Ref ID : 3064
Sudzuki Minoru; [On the General Structure and the Seasonal Occurrence of the Males in Some Japanese Rotifers. I.]. Zoological Magazine (Dobutsugaku Zasshi) 64(3):126-129, 1955
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This paper deals with the general structure and the seasonal occurrence of the males in two species of rotifers (Pompholyx sulcata under Testudinellidae and Gastropus hyptopus under Gastropodidae) occurring in a small reservoir (R1) and a marsh (M1) at Urawa near Tokyo, during 1951-'54. Pompholyx sulcata Hudson: Perennial. Male-Female appeared in the middle of April and the beginning of September in M1, but in R1 it was found from the beginning of April to the end of May and from the end of September to the middle of December. Though the mictic females appeared usually in spring and fall, D-Female occurred often in the middle of June and also in early winter; therefore, this species may be considered to be polycyclic (in 1954 no sexual period was seen in spring at both places). Total length 68 µm, body length 56 µm, width 37 µm, height 23 µm. Gastropus hyptopus (Ehrenberg): A cold stenothermal form. The sexual females appear from the beginning of December to the middle of January in M1. Monocyclic. The cloacal copulation was recognized on January 12'54. 60-90 µm in length, 50-55 µm in height.