Odontostilbe fugitiva Cope, 1870

Bührnheim, Cristina M. & Malabarba, Luiz R., 2006, Redescription of the type species of Odontostilbe Cope, 1870 (Teleostei: Characidae: Cheirodontinae), and description of three new species from the Amazon basin, Neotropical Ichthyology 4 (2), pp. 167-196 : 169-179

Odontostilbe fugitiva Cope, 1870

Fig. 1

Odontostilbe fugitiva Cope, 1870: 566 [original description; dentition figured; type locality: “Pebas, Eastern Equador ”, actually Pebas, Loreto, Peru, in the Ampiyacu-Amazonas drainage]. -Eigenmann & Eigenmann, 1891: 54 [listed, Pebas, Villa Bella, Santarém]. - Eigenmann, 1910: 429 [listed, habitat: Ecuador (following Cope, 1870; currently Peru)]. - Fowler, 1913: 529, 532 [comparison to O. madeirae and O. drepanon ]. - Eigenmann, 1915: 90 [redescription based on specimens of San Antonio de rio Madeira, Amazon basin; erroneous distribution from Panama and Trinidad to La Plata and Peruvian Amazon; in key]. -Eigenmann & Allen, 1942: 45, 265 [listed for the Amazon basin between lower Marañon, Pongo de Manseriche, to Tabatinga; annotated list in Pebas region, lower Marañon]. - Fowler, 1945a:134 [listed, Pebas, Peru]. - Fowler, 1948: 195 [listed, rio Amazonas, Brazil, Equador (following Cope, 1870; actually Peru)]. - Böhlke, 1954: 137-139 [listed, Odontostilbe fugitiva as possible synonym of Odontostilbe pulchra ]. - Géry, 1972a: 20-21 [ O. caquetae Fowler, 1943 , O. madeirae Fowler, 1914 and O. drepanon Fowler, 1914 as a probable synonyms of O. fugitiva , table with measurements and meristics of type material of O. madeirae Fowler and O. drepanon Fowler ]. - Géry, 1977: 555, 558 [in key, O. madeirae , O. drepanon and O. caquetae as synonyms of Odontostilbe fugitiva , compilation of Fowler’s drawings of O. madeirae and O. drepanon ]. -Sánchez-Botero & Araújo-Lima, 2001: 440 [listed] - Petry et al., 2003: 562, 565, 575 [habitat, listed].

Chirodon fugitivus . - Lütken, 1875: 237 [listed; Amazon basin, Pebas].

Chirodon (Odontostilbe) fugitiva . -Steindachner, 1882: 39 [redescription based on specimens from Amazon basin, Villa Bella, Santarém].

Cheirodon fugitiva . - Ulrey, 1895: 288-290 [in key; erroneous compilation of distribution in Petras (= Pebas), and Brazil]. -Ortega & Vari, 1986: 8 [listed,Amazon basin, distribution compiled from Géry (1964)].

Odontostilbe madeirae Fowler, 1913: 527-529 [description, type locality: tributary of rio Madeira, near Porto Velho, Brazil; fig. 6, illustrated specimen; holotype ANSP 39193, 16 paratypes ANSP 39194-209: 12 ANSP 39194, 1 ANSP 39206, 1 c&s ANSP 39207, 1 ANSP 39208, now Géry collection, 1 missing ANSP 39209, same data as holotype]. - Fowler, 1948: [in list; 197-198, rio Madeira; compilation of drawing of original description]. - Böhlke, 1954: 138 [in list].

Odontostilbe drepanon Fowler, 1913: 529-532 [description, type locality: tributary of rio Madeira, near Porto Velho, Brazil; fig. 7, illustrated specimen; holotype ANSP 39210, 6 paratypes ANSP 39211-16, same data as holotype]. - Fowler, 1948:195-196 [in list; rio Madeira; compilation of drawing of original description]. - Böhlke, 1954: 138 [in list].

Odontostilbe caquetae Fowler, 1943: 230-232 [description, type locality: Florencia, río Orteguasa, Colombia; fig. 13, illustrated specimen; holotypeANSP 70495].- Fowler, 1948: 194- 195 [in list; AltoAmazonas, Colombia; compilation of drawing and original description]. - Böhlke, 1954: 138 [in list].

? Odontostilbe fugitiva . - Géry, 1964:18-19 [incorrect date of Cope’s description 1871, description of one specimen near Iquitos].

Neotype [by present designation]. MUSM 27501 , 1 (male 34.6 mm SL), Peru, Loreto, Amazon basin, [lower] río Napo drainage, Yuto cocha on right bank of río Mazán , 3°30’53’’S 73°10’05’’W, S. O. Kullander, J. Cruz, N. Sarmiento & A. Hogeborn, 16 Aug 1984.

Type material examined. Odontostilbe madeirae . Holotype ANSP 39193 , 1 m, x (female 32.1 mm SL), Brazil, tributary of rio Madeira , near Porto Velho, E. A. Smith, Jan 1913 . Paratypes: ANSP 39194 , 8 x, c of 12 females (females 25.3-29.2 mm SL,), same data as ANSP 39193; ANSP 39206 , 1 (female 33.0 mm SL), same data as ANSP 39193; ANSP 39207 , 1 (female c&s), same data as ANSP 39193. Odontostilbe drepanon . Holotype ANSP 39210 , 1 m, x (male 30.5 mm SL), Brazil, tributary of rio Madeira , near Porto Velho, E. A. Smith, Jan 1913 . Paratypes: ANSP 39211 , 6 m, x (males 25.2-28.8 mm SL), same data as ANSP 39210. Odontostilbe caquetae . Holotype ANSP 70495 , 1 m, x (unsexed 28.0 mm SL). Colombia, Caquetá, Florencia, río Orteguasa Basin, Amazon watershed [rio Caquetá- Japurá], N. Maria, 1932 .

