The taxonomy of Diplectanum Diesing, 1858, a genus of monopisthocotylean monogeneans, remains unsettled and needs to be revised based on new morphological criteria. Recent studies in monopisthocotyleans have shown that the muscle arrangement in the posterior attachment organ (haptor) differs between congeneric species and can be used as an additional criterion in genus-level taxonomy. To explore the possibility of using the haptoral musculature and nervous system in the taxonomy of Diplectanum, we conducted a detailed confocal-microscopy study of three species of Diplectanum (D. aculeatum Parona et Perugia, 1889, D. sciaenae van Beneden et Hesse, 1863 and D. similis Bychowsky, 1957) with phalloidin staining for muscle and indirect immunostaining for 5HT and FMRFamide. A further goal was to clarify the functional mechanics of the haptor and the role of its essential components (squamodiscs and anchors) in attachment to the host. The system of connecting bars and gaffing anchors was found to have a complex musculature consisting of 23 muscles in D. aculeatum and D. sciaenae, and 21 muscles in D. similis. The squamodiscs were shown to be operated by several groups of muscles attached primarily to the area termed the squamodisc fulcrum. Most of the haptoral musculature is identical in D. aculeatum and D. sciaenae and these species differ only in the presence of a muscle sheath around the tissue strand between the squamodiscs in D. sciaenae and in the different patterns of superficial squamodisc muscles. Diplectanum similis shows more significant differences from the other two species: besides lacking two of the haptoral muscles, it also differs in the shapes and arrangement of several other muscles. The nervous system of all three species conforms to the general pattern typical for the Dactylogyroidea and shows little variation between species.
双盘吸虫属（Diplectanum Diesing，1858）是单殖吸虫纲单后盘目的一个属，其分类尚未确定，需要根据新的形态学标准进行修订。近期对单后盘吸虫的研究表明，同属物种的后附着器（抱握器）中的肌肉排列有所不同，可作为属级分类的额外标准。为了探索在双盘吸虫属分类中使用抱握器肌肉组织和神经系统的可能性，我们对三种双盘吸虫（1889年的尖刺双盘吸虫D. aculeatum Parona et Perugia、1863年的海鲷双盘吸虫D. sciaenae van Beneden et Hesse和1957年的相似双盘吸虫D. similis Bychowsky）进行了详细的共聚焦显微镜研究，采用鬼笔环肽染色法观察肌肉，间接免疫染色法观察5羟色胺（5HT）和苯甲酰酪胺苯丙氨酸酰胺（FMRFamide）。另一个目标是阐明抱握器的功能机制及其主要组成部分（鳞状盘和锚）在附着于宿主过程中的作用。发现连接棒和钩状锚系统具有复杂的肌肉组织，尖刺双盘吸虫和海鲷双盘吸虫中有23块肌肉，相似双盘吸虫中有21块肌肉。鳞状盘由几组主要附着于称为鳞状盘支点区域的肌肉操作。尖刺双盘吸虫和海鲷双盘吸虫的大多数抱握器肌肉组织相同，这两个物种的差异仅在于海鲷双盘吸虫中鳞状盘之间组织束周围存在肌肉鞘以及鳞状盘表面肌肉的不同模式。相似双盘吸虫与其他两个物种表现出更显著的差异：除了缺少两块抱握器肌肉外，它在其他几块肌肉的形状和排列上也有所不同。所有三个物种的神经系统均符合指环虫总科的一般模式，物种间差异不大。
