Brazil Rio Xingú

By Peter Petersen

This Zebra Pleco Hypancistrus zebra was caught under the rocks in the background and put back after this photo session.

The beautiful Hypancistrus zebra is endemic to a very small area in the Rio Xingú. I found most of the fish between the big rocks like this.

This is the habitat. Rocks and sand seems to dominate the area. But a few roots were caught between some of the rocks.

Above water to check if the boat was still there and then down again to explore some more fish in their beautyful habitat.

Mark Henry Sabaj is one of the scientists working with the species of the Rio Xingú. Very dedicated guy doing very important work for the future of this river.

The future of this amazing fish is questinable. The habitat is getting smaller. The construction of a large dam (Belo Monte) have changed the current of the river and the visibility of the water. Silt makes the water look cloudy like this.

Here is a local fisherman with the beautiful Hypancistrus zebra. The fish were released back at the exact spot where it was caught after this photo was taken.

An old beer turned out to be an excellent pleco cave. I found a small Hypancistrus zebra in this can.

Hypancistrus zebra is one of the jewels that might save this river. People like prof. Leandro Sousa is preserving and protecting the area. His work is very important for the future of this amazing place and these unique species.

Brycon pesu is abundant in Rio Xingú. Its a small species, very active. I found them in all locations both in still and fast flowing water.

Usually Brycon pesu occur in small schools like this.

Here Brycon pesu with Tometes kranponhah and Hypomasticus julii.

Peckoltia sabaji right after capture.

Here Mark Henry Sabaj with Peckoltia sabaji. The pleco named in his honour.

One of our boats taking of from a location near Volta Grandé.

Tometes kranponhah is an amazing fish. One amoung many unique species of the Rio Xingú.

I found Tometes kranponhah in many different areas. Mostly around fast flowing water. But even in the still water river bays they appeared.

This Tometes kranponhah was climbing the massive waterfall Volta Grande. Notice the Baryancistrus xanthellus hiding with just the dorsal fin showing.

Tometes kranponhah school here with Bryconops alburnoides, Moenkhausia heikoi and Jupiaba apenima.

Juvenile Tometes kranponhah caught in the Volta Grande.

A simular looking species is this Myleus setiger in the photo below. The mouth and the body shape is different but the coloration is simular.

Rio Xingú has many riverweeds (Podostemaceae). Many of which are endemic to the river. I found these dry Castelnavia princeps along with several other species at the same waterfall.

This is another riverweed (Podostemaceae) species from the same waterfall. This is most likely the species Mourera weddelliana.

The riverweeds (Podostemaceae) grow in the waterfalls. Here again the same species probably Mourera weddelliana.

Another riverweed (Podostemaceae) species present here was this one below. Probably a Apinagia species.

A close up photo of the flower of the same species. Probably a Apinagia sp.

Here Julian Dignall (Jools) from www.planetcatfish.com next to the riverweeds (Podostemaceae).

Scobinancistrus raonii (L082 Opal Spot Pleco) a magnificent species which also were present here. I only caught a few specimens though. It seemed to be a rare species in the river.

Mixed fish from the same habitat. The river is rich in species.

Baryancistrus xanthellus in the jaws of a Lugubria sp. "Rio Xingu" (formerly Crenicichla sp. "Rio Xingu") with Leporinus villasboasorum , Brycon pesu, Moenkhausia heikoi and Geophagus argyrostictus in the same picture. Major diversity.

The fast flowing water is producing oxygen for species under water as well as above the surface. Endemic riverweed (Podostemaceae) species is growing on the rocks.

This is a juvenile Scobinancistrus aureatus also a colorful species present in this region. It seemed to be a rare species in the river and this was one of my only encounters with this species.

Look in the upper part of the picture beyond the big rock you can hardly se the Scobinancistrus aureatus. In the middle right you will also notice an Ancistomus feldbergae.

This area below is where I found Scobinancistrus aureatus.

Hemiodus vorderwinkleri is a common species here but they are hard to get close to. Itś a shy species and observing them was difficult.

well camouflaged on the bottom I found Spatuloricaria tuira. This species I found both in fast-flowing water and in still-water pools.

Here is Julian Dignall (Jools) in the habitat of Spatuloricaria tuira and Peckoltia vittata.

Under the surface this habitat looks like this

Closer to the fast flowing stream the water becomes more clear.

Still particles in the water though.

At first glance just a trunk. But a perfect hiding place for a young Peckoltia vittata.

I found this Peckoltia vittata hiding in the trunk. Closer to the water falls but in still water.

The are several species of pike cichlids in the river but most of them seem to be undescribed. This is a juvenile of the species I found to be most common there. Lugubria sp. "Rio Xingu" (formerly Crenicichla sp. "Rio Xingu").

They seem to have parental care for a much longer period of time than other pike cichlids I have encountered. Here a group of juvenile Lugubria sp. "Rio Xingu" (formerly Crenicichla sp. "Rio Xingu")

These juvenile Lugubria sp. "Rio Xingu" (formerly Crenicichla sp. "Rio Xingu") are around 12-15 cm and still under their parents care.

