Mylossoma aureum ( Agassiz, 1829 )

Mateussi, Nadayca T. B., Oliveira, Claudio & Pavanelli, Carla S., 2018, Taxonomic revision of the Cis-Andean species of Mylossoma Eigenmann & Kennedy, 1903 (Teleostei: Characiformes: Serrasalmidae), Zootaxa 4387 (2), pp. 275-309 : 287-293

publication ID	https://doi.org/ 10.11646/zootaxa.4387.2.3
publication LSID	lsid:zoobank.org:pub:366DF9BF-EA85-4DB4-9857-8E6D7B3B3E31
DOI	https://doi.org/10.5281/zenodo.5965009
persistent identifier	https://treatment.plazi.org/id/014587BD-924A-FFFF-FF2C-FDB2B441F991
treatment provided by	Plazi
scientific name	Mylossoma aureum ( Agassiz, 1829 )
status

Treatment

Mylossoma aureum ( Agassiz, 1829) View in CoL

( Figs 10–15 View FIGURE 10 View FIGURE 11 View FIGURE 12 View FIGURE 13 View FIGURE 14 View FIGURE 15 , Table 3)

Myletes aureus Agassiz, in Spix & Agassiz, 1829: 74 View in CoL , plate XXI [original description; type-locality: "Brasiliae aequatorialis fluviis"; cited as Tetragonopterus aureus in the plate].— Kottelat, 1984: 146 [designation of potential syntypes].— Kottelat, 1988: 84 [designation of potential syntypes; details on autorship].

Myletes herniarius Cope, 1872: 268 View in CoL [original description; type-locality: "Ambyiacu"].— Böhlke, 1984: 48 [type-material listed].

Starksina herniarius .— Fowler, 1907: 476 [redescription of type specimens; lectotype designation].

Mylosoma [sic] aureum .— Eigenmann, 1910: 444 [listed, catalog of South American freshwater fishes].

Mylosoma aureus .— Eigenmann, 1915: 265 [redescription].

Mylossoma aureum View in CoL .— Norman, 1929: 813 [brief description].— Eigenmann & Allen, 1942: 249 [description, Peru].— Géry, 1976: 48 [listed].— Ortega & Vari, 1986: 9 [listed, Peru].— Machado-Allison & Castillo, 1992: 17 [morphology; allometry; Orinoco basin, Venezuela].— Taphorn, 1992: 477 [description; río Apure basin, Venezuela].— Machado-Allison & Fink, 1996: 78 [Rio Orinoco basin, Venezuela; brief description]— Oliveira & Araújo-Lima, 1998 [larvae habits and distribution].— Jégu, 2003: 187 [listed].— Ota et al., 2013: 27 [rio Madeira basin, Brazil; brief description, photo].

Mylossoma ventriosa Norman, 1929: 815 View in CoL [original description, type-locality: "Solimões, R. Amazon"].

Mylossoma aureus View in CoL .— Nelson, 1961: 608 [swim bladder morphology].

Diagnosis: Mylossoma aureum differs from all congeners by presenting the last abdominal spine clearly separated from the anal-fin origin (vs. last abdominal spine reaching the anal-fin origin or almost) and 38–39 vertebrae (vs. 35 to 37).

Description: Morphometric data presented in Table 3. Body deep, compressed laterally. Dorsal profile concave at posterior region of head and convex between head and dorsal fin. Ventral profile convex; slightly concave at isthmus and strongly convex from this point to end of anal fin. Highest body depth on vertical line passing through dorsal- and pelvic-fins origins. Caudal peduncle deeper than longer.

Small head. Eyes lateral at middle of head; upper margin of eyes below longitudinal axis of lateral-line origin. Frontal and parietal fontanel broadly expanded laterally. Snout short and rounded on lateral view. Nostrils dorsolateraly positioned, above longitudinal axis through upper margin of eye.

Mouth terminal to slightly upturned, at same level of orbits. Premaxilla projected forward, with inner premaxillary row over or surpassing dentary teeth ( Fig. 12 View FIGURE 12 ). Premaxillary teeth molariform with robust base; outer portion of anteriormost three teeth of outer row and posterior portion of remaining teeth pointed. Inner premaxillary row with two teeth, separated from outer row. Outer premaxillary row with five teeth. Dentary with four (rarely five) tricuspid, robust, molariform teeth; symphyseal dentary teeth present, with robust base and large conical cusp, behind main row ( Fig. 2 View FIGURE 2 ). Maxilla edentulous.