Non-type material. Río Ucayali basin, PERU , UCAYALI: CAS 70915, 8 (unsexed 23.8-27.5 mm SL), lago Cashiboya , cut off lake of río Ucayali above Contamana , connected to river by narrow channel . MZUSP 26039 , 1 (unsexed 23.8 mm SL), Coronel Portillo, Iamiricocha, Masisea , [near mouth of río Pachitea] . MZUSP 26066 , 1 (male 33.1 mm SL, 3 unsexed 31.2-34.9 mm SL), río Huacamayo, road Pucallpa-Huánuco . MZUSP 26145 , 1 (female 34.7 mm SL), Coronel Portillo, Bagazán [Nuevo Bagazán, río Ucayali] . MZUSP 26151 , 16 m (11 males, 32.7-37.8 mm SL, 5 females, 34.0- 35.9 mm SL), same data as MZUSP 26151 . MZUSP 26389 , 4 (unsexed 28.8-33.0 mm SL), Pucallpa , Ucayali, río Ucayali. MZUSP 26473 , 6 m (females 32.1-40.5 mm SL), río Neshuya, road Pucallpa- Huánucu . USNM 280627 , 2 (unsexed 25.9-26.3 mm SL), Coronel Portillo , main channel and side pools of río Ucayali, approximately 10 km upstream of Pucallpa, 08°31’S 74°22’W. USNM 324110 , 2 (unsexed 20.4-21.3 mm SL), same locality as USNM 280627. PERU , LORETO: NRM 15720, 2 m (unsexed 30.3-30.5 mm SL), quebrada Copal at km 15 on road Jenaro Herrera-Colonia Angamos , 04°57’S 73°32’W . MCP 27380, 5 m of 18 (unsexed, 28.3-37.1 mm SL), Maynas, Reserva Nacional Pacaya-Samiria, caño Yarina , Pacaya tributary, 5°20’34’’S 74°30’01’’W . MCP 35585, 1 (unsexed 27.1 mm SL), río Pacaya, cocha Yanayacu , río Ucayali drainage. MCP 35586, 5 (unsexed 24.5-27.4 mm SL), same locality as MCP 35585. MCP 27378, 4 (unsexed 26.5-29.9 mm SL), Maynas, río Pacaya, on the road of lagoons Shauinto and Yanayacu , Reserva Nacional Pacaya-Samiria , 5°16’59’’S 74°25’29’ ’W . MCP 35587, 1 (unsexed 28.8 mm SL), río Pacaya, PV 2, caño, lago Yarina , río Ucayali drainage. PERU , JUNÍN: AMNH 20910 , 1 (female 40.8 mm SL), Osherato, either río Tambo, brook Osherato or brook Onkoneni , [río Tambo basin or río Ene-Tambo, upper río Ucayali]. PERU , PASCO: MCP 14974, 10 (4 males 25.3-27.4 mm SL, 3 females 35.8-38.7 mm SL, 3 unsexed 26.4-29.5 mm SL), Puerto Bermudez, upper río Pachitea. Upper río Ucayali, río Urubamba basin, PERU , CUSCO, LA CONVENCIÓN, ECHARATE : USNM 362022 , 8 m of 34 (15 males 30.2-38.6 mm SL [4m males 32.0- 38.6 mm SL], 6 females 33.9-37.2 [4m females 33.9-36.8 mm SL], 13 unsexed 26.1-36.6 mm SL) , río Urubamba , quebrada Pakiria . USNM 362027 , 3 (females 35.9-38.3 mm SL), Segakiato, quebrada Prokigiato . USNM 362028 , 6 (2 males 36.9-38.0 mm SL, 4 unsexed 28.8-35.9 mm SL), Segakiato, río Camisea . USNM 362029 , 2 (females 35.3-35.8 mm SL), Malvinas , Cocha Nueva . USNM 362034 , 4 (1 male 38.9 mm SL, 2 females 38.7-39.5 mm SL, 1 unsexed 28.9 mm SL), Peruanita, cocha, Konkariari . USNM 362035 , 1 (unsexed 33.8 mm SL), Segakiato, quebrada Anuintoniato. PERU , UCAYALI, ATALAYA: USNM 362024 , 6 (4 males 35.1-40.2 mm SL, 2 unsexed 32.3-38.7mm SL), Sepahua, quebrada Shamboyacu . USNM 362031 , 8 (unsexed 26.1-34.2 mm SL), lower río Urubamba, Nueva Itália . USNM 362041 , 9 (unsexed 27.9-37.8 mm SL), Sepahua, quebrada Pulija, lower río Urubamba . USNM 362043 , 10 (2 males 29.7 mm SL & 33.7 mm SL, 7 females 31.9-38.5 mm SL), Sepahua, río Urubamba, quebrada Shambuyacu. Rio Marañon basin , ECUA- DOR, PASTAZA: FMNH 113504 , 2 (unsexed 35.9-36.2 mm SL), stream about 100 m from beach called Waama, río Pastaza drainage, 02°16’56"S 77°11’05"W . MZUSP 87746 , 11 m (1 male 37.2 mm SL, 8 unsexed 33.4-43.1 mm SL, 2 females 36.2 -39.3 mm SL c&s), dead arm of río Pastaza , 02°17’75"S 77°10’13"W. ECUADOR , MORONA-SANTIAGO: FMNH 113515 , 12 m of 26 (6 males 36.4-45.1 mm, 6 unsexed 34.2-42.7 mm SL), tributary of río Pastaza at [Puerto] Pakintsa , 02°15’46"S 77 °14’17"W. PERU , LORETO: ASNP 150016 , 14 m of 24 (7 males 28.1-35.3 mm SL, 7 females 28.8-33.1 mm SL), río Huallaga, Yurimaguas creek . FMNH 113503 , 11 (unsexed 24.0- 34.2 mm SL), río Huitoyacu [río Pastaza drainage], about 0.5 km upstream from the mouth, 04°11’54"S 76°32’38"W . INHS 54760 , 6 (unsexed 21.2-25.4 mm SL), floodplain along south bank of south channel of río Marañon due south of Nauta , 04°30.6’S 73°34.1’W . MCP 14944, 5 (2 males 29.5-30.7 mm SL, 3 females 30.6-33.6 mm SL), same data as ANSP 150016 . MZUSP 77834 , 5 m of 49 (28.1-31.3 mm SL), cocha Huanayo , 4°10’50’’S 76°33’5 ’’W . MZUSP 77843 , 5 m of 147 (23.0- 26.1 mm SL), laguna Huayruri , 3°37’32 ’’S 76°24’48’’W . NRM 15756, 19 unsexed of 100 (unsexed 14.3-22.7 mm SL), Teniente López, beach and meadows on left bank of río Corrientes , [río Tigre drainage] . NRM 15653, 1 (female 32.5 mm SL), Nuevo Andoas , pools on Isla Yanayacu and right bank sandy beach in río Pastaza . NRM 50321, 13 m (3 males 31.4-34.8 mm SL, 4 females 34.2-39.1 mm SL, 6 unsexed 32.3-34.6 mm SL), río Tigre drainage, San Jacinto , quebrada at km 45.5. PERU , MORONA: ANSP 150047 , 4 (2 males 34.1- 35.6 mm SL, 2 unsexed 21.9-27.7 mm SL), [río Morona basin], Gosulima Cocha. PERU , HUÁNUCO: ANSP 136951 , 4 (females 47.0- 48.7 mm SL) , Huánuco, vicinity of Tingo Maria, main stream of río Tullamayo , near Puerto Nuevo. Río Yanayacu basin, PERU , LORETO: ASNP 178383 , 2 m (unsexed 20.4-21.9 mm SL), Maynas, at mouth of caño Chincana & Emerald Forest Lodge, approximately 25 miles south of Iquitos. Río Itaya basin, PERU , LORETO: ANSP 178908 , 12 m (5 males 31.7-35.5 mm SL, 1 female 36.9 mm SL, 1 female 35.5 mm SL c&s, 5 unsexed 29.8-34.7 mm), Maynas, [lower río Itaya] at bridge on Iquitos-Nauta highway, approximately 25 miles SSW of Iquitos. INHS 40226 , 1 (unsexed 22.5 mm SL), quebrada Mazana, around 1 km up from confluence with río Itaya, S of Belém, Iquitos. Lower río Napo basin, río Mazán , PERU , LORETO: NRM 15719, 6 m (3 males 32.2-34.0 mm SL, 3 unsexed 32.8-35.2 mm SL), same data as neotype. Río Ampiyacu basin, PERU , LORETO: ANSP 131535 , 1 m (unsexed 30.8 mm SL alizarin stained), near Pebas, Chancho caño . CAS 136607 , 1 m (unsexed 32.8 mm SL), caño Chancho . CAS 136608 , 1 m (unsexed 35.2 mm SL), caño Chancho [lower río Ampiyacu basin, near Pebas] . USNM 175990 , 1 m (unsexed 35.8 mm SL), caño [ Chancho ] . USNM 207666 , 1 (unsexed 21.1 mm SL), near [Pevas], río Ampiyacu drainage. Río Orosa basin, PERU , LORETO: INHS 39313 , 2 (unsexed 20.0- 20.7 mm SL), Mayuruna Cocha, around 30 minutes by boat downstream of mouth of caño Tonche , 71.7 miles east Iquitos. INHS 39789 , 1 (unsexed 23.8 mm SL), lago Pabellon, around 40 minutes upstream by boat from Paucarillo base camp 57.1 miles east Iquitos. Río Yavari / Javari basin, PERU , LORETO: NRM 15671, 3 m of (unsexed 26.8-30.6 mm SL), Colonia Angamos, quebrada behind school building. Upper río Amazonas basin, PERU , LORETO: ANSP 136955 , 6 (unsexed), vicinity Iquitos, río Nanay opposite naval base, backwater pools off coche, 4 miles above Amazon. ANSP 136958 , 3 (unsexed), same data as ANSP 136955 . ASNP 178239 , 1 m (unsexed 35.5 mm SL), Maynas, río Amazonas main channel along W bank, ca. 30-45 min. upstream from inlet to Iquitos (=mouth río Itaya ) . CAS 70897, 1 (unsexed 26.6 mm SL), Iquitos, río Amazonas . INHS 39852 , 1 (unsexed 21.2 mm SL), río Amazonas, across from Puebla Gallito , 7.68 miles SE Iquitos. INHS 540237 , 1 (unsexed 22.9 mm SL), río Amazonas, ca. 10 & 40 minutes upstream from mouth caño Zapatilla, near town of Yanashi . COLOM- BIA, AMAZONAS: FMNH 85346 , 27 (unsexed 19.9-25.5 mm), black water river at Yauacaca and first tributary upstream from Leticia on the Colombian side . MCP 14949, 8 m of 10 (1 male 33.4 mm SL, 2 females 32.7-34.2mm SL, 5 unsexed 31.9-34.0mm SL), Leticia, backwater (the lakes) area cut off from río Amazonas , formerly ANSP 135937 . MCP 35263, 2 (males 32.4-34.0 mm SL), same data as MCP 14949, formerly ANSP 135975 . ROM 56384, 6 (unsexed 24.2-31.0 mm SL), 10-60 miles upstream from Letícia, río Amazonas , 4°09’S 69°57’W . ROM 56443, 42 (9 males 31.8-33.4 mm SL, 33 unsexed 31.3-33.9 mm SL), same place as ROM 56384. Río Putumayo basin, PERU , LORETO: NRM 26365, 4 m (unsexed 21.8-24.4 mm SL), Estrecho, río Putumayo right bank, 02°28’S 72°42’W. COLOMBIA , AMAZONAS: NRM 26430, 3 m (unsexed 29.5-32.1 mm SL), río