Microglanis, Eigenmann, 1912

Ruiz, William Benedito Gotto & Shibatta, Oscar Akio, 2011, Two new species of Microglanis (Siluriformes: Pseudopimelodidae) from the upper-middle rio Araguaia basin, Central Brazil, Neotropical Ichthyology 9 (4), pp. 697-707 : 705-706

Key to the species of Microglanis from the rio Amazon basin

1. Absence of light transverse band on nape; presence of melanophores surrounding the neuromasts of superficial lines, forming series of black dots ....................................... 2

1’. Presence of a light transverse band on nape; absence of melanophores surrounding the neuromasts of superficial lines .......................................................................................... 3

2. Dark brown trunk with light brown stripes imparting a ground color similar to tree bark; absence of light marks on nape; snout length 11.4-12.9% SL ........ Microglanis xylographicus

2’. Light brown trunk with dark brown saddles below dorsal and adipose fins; light cordiform blotch on nape; snout length 9.1-10.7% SL .............................. Microglanis robustus

3. Very wide dark-brown stripes on fins ................... ...................................................... Microglanis pellopterygius

3’. Dark brown stripes on fins absent or narrow ..................... 4

4. Lateral line long, reaching the vertical line through middle of adipose fin; number of pores 14-20 ........................ .................................................................. Microglanis iheringi

4’. Lateral line short, not reaching the vertical line through middle of adipose fin; number of pores 3-9 ......................... 5

5. Tip of pectoral-fin spine bifurcated ...................... ............................................................... Microglanis secundus

5’. Tip of pectoral-fin spine undivided ................................... 6

6. Caudal fin rounded; all anterior serrae of the pectoral spine retrorse, except the last antrorse ........... Microglanis zonatus

6’. Caudal fin slightly bilobed; upper lobe of caudal fin more developed than lower lobe; anterior serrae of pectoral-fin spine antrorse and retrorse, with a single Y-shaped serration in between ............................................................ 7

7. Lateral line reaching the vertical through middle of dorsalfin base; 5-7 total gill rakers in the first branchial arch; 6 pleural ribs; i,12,i caudal-fin rays ........................... ................................................................. Microglanis poecilus

7’. Lateral line reaching the vertical through base of dorsalfin spine; 3-6 total gill rakers in the first branchial arch; 4-5 pleural ribs; i,10,i or i,11,i caudal-fin rays ..................... ................................................................. Microglanis oliveirai