Aphanotorulus

Ray, C. Keith & Armbruster, Jonathan W., 2016, The genera Isorineloricaria and Aphanotorulus (Siluriformes: Loricariidae) with description of a new species, Zootaxa 4072 (5), pp. 501-539 : 508

Key to the species of Aphanotorulus

1a. Multiple buccal pappilae. Teeth unicuspid in nuptial males..................................................... 2

1b. Single, large buccal papilla. Teeth bicuspid in all individuals................................................... 3

2a. Ridges formed by the compound pterotics on the head present and depressed pectoral fin that reaches well past insertion point of last pelvic-fin ray. In specimens larger than 75mm SL, orbit diameter to snout length ratio 18.5–27.9%, caudal depth to pectoral spine length ratio 19.8–25.5%, and pectoral spine length to thorax length ratio 117.0–136.3%.......... A. ammophilus

2b. Ridges formed by the compound pterotics on the head absent and depressed pectoral fin that extends maximally to insertion point of last pelvic-fin ray. In specimens larger than 75mm SL, orbit diameter to snout length ratio 28.0–42.2%, caudal depth to pectoral spine length ratio 25.6–35.1%, and pectoral spine length to thorax length ratio 99.3–116.9%........... A. unicolor

3a. Hypertrophied odontodes covering all lateral and ventral surfaces except the head in breeding males......... A. phrixosoma

3b. Hypertrophied odontodes present on covering lateral and dorsal surfaces in breeding males, but very reduced in size. Elongate hypertrophied odontodes present mostly on pectoral, pelvic, and caudal fins spines................................. 4

4a. Found in the Jaguaribe River, Ceará state, Brazil...................................................... A. gomesi

4b. Found in other waters of South America................................................................... 5

5a. Circular spots on the dorsal and paired fins remain unfused across the length of the fin. Snout-nares distance to interorbital width ratio generally 98–175.4% (separates 92% of specimens examined)............................. A. emarginatus

5b. Spots fuse into bands across the dorsal and paired fins in adults. Snout-nares distance to interorbital width ratio generally 70.5– 97.8% (separates 92% of specimens examined)..................................................... A. horridus