The ant fauna of the Krakatau Islands, Indonesia is reviewed. All the collection records obtained in five survey periods since the catastrophic eruption in 1883 are presented for each of the four islands of the Krakatau group. In 2005–07 the actual species number was 99, and the colonisation curve was still rising without any indication of reaching an equilibrium species number. Formicinae were earlier colonists at both genus and species level, while Myrmicinae and Ponerinae tended to have arrived later. Nesting biology of ants was also studied. Among the 49 species for which the nesting site was confirmed 74% were found from dead wood and twigs, while 14% from ground surface and in soil. A Leptogenys species adopting fission as colony mutiplication was found in 1982 and 2007. All this indicates that the immigration of many species was by rafting on the sea but that dispersal by air also occurred. Early colonsation of pioneer plants with extrafloral nectaries may have been important for the early ant colonisers to survive under poor vegetation. Fifteen tramp species have been so far recorded, of which only one (Pheidole megacepahla) has become extinct. Most turnover events are considered to have occurred in association with vegetation succession.

Kokuraichthys tokuriki is described from the Early Cretaceous Dobaru Formation of the Wakino Subgroup, Kitakyushu in the northern part of Kyushu, Japan, as a new genus and species of Osteoglossomorpha. This new species is considered to be more closely related to Hiodontiformes or Lycopteriformes than Osteoglossifonnes because it has a single epural and no neural spine on the first ural centrum. Although it has significantly fewer vertebrae (36 or 37), K. tokuriki is tentatively assigned to Hiodontiformes because of the long anal fin base, the anterior position of the dorsal fin and the reduced neural spine on the first preural centrum.