The nervous system ofDiplostomum pseudospathaceum Niewiadomska 1984 (Trematoda, Diplostomatidae)

Abstract

The structure and development of the nervous system in the metacercaria ofDiplostomum pseudospathaceum Niewiadomska 1984 have been studied, using the method of Koelle (1951) for the detection of cholinesterase activity. It has been found that during the first 10–14 days of development the nervous system of the metacercaria fits the pattern described in the cercaria — paired central ganglia connected by the commissure, four anterior and three posterior pairs of trunks, eight commissures — despite the significant increase in body size. During this period the subtegumental nerve fibres develop. This pattern changes during the subsequent days of development. Numerous new commissures are formed, giving an appearance of a dense net to the whole nervous system; innervation of the holdfast organ and of the lappets develops as well as the innervation of the hindbody.