Description of Notarius biffi n. sp. and redescription of N. insculptus (Jordan and Gilbert) (Siluriformes: Ariidae) from the eastern Pacific, with evidence of monophyly and limits of Notarius

Abstract

A new species of ariid catfish, Notarius biffi n. sp., from the eastern Pacific, is described. The species is distinguished from other eastern Pacific species of Notarius by the following features: mouth small (width 34.2 39.3% head length); eye large (diameter 3.8 4.5% standard length); mandibulary barbels short (length 10.2 13.1% standard length); distance between anterior nostrils short (17.9 20.8% head length); caudal peduncle relatively slender (depth 6.1 6.7% SL); gill rakers on the first arch 11 12. N. insculptus (Jordan and Gilbert, 1883) new combination is redescribed herein. This species is distinguished from other eastern Pacific Notarius as follows: highly developed, sculptured epioccipital bones, forming with the supraoccipital a basally wide complex process which tapers drastically posteriorly; supraoccipital process length 0.7 0.9 in the base of the complex process; predorsal plate narrow and crescent-shaped; mouth large (width 45.8 54.8% head length); maxillary barbels long (length 26.7 30.3% standard length). Based on mitochondrial phylogenetic evidence (combined cytochrome b and ATP synthase 8/6 data set with 1937 base pairs) and general morphology, the amphiamerican genus Notarius is expanded to include a total of 14 species, eight of which are presented as new combinations (N. cookei, N. insculptus, N. kessleri, N. luniscutis, N. neogranatensis, N. phrygiatus, N. quadriscutis, and N. rugispinis). The nomenclatural status of the eastern Pacific ariids Hexanematichthys henni, Arius hassleriana, A. festae, A. labiatus, A. planiceps, and A. osculus is discussed. Finally, a key to identify seven described species of Notarius from the eastern Pacific is presented.