First gill arch with elongated and conical gill rakers; epibranchial gill-rakers 10(19), 11(15), 12(21) or 13(1); one (45) gill raker at cartilage between epi- and ceratobranchial; ceratobranchial gill-rakers 12(2), 13(3), 14(11), 15(24), 16(10) or 17(5).

Body completely covered by small cycloid scales. Accessory scales covering intersections of major scales, mainly at anterior portion of body. Lateral line complete, with 81(1), 82(3), 84(3), 85(2), 86(3), 87(5), 88(2), 89(4), 90(8), 91(9), 92(6), 93(7), 94(6), 95(7), 96(7), 97(3), 98(2), 99(4), 100(2), 102(1) or 104(1) perforated scales, extending into caudal fin. Scales above lateral line 42(1), 44(2), 45(1), 46(3), 48(1), 49(1), 50(4), 51(3), 52(5), 54(4), 55(4), 56(9), 57(6), 58(3), 59(3), 64(1) or 68(1). Scales below lateral line 38(1), 39(1), 40(1), 42(2), 43(3), 44(1), 45(8), 47(5), 48(2), 49(4), 50(2), 51(2), 52(1), 53(4) or 56(2). Circumpeduncular scales 28(8), 30(15), 31(2), 32(21), 33(3), 34(11), 35(1) or 36(2). Ventral keel with well-developed spines forming high serra. Prepelvic spines 25(2), 26(2), 27(4), 28(13), 29(19), 30(24), 31(15), 32(10), 33(10), 34(2) or 35(1). Postpelvic spines 10(6), 11(17), 12(23), 13(25), 14(16) or 15(4); anal spines small, maximum 3, clearly separated from anal-fin origin, discernible only if dissected ( Fig. 12 View FIGURE 12 ).

Dorsal fin not preceded by spine, its origin equidistant from tip of snout and end of hypural plate. First dorsalfin ray much shorter than second ray; in some specimens covered by skin, in such cases discernible only if dissected or x-rayed ( Fig. 12 View FIGURE 12 ). Branched dorsal-fin rays gradually decreasing in size; dorsal-fin rays 12(1), 14(14), 15(62) or 16(27). Adipose fin short, entirely covered by small scales. Pectoral fin falcate, with i(88) + 12(1), 13(7), 14(34), 15(38), 16(22) or 17(3) rays. Pelvic fin small, with i + 6(89) branched rays. Anal fin long, with convex edge, median and posterior rays longer than anterior ones, not lobed; sheath of scales covering at least two-thirds of anal-fin length; anal-fin rays 28(7), 29(13), 30(21), 31(39), 32(18), 33(5), 34(2) or 35(1). Caudal fin bifurcated, lobes of similar size, with 16(6), 17(69), 18(6), 19(2) or 21(1) rays. Vertebrae 38(9) or 39(2). Supraneurals 4(11).

Color in alcohol. General body color silvery-brownish or silvery-yellowish, darker dorsally ( Fig. 11 View FIGURE 11 ). Fins hyaline with yellow hue; caudal-fin and anal-fin bases, and distal margin of anal fin slightly dark. Dark to brown blotch on opercle usually absent or inconspicuous. Juvenile specimens with vertical, faded brown bands on flanks; a rounded brown ocellar blotch below dorsal fin, small and inconspicuous, sometimes absent ( Fig. 13 View FIGURE 13 ).

Color in life. General body color silvery; darker dorsally; orange or reddish tint on anterior portion of abdominal region, head and around the eyes. Black or brownish blotch on opercle usually absent, if present, inconspicuous. Anal fin with orange or yellow tint, sometimes with a dark band along distal margin; dorsal, pectoral and pelvic fins with orange base and posterior portion hyaline; caudal fin hyaline. Juveniles with vertical dark, relatively inconspicuous stripes along flanks ( Fig. 14 View FIGURE 14 , 15 View FIGURE 15 ).

Geographic distribution. Mylossoma aureum is widely distributed across the Amazon and Orinoco river basins ( Fig. 3 View FIGURE3 ).

Ecological notes. Mylossoma aureum is a highly fecund, fast growing species with high mortality rates in early life stages ( Lima & Araújo-Lima, 2004). The species is considered an omnivore with high tendency to herbivory, feeding mainly on vegetal matter and invertebrates. Mylossoma aureum undertakes reproductive migrations, and the spawning occurs during the flood season, mainly in white waters rivers and associated wetlands ( Santos et al., 2006). Mylossoma aureum has moderate importance in commercial fisheries ( Santos et al., 2006).

