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Pygopristis denticulata, photo by Frank Magallanes, OPEFE USE ONLY.WELCOME TO OPEFE ARCHIVES

Caribe, Palometa, Mapara

genus Pygopristis

Müller and Troschel, 1844

Etymology: Greek, pyge = rump + Greek, pristis = saw; denticulata = finely toothed

 

 

 

 

FROM FRANK MAGALLANES

 

I first purchased P. denticulata (then classified as S. brandtii in an old piranha book) in 1964. I also foolishly tested its weak jaw muscles by sticking my finger in a 3 inch specimens mouth! Interestingly, the fish was not able to draw blood or flesh. But I would never try it with a larger specimen nor should YOU! The map to the left is based on the Jégu & dos Santos exploration (1988). Rev. Hydrobiol. trop. 21 (3): 239-274.

 

The fish is widespread, found also in Peru and Venezuela.

 

A single species placed in genus Pygopristis, is (in my opinion) absolutely one of the prettiest of the Serrasalminae this non-dangerous piranha feeds principally on fins, seeds, fruits and such that fall into the water (click here to view). When OPEFE brought this to the attention of a neo-tropical division at a local state college, there was snickering and skepticism that a piranha would feed on seeds or fruits instead of whole flesh. Since then, OPEFE provided documented proof of the seed and fruit eating behavior and their skepticism is no longer the case. Other field researchers have since confirmed the eating habits of this species in the wild.

 

 

 

Map of range.

Penticuspid teeth. Photo by Frank Magallanes

Closeup image of P. denticulata teeth. Photo by Frank Magallanes Crenulated teeth. Often called BIG TOOTH piranha, but teeth are actually quite small. Photo by Frank Magallanes

Another visual of the teeth. Photo by Frank Magallanes

Tooth structure (penticuspid) specialized for seeds and fruit husking

 

A monotypic genus this pirambeba is predaceous but to a much lower degree than previously thought.  There seem to be different forms in terms of coloration and other unique features; possess dark bands along the flank with some lightly peppered spotting. These are sometimes erroneously imported as P. striolatus from Peru.

 

Pygopristis denticulata skeletal articulation by Steve Huskey, Ph.D

Skeletal articulation by Steve Huskey, Ph.D Western Kentucky Universtiy.

Head shot. Copyright. Do not use outside of OPEFE without permission.

Head shot. Note gill plates.

Placement of serrae. Copyright. Do not use outside of OPEFE without permission.

Serrae shown.

Full body view of Pygopristis denticulata. Photo by Frank Magallanes

There are some specimen coming in from Peru that somewhat resemble Pristobrycon striolatus, except for the teeth!

This dead specimen illustrates the head shape, serrae (skin removed) and body shape

 

We have had live specimens of denticulata donated here that were emaciated and the previous owners thought they would die in captivity (which most did). OPEFE fed them an exclusive diet of common wild bird seed as found in some feed stores and the Pygopristis made a miraculous recovery. The fish even fed from the bottom where some of the seeds lay. Live colors are variable, but normally the dorsum is blue, the ventral part of the body as well as the base of the caudal fin yellow, or orange, and the rest of the body bright red (eye, cheeks, and fins, in their distal part for the dorsal and caudal fins). There is a grayish-white margin distally on the dorsal, anal and caudal fins. The body has a series of bars and sometimes wild caught specimens are very dark. The suborbitals are weak as are the muscles of the lower mandible. There is no spine after the anus (like Pristobrycon striolatus). The species is sexually dimorphic. Two specimens approximately 8 inches SL are candidates for this experiment. The aquarium (90 Gallons) is setup with silica sand, sponge filters, outside filtration (Whisper 4) and the for plants; java moss, is being used. Reminder to aquarists keeping P. denticulata, do not overfeed seeds as it will pollute the aquarium. Use seeds/fruits as a side dish along with fish matter. Remember, piranhas are carnivorous even this one!

 

juvenile

juveniles

Peru specimen photo by Rodgers Aquatics used by Permission. OPEFE USE ONLY Collected Peru. Pygopristis denticulata. Photo by Frank Magallanes. Specimen courtesy of Aquasacape.com Collected Peru. Pygopristis denticulata. Photo by Frank Magallanes. Specimen courtesy of Aquasacape.com

Collected Peru. Pygopristis denticulata. Photo by Frank Magallanes. Specimen courtesy of Aquasacape.com

The images above illustrate two different geographical variations.

 

AQUARIUM ADVICE

 

Hobbyists can consider this species somewhat harmless in the aquarium. But they do have sharp if not the smallest teeth of the pirambeba-like fish. They will eat small fishes. Care is still required in handling them, they have weak jaws, but do not assume that a large specimen cannot lacerate you! The species may be kept with its relatives the silver dollars (genus Metynnis). It is not uncommon to find them mixed up together in pet stores when juvenile, since they externally resemble that genus.

