Nematolebias Costa

Costa, Wilson J. E. M., 2006, Descriptive morphology and phylogenetic relationships among species of the Neotropical annual killifish genera Nematolebias and Simpsonichthys (Cyprinodontiformes: Aplocheiloidei: Rivulidae), Neotropical Ichthyology 4 (1), pp. 1-26 : 15

Nematolebias Costa

Nematolebias Costa, 1998a: 75 (type species Cynolebias whitei Myers , by original designation).

Diagnosis. Differs from all other members of the Cynolebiatini by the following unambiguous synapomorphies: widened ventral process of angulo-articular (vs. narrow), neural spine of the first vertebra directly attached to the neural prezygapophysis of the second vertebra (vs. connected by thin ligaments), hypertrophied tubular contact organs on the medial surface of the dorsal half of the pectoral fin in males, its basal portion ossified, forming a cup-shaped osseous structure (vs. papillate contact organs, when contact organs are present), and a subdistal orange stripe with transverse golden lines contrasting with a black zone dorsal to the orange stripe on the anal fin in males (vs. never a similar color pattern). Some synapomorphies of Nematolebias , homoplastically occurring in other cynolebiatins, are: widened basihyal in older males (also occurring in the S. antenori species group) (vs. narrow basihyal), absence of second pharyngobranchial teeth (also occurring in Simpsonichthys , subgenera Xenurolebias and Simpsonichthys ) (vs. presence), preopercular and mandibular series of neuromasts continuous (also occurring in Cynolebias ) (vs. preopercular and mandibular series of neuromasts separated), absence contact organs on the flank (also occurring in Ophthalmolebias , Spectrolebias and in the S. antenori species group) (vs. contact organs present), iridescent line on subdistal zone of caudal fin in males (also occurring in the subgenus Simpsonichthys ) (vs. subdistal line absent), and pectoral-fin reddish brown with iridescent spots in males (reddish brown also in the S. notatus group, and iridescent spots also in the subgenus Simpsonichthys ) (vs. never a similar color pattern).

Included species. Nematolebias papilliferus Costa and N. whitei (Myers) .