Molecular data. DNA barcoding showed a variation of 0.084 to 0.091 between examined samples of M. aureum and the remaining analyzed species, with M. albiscopum (identified as M. duriventre group 5) being the closest related species ( Mateussi et al., 2016).

Remarks. Agassiz (in Spix & Agassiz, 1829) mentioned that three specimens were examined for the description of Myletes aureus : " In Museo Monacensi specimina tria in spiritu vini servantur ". Kottelat (1984, 1988) designated the lots MHNN 787 and MHNN 788 as possible syntypes for Myletes aureus . However, the examination of pictures of these specimens revealed that specimen MHNN 787 belongs actually to Mylossoma albiscopum . Thus, we designate the specimen MHNN 788-A as lectotype of M. aureum and the specimen MHNN 788-B as a paralectotype.

Taphorn (1992), Machado-Allison & Castillo (1992), and Machado-Allison & Fink (1995) presented morphological data from Mylossoma aureum specimens from the Orinoco basin. We unfortunately were unable to examine specimens of Mylossoma aureum from the Orinoco basin, but the data presented by these authors indicates that this population is clearly conspecific with the population occurring at the Amazon basin.

Material examined. Type material. MHNN 788-A, 1, Brazilian equatorial rivers. Lectotype (by present designation) of Myletes aureus . MHNN 788-B, 1, Brazilian equatorial rivers. Paralectotype of Myletes aureus . ANSP 8025, 1 (rd), río Ambyiacu, Peru. Lectotype of Myletes herniarius (designated by Fowler, 1907). BMNH 1923.10.28.263, rio Solimões. Holotype of Mylossoma ventriosa . Non-type material. Brazil. Rio Amazonas basin. Amazonas: INPA 20264, 3, 87.0– 88.5 mm SL, Manaus, Canal Xiborena, 03°12'30"S 59°59'00"W, 14 Apr 2000, C. Cox-Fernandes et al. INPA 20287, 4, 15.7–55.0 mm SL, Manaus, Canal Xiborena, 03°12'30"S 59°59'00"W, 15 Mar 2000, L. Rajys et al. . INPA 20332, 1, 48.6mm SL, Iraduba, lago Pirapora at Catalão lakes complex, 03°10'09''S 59°54'43''W, 13 Jul 2000, L. R. Py-Daniel & J. Zuanon. INPA 20337, 1, 65.8 mm SL, lago do Padre, 03°25'31"S 60°57'56"W, Jul 2000, L. R. Py-Daniel et al. INPA 29063, 1, 103.4 mm SL, Carauarí, RDS Uacari, rio Juruá, 05°56'26"S 67°48'21"W, 24 Nov 2007, R. G. Frederico & L. J. Queiroz. INPA 29699, 1, 99.9 mm SL, Carauarí, RDS Uacarí, lago da Terra, rio Juruá tributary, 05°30'34"S 67°27'58"W, 28 Nov 2007, R. G. Frederico & L. J. Queiroz. INPA 29749, 1, 93.9 mm SL, Carauarí, RDS Uacari, rio Juruá, 05°56'26"S 67°48'21"W, 22 Nov 2007, R. G. Frederico & L. J. Queiroz. INPA 33885, 1, 98.7 mm SL, Nhamundá, rio Nhamundá, 02°13'51"S 56°46'23", 21 Sep 2011, R. Leitão & H. Lazzarotto. INPA 39641, 3, 9.2–12.16 mm SL, Itacoatiara, igarapé do Centenário, 03°08'25"S 58°27'25"W, 16 Apr 2011, E. L. H. Takahashi. INPA 43781, 1 (sk), Iranduba, lago Pirapora, 03°10'09"S 59°54'43"W, 0 1 Jul 2014, S. A. Amadio. INPA 46096, 1, 68.2 mm SL, Carauarí, RDS Uacari, rio Juruá, 05°56'26"S 67°48'21"W. MPEG 1542, 1, 74.7 mm SL, Japurá, lago Amanã, rio Japurá, 02°35'48"S 64°39'46"W. Pará: MCP 20962, 2, 71.4–74.2 mm SL, Alenquer, ilha de São Miguel, rio Amazonas, 01°56'S 54°44'W, 26 Nov 1997, R. B. Oliveira. MCP 21042, 1 (rd), 107.8 mm SL, Alenquer, ilha de São Miguel, rio Amazonas, 01°56'S 54°44'W, 26 Nov 1997, R. B. Oliveira. MPEG 5225, 1, 110.0 mm SL, Oriximiná, rio Trombetas, 01°43'10"S 55°55'22"W. MPEG 14102, 1, 82.6 mm SL, Juruti, rio Amazonas, 02°11'23.7"S 56°08'04"W. Rondônia: UFRO-ICT 13555, 1, 13.7 mm SL, Pimenteiras do Oeste, Porto Surpresa, rio Guaporé, 11°53'13"S 65°01'16.1"W, 11 Jan 2012. Rio Madeira basin. Amazonas: INPA 24346, 11, 106.4– 144.8 mm SL, comunidade Itapinima, rio Madeira, 05°24'37"S 60°43'16"W, 22 Sep 2004. INPA 24347, 2, 120.6– 125.6 mm SL, comunidade Itapinima, rio Madeira, 05°24'37"S 60°43'16"W, 21 Sep 2004, L. R. Py-Daniel et al.. INPA 24349, 1, 118.8 mm SL, comunidade Vencedor, lago do Acará, rio Madeira, 03°38'9.69"S 62°42'31.95"W, 22 Sep 2004, L. R.

