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Serrasalmus (Pristobrycon) humeralis PIRAMBEBA
FROM FRANK MAGALLANES
Updated: August 1, 2009
While the present work on S. humeralis remains to be completed by future systematizing, Jégu is basically stating that S. eigenmanni might be a synonym of S. humeralis. Further collections in the future may help provide additional material and hopefully resolve this question of taxonomic placement. S. hollandi, by variance of length may also be resolved within this complex. A problem remains with Pristobrycon scapularis since Géry (1972, 1977) placed this species as a junior synonym of S. serrulatus. S. humeralis from all appearances is a Pristobrycon and not a Serrasalmus, but that may yet be determined by science. Allegedly, a population was found in Dade County Florida (Monkeyland) in the early 1977 (Shafland and Foote 1979; identified as Serrasalmus humeralis). However, preserved specimens from the Miami area deposited at UF were determined by W. L. Fink [personal communication between Leo Nico Florida DNR and W. L. Fink, Voucher specimens: Florida (UF 87975, UF 97059 ) to be S. rhombeus]. There is much work to be done in this genus and in particular this species since it appears there is a complex of species consisting of this one, S. hollandi, S. serrulatus, S. eigenmanni, and Pristobrycon scapularis. It is my contention this fish will likely be rehabilitated and placed in genus Pristobrycon once it is officially reviewed in the future. At the present time, this complex of species which are composed of similar species includes; S. humeralis, S. eigenmanni, S. nalseni, S. hollandi and S. serrulatus needs to be analyzed for thoroughly.
Researchers should not abide by my personal decision on this matter until it is reviewed by a competent authority. Once the species is rehabilitated, I will make changes to this page with the updated information.
INTRODUCTION
FRENCH
Les Individus recueillis dans l'Oyapock, la Rivière de Kaw et l'Approuague ne diffèrent pas significativement de ceux du bassin de l'Araguaia (= "Araguay" selon Castelnau qui y a recueilli le type de S. humeralis), et dont la description complémentaire a été fait par l'un de nous (Géry, 1964, 1972, 1979), mais ils ont un peu plus de serrae : 30-36 mode 33, chez 28 ex. de Kaw-Approuague, et 30-35, mode 31-32, chez 16 ex. de l'Oyapock, ce qui les rapproche du type de l'espèce (38), très problement anormal à cet égard (puisque, jusqu'à présent, un seul exemplaire, de l'Aripuana, a été trouvé porteur de (37 serrae). Rayons ramifiés de l'anale 29-31, mode 30-31, sur 44 ex. des deux bassins (même distribution). Escailles 72-82 en ligne latérale. Dents ptérygoïdiennes au nombre diminuant avec l'âge, 5-7 jusqu'à 100 mm LS, et 3 ou 4 ensuite; un individu de 180 mm LS n'a plus de dents ptérygoïdiennes.
Le tableau XII donne les principales proportions de 12 individus de l'Approuague de 75-176 mm LS; hauteur 1,71-1,87 (Moyenne 1,79, s=0.05) et tête 3,12-3,45 (moyenne 3,25, s = 0.1) fois dans la LS. Le rapport hauteur/tête (peut-être discriminant dans la comparaison avec S. serrulatus, syn. scapularis) est de 1,7 à 1,95 environ (2,05-2,55 chez 17 ex. de S. serrulatus).
Une tache humérale triangulaire, assez diffuse mais bien apparente chez les grands exemplaires bien conservés; une grande tache en croissant à la base de la caudale, caractéristique de l'espèce; pas de bande caudale marginale, mais parfois la partie submarginale de la caudale, chez les très grands exemplaires, est un peu plus foncés; les individus de l'Oyapock ont généralement de petites taches grises parsement les flancs et unde bande noire à la base de l'anale; ceux de l'Approuague de même (vers 150 mm) ont le corps non tacheté, la ligne à base de l'anale très peu visible, mais en revanche les ventrales et l'adipeuse noirâtres (dès la taille de 75 mm LS) (de telles modifications dans le type de coloration des Serrasalmus dépendent souvent de la nature de l'eau).