Putumayo drainage, Buenaventura, flooded river margin. Rio Jutaí basin, BRAZIL , AMAZONAS: MZUSP 17585 , 8 (unsexed 21.4-28.1 mm SL), rio Içapó, mouth of rio Jutaí. Rio Juruá Basin , BRAZIL , ACRE: MPEG 1951 , 3 (unsexed 21.0- 23.8 mm SL), Marechal Taumaturgo, rio Juruá, Seringal do Oriente . MPEG 6790 , 10 m of 30 (unsexed 29.4-32.9 mm SL), Tarauacá, rio Tarauacá . MZUSP 30372 , 4 m (3 unsexed 20.0- 24.7 mm SL, 1 female 32.2 mm SL), same locality as MPEG 6790 . MZUSP 31820 , 1 (unsexed 22.8 mm SL), same locality as MPEG 6790 . MZUSP 42842 , 21 (unsexed 18.5-22.0 mm SL), same locality as MPEG 6790 . MZUSP 87749 , 2 m (unsexed 21.6-29.7 mm SL), same locality as MPEG 6790. Rio Japurá Basin , BRAZIL , AMAZONAS: MZUSP 27760 , 13 (unsexed 17.9-28.0 mm SL), Tefé, Costa Japão , lower rio Japurá . MZUSP 74964 , 22 (unsexed 22.0- 31.6 mm SL), Serrinha, rio Japurá in Serrinha, right margin . MZUSP 77466 , 2 (unsexed 34.9-36.4 mm SL), Vila Bitencourt . MZUSP 77535 , 9 of 19 (unsexed 24.8-28.7 mm SL), rio Japurá in Serrinha. Rio Purus Basin, BRAZIL , ACRE: MCP 37473, 1 (unsexed 38.5 mm SL), small affluent of rio Iaco, road Sena Madureira-Rio Branco, about 8 km of Sena Madureira . MCP 38106, 2 (unsexed 25.6- 24.3 mm SL), rio Acre, Xapuri. MZUSP 49580 , 3 (unsexed 20.8-22.4 mm SL), rio Acre. MZUSP 49669 , 1 (unsexed 28.2 mm SL), Porto Acre, rio Acre, Seringal Bom Destino (1 hour upper Porto Acre), Instituto. MZUSP 49767 , 2 (unsexed 23.0- 27.3 mm SL), rio Acre, between Seringal Paraíso and lago Amapá. MZUSP 87754 , 29 (unsexed 23.0- 33.4 mm SL), Manoel Urbano, rio Purus. BRAZIL , AMAZONAS: MZUSP 49512 , 11 of 22 (unsexed 21.4-27.2 mm SL), Boca do Acre, rio Acre. Rio Solimões basin, BRAZIL , AMAZONAS: MCP 38314, 20 (unsexed 22.5-30.9 mm SL), stream in Jacaré, near Fonte Boa . MZUSP 6315 , 1 (unsexed 24.7 mm SL), lago Castro, mouth of rio Purus . MZUSP 9644 , 2 (unsexed 23.4-26.6 mm SL), lago Supiá in front of Codajás . MZUSP 9647 , 5 (unsexed 16.2-19.5 mm SL), same data as MZUSP 9644 . MZUSP 16690 , 1 (unsexed 23.8 mm SL), Benjamin Constant , [rio Solimões] . MZUSP 17344 , 8 (unsexed 18.8-25.3 mm SL), rio Solimões, Ilha Sorubim, above Coari . MZUSP 17415 , 10 (unsexed), same data as MCP 38314. MZUSP 17421 , 175 (unsexed 17.9-31.6 mm SL), same data as MCP 38314. MZUSP 17438 , 3 (unsexed 18.1-24.9 mm SL), igarapé Manduaçú, paraná de Iupiá , NW Fonte Boa . MZUSP 17498 , 5 (unsexed 18.0- 37.9 mm SL), rio Solimões, near Ilha de Baruruá, above mouth of rio Jutaí . MZUSP 17395 , 33 (unsexed 16.5-28.1 mm SL), rio Solimões . MZUSP 17520 , 2 (unsexed 22.1-30.5 mm SL), Santo Antônio do Içá, mouth of rio Içá . MZUSP 17632 , 4 (unsexed 28.7-31.0 mm SL), Fonte Boa, rio Solimões . MZUSP 27751 , 13 (unsexed 15.4-24.3 mm SL), Benjamin Constant, paraná do Capacete, rio Solimões . MZUSP 78108 , 11 of 23 (unsexed 15.5- 21.1 mm SL), Costa do Anori, pool, rio Solimões, near mouth of rio Purus . MZUSP 78109 , 3 (unsexed 18.9-21.5 mm SL), same data as MZUSP 78108 . USNM 310856 , 3 (2 males 34.1-34.4 mm SL, 1 unsexed 33.6 mm SL), muddy igarapé connecting rio Solimões and blackwater lake ca. 15 miles west of Coari. BRAZIL , AMAZONAS, municipality of Manaus and proximities (including municipalities of Iranduba or Careiro ) : INPA 18461 , 9 (8 males 32.6 mm SL, 1 female 35.1 mm SL), lago Janauacá , mouth of channel . INPA 18465 , 66 m of 73 (34 males 33.0- 36.5 mm SL, 2 males 34.9-37.2 mm SL c&s, 13 females 32.9-38.1 mm SL, 2 females 34.5-38.4 mm SL c&s, 15 unsexed 29.7-35.9 mm SL), Ilha da Marchantaria . INPA 18467 , 25 (7 males 31.7-34.4 mm SL, 18 unsexed 22.5-36.3 mm SL), same locality as INPA 18465 . INPA 18506 , 10 m of 50 (1 male 32.4 mm SL c&s, 1 female 33.9 mm SL c&s, 1 unsexed 23.7 mm SL c&s, 7 unsexed 22.2-24.4 mm SL), paraná do Xiborena . INPA 18510 , 132 (unsexed 19.1-29.2 mm SL), lago Pirapora, Catalão . INPA 18512 , 1 m (male 34.9 mm SL c&s), same locality as INPA 18510 . MCP 35775, 110 (61 males 30.0- 36.2 mm SL, 45 females 30.9-36.9 mm SL, and 4 unsexed 28.8-30.0 mm SL), Janauari, lago Terra Preta . MCP 35777, 12 m of 36 (6 males 30.6-36.6 mm SL, 6 females 34.5- 37.2 mm SL), same locality as MCP 35775. MZUSP 6047 , 1 (unsexed 26.9 mm SL), lago do Rei , Ilha do Careiro . MZUSP 18736 , 2 (unsexed 26.3-33.7 mm SL), lago Janauacá, left margin of rio Solimões . MZUSP 18743 , 1 (unsexed 33.0 mm SL), lagoon linked to channel of lago Janauacá, left margin of rio Solimões . USNM 307448 , 21 (14 males 32.5-36.7 mm SL, 7 females 37.9 mm SL), São José, lago do Castanho, Janauacá . USNM 308329 , 20 (7 males 31.2-34.4 mm SL, 13 unsexed 27.9-34.3 mm SL), lago Terra Preta, Janauari . USNM 310851 , 2 (males 31.0- 31.4 mm SL), lower rio Negro: igarapé Xiborena ca. 30 km east Manaus. USNM 315907 , 29 (unsexed 20.7-26.9 mm SL), lago Murumuru , cattle enclosure . USNM 332135 , 1 (male 32.6 mm SL), near Manaus, lago Janauari, lago Terra Preta . USNM 323629 , 3 (unsexed 27.0- 29.9 mm SL), northwest shoreline of Ilha Paciência, rio Solimões, southeast of Manaus. Lower rio Amazonas basin, BRAZIL , AMAZONAS: MZUSP 76436 , 2 (unsexed 34.4-35.4 mm SL), Parintins, São José, rio Amazonas , left margin, stream mouth . MZUSP 76437 , 1 (unsexed 37.6 mm SL), same as MZUSP 76436 . BRAZIL , PARÁ: ANSP 150113 , 5 (3 males 35.1-35.3 mm SL, 2 females 35.7-36.9 mm SL), paraná-Mirim, lagoa Grande, east of Óbidos . ANSP 149979 , 4 (unsexed 34.6-35.6 mm SL), Centro Comercial, brook into lago Grande [near Santarém] . MCP 14959, 4 (3 males 32.6-36.2 mm SL, 1 female 39.2 mm SL), same as ANSP 150113 . MZUSP 9498 , 7 (unsexed 18.3-24.2 mm SL), Monte Alegre, rio Amazonas . MZUSP 16565 , 2 (unsexed 27.0- 27.3 mm SL), Oriximiná, Paissandu, [mouth of rio Trombetas]. Rio Madeira Basin , BRAZIL , RONDÔNIA, CALAMA: MCP 38482, 12 m (5 males 32.1-33.1 mm SL, 7 unsexed 30.9-35.4 mm SL), paraná do Caraparú, rio Madeira . MPEG 3211 , 1 (female 38.6 mm SL), same locality as MCP 38482. MPEG 3213 , 1 (female 36.7 mm SL), paraná do Flechal . MZUSP 30212 , 1 (unsexed 21.2 mm SL), beach of rio Madeira . MZUSP 30213 , 1 (unsexed 24.9 mm SL), same locality as MCP 38482. MZUSP 30216 , 1 (female 42.5 mm SL), same data as MPEG 3213 . MZUSP 30218 , 37 (23 males 29.4-32.8 mm SL, 14 unsexed 29.7-34.3 m SL) , same data as MCP 38482. MZUSP 30219 , 1 (unsexed 29.2 mm SL), rio Madeira, mouth of rio Machado . MZUSP 30220 , 1 m (male 33.0 mm SL) . MZUSP 30221 , 1 (unsexed 31.4mm SL), rio Madeira . MZUSP 31784 , 1 unsexed 30.9 mm SL, same locality as MCP 38482. MZUSP 35600 , 11 (unsexed 21.8-34.2 m SL) . MZUSP 42838 , 11 (unsexed 15.1-27.6 mm SL), poço da Angélica, rio Madeira . BRA- ZIL, AMAZONAS: MZUSP 6961 , 3 (unsexed 19.7-27.7 mm SL), 25 km below Nova Olinda. MZUSP 18658 , 20 (unsexed 19.1-27.2 mm SL), igarapé Xicanga, 5 km from Humaitá, east part of Transamazônica . MZUSP 35591 , 3 (unsexed 27.3-29.1 mm SL), mouth of igarapé Puruzinho, rio Madeira . MZUSP 35618 , 20 (unsexed 21.2-27.9 mm SL), ilha do Puruzinho, rio Madeira . MZUSP 55922 , 3 (unsexed 19.2-20.1 mm SL), rio Madeira, 17.3 km below paraná do Maracá , 3°40’48"S 59°5’30"W . MZUSP 57082 , 1 (unsexed 25.6 mm SL), rio Madeira, 15.9 km below paraná do Maracá , 3°43’6"S 59°5’56"W . USNM 310855 , 19 (unsexed 18.6-25.2 mm SL), same data as MZUSP 18658. BRAZIL , RONDÔNIA: FMNH 57880 , 3 (unsexed 27.7-33.4 mm SL), Santo Antonio, rio Madeira . MZUSP 31821 , 1 (unsexed 19.0 mm SL), rio Madeira, cachoeira de Teotônio . MZUSP 35605 , 2 (unsexed 26.7-31.4 mm SL), rio Madeira, cachoeira de Santo Antônio . MZUSP 35610 , 2 (unsexed 23.4-27.7 mm SL), same data as MZUSP 35605 . MZUSP 42840 , 22 (unsexed 16.3-26.9 mm SL), rio Madeira, cachoeira de Teotônio . MZUSP 74227 , 30 of 233 (unsexed 22.0- 28.3 mm SL), rio Machado near mouth . MZUSP 74321 , 30 of 455 (unsexed 23.2-27.9 mm SL), same data as MZUSP 74227 . MZUSP 76551 , 1 (unsexed 26.0 mm SL), Santo Antônio, rio Machado , beach . MZUSP 76829 , 1 (unsexed 27.5 mm SL), Santo Antônio, rio Machado , beach . MZUSP 80041 , 30 of 91 (unsexed 22.6-28.6 mm) SL, same data as MZUSP 74227 .

