Pachypops fourcroi (La Cepede 1802)

Lilian Casatti, 2002, Taxonomy of the South American genus Pachypops Gill 1861 (Teleostei: Perciformes: Sciaenidae), with the description of a new species., Zootaxa 26, pp. 1-20 : 4-10

Pachypops fourcroi (La Cepede 1802)

(Fig. 3)

Perca fourcroi La Cepede 1802 : 398, 424 (type locality: not stated, but probably Suriname, since according to La Cépède, the material was donated by the Netherlands to France).

Corvina furcroea : Cuvier in Cuvier and Valenciennes 1830: 111 (based on the holotype of Perca fourcroi ).

Corvina biloba Cuvier in Cuvier and Valenciennes 1830 : 112 (type locality unknown), Steindachner 1864: 206 (redescription as Pachypops biloba ), Steindachner 1879: 12 (synonym of Pachyurus furcraeus ).

Corvina furcraea : Steindachner 1863: 165 (junior synonym of Pachypops furcraeus ), Steindachner 1879: 12 (synonym of Pachyurus furcraeus ).

Perca furcraea : Steindachner 1863: 163 (as Pachypops furcraeus ).

Pachyurus natteri : Steindachner 1863: 171, pl. 3 (misspelling of Pachyurus nattereri ).

Pachyurus nattereri Steindachner 1863 : 174, pl. 3 (type locality: Rio Branco and Rio Negro), Steindachner 1879: 11 (as junior synonym of Pachyurus schomburgkii ), Eigenmann 1894: 630 (in listing of South American fishes, as synonym), Jordan and Eigenmann 1889: 412 (review of American Sciaenidae), Campos 1942: 17 (review of Brazilian sciaenid).

Pachypops furcraeus : Steindachner 1863: 165 (redescription based on specimen from Rio Negro, Brazil), Steindachner 1879: 12 (as junior synonym of Pachyurus furcraeus ), Jordan and Eigenmann 1889: 413 (in review of American Sciaenidae, valid), Eigenmann and Eigenmann 1891: 67 (listed), Jordan and Evermann 1896: 399 (listed, Guyana), Eigenmann 1910: 468 (listed), Fowler 1914: 277 (listed, Rupununi River), Campos 1942: 18 (in review of Brazilian sciaenid), Boeseman 1948: 367 (listed, Suriname), Travassos and Rego-Barros 1971: 60 (listed, Brazil), Chao 1978: 42 (listed, West Atlantic Sciaenidae), Taphorn et al. 1997: 99 (listed, Venezuela).

Pachypops biloba : Steindachner 1864: 206 (redescription based on two specimens from Suriname).

Pachyurus furcraeus : Steindachner 1879: 12 (as senior synonym of Corvina furcraea and Pachypops furcraeus ).

Pachypops fourcroi : Fowler 1954: 253 (freshwater fishes of Brazil), Lowe-McConnell 1966: 24 (listed, Guyana), Aguilera 1987: 91 (soft anatomy), Cervigón 1982: 238 (comparison with P. cevegei ).

Pachypops furchraeus : Ferreira et al. 1998: 146 (key, commercial fishes of Santarém, Brazil).

Material examined. Type specimens: - MNHN 7539, holotype of Perca fourcroi (134.2 mm SL), locality not mentioned. - MNHN 7683, holotype of Corvina biloba (75.9 mm SL), unknown locality. - NMW 15178:1, lectotype of Pachyurus nattereri herein designated (80.9 mm SL), Rio Branco or Rio Negro, Brazil. - NMW 15178:2-3, paralectotypes of Pachyurus nattereri herein designated, Rio Branco or Rio Negro, Brazil (53,0-58,9 mm SL).

