Brazilian killifish expert Wilson Costa has described a new species of Rivulus killifish from southern Brazil in the latest issue of Ichthyological Exploration of Freshwaters.
The new species, Rivulus jurubatibensis, is a member of the Rivulus santensis group and can be distinguished from the other species in this group in having a fewer scales in the longitudinal series.
It is further distinguished by the color pattern of the caudal fin in males and females and is also the smalles member of the R. santensis species group (maximum size 26 mm standard length vs. 35"45 mm in other species).
The new species is known only from the type locality, a freshwater swampy coastal area in the Parque Nacional de Jurubatiba (after which it is named).
The swamp contained dense aquatic vegetation, with the water being clear and acid (pH 5.3).
For more information, see the paper: Costa, WJEM (2008) Rivulus jurubatibensis, a new aplocheiloid killifish from the southeastern Brazilian coastal plains (Cyprinodontiformes: Rivulidae). Ichthyological Exploratin of Freshwater, 19, pp. 135"140.