ENGLISH TRANSLATION (Not to be considered accurate translation)
The Individuals collected in the Oyapock, the Rio Kaw and the Approuague do not differ significantly of those of the Rio Araguaia ( = "Araguay" according to Castelnau who collected the type of S. humeralis), and of which the supplementary description was done by the one of us (Géry, 1964, 1972, 1979), but they have a little more serrae: 30-36 usually 33, with 28 ex. of Kaw-Approuague, ex. 16 with those of Oyapock, which comes close to the type of the type (38), very abnormal problem in this respect since, so far, a single specimen of Aripuana, was found with differences (37 serrae). Branched rays of the anal total 29-31, usually 30-31, 44 on the two basins (same distribution). Scales 72-82 in lateral line. Ectopterygoid teeth number diminishing with the age, 5-7 until 100 mm SL, and 3 or 4 next; an individual of 180 mm SL has not anymore Ectopterygoid teeth. The picture XII gives the principal proportions of 12 individuals of the Approuague of 75-176 mm SL; height 1.71-1.87 (average 1.79, s = 0.05) and head 3.12 - 3.45 (average 3.25, s = 0.1) times in the SL. The head width reported (maybe differentiating in the comparison with S. serrulatus, syn. scapularis) is 1.7 to 1.95 about (2.05 - 2.55 with 17 former one of S. serrulatus). A humeral triangular spot, very prominent and very apparent with the large preserved specimens; a large dark margin at the base of the caudal fin, characteristic of the type; not any marginal tail band, but sometimes a submarginal of the tail fin (See fig. 1 and fig. 2), with the very big specimens, a little more prominent; the individuals of the Oyapock generally have small gray spots sprinkling the flanks and a black band at the anal base; those of the Approuague (about 150 mm) have the body non-spotted, the line to anal base not very visible, but on the other hand the ventral ones and the blackish adipose (as young as the size of 75 mm SL) (of such modifications in the coloring type of the Serrasalmus depend often nature of water).
DISCUSSION
FRENCH
En difféntes occasion, nous avons pu examiner des toptypes de Serrasalmus eigenmanni Norman (Guyana), le type de S. humeralis et des exemplaires topotypiques de l'Araguia, et de nombreux examplaires amazoniens de l'espèce, en particulier du bassin du Rio Madeira et du Xingu. Nous n'avons pu trouver aucun caractère discriminant permettant de séparer eigenmanni de humeralis, défini par le type de l'Araguaia (bien figuré par Castelnau, qui ne montre aucune bande marginale à la caudale) et par les exemplaires recueillis depuis dans l'Araguay (cf. Géry, 1979 pls. VII et VIII). La synonymie de S. eigenmanni est donc des plus probables.
Au cours d'une expédition récente (7.1989) dans l'Arataye, affluent de l'Approuague, et après la rédaction de ce travail, MM. Boujard, Meunier et Pascal ont découvert une forme sympatrique de S. humeralis qu l'on pourrait qualifier de jumelle si elle n'était pas reconnaissable (sur le terrain seulement) à sa couleur différente. Parvenus au laboratoire, les trois exemplaires récoltés se sont révélés effectivement très semblables par les caractères morphométriques, mais ils semblent un peu plus allongés et pourraient être rapportés, à titre d'hypothèse, à S. hollandi. Il faut attendre un matériel plus abondant et une connaissance précise de la colloration in vivo grâce à des diapositives pour se prononcer. Aussi, cette forme n'est-elle pas comprise dans le compte des espèces de l'Oyapock et de l'Approuague.
N.B. - Serrasalmus rhombeus n'a été recueilli ni dans l'Oyapock ni dans l'Approuague: sa niche écologique est peut-être occupée par S. humeralis. Des vicariances du même ordre ont été constatées dans certains fleuves côtiers de Guyane (voir conclusion), et nous espèrons revenir sur la description et la distribution géographique de ces espèces dans un futur travail (Jégu, 1991).
ENGLISH TRANSLATION
In different occasions, we were able to examine topotypes of Serrasalmus eigenmanni Norman (Guyana), the type of S. humeralis and exemplary topotypes of the Araguia, and many examplary Amazonia of the type, in particular basin of the Rio Madeira and Xingu. We were not able to find any differentiating character allowing separating eigenmanni from humeralis, defined by the type of the Araguaia (well figured by Castelnau, that does not show no marginal band to the tail one) and by the samples collected since in the Araguay (cf. Géry, 1979 pls. VII and VIII). The synonym of S. eigenmanni is therefore more probable. During a recent expedition (7.1989) in the Arataye, flow Approuague, and after the compilation of this work, MM. Boujard, Meunier and Easter discovered a sympatric form of S. humeralis which one could qualify as a twin one if it were not recognizable (in the field only) to its different flows. Examined in the laboratory, the three harvested specimens revealed themselves effectively very similar by the morphometric characters, but they seemed a little more lengthened and could be placed, by way of hypothesis, to S. hollandi. It is necessary to await a more abundant collection and specific knowledge of the live coloration thanks in part to. Also, this form is not fully understood in the account of the types of the Oyapock and Approuague.
N.B. - Serrasalmus rhombeus was not collected or in the Oyapock or in the Approuague: Its ecological niche maybe occupied by S. humeralis. Variance of the same order were noted in certain coastal rivers of Guyana (to see conclusion), and we inspire to go back over the description and the geographic distribution of these types in a future work (Jégu, 1991).
DISTRIBUTION
Amazon River basin: Bolivia, Brazil and Peru.
MAXIMUM SIZE
20.0 cm SL (7.8 inches SL) or approximately 9 inches TL.
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