Fig. 1
Lateral ethmoid of: a.
Epactionotus bilineatus, MCP 14806; b.
Hypoptopoma thoracatum, MCP 35872; and c.
Otocinclus cocama, MCP 34842. Solid arrows indicate the ventral ridge of the lateral ethmoid; dashed arrows indicate the ventrally projected strut of the bone. Ventral view, anterior towards top. Scale bar = 1 mm.
Fig. 2
Dorsal surface of head of: a.
Hypoptopoma thoracatum, MCP 35872; b.
Microlepidogaster perforata , MCP 17717; c.
H. bianale, MZUSP 36211; and d.
H. steindachneri, MZUSP 36218. f = frontal; io5 = infraorbital 5; le = lateral ethmoid; n = nasal; pf = prefrontal; pnp = paranasal plates; sp = sphenotic. Dorsal view, anterior towards the top. Scale bar = 1 mm.
Fig. 3
Preopercle of: a.
Epactionotus bilineatus, MCP 29116; b.
Otocinclus vittatus, MCP 15597; and c.
Leptotocinclus ctenistus, MCP 51461. Lateral view, anterior towards left. Scale bar = 1 mm.
Fig. 4
Predorsal region of body of: a.
Otocinclus arnoldi, MCP 25245; b.
Hypoptopoma thoracatum, MCP 35872; c.
Oxyropsis wrightiana , MCP 34503; d.
Acestridium discus, MZUSP 85321; and e.
A. martini, MZUSP 74275. Arrow indicates third plate of the mid-dorsal series. cp = compound pterotic; pnp = prenuchal plate; sop = supraoccipital. Dorsal view, anterior towards top. Scale bar = 1 mm.
Fig. 5
Ventral process of complex center (VPCC) of: a.
Otocinclus hasemani, MCP 22547; and b.
Oxyropsis wrightiana , MCP 34503. Ventral view, anterior towards top. Scale bar = 1 mm.
Fig. 6
Pectoral-fin radials of: a.
Hypoptopoma thoracatum, 35872; and b.
H. gulare, MCP 25489. pfr = pectoral-fin radial. Ventral view, anterior towards top. Scale bar = 1 mm.
Fig. 7
Abdominal region of body of: a.
Otocinclus vittatus, MCP 15597; b.
Hypoptopoma gulare, MCP 33108; c.
Nannoptopoma sternoptychum, MCP 46940; d.
Hypoptopoma thoracatum, MCP 35872; e.
Leptotocinclus madeirae, MCP 35886; f.
Leptotocinclus ctenistus, MCP 51461; g.
Acestridium discus, MZUSP 85322; and h.
A. scutatum, MCP 43198. cl= cleithrum; co = coracoids; lap = lateral abdominal plates; map = median abdominal plates; pap = preanal plate; pclp = pre-cleithral plates. Ventral view, anterior towards top. Scale bar = 3 mm.
Fig. 8
Abdominal region of body with abdominal plates removed of: a.
Hypoptopoma thoracatum, MCP 35872; and b.
Nannoptopoma spectabile, MCNG 26579. bpt = basipterygium; cl = cleithrum; co = coracoids; lpt = lateropterygium. Ventral view, anterior towards top. Scale bar = 1 mm.
Fig. 9
Rostral plate of: a.
Nannoxyropsis acicula, MCP 51462; b.
Acestridium triplax , MCP 41746; c.
A. discus, MZUSP 85322; and d.
A. martini, MZUSP 74275. io1 = infraorbital 1; prp = postrostral plate; r = rostral plate. Ventral view, anterior towards top. Scale bar = 1 mm. Modified from Reis, Lehmann (2009Reis RE, Lehmann PA. Two new species of Acestridium Haseman, 1911 (Loricariidae: Hypoptopomatinae) from the Rio Madeira Basin, Brazil. Copeia. 2009; 2009(3):446-52.).
Fig. 10
Ventral surface of head of: a.
Oxyropsis wrightiana, MCP 34503; and b.
Nannoxyropsis acicula, MPEG 25249. cp = canal cheek plate; io1 = infraorbital 1; io3 = infraorbital 3; io4 = infraorbital 4; prp = postrostral plates; r = rostral plate. Ventral view, anterior towards top. Scale bar = 2 mm. Infraorbitals.
Fig. 11
Infraorbital 4 of: a.
Nannoxyropsis acicula, MCP 51462; b.
E. bilineatus, UFRGS 4491; and c.
Acestridium discus, MZUSP 26822. Lateral view, anterior towards left. Scale bar = 1 mm.
Fig. 12
Odontodes of posterior portion of caudal peduncle of: a.
Hypoptopoma psilogaster, MPEG 18962; b.
Oxyropsis wrightiana, MCP 34503; and c.
Nannoxyropsis acicula , MPEG 25249. Lateral view, anterior towards left. Scale bar = 1 mm.
Fig. 13
Dorsal surface of pelvic fin of male of Leptotocinclus ctenistus, MCP 51461. a. General aspect; b. detail showing the enlarged odontodes on dorsal surface of first branched ray. Lateral view, anterior towards left. Scale bar = 1 mm.
Fig. 14
Strict consensus of the 162 maximally parsimonious trees. Length 382 steps, consistency index 0.41, and retention index 0.83. Numbers at nodes are clade numbers; numbers below each branch are Goodman-Bremmer support values. Outgroup in blue.
Fig. 15
Leptotocinclus ctenistus, INPA 53272, holotype, male, 26.5 mm SL, Brazil, Amazonas, Maraã, igarapé São Sebastião, tributary to igarapé do Baré, lago Amanã basin (02°17’06”S 64°40’36”W).
Fig. 16
Geographic distribution of Leptotocinclus ctenistus (squares), Leptotocinclus madeirae (dots), Nannoxyropsis acicula (triangles), and Nannoxyropsis ephippia (diamond). T = type-locality.
Fig. 17
Plots of factor scores of principal component analysis of the species of Leptotocinclus. Dot, L. ctenistus; Square, L. madeirae. H = holotypes.
Fig. 18
Leptotocinclus madeirae, MCP 51352, holotype, female, 30.4 mm SL, Brazil, Amazonas, Humaitá, igarapé do Vinte e Dois at Recanto do Sanari, Transamazon road ca. 20 km SW of rio Madeira towards Lábrea (07°35’36”S 63°10’27”W).
Fig. 19
Nannoxyropsis acicula, MCP 51326, holotype, female, 27.1 mm SL, Brazil, Pará, Itaituba, Igarapé Capiteo on Transamazon road between Comunidade 28 and Vila Rayol (04°22’43”S 56°16’32.9”W).