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Pseudoplatystoma fasciatum (Linnaeus, 1766)
(Figure 10, Table 1)
Historical review. Linnaeus (1766) described Silurus fasciatus ZBK based on external morphology, including number of fin spines and rays, pigmentation, shape of the rostrum, and texture of the skin. Linnaeus mentioned in his original description the names of Gronovius and Seba, two reknowned cabinet owners (i.e., collectors) at that time. Linnaeus based his description on material owned by one of these gentlemen, apparently Albertus Seba. Engel (1961) and Boeseman (1970) tried to trace the ultimate destination of Seba's zoological material with the intention of helping taxonomists find type specimens. They concluded that only a small part of Seba's original material can be located accurately (Boeseman, 1970). His collections may have found their way to museums in Leningrad, Berlin, Bremen, Stockholm, and The Hague (Boeseman, 1970), as well as London and Paris. We have not been able to locate any type of Silurus fasciatus ZBK .
An English translation of Linnaeus’ original description is as follows:
"Posterior dorsal fin adipose. Anal fin with 13 rays, pelvics with 6 and spotted. Dorsal with 7 rays, caudal 17. Lower jaw short, rostrum flat and dark. Head long, flat, round anterior and reaching 1/2 the length of the body. Dorsum with black and white stripes on each side. Abdomen white. All fins sprinkled with black spots. Dorsal fin near the head, adipose near the tail. Habitat: Brazil and Suriname."
Linnaeus considered both Brazil and Suriname as the type locality of his Silurus fasciatus ZBK . We presume that the locality of Suriname is based directly on the collection that Seba made there in 1758 (Mees, 1974), whereas the reference to Brazil is based indirectly through Seba from Marcgrave (Mees, 1974). We follow Mees (1974:129), the first revisor, in restricting the type locality of P. fasciatum to Suriname.
Eigenmann and Eigenmann (1888, 1889) described four subspecies of P. fasciatum from the Amazon basin; P. f. brevifile ZBK , P. f. nigricans ZBK , P. f. intermedium ZBK and P. f. reticulatum ZBK . The allocation and taxonomic status of these names has not been clarified despite their repetition in standard catalogs (see Gosline, 1945; Fowler, 1915; Mees, 1974). Eigenmann and Allen (1942), Ringulet et al., (1967) and Mees (1974) placed these names in the synonymy of P. fasciatum . Conversely, we place the following names, P. fasciatum brevifile ZBK , P. fasciatum nigricans ZBK , P. fasciatum intermedium ZBK , in the synonymy of P. punctifer , a valid name applied to a species inhabiting the Amazon River (see P. punctifer account below). Pseudoplatystoma fasciatum reticulatum ZBK is elevated herein as P. reticulatum ZBK for a distinct population that inhabits the Parana and Amazon rivers (see below).
Neotype : FMNH 116903 , 516 mm SL, Linker Coppename River, ca. 1 km downstream from confluence of Midden and Linker Coppename rivers , 4°14’5.6”N , 56°36’5.8”W , Suriname , Ted Jantz et al. , 28 February 2004 .
Geographic distribution: Guyana region, including the Essequibo and Suriname rivers and their tributaries, in the countries of Guyana, Suriname, and French Guiana (Guyana) (Fig. 11).
FIGURE 10. Pseudoplatystoma fasciatum (Linnaeus, 1776) , INHS 48973, 516 mm SL.
Material examined: ANSP 175801 , (1), 188 yd. up stream from Essequibo campsite Maipuri , 4º45'43"N , 58º45'52"W , Essequibo River , county of Siparuni VIII -2 , Guyana , D. Allicock , 27 January 1997 . ANSP177346 , (1), (1 ds), Black Water camp , 4°44'00"N , 58°59'00"W , Siparuni River, Essequibo River , county of Essequibo , Guyana , G. Watkins et al. , 6 December 1997 . ANSP 8385 , (1), Suriname River , Suriname . ANSP 177351 , (1), rocky area 200m downstream from Paddle Rock campsite , 4°44'23"N , 58°42'42"W , Essequibo River , Guyana , D. Torres et al. , 6 December 1997 . BMNH 1822.214.171.124 , (1), Suriname , purchased by Damon . BMNH 1971.729.92.93 , (2; 1 ds), Karanambo pools, Rupununi River , Guyana , R. H. Lowe-McConnell , 1971 . BMNH 18126.96.36.199 , (1), Suriname , purchased by Damon . CAS 11626 , (2), Rupununi River , Guyana , C. H. Eigenmann , 1908 . INHS 48974 , (1 ds), Mazaruni-Potaro , 5°59'07.5"N , 58°33'02.9"W , Essequibo River , Guyana , J.W. Armbruster et al. , 19-20 October 1998 . INHS 48973 , (1), large sandbar & small cataract, 31.9 miles SSW Rockstone , 05°31'39.5"N , 58°37’43.6"W , Mazaruni-Potaro , Essequibo River , Guyana , J. W. Armbruster et al. , 21 October 1998 . NRM 6050 , (2), Suriname , Barnet-Lyon1991 . UF 16271 , (1), Marowijne River, at Albina , Suriname , Tjon-A-Hie , July-August 1967 . USNM 225437 , (3; 1 ds), Koekwie creek , 5°31'00"N , 57°10'00"W , Suriname , H. M. Madarie , 15 May 1980 .