Non-type (193 specimens). - Venezuela: Bolivar: Río Orinoco, close to mouth of Río Caura, 7º38’N 64º52’W, ANSP 160329 (2, 82.8-90.2) ; Río Cano, in the confluence of Río Caura with Río Orinoco, 7º37’N 64º50’W, ANSP 163025 (2, 88.5-102.8) ; Río Orinoco, CAS 156590 (SU 56590) (1, 59.9) ; Río Orinoco, Delta Amacuro, 8º41’N 62º03’W, USNM 233770 (1, 36.7) ; Lago Tineo Anzoategui, 8º11’N 6º28’W, ANSP 166482 (1, 163.4) ; Río Orinoco, close to mouth of caño Yagual, 3º33’N 66º47’W, ANSP 162850 (1, 83.5) ; Río Orinoco, 3º10’N 65º33’W, ANSP 162855 (2[3], 45.5-53.4) ; Río Orinoco, Santa Barbara, CAS 14873 (SU 48673) (2, 39.8-44.1) . - Amazonas: Río Negro, CAS 148668 (4[6], 40.4-61.2) ; Río Negro, mouth of Río Casiquiare, CAS 148671 (2[9], 43.3-43.9) ; Río Ventuari, 4º4’N 66º56’W, ANSP 162848 (2[13], 44.5-65.0) ; Río Casiquiare, 3º50’N 65º55’W, ANSP 162853 (2[7], 14.8-39.4) ; Río Orinoco, 3º50’N 67º20’W, ANSP 162854 (2[5], 43.7-50.9) ; Río Orinoco, 3º4’N 66º28’W, ANSP 162849 (2[4], 30.7-46.3) ; Río Cunucunuma, 3º23’N 65º59’W, ANSP 162847 (1, 165.8) ; Río Orinoco, 2º59’N 66º4’W, ANSP 162852 (1, 47.9) ; Río Orinoco, Playa de Tamatama, CAS 56829 (SU 56829) (1, 149.0) ; Río Orinoco, Playa de Tamatama, CAS 148672 (SU 48672) (1, 81.0) ; Río Casiquiare, 2º48’N 65º57’W, ANSP 162851 (1, 150.1) ; Río Pamoni, 2º49’N 65º55’W, ANSP 162846 (2[3], 163.9-166.2) . - Guyana: Mora Passage, FMNH 53953 (1, 155,7) ; Essequibo River, CAS 78552 (4[28], 27.7-81.1) , AMNH 215000 (1, 42.9) , FMNH 53956 (1, 46.3) ; Essequibo River, Wismar, FMNH 53954 (1, 52.4) , Essequibo River, Kartabo, AMNH 220370 (2[30], 34.6-153.4) , AMNH 220366 (1, 61.3) ; Demerara River, CAS 78551 (IU 12570) (1, 108.2) , AMNH 214915 (1, 39.8) , AMNH 214916 (2[12], 34.6-56.6) ; Essequibo River, Bartica, FMNH 53955 (2[26], 29.5-92.0) , FMNH 7359 (2[5], 25.4-58.8) , CAS 121969 (SU 21969) (2[5], 28.0-49.4) , AMNH 215091 (1, 41.0) , USNM 66280 (2[5], 29.1- 48.0) ; Essequibo River, Crab Falls, CAS 56204 (IU 12572) (2, 38.7-51.2) . - Suriname: Nickerie District: Corantijn River, 5º50’N 57º07’W, USNM 226102 (2[17], 13.1-24.0) , USNM 226097 (2[3], 29.5-38.8) , USNM 226101(2[8], 14.2-26.0) ; Corantijn River, 5ºN 57º17’W, USNM 226103 (2[4], 125.4-141.8) ; Corantijn River, 5º31’N 57º12’W, USNM 226098 (2[11], 66.4-95.2) ; Corantijn River 5º30’N 57º13’W, USNM 226099 (2[4], 79.0- 97.1) ; Mattapi Creek, 5º01’N 57º17’W, USNM 226100 (2, 89.6-186.0) . - French Guyana: Approuague River, INPA 3190 (2, 110.9-122.8) . - Colombia: Río Negro, Cucui, CAS 32059 (1, 43.8) . - Brazil: Amapá: Rio Araguari (2, 100.0-117.8) ; Rio Araguari, Ferreira Gomes, MZUSP 62895 (1, 138.7) ; Rio Araguari, Ferreira Gomes, MZUSP 34099 (2, 95.2- 130.6) . - Amazonas: Rio Uaupés, Cachoeira do Ipanoré, INPA 4980 (1, 187.0) ; Rio Marauia, upriver from Barcelos, MPEG 809 (1, 103.4) ; Rio Negro, Mandiquié, MPEG 806 (1, 178.4) ; Rio Negro, São Gabriel da Cachoeira, MZUSP 34103 (2[3], 35.6-49.6) ; Rio