|
Villa Constitucion, Salto Grande, Uruguay
November 29, 2006
Google Earth image of collecting site. Eye elevation = 2600 ft.
GPS Coordinates: South 31 degrees 03.987' West 057 degrees 50.834'.
This slightly muddy habitat is a flooded lake connected to the mail channel of Rio Uruguay. The tiny town of Constitucion is a 45 minute drive north from the city of Salto. It is an excellent spot to sample some of the species traditionally associated with more northern rivers (like Parana and Paraguay), such as Gymno. balzanii and Crenicichla vittata.
This is my favorite spot in Uruguay to collect Gynogeophagus balzanii. Salto is near the southern border of their distribution. The areas near the confluence of Rio Negro (the one in Uruguay, not the Amazonian black water giant) and Rio Uruguay is their southern most limit. Of all the fishes from Uruguay, these appear to be the most cold sensitive. Ick is often an issue if you subject them to temperature variations right after collections. In my observation, the water and air temperature here is always higher than in most other Uruguayan habitats and could possibly explain the presence of this more northern species.
Easily distinguished from the other gymnogenys group species in Uruguay by their twin vertical bars, Gymnogeophagus australis like this male, is abundant in Salto.
The Uruguayan population of Crenicichla vittata is not as colorful as those from Paraguay and northern Argentina. Still, this is one of the few large pikes that can be easily reproduced in aquaria. In the wild, they breed in November and during my last trip in March 2001, the November-born C. vittata were about 3 inches long. They bred in one of my 60-gal (!) tanks at just 7 or 8 inches. Intra-pair friction did not flare up until after the fry were about an inch long. Unable to find a home for my 300 plus fry, I sold the whole lot to a friend and exporter, Wesley Wong, here in LA, who immediately shipped them all to South Korea for a nice tidy profit! It's all about who you know!
Need help with this Rhamdia (?) species ID.
Cichlasoma pusillum are relatively common here in Salto. I have a 6-year-old grouchy male from the 2001 trip in one of my tanks. Too delicate to be kept with large pikes but also too pushy to be kept with small Gymnos, he's been isolated in a 20 gal.
G. balzanii are usually in deep water and thanks to Felipe's efforts, we netted quite a few. This shore of the lake was guarded by an 'Attack Pig' that charged Jeff even though he was thigh deep in water. He fell but managed to keep his Nikon D200 above water. Two dead cameras on one trip would have been too much to bear!
The amount of purple on this fish is hard to see in this image, but it is truly a spectacular animal. This species has twin vertical dark bars on its flanks, a trait they share with Gymno. australis.
Piranha - Serrasalmus cf. ternetzi (?). Adults are yellow with faint black spots over the body. It does not appear to be abundant or a large species - the largest collected specimen was about 6 inches.
Swampy pond near Villa Constitucion, Salto Grande, Uruguay
November 29, 2006
Gymnogeophagus sp. Norte appear to be restricted to the Arapey drainage.
A very similar species is found almost 600 Km to the south near the capital, Montevideo, but nowhere in between. It is not known if these two are distinct species or the same fish that was introduced by humans to the areas near Montevideo - quite plausible since this is arguably the most colorful cichlid in Uruguay.
Hoplias lacerdae. This habitat supports both H. lacerdae and H. malabaricus. The former is said to grow much larger (more than 3 feet) in the Uruguayan Rio Negro. The only distinguishing character that I know is on the folds of the 'chin'.
Google Earth image of collecting site. It is on the bottom right of the image. This is a dam-flooded habitat and is directly connected to the main channel of the Rio Uruguay. The dam is just north of the city of Salto. The yellow line is the border with Argentina. Eye elevation = 14,000 ft.
Fish species found at Villa Constitucion in Salto Grande:
- C. vittata
- C. cf. lepidota
- Gymno. australis (gymnogenys group)
- Gymnogeophagus balzanii
- Hoplias lacerdai
- Hoplias malabaricus
- Cyanocharax uruguayensis
- Astyanax sp. Blue
- Astyanax sp. Bar Tail
- Gymno. sp. Norte (rhabdotus group)
- Acestrorhynchus paraguayensis
- Leporinus sp.
- Oligosarchus sp.
- Serrasalmus cf. ternetzi
- Cichlasoma pusillum
- Apistogramma commbrae
- Corydoras paleatus
- Giant Blue Grey Pleco (sp.?)
- Freshwater drum
- Freshwater flounder
- Rhineloricaria sp.
- Salmo maxillaris
- Southern Kingfish (Odontesthes argentinensis)
- Pimelodella sp. Spotted
- Prochilodus sp.
- Hyphessobrycon anistisi
|