Diagnosis. The combination of the following characters distinguish Odontostilbe fugitiva from all the other species of the genus: (1) mouth terminal, mouth slit nearly at horizontal through middle of eye (vs. subterminal, mouth slit at horizontal near lower eye edge in O. euspilura and O. microcephala ; or slightly subterminal, mouth slit at horizontal below middle of eye in O. dierythrura ); (2) in males snout not very protruding, but slighthly pointed or blunt (vs. very protruded in O. euspilura , O. microcephala , and O. dierythrura ); (3) usually 7 large dentary teeth, with seven cusps (vs. 4 large dentary teeth with 3 large and compressed central cusps and 2, 3 lateral small cusps in O. pequira ); (4) elongation of 2 nd unbranched dorsalfin ray (vs. no elongation in O. euspilura , or very short elongation in O. pulchra ); (5) pectoral-fin never extending beyond pelvic-fin origin (vs. extending beyond in males of O. pulchra ); (6) branched anal-fin rays 19-24 (mostly 21-22) [vs. 16-20 (mostly 17-18 in O. microcephala , and 17-20 (mostly 18-19) in O. euspilura ]; (7) 1 st to 9 th (mostly 6 th- 7 th) anal-fin branched rays of males with hooks, positioned at distal half-length of fin rays, tiny hooks occasionally present distally up to 19 th anal-fin branched ray (vs. well-developed hooks on 1 st to 22 nd anal-fin branched rays at distal half length of fin rays in O. pulchra ); (8) no hooks found on 1 st unbranched pelvic-fin rays (vs. 1-2 unpaired hooks per segment on 1 st unbranched pelvic-fin ray occasionally present in O. euspilura and O. pulchra ); (9) gill rakers on upper branch usually 6-7, lower branch usually 12-13 (vs. usually 10-12 on upper branch and 14-16 on lower branch in O. microcephala ; 11-12 on lower branch in O. dierythrura and O. pulchra ; 5-6 on upper branch and 9-10 on lower branch in O. euspilura ; and 7-8 on upper branch and 13-15 on lower branch in O. pequira ); and (10) 4 separate supraneurals (vs. supraneurals partially fused in O. paraguayensis ). Upper gill raker counts differ O. fugitiva (5-6) from O. ecuadoriensis , O. nareuda , and O. parecis (6-7).

