Figure 2 from: da Costa e Silva G, Roxo F, Oliveira C (2014) Hisonotus acuen, a new and phenotypically variable cascudinho (Siluriformes, Loricariidae, Hypoptopomatinae) from the upper rio Xingu basin, Brazil. ZooKeys 442: 105-125. https://doi.org/10.3897/zookeys.442.7870

Figure 2 - Spinelet variation among Hisonotus species. Figure a-f showing the extension of the bone forming a lock mechanism. In figure g–h, the bones lack the lock mechanism: a Hisonotus acuen, LBP 16276, 21.4 mm SL b Hisonotus acuen, LBP 16274, 21.1 mm SL c Hisonotus oliveirai LBP 13332, 23.7 mm SL d Hisonotus chromodontus, LBP 7964, 28.3 mm SL e Hisonotus piracanjuba, LBP 17256, 27.1 mm SL f Hisonotus paresis, NUP 10928, 23.6 mm SL g Hisonotus cf. notatus, LBP 3472, 25.8 mm SL h Hisonotus depressicauda, LBP 17474, 28.1 mm SL. Scale bar = 0.5 mm