Rhinodoras armbrusteri Sabaj Pérez, 2008
photo by Sabaj Pérez, M.H.

Family:  Doradidae (Thorny catfishes), subfamily: Doradinae
Max. size:  9.62 cm SL (male/unsexed)
Environment:  demersal; freshwater
Distribution:  South America: Takutu River (including its tributary, Ireng) that drains into the upper Rio Branco (Amazonas basin), Guyana and Brazil, and the Rupununi River (Essequibo basin) in Guyana.
Diagnosis:  Dorsal spines (total): 1-1; Dorsal soft rays (total): 6-6. Differs from all nominal species of the genus Rhinodoras by the following combination of characters: heavy pigmentation on ventral surfaces with many dark speckles or larger spots on belly usually extending onto gular region; anterior midlateral plates moderately deep, depth fifth plate 26.3-29% of corresponding body depth; depths of dorsal and ventral wings of anterior plates subequal, depth of dorsal wing slightly less than twice that of ventral; midlateral plates 57-60, midlateral plates anterior to vertical through pelvic fin origin usually five; tympanal portion of lateral-line canal moderately ossified with two or three distinct plates, posterior-most largest with low medial ridge or thorn and moderately developed wings with serrated margins; postcleithral process moderately short and broad, depth 36.8-44.3% of length; adipose eyelid moderate to large, horizontal diameter 11.4-14.2% of HL; pectoral fin usually I,8; and gas bladder one-part with terminal diverticula small and fused. This fish most closely resembles Rhinodoras boehlkei and can be differentiated from this by the following features: heavy pigmentation with many dark speckles or spots on ventral surfaces more elongated postcleithral process, depth 36.8-44.3%; larger adipose eyelid, horizontal diameter 11.4-14.2%; and midlateral plates 57-60 (Ref. 75166). Description: Dorsal fin I,6; Anal fin iii-iv,8-10; Pectoral fin I,7-8; Pelvic i6 (Ref. 75166).
Biology:  There were individuals encountered during the day hiding in cavities in lateritic boulders submerged in less than three meters of water. An adult specimen was observed at night in a swift shallow run over bedrock (Ref. 75166).
IUCN Red List Status: Not Evaluated (N.E.) Ref. (130435)
Threat to humans:  harmless
Country info:   
 


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