Description. Morphometric data in Table 1. Largest male 45.1 mm SL, female 48.7 mm SL. Body elongate and compressed. Males with more compressed bodies than females. Greatest body depth at dorsal-fin origin. Snout slightly pointed or blunt in males. Head profile gently convex from snout to posterior tip of supraoccipital bone. Predorsal profile slightly convex to straight between posterior tip of supraoccipital bone and dorsal-fin origin, then straight from dorsal-fin origin to caudal peduncle. Ventral profile convex from mouth tip to anal-fin origin. Anal-fin base straight. Caudal peduncle slightly longer than deep.

Head relatively small. Posterior margin of opercle sinusoidal with upper portion concave and lower portion convex. Mouth terminal, mouth slit nearly at horizontal through middle of eye. Obliquously positioned maxilla ending at vertical near or at anterior border of eye and at horizontal on inferior eye border, not crossing these limits. Dentition (based on 10 c&s specimens and 17 alcohol specimens). Premaxillary teeth 5-6, bearing 6-11 cusps (usually 8, 9, and 10); midcentral cusp longer than others; smaller lateral cusps of each tooth overlap cusps of adjacent teeth, except anteriormost teeth ( Fig. 2 ). Premaxillary teeth juxtaposed external to dentary teeth, leaving premaxillary tooth cusps exposed when mouth closed. Maxilla with 2-3 teeth bearing 1-9 cusps (mostly 7-9), decreasing cusp number toward posterior tip of maxilla. Dentary teeth 8-10 bearing 1-9 cusps, gradually decreasing in size posteriorly, first 6-7 teeth largest with 5-9 cusps (mostly 7), 1 medium-sized tooth with 4-7 cusps and last 1-3 teeth very small, conic or with 2-5 cusps. Smaller cusps of dentary teeth overlaping adjacent tooth cusps, usually not in posteriormost teeth. All dentary tooth cusps upwardly pointed or slightly recurved towards interior of mouth.

Dorsal-fin rays ii (259), 8(1), or 9 (258). Dorsal-fin origin slightly posterior to midlength of body, and slightly posterior to pelvic-fin origin. First unbranched dorsal-fin ray in females and immature males about half length of second unbranched dorsal-fin ray. Second unbranched dorsal-fin ray slightly elongate in mature males, extending beyond dorsal-fin distal profile.Anal-fin rays iv (14), v(241) or vi(4), 19(14), 20(57), 21(103), 22 (57), 23(23), or 24(5). Anal-fin distal border concave, anterior 6-7 branched rays longest. Pectoral-fin rays i (259), 9(1), 10(11), 11 (135), 12(105), or 13(7). Unbranched pectoral-fin ray reaching or not pelvic-fin origin, never extending beyond that point. Pelvic-fin rays i (259), 6(4), 7 (244), 7i(7), or 8(4). Unbranched pelvic-fin ray longest in mature males, extending beyond origin of anal fin. Lateral skin border of unbranched pectoral-fin ray and unbranched pelvic-fin ray thickened in mature males, bearing thin laterodorsal projection of hard tissue covered with soft tissue. Principal caudal-fin rays 19 (254), rarely 16(1), 17(1), 18(7) or 20(2). Procurrent caudal-fin rays: dorsal 10(34), 11 (113), 12(96), 13(9), or 14(4); ventral 7(1), 8(14), 9(133), 10 (94), or 11(14). Anterior 1 or 2 ventral procurrent caudal-fin rays sometimes laterally expanded, bifurcated, or S-shaped. Caudal-fin ray flaps ventrally on 2 nd- 8 th (mostly 4 th- 7 th) branched rays of upper lobe, and dorsally on 12 th- 16 th (mostly 13 th- 15 th) branched rays of lower lobe. Adipose-fin at vertical through last anal-fin ray insertion.

