The annual fish genus Cynopoecilus (Cyprinodontiformes: Rivulidae): taxonomic revision, with descriptions of four new species Author M., Wilson J. E. text Ichthyol Explor. Freshwaters 2002 2002-05-31 13 1 11 24 journal article 295776 10.5281/zenodo.11130615 bbd6d2c0-9584-424d-b57c-f1cf9a9dab83 11130615 Cynopoecilus Regan Cynopoecilus Regan, 1912b: 642 ( type species Cynolebias melanotaenia Regan , by original designation). Diagnosis. Differs from all other rivulid genera by the following synapomorphies: a concavity on the median portion of the posterior border of autopalatine(vs. no concavity); minutecaudal accessory cartilages(vs. caudalaccessory cartiabsent); anterior part of anal fin of male thickened(probably glandular tissue,vs. no modificationon anal-fin surface of male);eight nine anal-fin rays attached to the first proxiradial(vs. two rays);anteriorly curved sixth seventh anal-fin rays of males(vs.not distinctively curved);posteriorly curved 10th to12th anal-fin rays of males vs.not distinctively curved); five minute rays at the anterior portion anal fin(vs. one or no minuteray);a reduced pelvic fin,its tip not reaching anal-fin origin (vs. reduced,reaching anal-fin base);a bulbshaped structure on the urogenital region of male never a bulb-shaped structure);a slender urohyal(vs. deep), a broad longitudinal black from tip of lower jaw to caudal-fin base (vs. such stripe),an oblique longitudinal black from pectoral-fin base to posterior part of anal-fin base (vs. no such stripe), and a zigzag display during male courtship behavior(vs.no courtship behavior pattern). Remarks. For a description and discussion on polarization of the above diagnostic features see Costa (1995a , 1998 ). Distribution. Lagoa dos Patos system and adjacent coastal areas, southern Brazil and eastern Uruguay ( Fig. 1 ).