Py-Daniel et al. UFRO-ICT 1137 , 1 (rd), 132.8 mm SL, Humaitá, lago do Puruzinho , rio Madeira , 07°22'21.3"S 63°03'10.1"W, 0 2 Dec 2008, L. J. Queiroz. UFRO-ICT 1259 , 1 (rd), 155.1 mm SL, Novo Aripuanã, rio Aripuanã , rio Madeira GoogleMaps , 05°08'30.5"S 60°24'03.3"W, 0 5 Dec 2008, A. Cella-Ribeiro. Rondônia: INPA 3791 View Materials , 5 View Materials (4), 153.6– 176.5 mm SL, rio Machado GoogleMaps , 08°20'18"S 62°42'33"W, 0 1 Sep 1977, M. Goulding. UFRO-ICT4776 , 1 (rd), 116.4 mm SL, Nova Olinda do Norte , lago Sampaio, rio Madeira basin GoogleMaps , 03°49'06"S 59°05'27"W, 30 Jan 2012, A. Cella- Ribeiro. UFRO-ICT 7500, 2, 118.1– 120.8 mm SL, Porto Velho, rio Machado , 08°20'18"S 62°42'33"W, 0 1 Dec 2011. UFRO-ICT 9278 , 2 (rd), 109.2–112.2 mm SL GoogleMaps , Porto Velho, cachoeira Santo Antônio, rio Madeira , 08°47'32"S 65°56'05"W, 24 Oct 2010, W. M. Ohara. UFRO-ICT 13307 , 1 , 132.0 mm SL GoogleMaps , Porto Velho, cachoeira Santo Antônio, rio Madeira , 08°48'30"S 63°36'53"W, 13 Dec 2008, Equipe SET. UFRO-ICT 19346 , 1 , 112.0 mm SL GoogleMaps , Porto Velho, Igarapé Jatuarana, rio Madeira , 08°45'54''S 64°02'39''W, 19 Feb 2013, E. Façanha. Rio Negro. Amazonas: LBP 21832, 2, 103.7– 109.4 mm SL, Manaus, Catalão, rio Negro , 03°12'00''S 59°57'39''W, 12 May 2016, N.T.B. Mateussi et al. Rio Purus basin. Acre: MCP 28927, 2 View Materials (1), 123.6 mm SL, Sena Madureira, rio Purus (bought at the Sena Madureira fish market) GoogleMaps , 09°08'59"S 68°35'00"W, 0 8 Aug 2001. Amazonas: INPA 16776, 1, 124.6 mm SL, beach at Reserva Biológica do Abufari, rio Purus, c. 05°32'5"S 63°04'44"W, 0 9 Dec 2000, L. R. Py- Daniel & M. Garcia. INPA 18533, 2, 60.1–61.2 mm SL, Reserva Biológica do Abufari, rio Purus, 05°32'5"S 63°04'44"W, 0 8 Dec 2000, L. R. Py-Daniel et al. INPA 46974, 5 (rd), 86.5–182.3 mm SL, Tapauá, igarapé Castanhalzinho, 04°59'50"S 62°59'38"W, 10 Aug 2012, L. R. Py-Daniel et al. Rio Solimões basin, Amazonas: INPA 11093 View Materials , 1 View Materials , 61.6 View Materials mm SL, Iranduba, ilha da Marchantaria, rio Solimões GoogleMaps , 03°17'05"S 60°11'10"W, 17 Jun 1988, Equipe de Ictiologia do INPA. INPA 18813 View Materials , 15 View Materials , 24.0– 55.4 mm SL, Reserva Mamirauá, lago Secretaria ( rio Solimões ), c GoogleMaps . 02°11'32"S 65°42'30"W, 0 1 Mar 2001, W. Crampton. INPA 19533 View Materials , 1 View Materials , 77.8 View Materials mm SL, Alvarães, rio Solimões , c GoogleMaps . 