Males with acute, elongate, retrorse hooks on posterior margin of pelvic- and anal-fin rays. One or two (rarely 3) paired and unpaired hooks per segment of lepidotrichia, on last unbranched anal-fin ray, and 1 st to 8 th (mostly 6 th- 7 th) anal-fin branched rays, positioned at distal half-length and not extending to ray tip; tiny hooks can be present distally up to 19 th anal-fin branched rays in very developed males (e.g. INPA 18506, ANSP 178908, ANSP 15006, and neotype). One or two (rarely 3) unpaired and long hooks per segment of lepidotrichia along almost all length of 1 st to 7 th branched pelvic-fin rays, reaching distal tip of fin ray (expect on 1 st branched pelvic-fin ray, on midlength portion). No hooks found on 1 st unbranched pelvic-fin ray. One to 3 unpaired hooks sometimes present on anterior border of anal- and pelvic-fin rays branches.

Scales cycloid; lateral line complete 34(3), 35(21), 36 (90), 37(4), or 38(1); predorsal row 9(4), 10(98), 11 (122), or 12(6); scale rows between lateral line and dorsal-fin origin 5(31), 6 (190), or 7(5); scale rows between lateral line and anal-fin origin 4 (238) or 5(5); scale rows around caudal peduncle 14 (186). Triangular modified scale on pelvic fin base extends posteriorly covering 1-3 scales (mostly 2). Scales on anal-fin base 5, 6, or 7.

Cleared and stained specimens (11): supraneurals 4-5(11); precaudal vertebrae 16(9) or 17(2); caudal vertebrae 18(3), 19(7), or 20(1); gill rakers, upper 6(1) or 7(5), lower 12(6) (2-3 on hypobranchial). Alcohol specimens (174): gill rakers, upper 6(83), 7 (89), or 8(2), lower 11(15), 12(119), 13 (36), or 14(4). Upper gill rakers with 1-5 recurved denticles on anterolateral Color in alcohol. General ground body color brownish or pale yellow. Dark dorsum pigmentation from head to caudal peduncle, dark chromatophores mostly on border of scales forming reticulated pattern. Pigmented scales extend laterally on body below longitudinal stripe, also on pseudotympanum area or not. Dorsal fin entirely scattered with dark chromatophores along fin rays, densely along 1 st- 2 nd unbranched dorsal-fin rays. Dark chromatophores along 1 st- 9 th dorsal branched fin rays, except almost hyaline 9 th branched fin ray. Pectoral and pelvic fins with scattered dark chromatophores, more numerous on anteriormost portions of fins. Fresh specimens only with 7 th branched pelvic-fin ray hyaline. Neotype with 1- 5 th branched pelvic-fin rays pigmented. Pelvic fin mainly hyaline in old-preserved specimens.Anal fin with dark chromatophores spread on all fin rays or on more central branched anal-fin rays, except at tips of last unbranched fin rays and 1 st branched fin ray. Adipose fin not pigmented. Caudal fin almost entirely covered with diffuse dark chromatophores along fin rays, except clear areas on base of caudal-fin lobes just behind caudal-fin spot. Rounded black to brown spot on base of caudal fin, reaching upper and lower border of peduncle, or upper border only, sometimes extending little onto proximal portion of 7 th to 12 th central principal caudal-fin rays.

Numerous dark chromatophores, somewhat contiguous, on snout, upper and lower lips, anteriormost portion of maxilla, and 1 st, 2 nd, and 6 th infraorbitals. Top of head on frontals and parietals pigmented, with deep-lying dark chromatophores over brain membranes below frontals and parietals, and fontanel. Body with faint dark and silver midlateral stripe, sometimes forming black line along middle longitudinal body axis, beginning behind or on pseudotympanum, above lateral line, and reaching caudal spot. Guanine on eye iris, opercle, isthmus, and most of 3 rd infraorbital. Below lateral line, belly faint almost without pigmentation, chromatophores above anal-fin base forming 12 to 15 chevron shaped markings.

Color in life. Life color of specimen from lower Ucayali drainage ( Fig. 4 ). One red spot on base of each caudal fin lobe, just posterior to caudal fin black blotch. Red and yellow pigments most on dorsal and anal fins. White pigment on tips of last unbranched and 1 st- 2 nd branched anal-fin rays, and of unbranched and first branched pelvic-fin rays.

border, and anteriormost upper gill rakers with none or 1 similar denticle on posterolateral border; lower gill rakers with 1- 4 denticles on anterolateral border, and none or 1 on posterolateral surface; and posteriormost lower gill raker with none or 1 recurved denticle on anterolateral border, and none, 1 or 2 similar denticles on posterolateral border ( Fig. 3 ). Denticulation mainly on basal portion of gill rakers.

Sexual dimorphism. Males with hooks on anal- and pelvicfin rays, and elongate dorsal- and pelvic-fin rays, in contrast to absence of these features in females. A gill gland (Burns & Weitzman, 1996) present in mature males on first gill arch, covering about 8 to 10 anterior branchial filaments ( Fig. 3 ). Sexual dimorphism in general body shape is also recognized by principal component analysis performed on measurements of males and females ( Fig. 5 ). Principal component 2 (PC2) grouped males and females separately. It was affected strongly and negatively by pelvic-fin length, snout length, and dorsal-fin length; and positively by depth at dorsal-fin origin. Males are particularly distinct from females in all of these characters, having higher values of pelvic-fin length, snout length, and dorsal-fin length than females, while females have higher depth values at dorsal-fin origin than males ( Table 1). Principal component 3 (PC3) was affected strongly and positively by snout length and upper jaw length, and negatively by pelvic-fin length and dorsal-fin length. Variation on PC3 seems to be related to the level of development of pelvic- and dorsal-fin rays, snout protusion (snout length, and upper jaw length) in males, because males with higher values for these features are located upper on PC3 axis ( Fig. 5 ).

Remarks on the holotype of Odontostilbe fugitiva . The short description of O. fugitiva by Cope (1870) makes no reference to type specimens. Most type-specimens of fishes described by Cope were deposited at ANSP, although some at USNM and some are missing ( Böhlke, 1984; Vari & Howe, 1991). Henry W. Fowler was the first full-time curator of the fish collection at ANSP, and one of his first tasks was the cataloging of the extensive collection of Edward D. Cope ( Böhlke, 1984). During his stay at ANSP, Fowler (1913: 529, 532) described O. madeirae and O. drepanon and Fowler (1940) O. dierythrura and O. hasemani , but he did not mention any type specimens for O. fugitiva . Finally, when describing O. caquetae, Fowler (1943: 232) stated that the type of O. fugitiva was lost. Géry (1972a) also affirmed the holotype of O. fugitiva was lost after visiting ASNP to study Fowler’s type material. Vari & Howe (1991) did not list O. fugitiva among characiform type specimens at USNM.