 

I do not recommend mixing this species with any other piranha or pirambeba. The main reason is because they likely would get eaten by their more opportunistic sisters. I consider them to be an excellent specimen for the home aquarium and worth collecting. 

 

SCIENCE

Photo courtesy of NEODAT II AMNH

Image courtesy of NEODAT II Plate image of S. punctatus, Schomburgk 1841

 

 

VALID NAME

 

Pygopristis denticulata CUVIER 1819 (species name is corrected to reflect proper).

 

Synonyms

 

Serrasalmus punctatus Schomburgk, 1841.

 

OTHER HISTORICAL NAMES APPLIED:

 

Eigenmann, C. H. 1910 (12 Feb.) Catalogue of the fresh-water fishes of tropical and south temperate America. In: Reports of the Princeton University expeditions to Patagonia 1896-1899.

pg. 241. Pygopristis denticulatus (Cuvier). Serrasalmo denticulatus Cuvier, Mem. Mus. d'Hist. Nat., V, 1819, 371.—Gunther, Catalogue, V, 1864, 367 (British Guiana).

Pygopristis derdiculatus Muller and Troschel, Horse Ichth., I, 1845, 21, 34, pi. 9, fig. 1 (Guiana); in Schomburgk, Reisen, III, 1848, 637 (Essequibo ; Takutu ; Rupununi).—Cuvier and Valenciennes, Hist. Nat. Poiss., XXII, 1848, 297 (Essequibo).—Eigenmann and Eigenmann, Proc. U. S. Nat. Mus., XIV. 1891, 59.—Ulrey, Ann. N. Y. Acad. Sci., VII, 1895, 296 (Lower Amazon) .- Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, 441.

Pygopristis fumarius Muller and Troschel, Horse Ichth., I, 1848, 21, 35, pi. 9, fig. 2; in Schomburgk, Reisen, III, 1848, 637 (Rupununi; Essequibo).—Kner, "Familie der Characinen," ii, 1859, 27 (Rio Branco).

Serrasabno punctatus Schomburgk, Fishes Brit. Guiana, I, 1841, 223, pi. 17. Twenty-three specimens, 151-234 mm. Lama Stop-Off. (C. M. Cat. No. 1118a-d; I. U. Cat. No. 11637.) Head 3.5; depth 1.66; D. 18 or 19; A. 34-38; scales with pores 87-95; eye 4 in head, 2 in interorbital; abdominal serrse 36 + 4, 33 + 3, 38 + 4, 31 + 4 in four individuals respectively.

Pumpkin-seed shaped; snout rounded, lower jaw heavy, truncate, its anterior profile forming a continuous oblique line with the snout. Second suborbital leaving four-tenths of the cheeks naked ; opercular bones and suborbitals but little striate ; mouth small; teeth nearly symmetrical, with a central lobe and two much smaller lobes on each side; six teeth on each premaxillary, in a single series, the third tooth much smaller than the rest. Gill-rakers 9 + 9, small. Dorsal broadly rounded, its base equal to its distance from the caudal; adipose short; caudal lobes pointed; anal with its first two or three developed rays slightly prolonged, the rest of the margin of the fin nearly straight; ventrals reaching anal groove, pectorals not quite to ventrals. Lateral line decurved; anterior scales of the lateral line largest; rows of scales along the middle of the sides more numerous than the pores in the lateral line, the pores corresponding to the rows of scales on the caudal peduncle and over the posterior fourth of the anal; a wide naked area from the dorsal to the occipital.

Dorsal faintly spotted. Iridescent steel-blue above. Pectorals, ventrals, and most of the anal brick-red; opercle orange; a narrow margin of the caudal and anal colorless; caudal submarginally orange, ranging to lemon-yellow and olive.

Species is sexually dimorphic based on a lobed anal fin on male P. denticulata.

 

Gosline published the origin and evolution of the Serrasalminae (1951:54) and indicated ..."The diagnosis of this kind is the same one that is established for Serrasalmus. The species of Serrasalmus are transformed imperceptibly inside Pygopristis, and the distinction among the two, based on the number of tubercles in the teeth seems to be of doubtful generic rank."

 

Géry (1976) and Machado-Allison (1985) nonetheless demonstrated the genera Pygopristis, Pristobrycon and Pygocentrus should be maintained because of the variety and number of species with the former author treating them as a subgenus of Serrasalmus. Only one, Machado-Allison (1982a and 1985), using Phylogenetic and cladistics in the subfamily, indicated Pristobrycon is the most recognized from Serrasalmus, Pygocentrus and from Pygopristis. This species is the closest appearing to P. striolatus (Steindachner).

 

MAXIMUM SIZE

 

20.0 cm TL

 

DISTRIBUTION

 

Orinoco river basin, North and East Guiana Shield rivers; tributaries of lower Amazon: Brazil, French Guiana, Guyana, Suriname and Venezuela.

 

REFERENCES 

 

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UPDATED: 12/06/2015