Diagnosis: A species of Pseudoplatystoma ZBK distinguished by a combination of the following features: 42- 44 vertebrae versus 37-40 in the most similar species, P. punctifer (see Tables 1, 5 and 9); vertebral complex supporting Weberian apparatus longer than wide; skull at least 1/6 narrower than in other species; usually 10- 11 dark vertical bars, relatively wider than similar species from Amazon River; white vertical bars fewer than black vertical ones; generally, darker dorsally than congeners; pectoral and pelvic fins darker with few or no spots; bars posterior to head and opercle relatively more loop-like than straight; first spinelet of anal fin contacts haemal arch of 24th vertebra; conversely, it contacts haemal arch of 22nd vertebra in P. punctifer from Amazon River; last five vertebral centra shorter than in other species.
Description: Maximum size recorded 900 mm TL. Body moderately slender, profile of head an acute triangle, almost flat anteriorly. In dorsal view, head margins almost parallel, widening anteriorly. Anterior margin of mouth rounded, covered by thick skin. Body widest at pectoral fins, and gradually diminishing in width to caudal peduncle. Dorsal margin from dorsal fin to adipose fin somewhat concave, posterior to adipose fin straight. Ventral margin of body straight. Dorsal surface of cranium rough posteriorly with thin skin firmly attached, anterior region smooth with thicker skin. Middle fontanel extending along dorsal surface of head. Anterior nostril tubular, posterior one covered by small triangular flap. Eye dorsolateral, somewhat ovoid or circular at middle of head. Maxillary barbel very long, reaching beyond pelvic fin, dark dorsally, pale ventrally. Anterior ventral chin barbel shorter, 3/4 of the head length, pale. Posterior ventral chin barbel longer, reaching tip of pectoral spine, pale. Opercular margin pale.
Pigmentation somewhat regular in individuals of this species. Head and body dark dorsally and laterally. Dark pigmentation extending to the lateral line. Ventral region of body whitish. Darker bands present as vertical bars or loops. Vertical bars distributed along side posteriorly to pectoral fin and may reach ventral region of body; some of them with pale bars. Loops in area surrounding the dorsal fin. Dorsal fin rays with spots along their length. Adipose fin with small spots. Caudal fin with few spots, usually 29-40. Pectoral and pelvic fins usually dark. A comparison with other species of Pseudoplatystoma ZBK is in Table 9.
TABLE 1. Descriptive measurements of the body size and shape (in mm), and number of vertebrae for P. fasciatum . Number of individuals measured, 23.
|Snout-posterior occipital process||179.7||115.8+28.7||80-197.4|
|Snout-posterior margin of the opercle||179.7||111.3+29.5||87.3-194.8|
|Dorsal fin spine length||56.7||33.2+10||18.6-58.3|
|Pectoral fin spine length||76||45.5+13||27.8-80.3|
TABLE 1. (continued)
|Maxillary barbel length||219||156.1+29.6||111.3-209.4|
|Anterior chin barbel length||169.3||132+20.5||99.8-169.3|
|Insertion maxillary barbel -eye||72.5||46+10.5||30.6-72.5|
|Insertion maxillary barbel -joint pectoral spine||143.5||87+24.2||58.5-155.4|
|Insertion maxillary barbel -joint dorsal spine||201.6||122.9+32.3||83.8-209.8|
|Eye -joint pectoral spine||80.5||45.8+14||29.2-84.6|
|Eye -joint dorsal spine||129.5||76.7+21.1||52.7-134.4|
|Joint pectoral spine -joint dorsal spine||90.1||50.9+14.5||33-90.5|
|Joint pectoral spine -joint first pelvic ray||128.2||68.5+22.8||46.1-137.2|
|Joint pectoral spine -joint last ray of dorsal fin||114||65.7+18.9||43.2-119.8|
|Joint dorsal spine -joint first pelvic ray||101.2||50.9+18.8||34.1-107.5|
|Dorsal fin base length||38.9||22.3+7.2||14.2-41.9|
|Joint first pelvic ray -joint last dorsal fin ray||74.2||36.3+14.2||25.8-80.5|
|Joint first pelvic ray -anal fin origin||122.5||69+19.6||45.4-122.5|
|Joint first pelvic ray -origin adipose fin||131.8||71.6+20.4||50.2-131.8|
|Last dorsal fin ray -anal fin origin||153.9||84.4+26.2||60.5-153.9|
|Last dorsal fin ray -adipose fin origin||131||72.6+20.4||52.9-131|
|Anal fin origin -adipose fin origin||61.3||32.2+11.2||20.6-64.7|
|Anal fin base length||55.5||30.4+10.1||21.6-55.5|
|Anal fin origin -adipose fin terminus||62||33.6+11.1||24.5-66.1|
|Adipose fin origin -anal fin terminus||67.7||38.7+13||24-77.6|
|Adipose fin length||39.2||24.1+7.9||12.1-39.2|
|Anal fin terminus -adipose fin terminus||36.6||20.5+6.7||14.4-36.6|
|Anal fin terminus -ventral caudal fin origin||17.9||11.4+3.7||6.9-23.6|
|Anal fin terminus -dorsal caudal fin origin||34.4||21.3+5.9||15.9-39.2|
|Adipose fin terminus -ventral caudal fin origin||46.4||27.4+7.8||19.4-51.6|
|Adipose fin terminus -dorsal caudal fin origin||26.2||17.7+4.4||13.3-31.6|
|Caudal peduncle depth||31.9||17.9+5.4||12.6-31.9|
|Number of vertebra||43||43.2+0.83||42-44|