Böhlke (1984: 46) indicated ANSP 8059 as the holotype of O. fugitiva , and noticed that “original Cope label and catalog indicate this to be type of O. fugitiva ”. However, in the same publication, Böhlke (1984: 46) remarked the same lot (ANSP 8059) was listed by Fowler (1906) as the holotype of Aphyocharax filigerus , valid as Prionobrama filigera ( Cope, 1870) . Examination of ANSP 8059 confirmed this is a specimen of P. filigera . Both authors have fruitlessly searched the ANSP and USNM fish collections after the type material of O. fugitiva [including the lot ANSP 8073 listed by Fowler (1906) as cotypes of Aphyocharax filigerus ].

Neotype designation. Odontostilbe fugitiva is the type species of Odontostilbe , and the designation of a neotype, as well as establishment of the identity of the type species is essential in solving nomenclatural questions among cheirodontines. The neotype was not caught at Pebas, the original type locality of O. fugitiva . Pebas is located at the confluence of río Ampyiacu with río Amazonas, Loreto, Peru. The neotype is a mature male from an affluent of lower río Napo basin, río Mazán, upper rio Amazonas, Loreto, Peru. Río Mazán is to the west of the type locality, being the nearest site ( Fig. 6 ) with the best preserved mature male ( Fig. 1 ) available, being in conformity with ICZN (1999). Since secondary sexually dimorphic characters are important to distinguish Odontostilbe and other Cheirodontinae genera, a mature male is preferred as the neotype. The chosen male has entire elongate 2 nd unbranched dorsal-fin ray and unbranched pelvic-fin rays, well-developed acute retrorse hooks on pelvic- and anal-fin rays, preserved scales, and well-preserved color pattern ( Fig. 1 ). Cope (1870: 566) referred to a “transverse line [of scales] at vent 11; at ventral fins 5-5”. Although distinct from the counts of the neotype, these counts are included in the range found herein for the species (5-7 between lateral line and dorsal-fin origin and 4-5 between lateral line and anal-fin origin).

The status of Odontostilbe madeirae and Odontostilbe drepanon . Both species were described in the same paper by Fowler (1913). The holotype ( Fig. 7) and all paratypes but one of O. drepanon have the dimorphic characters unique to males of Odontostilbe : elongation of 2 nd unbranched dorsal-fin ray and 1 st unbranched pelvic-fin rays, and presence of hooks on pelvic-fin rays and anal-fin rays. On the other hand, the holotype ( Fig. 7) and all paratypes of O. madeirae lack these characters, and have higher body depth, the diagnostic features for females (see Table 1 and description under Sexual Dimorphism above). The two species described by Fowler (1913) overall match the O. fugitiva diagnosis, and this is a case of misunderstanding dimorphic males and females as two different species. Fowler (1913: 529) remarked that the absence of “the dark-edged silver lateral band” in O. madeirae is a character to distinguish it from O. fugitiva . The holotype and paratypes of O. madeirae actually have a faded longitudinal line of chromatophores posterior to the pseudotympanum.

The holotype of O. madeirae has few dentary teeth remaining, but laterally 4 teeth remain, each with 7 cusps. Premaxillary teeth 5 with 7-8 cusps and maxillary teeth 2 with 7 cusps. The holotype of O. drepanon also lacks most dentary teeth, but on the right side four teeth remain each with about 7 cusps. Premaxillary teeth 5 with 7-9 cusps, and maxillary teeth 2 with 7 cusps. The 2 nd unbranched dorsal-fin ray is broken.

The status of Odontostilbe caquetae . Odontostilbe caquetae was described from a single immature specimen (28.0 mm SL). Fowler diagnosed O. caquetae comparing the holotype with data available in the short redescription of O. fugitiva by Eigenmann (1915:93), which was based on four specimens examined from “San Antonio de Rio Madeira”, measuring “largest 41 mm ”. Following Fowler’s diagnosis, O. caquetae would have a smaller head, smaller eye and larger snout than O. fugitiva . However, measurements and counts of the holotype of O. caquetae overlap those of O. fugitiva ( Table 1), not supporting any of Fowler’s diagnostic characters. For that reason, we consider O. caquetae as a synonym of O. fugitiva .

The holotype is now dark colored and damaged with most dorsal-fin rays and caudal-fin rays broken ( Fig. 8 ). Infraorbitals 2-5 are lacking on the left side. Premaxilla probably would have five teeth, but just two of them remain on each left and right sides, bearing 8-7 cusps. Right maxilla with 2 teeth bearing 8-9 cusps, and left maxilla with only one tooth with 8 cusps. Four dentary teeth remain on each side bearing 5-6 cusps. This dentition is similar to that found in smaller specimens of O. fugitiva , O. pulchra , O. euspilura or O. ecuadorensis . The type locality of O. caquetae is Florencia, río Portuguesa, río Caqueta drainage, where O. euspilura occurs ( Fowler, 1945b). The main reason for not considering O. caquetae as synonym of O. euspilura is the terminal mouth in the former, against the inferior mouth in the latter.

The first right gill arch of the holotype was found cut off from branchial apparatus, but kept under the operculum. Both first gill arches have 6 gill rakers on upper branch and 11 on lower branch. Fowler (1943: 232) described 7+11 gill rakers and it is possible the first gill raker was lost in the damaged upper branches of both gill arches. Specimens of Odontostilbe examined from rio Japurá, the Brazilian name for mid and lower río Caqueta, match O. fugitiva in measurements and counts, including 6, 7 gill rakers on upper gill arch and 12 on lower (one among 10 examined specimens of rio Japurá has 6+11 gill rakers as the holotype of O. caquetae ). Therefore we consider O. caquetae as synonym of O. fugitiva . However, we consider this synonym provisional since no mature males of Odontostilbe were available from upper río Caqueta or rio Japurá.

Distribution and geographical variation. Odontostilbe fugitiva is the most widespred Odontostilbe species in the Amazon basin, occurring from the major western tributaries to the lower rio Amazonas ( Fig. 6 ). More extense records are from the río Ucayali, río Marañon, rio Amazonas and rio Madeira basins. Records from western major tributaries of the Amazon, Purus and Juruá systems, are relatively scarce. Predominantly, the species occurs in major whitewater rivers of the Amazon basin, being not so far identified from the rio Negro, rio Trombetas, rio Tapajós, rio Xingu, rio Tocantins- Araguaia. The well-sampled fish fauna of the rio Negro did not reveal O. fugitiva ( Goulding et al., 1988) , though they listed 12 specimens of “ Cheirodon sp. ” (not found at INPA collection). Chao (2001) also did not include O. fugitiva in a list of fishes of rio Negro basin and lower rio Branco caught by Project Piaba. Personal searches [CMB] at INPA and Project Piaba fish collections failed in finding O. fugitiva in rio Negro material. Lowe McConnell (1991) listed O. cf. fugitiva from a tributary of the rio Araguaia, the rio das Mortes. However, the examination of material from the rio Araguaia basin failed to reveal any O. fugitiva .

