The nervous system of Diplostomum pseudospathaceum Niewiadomska, 1984 (Trematoda, Diplostomatidae)

Abstract

The nervous system of adult Diplostomum pseudospathaceum Niewiadomska, 1984 was studied using Koelle's (1951) method for revealing cholinesterase activity. The nervous system in the fore body grows but its pattern remains the same as in the metacercaria: three pairs of stems connected by numerous commissures and differentiated innervation of various organs in this part of the body. In the elongated hind body the nervous system develops according to another pattern: two pairs of stems connected by a number of commissures form a loose net surrounding the whole segment. The net is more dense at the body end around the genital opening and copulatory organs. A brief discussion of the development of the nervous system of D. pseudospathaceum from cercaria to adult stage is given.

Cercarial chaetotaxy of Codonocephalus urniger (Rudolphi, 1819) (Trematoda: Diplostomidae)

“…The chaetotaxy of several species belonging to the family Diplostomidae has been studied (Shigin, 1968(Shigin, , 1969(Shigin, , 1973(Shigin, , 1974(Shigin, , 1977Richard, 1971;Niewiadomska, 1982Niewiadomska, , 1986. We have compared in detail our observations with the recent descriptions and interpretations of the sensory pattern of D. pseudospathaceum Niewiadomska, 1984 andD.…”

“…We have compared in detail our observations with the recent descriptions and interpretations of the sensory pattern of D. pseudospathaceum Niewiadomska, 1984 andD. spathaceum (Rudolphi, 1819) cercariae given by Niewiadomska (1982Niewiadomska ( , 1986 (Table I) 3CnV 2 + 2CuV 6(4) + 6(4)CnL 5(6) + 5CnL II(13)CnL 2(1)CUD 2(3)CUD 2CuD 1(2) + (1 + 2)CInV 1 + 2CmV 1 + 3CulV 1 + 1CmL 1 + 1CInL ICIIIL 1CnlD 1CmD 3CnlD…”

“…Despite some problems of nomenclature and differences in interpretations of the sensory pattern in the descriptions given by different authors, we have tried to compare the data available for D. helveticum (Dubois, 1929) [= D. indistinctum (Guberlet, 1923) sensu Shigin (1968); = D. spathaceum (Rudolphi, 1819) sensu Niewiadomska (1984)], D. mergi Dubois, 1932, D. gobiorum Shigin 1969, and D. spathaceum (Rudolphi, 1819 as described by Shigin (1968Shigin ( , 1969Shigin ( , 1973Shigin ( , 1974Shigin ( , 1977; for D. spathaceum as described by Richard (1971); and for D. spathaceum and D. pseudospathaceum as described by Niewiadomska (1982Niewiadomska ( , 1986. We have also used the brief descriptions of the distribution of sensilla on the ventral sucker, tail stem and furcae given by Shigin (1974) for other members of the Diplostomidae: Hysteromorpha triloba (Rudolphi, 1819), Ornithodiplostomum scardinii (Schulman, 1952), Posthodiplostomum brevicaudatum (Nordmann, 1832) and Tylodelphys clavata (Nordmann, 1832).…”

“…In this they differ from D. spathaceum, as described by Shigin and Richard, and from D. pseudospathaceum, as described by Niewiadomska, which have three pairs of medio-ventral sensilla. Niewiadomska (1982) suggested that the chaetotaxy of D. pseudospathaceum has been described by Richard (1971) under the name D. spathaceum. It seems possible that Shigin (1973) has also described the D. pseudospathaceum chaetotaxy under the name D. spathaceum, since the two species were not differentiated until Niewiadomska's (1986) study.…”

The nervous systems of Tylodelphys metacercariae (Digenea: Diplostomidae) from the catfish Clarias gariepinus (Clariidae) in freshwater habitats of Tanzania

“…Studies of the nervous system of diplostomids are commonplace in Europe; those of Diplostomum pseudospathaceum in particular – its nervous system has been well documented in all stages of the life cycle (Niewiadomska & Moczon, 1982, 1984, 1987, 1990). In Africa, on the other hand, knowledge of the nervous system of diplostomid species is missing, with the exception of the partially studied T. mashonense (Beverley-Burton, 1963).…”