Nematolebias Costa

Nematolebias Costa View in CoL View at ENA

Nematolebias Costa, 1998a: 75 View in CoL ( type species Cynolebias whitei Myers View in CoL , 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) .