Specimens from upper río Marañon, upper río Ucayali drainages, and middle rio Amazonas (rio Solimões) showed some variation in morphometry. This seems to be related to some exceptionally developed males and females in samples from upper portions of Marañon and Ucayali. Indeed, the largest mature specimens of O. fugitiva come from upper río Pastaza, Ecuador (FMNH 113515), and upper río Huallaga, Peru (ANSP 136951), both upper affluents of Maranõn, with some comparable size specimens only from río Urubamba, upper Ucayali. Noteworthy, males from río Marañon basin (río Pastaza, río Tigre, and río Huallaga) show a tendency to have longer snout lengths and upper jaw lengths than males of most populations of upper río Amazonas basin (río Putumayo, río Itaya, río Mazán, río Ampyiacu, río Yavari, and the río Amazonas). However, no additional differences were found to support the recognition of a separate species for río Marañon basin. Some specimens from the upper río Pastaza (FMNH 113515) show a somewhat subterminal mouth similar to O. dierythrura and other undescribed species from río Madre de Dios, upper rio Madeira basin. Odontostilbe dierythrura and this undescribed species, however, possess larger upper jaw length ( Fig. 9 ), and more pronounced snouts than O. fugitiva , including the Marañon population.

Males of río Ucayali basin also had differences in snout and upper jaw length when contrasted with males from the main rio Amazonas basin, having snout length difference statistically significant in the coincidental regression test (F

(2,

74)

= 11.8, p<0.00) ( Fig. 10). When compared to O. fugitiva , O. dierythrura and Odontostilbe n. sp. from Madre de Dios, the upper jaw length of the population from río Urubamba, upper Ucayali, remains at an intermediate range between O. fugitiva and the other two species ( Fig. 11 ). Again, considering there were no additional characters differing these populations, and the overlaps in statistics for snout length and upper jaw length, the Ucayali population is considered to be O. fugitiva .

A significant statistical difference in measurements was also found when comparing rio Solimões samplings from the region near Manaus to overall O. fugitiva material from upper rio Amazonas basin, including río Ucayali and río Marañon systems. Not only males, but females and unsexed specimens jointly, show differences in snout to pectoral-fin length (F (2,200) = 85.6, p<0.00) ( Fig. 12 ). This difference is also considered a variation among O. fugitiva populations. However, there is a lack of mature males and females among specimens available from an extensive portion of the rio Solimões between Letícia, Colombia, and Manaus, Brazil. Most samples from Solimões consisted of material caught near Manaus by Peter Bayley in 1970s or more recently by INPA researchers.

Examined specimens from rio Juruá basin are unsexed, probably juveniles. Exceptionally, two specimens among 8, have 8 upper gill rakers, and 3 specimens have 14 lower gill rakers ( Fig. 13a ). Higher gill raker counts occur in O. dierythrura and in an undescribed species from Madre de Dios. However, the upper jaw lengths of the avaliable specimens of Juruá fit that of O. fugitiva . One specimen of O. fugitiva from the rio Madeira also has 14 lower gill rakers ( Fig. 13b ). Similarly, specimens examined from rio Purus contain only unsexed specimens. In the lack of fully developed, mature specimens, we tentatively assign Juruá and Purus specimens to O. fugitiva .

Ecological notes. Recorded mainly from whitewaters; blackwater as “black-muddy” is cited only for FMNH 85346, a stream near Leticia, Colombia. Sánchez-Botero &Araújo-Lima (2001) referred to Odontostilbe piaba , Odontostilbe sp. and Odontostilbe fugitiva in a list of species associated with roots of aquatic macrophytes during high water period at three floodplain lakes of rio Solimões. Sánchez-Botero et al. (2003) listed Odontostilbe aff. piaba caught under macrophytes Eichhornia azurea and Eichhornia crassipes in lago Camaleão, considering Odontostilbe among the typical fish genera associated to Eichhornia spp. , along with Ctenobrycon, Synbranchus , Hemigrammus , Moenkhausia, Mylossoma , and Hoplias . Some of the fish collected by Sánchez-Botero & Araújo-Lima (2001) were examined at INPA. Three distinct species of Cheirodontinae were identified by those authors as “ O. fugitiva ”, including two Serrapinnus species , plus O. fugitiva . That is not surprising, since O. piaba [actually Serrapinnus piaba ] for example is used in the literature as a misidentification of several Serrapinnus spp. In any case, Sánchez-Botero & Araújo-Lima (2001) results pointed out a high abundance of the cheirodontine O. fugitiva and at least three Serrapinnus spp. ( Serrapinnus micropterus , Serrapinnus gr. microdon, and Serrapinnus n. sp., our identifications) in lakes from the rio Solimões floodplain. Peter Bayley fish collections undertaken during the late 1970’s from the same lakes were also extensively examined (material at ANSP, MCP, and USNM), confirming that O. fugitiva is very common in these floodplain lakes. At the same localities, Marchantaria Isle (lago Camaleão), Janauacá, and Janauari, O. fugitiva was caught associated with macrophytes Echinochloa polystachya , E. crassipes , Paspalum repens , Panicum sp. , or unvegetated places, and considered as omnivorous ( Petry et al., 2003).

Two new cheirodontine species provisionally treated as “ Odontostilbe ”, but not described herein, are sympatric and have been found mixed with O. fugitiva in some jars. One of these new species mostly occurs in the río Ucayali basin and the second in the río Marañon basin.

Figures

Fig 9. Upper jaw length as a function of head length for males of Odontostilbe fugitiva, specimens widely distributed on rio Amazonas, andupper and middle río Maranõn basin, against O. dierythrura and Odontostilbe sp. of río Madre de Dios basin.

Fig 11. Upper jaw length as a function of head length for males of Odontostilbe fugitiva, specimens widely distributed on río Amazonas basin, and specimens of río Ucayali basin, against O. dierythrura and Odontostilbe sp. of río Madre de Dios basin.

Fig. 1. Neotype of Odontostilbe fugitiva, MUSM 27501, male 34.6 mm SL (top), and specimen NRM15719, female 35.2 mm SL (bottom).

Fig. 2. Dentition of Odontostilbe fugitiva,ANSP 178908, female 35.5mm SL. SEMphotograph of left side premaxilla (top), maxilla (middle), and dentary (bottom).

Fig. 4. Odontostilbe fugitiva from lower río Ucayali drainage. Photo by William Crampton (Ucamara Project).

Fig. 3. First gill arch of Odontostilbe fugitiva, MCP 35777, male 35.7 mm SL. SEM photographs of the first left side gill arch showing gill gland (top), in detail gill rakers on upper branchial branch (middle), and gill rakers on lower branchial branch (bottom). Lateral view.

Fig. 5. Principal component analysis of the 18 morphometric data of males (M) and females (F) of Odontostilbe fugitiva. Stronger loadings on the second and third principal components (PC2, PC3).

Fig. 6. Distribution of Odontostilbe fugitiva in central and northen South America. Circles (material examined, symbols can represent more than one lot, and more than one locality), and stars (type locality of neotype on the rigth and of the lost holotype on the left).

Fig. 8. Holotype of Odontostilbe caquetae, ANSP 70495, unsexed 28.0 mm SL.

Fig. 12.. Snout to pectoral-fin length as a function of standard length for males, females, and unsexed specimens of Odontostilbe fugitiva, specimens widely distributed in rio Amazonas basin against specimens of rio Solimões basin (middle rioAmazonas).

Fig. 13. Upper and lower gill rakers counts of Odontostilbe fugitiva populations, and three new species Odontostilbe ecuadorensis, Odontostilbe nareuda, and Odontostilbe parecis.