Costa Rican ichthyologist William Bussing has described a new species of livebearer from northwestern Costa Rica.
Describing Poeciliopsis santaelena as a member of the P. gracilis species complex in a recent issue of the journal Revista de Biologia Tropical, he distinguishes it from congeners in lacking lateral and ventral markings, having higher pectoral and caudal fin rays and with the dorsal fin more posteriorly displaced.
Poeciliopsis santaelena is named for the Peninsula Santa Elena that contains the Ro Potrero Grande, the only known locality of the new species.
The new species was collected in large shallow pools, along with the shrimps Macrobrachium americanum and Atya innocuous and the following species of fishes: Gobiomorus maculatus, Sicydium salvini, Agonostomus monticola and Eleotris picta.
For more information, see the paper: Bussing, WA (2008) A new species of poeciliid fish, Poeciliopsis santaelena, from Peninsula Santa Elena, Area de Conservacin Guanacaste, Costa Rica. Revista de Biologia Tropical 56, pp. 829"838.