Negro, Curuzu, MPEG 813 (2, 86.5-105.3) ; Rio Negro, MCZ 1007 (2, 100.8-109.4) ; Rio Negro, Anavilhanas, MZUSP 34095 (1, 79.9) ; Rio Japurá, Aruanã, MPEG 1662 (1, 135.5) ; Rio Tefé, Vista Escura, MPEG 816 (1, 157.0) ; Rio Uatumã, Igarapé do Arraya, INPA 14660 (2[3], 196.0-206.0) ; Rio Uatumã, INPA 11995 (1, 162.0) , INPA 11984 (3, 146.0-205.3) , INPA 11996 (1, 163.0) , INPA 2727 (1, 163.0) , INPA 2726 (1, 180.0) ; Rio Uatumã, Igarapé do Abonari, INPA 10473 (1, 182.0) ; Rio Uatumã, Balbina, INPA 5407 (2[5], 129.0-153.0) , INPA 10461 (2[3], 130.5-144.2) ; Rio Uatumã, Igarapé do Boto, MNHN 1996-1160 (1, 155.2) ; Rio Madeira, Nova Olinda, MZUSP 7027 (1, 72.5) . - Pará: Rio Jari, upriver from Cachoeira de Santo Antônio, INPA 10437 (2, 65.1-76.5) ; Rio Amazonas, USNM 52581 (2[3], 100.0-151.9) ; Rio Amazonas, Lago Grande de Monte Alegre, INPA 10180 (2, 107.3-113.2) ; Rio Amazonas, mouth of Rio Tapajós, INPA 8620 (1, 74.8) ; Rio Tapajós, Santarém, CAS 32054 (1, 152.6) ; Rio Tapajós, Alter do Chão, MZUSP 63603 (3[28], 60.6-89.0, 1 C & S) , MZUSP 34101 (3[6], 24.3-32.9) , MZUSP 9532 (3, 138.6-141.5) , INPA 7138 (1, 123.9) ; Rio Tapajós, between Itaituba and São Luis (3[21], 134.6-153.3) ; Rio Tapajós, Praia do Aeroporto, INPA 8546 (2, 63.1-86.8) ; Rio Tapajós, Maloquinha, MZUSP 14365 (1, 145.4) ; Rio Trombetas, upriver from Cachoeira Porteira, INPA 3267 (1, 149.0) , INPA 5733 (3[10], 55.5-93.5) ; Rio Trombetas, MCZ 8633 (2[8], 50.5-81.9) , MZUSP 50757 (1, 151.9) , MZUSP 34097 (4[5], 69.8-156.6) ; Rio Trombetas, Cuminá, INPA 810, (1, 97.6) , MZUSP 34096 (3[7], 95.8-107.6 [1 C & S]) ; Rio Trombetas, Oriximiná, MZUSP 14367 (2, 42.7-65.5) , CAS 78545 (1, 94.9) ; Rio Icoaracy, Furo do Maguari, INPA 615 (2[15], 67.8-151.1) ; Vila de Icoaracy, Belém, INPA 611 (2[17], 75.2- 132.2) ; Rio Tocantins, INPA 10419 (2, 114.1-144.3) , INPA 10471 (2[5], 85.0-98.7) ; Rio Tocantins, Mercado de Cametá, INPA 12990 (2[6], 46.0-84.9) ; Rio Tocantins, downriver from Tucuruí, INPA 10448 (2, 68.9-110.8) ; Rio Tocantins, Tucuruí, MPEG 2327 (3, 101.2-113.9) , MZUSP 51087 (2[4], 31.4-47.6) ; Rio Tocantins, Itupiranga, INPA 684 (2, 86.3-89.1) ; Rio Tocantins, Acaripucu, INPA 11999 (2[5], 86.1-139.8) , INPA 10468 (1, 80.2) , INPA 1332 (1, 132.4) , INPA 11997 (1, 110.8) ; Rio Tocantins, Icanguí, INPA 10464 (1, 109.8) , INPA 10467 (1, 102.2) , INPA 10466 (1, 87.2) ; Rio Tocantins, Icanguí-Acari- pucu, INPA 11998 (3, 122.4-130.1) . - Rondônia: Rio Machado, Jamarizinho, MZUSP 34102 (2, 38.7-49.8) ; Rio Jamari, INPA 10472 (2, 185.0-187.0) ; Rio Jamari, 15 km upriver from Usina Hidrelétrica de Samuel, INPA 12116 (1, 174.0) ; Rio Novo, upriver from Usina Hidrelétrica de Samuel, INPA 7761 (1, 180.0) . - Mato Grosso: Rio Aripuanã, Lago Castanhal, 1976, INPA 598 (1, 180.2) ; Peru: Loreto: Río Amazonas ( Maranõn), Iquitos, CAS 148674 (1, 111.1) ; Río Nanay, 3º45’N 73º17’W, ANSP 167218 (2, 98.8-123.8) , ANSP 139089 (2[3], 65.1-96.4) .

