Leptodoras linnelli Eigenmann, 1912
photo by Sabaj Pérez, M.H.

Family:  Doradidae (Thorny catfishes), subfamily: Doradinae
Max. size:  23 cm SL (male/unsexed)
Environment:  demersal; freshwater; pH range: 5.80000019073486 - 7; dH range: 18
Distribution:  South America: Upper Orinoco (rios Ventuari and Mavaca) and Casiquiare River basin in Venezuela; Atlantic Coast drainages of the Guianas and northern Brazil such as Essequibo, Demerara and Araguari); the rios Uatumã, Tacutu and Demini in Brazil (Ref. 56896). Recently collected from the rio Tiquié basin (right bank tributary of the upper rio Negro) in the Amazonas State and from the upper rio Aripuaña (tributary of the rio Madeira) in Mato Grosso State, Brazil, extending the known distribution of this species into the western limits of the Brazilian Shield (Ref. 79526).
Diagnosis:  Dorsal spines (total): 1-1; Dorsal soft rays (total): 6-6; Anal soft rays: 12-16. Upper labial extension very elongate, straight to weakly curved medially and nearly uniform in width with a bluntly rounded tip. Differs further from all Leptodoras except L. acipenserinus by having an adipose fin extending anteriorly as a low thin ridge to a point midway between the anterior insertion of the adipose fin and the posterior insertion of the dorsal fin. Distinguished from L. acipenserinus by a number of characters including a relatively longer predorsal distance (35.5-38.7% SL), inner flap of gill opening incomplete, lower sum of midlateral plates (74-81), anal-fin shape (tip of longest branched ray falls short of vertical through tip of last branched ray in extended anal fin and is more or less even with vertical through base of last ray; line defined by tips angled anteriorly, forming a 45-90° angle with long axis of body), pectoral-fin spine length 19.9-26.2% of SL and pectoral-fin spine dentation with teeth strongly retrorse along majority of posterior margin, becoming less retrorse distally, size relatively uniform along distal half, last denticulation usually subterminal (Ref. 56896).
Biology: 
IUCN Red List Status: Least Concern (LC); Date assessed: 30 July 2020 Ref. (130435)
Threat to humans:  harmless


Source and more info: www.fishbase.org. For personal, classroom, and other internal use only. Not for publication.