03°46'30"S 65°22'50"W, 29 Jan 2001, W. Crampton. INPA 19535, 2, 57.2–76.4 mm SL, ilha do Içé, rio Solimões, 03°16'36"S 64°41'01"W, 0 1 Jan 2001, W. Crampton. INPA 25758 View Materials , 1 View Materials , 99.5 View Materials mm SL, Manaus, lago Muratu, rio Solimões GoogleMaps , 03°20'51"S 60°12'34"W, 0 1 Jul 2003, M. C. Vega. INPA 25784 View Materials , 1 View Materials , 109.2 View Materials mm SL, Manaus, lago Muratu, rio Solimões GoogleMaps , 03°20'51"S 60°12'34"W, 0 1 Jun 2003, M. C. Vega. INPA 28919, 1, 75.8 mm SL, Carauarí, RDS Uacari, rio Juruá , 05°42'23"S 67°49'17"W, 26 Nov 2007, R. G. Frederico & L. J. Queiroz. INPA 29753, 1, 97.5 mm SL, Carauarí, RDS Uacari, rio Solimões , 05°54'20"S 67°51'59"W, 22 Nov 2008, R. G. Frederico & L. J. Queiroz. INPA 33132 View Materials , 1 View Materials , 52.3 View Materials mm SL, Tabatinga, rio Solimões GoogleMaps , 03°57'32"S 69°20'19"W, 0 2 Sep 2003, J. Zuanon et al. . INPA 33133 View Materials , 1 View Materials , 17.4 View Materials mm SL, Coari, Ressaca Geral, rio Solimões GoogleMaps , 03°51'10"S 63°28'07"W, 13 Sep 2003, L. R. Py-Daniel et al. . INPA 3790 View Materials , 26 View Materials (11), 27.5–71.3 mm SL, Iranduba, ilha da Marchantaria, rio Solimões GoogleMaps , 03°17'05"S 60°11'10"W, 20 Mar 1976, Ictiologia INPA. LBP 18401, 1 View Materials , 95.7 View Materials mm SL, Manacapuru, rio Solimões GoogleMaps , 03°18'53"S 60°38'58"W, 21 Aug 2013, C. Oliveira et al. LBP 21801, 1, 42.9 mm SL, Tefé, Paraná de Tefé, rio Solimões, 03°21.05'S 64°40.06'W, 19 May 2016, N.T.B. Mateussi et al. LBP 21777, 2, 26.2–33.1 mm SL, Alvarães GoogleMaps , Paraná do Icé, rio Solimões, 03°15.49'S 64°42.92'W, 19 May 2016, N.T.B. Mateussi et al. MCP 31679, 2, 103.7– 111.6 mm SL, Alvarães, lago Mamirauá ( rio Solimões basin) GoogleMaps , 03°06'37"S 64°47'45"W, 14 May 1998. MCP 31680, 1 View Materials , 40.3 View Materials mm SL, Tefé, rio Solimões GoogleMaps , 03°16'9"S 64°39'09"W, 11 Jan 2001. MCP 31681, 1 View Materials , 82.4 View Materials mm SL, Alvarães, ilha do Içé, rio Solimões GoogleMaps , 03°16'36"S 64°41'01" W. Rio Xingu basin, Pará: INPA 40703 View Materials , 1 View Materials , 94.2 View Materials mm SL GoogleMaps , Porto de Moz, rio Xingu , 01°43'54"S 52°15'16"W, 24 Sep 2013, M. Sabaj Perez. Colombia. Rio Amazonas basin, Amazonas: LBP 22515, 6, 49.1–63.0 mm SL, Leticia, Lago Yahuarcaca, rio Amazonas GoogleMaps , 04°11'45''S 69°57'20''W, 12 Nov 2016, C. Oliveira & B.F. Melo. Peru. Rio Amazonas basin, Loreto: LBP 22606, 5, 52.4–104.2 mm SL, rio Amazonas GoogleMaps , 04°14'04''S 69°57'42''W, 14 Nov 2016, C. Oliveira & B.F. Melo.