Four new species of the coccidian parasite Isospora (Apicomplexa, Eimeriidae), collected from Java white-bellied Mannikins from Malaya, are described. Species' data were recorded as follows: Isospora malayaensis sp. n. with ellipsoidal oocysts 22.5-27.8 x 15.3-18.9 µm (24.9 ± 0.25 x 16.9 ± 0.16) and pyriform sporocysts 13.5-15.5 x 8.5-10.5 µm (14.8 ± 0.10 x 9.3 ± 0.10). Isospora leucogastroides sp. n. with ellipsoidal oocysts 27-30.5 x 16-18.5 µm (28.5 ± 0.19 x 17.4 ± 0.15) and elongated sporocysts 14-15.5 x 9-10.5 µm (14.9 ± 0.064 x 9.8 ± 0.053). Isospora tenuis sp. n. with ellipsoidal oocysts 27.5-32.5 x 17.5-21 µm (29.3 ± 0.28 x 18.7 ± 0.21) and ovoidal sporocysts 14-17.5 x 10-13.5 µm (15.3 ± 0.16 x 11.6 ± 0.14). Isospora loaei sp. n. with spheroidal oocysts 18.5-22 x 16.5-20 µm (20.6 ± 0.23 x 18.5 ± 0.24) and ovoidal sporocysts 12-14.5 x 8.5-10 µm (13.1 ± 0.13 x 9.3 ± 0.08).
Isospora, Lonchura leucogastroides, Sporocysts, Malaya
