The first species of Microglanis from the rio Amazonas, Amazonas State, Brazil is described. This species differs from all congeners by the forked caudal fin, and color pattern of the supraoccipital region consisting of two elliptical and juxtaposed pale spots, besides a combination of morphometrics characters.
Bumble-bee catfish; Multivariate morphometrics; Systematics
| Characters | Holotype | Min.-Max. | Mean± SD |
| Standard length (mm) | 27.7 | 20.8-27.7 | 23.7±2.2 |
| Percents of SL | |||
| Head length | 29.7 | 27.4-30.0 | 28.4±1.1 |
| Pelvic fin length | 19.3 | 15.8-20.1 | 18.0±1.3 |
| Dorsal spine length | 15.9 | 11.4-15.9 | 13.0±1.4 |
| Pectoral spine length | 19.2 | 15.5-19.2 | 16.9±1.2 |
| Posterior cleithral process length | 11.9 | 9.6-14.5 | 11.8±1.7 |
| Predorsal length | 38.6 | 35.5-38.6 | 37.1±1.1 |
| Preventral length | 54.4 | 49.5-54.4 | 52.1±1.7 |
| Preanal distance | 72.5 | 68.1-74.1 | 70.9±2.1 |
| Caudal peduncle depth | 11.2 | 9.9-11.3 | 10.8±0.4 |
| Caudal peduncle length | 12.2 | 9.9-17.7 | 14.4±3.0 |
| Body width | 30.4 | 26.4-30.4 | 27.6±1.4 |
| Dorsal-fin base length | 13.5 | 9.7-14.4 | 13.0±1.4 |
| Adipose-fin base length | 16.6 | 13.1-16.6 | 14.6±1.1 |
| Anal-fin base length | 12.2 | 9.5-12.9 | 11.0±1.0 |
| Percents of HL | |||
| Interorbital length | 44.2 | 40.4-44.2 | 42.0±1.3 |
| Eye diameter | 9.8 | 8.0-9.8 | 9.1±0.7 |
| Snout length | 43.8 | 38.3-43.8 | 40.8±2.1 |
| Mouth width | 44.4 | 38.0-47.3 | 43.4±2.4 |
| Maxillary barbel length | 104.1 | 89.4-104.1 | 96.7±4.7 |
| CV1 (81.11%) | CV2 (16.47%) | |
| Head length | -0.14042 | -0.1891 |
| Interorbital distance | 0.10768 | 0.43904 |
| Eye diameter | -0.11396 | -0.19571 |
| Snout length | -0.014809 | 0.41971 |
| Mouth width | 0.10935 | 0.07983 |
| Maxillary barbel length | 0.023589 | 0.26127 |
| Anal fin length | -0.072884 | 0.050899 |
| Dorsal spine length | -0.069149 | 0.13113 |
| Pectoral spine length | 0.10587 | 0.31419 |
| Humeral process length | -0.037374 | 0.0036545 |
| Predorsal distance | -0.11807 | 0.060669 |
| Preventral distance | -0.088499 | -0.073199 |
| Preanal distance | 0.34928 | -0.38767 |
| Caudal peduncle height | -0.084459 | -0.26858 |
| Caudal peduncle length | -0.059994 | 0.10492 |
| Body width | -0.073092 | -0.2741 |
| Dorsal-fin base length | -0.061181 | 0.023965 |
| Adipose-fin base length | -0.061677 | 0.10203 |
| Anal-fin base length | -0.011569 | -0.18645 |