Diagnosis. A species of Pachypops distinguished by the following combination of characters: uniform light tan body without spots (versus brown spots present in P. pigmaeus n. sp.); body depth less than 4.1 in SL (versus 4.3 or more in P. pigmaeus n. sp.); horizontal diameter of eye 2.4-3.1 in HL (versus 3.0-3.6 in P. trifilis ); and absence of longitudinal stripes on trunk (versus stripes present in P. trifilis ).

Description. Morphometrics and meristics presented in Table 1. Body elongate, dorsal profile moderately arched, ventral profile nearly straight from prepelvic region to anal fin origin. Maximum body depth at origin of dorsal fin. Head pointed; mouth inferior and small. Maxillar not extending beyond vertical line through anterior edge of eye. Underside of lower jaw with three pairs of mental pores and three mental barbels. Teeth uniformly small, villiform, set in bands on both jaws.

Snout pointed, longer than horizontal diameter of eye, with 9-10 small pores. Nostrils closely set, anterior circular and posterior crescent-shaped. Eye elliptical, its horizontal diameter longer than vertical height. Laterosensory canal segments in infraorbitals, preopercle, and lower jaw visible externally. Preoperclar margin slightly serrate. Gill rakers short and slender; 17-25 (usually 24) rakers in first gill arch.

Scales usually ctenoid (cycloid on lachrymal, snout and preopercle). Anterior half of lateral line curved, posterior half extending straight to posterior margin of caudal fin; 45- 54 (usually 50) pored lateral-line scales from supracleithrum to hypural joint; 6-9 (usually 7) scale rows above lateral line; 7-10 (usually 8) scale rows below lateral line. Bases of second dorsal, pelvic, pectoral, and anal fins with 3 or 4 rows of small scales. Caudal fin almost completely covered with scales.

Dorsal fins: X + I-23-32 (usually 26), first spine small (less than 1/5 of the second one); notch present between first and second dorsal fins. Pectoral-fin: I + 15-18 (usually 16), falcate, its posterior tip reaches nearly to vertical through posterior tip of pelvic fin. Pelvic-fin: I + 5, first soft ray prolonged as filament, sometimes reaching anus. Anal-fin: II + 6-7 (usually 6), first spine reduced, approximately equal in length to first dorsal spine; second spine stiff and long, shorter than longest soft ray. Caudal-fin rhomboidal with 17 principal rays (9+8).

Swimbladder carrot-shaped with pair of short appendages anteriorly, from which a shorter paired appendages project posteriorly (Fig. 1a); posterior tip of appendages reach nearly to anus.

Color in alcohol. Background coloration tan on head and dorsal and three quarters of body. Dorsal surface from snout to first dorsal-fin darkly pigmented. Few individuals with dark chromatophores on superior one-quarter of trunk. Opercle sometimes with patch of dark pigmentation. Lower one-quarter silvery. First dorsal fin light tan with margin outlined by small dark chromatophores, giving dusky appearance. Second dorsal fin with dark chromatophores forming two longitudinal stripes. Pectoral, pelvic, anal, and caudal fins light yellow.

Distribution. Río Orinoco and Rio Amazonas drainage in Venezuela, Colombia, Brazil, and Peru; Essequibo River system in Guyana; Corantijn River system in Suriname, and Approuague River system in French Guyana (Fig. 4).

Geographic variation. Specimens from Rio Uatumã (INPA 11995, 14660, 11984, 11996, 2726, 2727, 10473, 5407, 10461, and MNHN 1996-1160), a left bank tributary of the Rio Amazonas, close to the Balbina Reservoir, have 27 to 30 dorsal-fin rays (usually 28), whereas those from other localities have 23 to 28 (usually 25). Although P. fourcroi shows this intraespecific meristic variation, there are no consistent differences that justify the subdivision of the species into more than one taxon.

Comments. Perca fourcroi was described based on a specimen from a collection which was probably donated by the Netherlands to France (La Cépède 1802: 424), suggesting that the collection could have come from the Dutch colony of Suriname. The holotype at MNHN is in good overall condition and the morphometric and meristic features are in agreement with the original description, except that there are 27 dorsal-fin soft rays (versus 28 in the original description). Although not mentioned by La Cépède, there are three mental barbels in the holotype.

An additional species not previously assigned to Pachypops is Pachyurus nattereri Steindachner (1863: 171), which was described based on three specimens from the Rio Branco and Rio Negro, Brazil. Based on the syntypes examination, Pachyurus nattereri is herein considered a junior synonym of Pachypops fourcroi , because their meristic and morphometrics values (Table 1) are in agreement with those found for the latter species. The syntype (NMW 15178:1, 54.3 mm SL) in that series in the best overall condition is designated as the lectotype, and the other two become paralectotypes (NMW 15178:2-3).

Examination of the holotype of Corvina biloba at MNHN (see Table 1) indicates that this species is a junior synonym of Pachypops fourcroi .