†Kenyaichthyidae fam. nov and †Kenyaichthys gen. nov - First Record of a Fossil Aplocheiloid Killifish (Teleostei, Cyprinodontiformes)

The extant Cyprinodontiformes (killifishes) with their two suborders Cyprinodontoidei and Aplocheiloidei represent a diverse and well-studied group of fishes. However, their fossil record is comparatively sparse and has so far yielded members of the Cyprinodontoidei only. Here we report on cyprinodontiform fossils from the upper Miocene Lukeino Formation in the Tugen Hills of the Central Rift Valley of Kenya, which represent the first fossil record of an aplocheiloid killifish. A total of 169 specimens - mostly extraordinarily well preserved and a sample of ten extant cyprinodontiform species were studied on the basis of morphometrics, meristics and osteology. A phylogenetic analysis using PAUP was also conducted for the fossils. Both the osteological data and the phylogenetic analysis provide strong evidence for the assignment of the fossils to the Aplocheiloidei, and justify the definition of the new family dagger Kenyaichthyidae, the new genus dagger Kenyaichthys and the new species dagger K. kipkechi sp. nov. The phylogenetic analysis unexpectedly places dagger Kenyaichthys gen. nov. in a sister relationship to the Rivulidae (a purely Neotropical group),a probable explanation might be lack of available synapomorphies for the Rivulidae, Nothobranchiidae and Aplocheilidae. The specimens of dagger K. kipkechi sp. nov. show several polymorphic characters and large overlap in meristic traits, which justifies their interpretation as a species flock in statu nascendi. Patterns of variation in neural and haemal spine dimensions in the caudal vertebrae of dagger Kenyaichthys gen. nov. and the extant species studied indicate that some previously suggested synapomorphies of the Cyprinodontoidei and Aplocheiloidei need to be revised

自家受精魚マングローブキリフィッシュ（Kryptolebias marmoratus）の生殖腺の形態

We conducted anatomical and histological observations of the gonads in the self-fertilizing mangrove killifish, Kryptolebias marmoratus to investigate the self-fertilizing mechanism of this species. The gonad has a bilobed structure. The elongated gonadal lumen (GL) along the dorsal surface of the gonad connects to the common genital sinus. The elongate testicular region is closely attached to the GL. Among the ovulated eggs in the GL, those in the anterior part of the GL have micropyles but no perivitelline space (are not yet fertilized), whereas those in the posterior part of the GL are fertilized. In our histological analysis, we found free sperm in the posterior area of the GL. We conclude that ovulated eggs may be self-fertilized in the posterior GL.マングローブキリフィッシュ（Kryptolebias marmoratus）の生殖腺の解剖学および組織学的な観察を行い，本種の自家受精機構を考察した。生殖腺は二葉に分かれ，生殖管は生殖腺背面を通り泌尿生殖口へ達した。精巣組織は生殖管に隣接していた。生殖管内に排卵された卵のうち，生殖管前方の卵には囲卵腔がなく卵門を有しており未受精であったが，生殖管後方の卵は受精していた。組織学的観察から，生殖管後方で排精の起こっていることが明らかとなった。排卵後に卵が生殖管を通る段階で自家受精が起こると考えられた

On the identity of the West African killifish Aphyosemion maeseni Poll, 1941 (Cyprinodontiformes : Aplocheilidae)

Populations of the West African killifish, traditionally identified as Aphyosemion maeseni Poll, 1941, have been classified for the last four decades in the tribe Callopanchacini. However, in a recent study, populations of this widespread species have been placed in a new genus and species, Nimbapanchax leucopterygius, while the unique holotype that Poll used to describe Aphyosemion maeseni has been referred to the genus Epiplatys. Comparison of 3D reconstruction images of the holotype of A. maeseni with cleared and stained specimens of several African Aplocheiloid taxa revealed that: the morphology of the epineural ribs and the neural processes of vertebrae 5-7 are typical of Callopanchacines and not like those of Epiplatys. Furthermore, the neural process of the second vertebra is fan-shaped, which is a synapomorphic characteristic of the recently described genus, Nimbapanchax. As the morphology of the holotype of A. maeseni and that of examined specimens of N. leucopterygius prove highly concordant and we are unable to record any morphological characteristic that would diagnose each as a member of a distinct taxon, we propose N. leucopterygius to be a junior synonym of A. maeseni. A species synonymy and re-diagnosis of Aphyosemion maeseni Poll, 1941 is provided