L. Forró szerk.: Miscellanea Zoologica Hungarica 9. 1994 (Budapest, 1994)

Forró, L.: Distribution and occurrence of Daphnia atkinsoni Baird, 1859 and Daphnia similis Claus, 1876 (Crustacea, Anomopoda) in Hungary

Previous records from Hungary Daday (1888) compiled the first monograph on the Cladocera fauna of Hungary, in this paper Daphnia atkinsoni and D. psittacea were listed. The former species was mentioned from six places, three of them are situated in the present-day Hungary, in the Hungarian Plain, while of the four localities of D. psittacea one, Kecskemét, is in the Hungarian Plain. In a subsequent publication he reported the occurrence of D. psittacea near Kisújszállás (Daday 1891). The specimens were found in small waters in late August. Daday (1893) was the first to study the aquatic microfauna of the sodic waters of the Hungarian Plain. During his survey in summer (July and August) he found D. atkinsoni at four sites. These localities ranged fron large permanent ponds to small, astatis sodic pools. Unfortunately, no exact chemical data were given on these localities. Kottász (1913) also found D. psittacea in small pools in the vicinity of Budapest, in October. Woynarovich (1938) dealt with the rotifer and microcrustacean fauna of small, astatic water bodies near Mezőcsát, Northern Hungary lying in the former flood-plain of the river Tisza. The pools represented two different groups, one of them was characterized by turbid, saline (rich in Na and CO3) water, and in spring D. psittacea occurred here in high densities. Megyeri published several papers on the microfauna of sodic waters of the Hungarian Plain. Daphnia atkinsoni was found in various small waters near Szeged between April and June, and D. psittacea was recorded in April (Megyeri 1950). Laterű. atkinsoni was found in several sodic waters near Bugac, between March and May (Megyeri 1958a). Both species were also recorded from dug holes, mainly in spring and after rainfalls. Megyeri (1958b) found D. atkinsoni also in the open water of a permanent pond between March and May, however, only few specimens occurred here. Megyeri (1959) summarized his studies on sodic waters, in this paper several localities of these two species were given. Daphnia atkinsoni was more frequently found, mostly in spring, but also in autumn, between September and November, while D. psittacea occurred in few localities only, between June and September. Also, there was one record from December. Later he reported D. atkinsoni from two permanent ponds, where the species occurred in May (Megyeri 1973). Between 1955 and 1959 Megyeri (1960) carried out hydrobiological investigations on rice fields in Southern Hungary and recorded both species, D. atkinsoni occurred at three localities in May and June, D. psittacea was found merely at one site in May. Ponyi & Dvihally (1954) investigated the chemistry and microcrustacean faun of the fishpond at Kistelek. A part of the pond was sodic, where D. atkinsoni and D. psittacea were found, the former species in November and then in February and March, while the latter one in April. Later, in another paper their summarized the results of their studies on the sodic waters near Kistelek (Dvihally & Ponyi 1957), a list containing 83 microcrustacean species was given. Daphnia atkinsoni was listed and also the curious record of D. carinata, very likely this might have been D. similis. The investigated waters were classified based on their chemical and faunal features, and D. atkinsoni was considered one of the typical species of sodic waters with Na, CO3 and HCO3 dominance. Ponyi & Kertész (1967) also found D. atkinsoni at Farmos in April, May, and in November. Nógrády (1956) recorded both species in sodic waters near Fülöpszállás, they occurred in April and May, and were considered characteristic for these waters. Bothár & Oertel (1977) investigated the Sphagnum-moor near Egerbakta and found four cladoceran species. One of them was D. atkinsoni occurring in the lagg zone in April. The authors considered its occurrence sporadic and occidental.