Embryonic and early development of the Zagros tooth-carp, Aphanius vladykovi (Actinopterygii: Cyprinodontidae)

DNA barcoding and species delimitation of the Old World tooth-carps, family Aphaniidae Hoedeman, 1949 (Teleostei: Cyprinodontiformes)

The fishes, which have currently named Aphanius Nardo, 1827 are the relict of the ancient ichthyofauna of the Tethys Sea. For a long time since 1827, the genus name has been subjected to revision by several researchers using mainly morphological features. Until recently, no comprehensive single- or multi-locus DNA barcoding study has been conducted on whole members of the family Aphaniidae. In the present study, by applying four conceptually different molecular species delimitation methods, including one distance-based method, one network-based and two topology-based methods, we examined a single-locus DNA barcode library (COI) diversity for the 268 sequences within the family Aphaniidae from the Old World (57 sequences are new in the present study and 211 sequences were retrieved from NCBI database). The molecular analyses revealed a clearer picture of intra-family relationships and allowed us to clarify the generic names, and also describe a new genus for the family Aphaniidae. Results supported distinction of three major clades related to three genera within this family: i) the first clade includes the A. mento group which are placed in a new genus, Paraphanius gen. nov., found in the Orontes (= Asi) and Tigris-Euphrates River drainage, the Levant in coastal waters and the Dead Sea basin, western Jordan, and in southern Turkey in the Mediterranean basins as well as in central Turkey. This clade positioned at the base of the phylogenetic tree, (ii) the second clade contains the A. dispar-like brackish water tooth-carps which are transferred to the genus Aphaniops Hoedeman, 1951 (type species, Lebias dispar), distributed in the coastal waters around the Red Sea and the Persian Gulf basins; and (iii) the third clade, the genus Aphanius Nardo, 1827 (type species Aphanius nanus = A. fasciatus) contains all the inland and inland-related tooth-carps, which are mainly distributed in the inland waters in Turkey and Iran and also in the inland-related drainages around the Mediterranean basin.

An embryonic staging series up to hatching for Cyprinodon variegatus: An emerging fish model for developmental, evolutionary, and ecological research

Using multiple taxa to research development is necessary for making general conclusions about developmental patterns and mechanisms. We present a staging series for Cyprinodon variegatus as a basis for further study of the developmental biology of fishes in the genus Cyprinodon and for comparative work on teleost fishes beyond the standard models. Cyprinodon are small, euryhaline fishes, widely distributed in fresh, brackish, and hypersaline waters of southern and eastern North America. Cyprinodontids are closely related to fundulids, providing a comparative reference point to the embryological model, Fundulus heteroclitus. Ecologists and evolutionary biologists commonly study Cyprinodon, and we have been using Cyprinodon to study skull variation and its genetic basis among closely related species. We divided embryonic development of C. variegatus into 34 morphologically identifiable stages. We reference our staging series to that already defined for a related model species, Oryzias latipes (medaka) that is studied by a large community of researchers. We provide a description of the early chondrogenesis and ossification of skull and caudal fin bones during the latter stages of embryonic development. We show that Cyprinodon are tractable for studying development. Eggs can be obtained easily from breeding pairs and our study provides a staging system to facilitate future developmental studies.