The adults of Lugubria sp. "Rio Xingu" (formerly Crenicichla sp. "Rio Xingu") can change color from black to this which seem to be their favorite color.

Rhinodoras boehkei is also hiding under til rocks in the fast-flowing water in the river. Perfectly camouflaged. I also found some under the leaves in the still-water pools.

This was one of the habitats I found Rhinodoras boehkei in.

This was another place I found Rhinodoras boehkei. Hiding among the leaves.

This freshwater sponge (probably the species Oncosclera navicella) seemed to prefer the shade. When I turned over rocks I often saw different species of sponges.

This white sponge in the photo below is Oncosclera navicella.

The black sponges seemed to prefer growing in direct sunlight. This spiky one was very common Drulia ctenosclera.

I observed Pseudacanthicus pirarara grazing on these spiky black sponges (Drulia ctenosclera). Making holes in the middle like in this picture.

Pseudacanthicus pirarara (L025) caught where Rio Xingú meets Rio Iriri.

This more smooth black sponge is also very common in the Rio Xingú. Itś most likely the species Tubella repens.

Near the water falls I often noticed these creamy colored sponges (presumably Uruguaya coralliodes) . The Baryancistrus xanthellus was grazing on these. In the sunny spots algae seem to grow on top of the sponges making them greenish.

I observed this Tometes kranponhah rasp off a black sponge (probably Tubella repens). I tried removing the sponge from the rock with my fingers without success. But the teeth of Tometes kranponhah is perfectly adapted for this task.

The Tometes kranponhah kept spitting out the sponge, grabbing it again repeatedly. Every time the sponge piece got smaller. after about 8-10 times all of the sponge was consumed.

The smaller pieces of the sponge were not wasted. I observed these Bryconops alburnoides chasing the sponge pieces which passed through the gills of the Tometes.

This Squaliforma emarginata is the biggest I have ever seen. It measured 52 cm TL.

Squaliforma emarginata rely on their camouflage. In this case it was a mistake.

The Squaliforma emarginata I found only in still water and in moderate flow.

Often in merky waters with a lot of small particles floating around. This Squaliforma emarginata is on alert.

Squaliforma emarginata is a colorful species with a unique appearance. Itś easy to recognize.

In some areas of the river large volcanic rocks like these are used as breeding caves for the many plecos and other fish found here.

The pattern and spots of Centromochlus schultzi varies a lot. Same locality had individuals with almost orange fins, with just a few spots and fish like this with many spots and plain grey fins.

Julian Dignall (Jools) looking for Plecos.

Hypostomus sp. (L087) trying to hide. It changes color in an instant.

Hypostomus sp. (L087) on alert, dorsal fin up and on the move.

Julian Dignall (Jools) capture the Hypostomus sp. (L087)

The sunset in pictures are never as impressive as the real thing. However I always attempt to capture the amazing colorations of the Amazon sunsets.

It is more interesting than it is beautyful. But I can not help to be amazed. The wide head and beard of the Ancistrus ranunculus males are astonishing.

I found them often cracked in between rocks in the very fast flowing parts of the river. Often next to waterfalls. Here is a view from below.

Another close related species is this Ancistrus sp. (L255). Here it ś in stress coloration. Normally itś black with small white spots. If you look closely you can still see the spots. Notice the white tip in the top of the caudal fin. It seemed to be present in only the young fish.

The view from the inside of a pleco cave

Sadly this was the closest I ever got to this Chasmocranus longior which was hiding under the rock. Very fast species. I only saw a few of them but never caught any.

Hypomasticus julii grazing on the rocks. well adapted to the life in this river system.

Hypomasticus julii is a colorful and very unique species. It very abundant in the Rio Xingú.

Hypomasticus julii often swim in groups consisting of different sized individuals.

The number of species present in this river is incredible. This is truly an amazing river system. This is a juvenile Scobinancistrus cf. pariolispos (L048).

Vultures are very common along the river. Here is a Black vulture Coragyps atratus drinking water from the safe shallow waves made by our boat.

Even though a lot of skilled ichthyologists are working with the fish of this river system there is still a lot of undescribed species here. Platydoras birindellii was described in 2018.

This species is also undescribed. A juvenile Baryancistrus sp. (L019) in stress-coloration. Notice that the dorsal fin and the adipose fin are not connected.

The mouth of Baryancistrus sp. (L019)

A young Baryancistrus sp. (L019) seconds after capture.

Adult Baryancistrus sp. (L019) in itś natural habitat. Beautyful species. This one is around 30-35 cm long.

The shape of the predator Cichla melaniae.

A video of Cichla melaniae in itś natural habitat in Rio Xingú in Brazil

Close up the Cichla melaniae is a beautyful fish and very tasty.

A fully grown wolverine Pleco (Hopliancistrus wolverine) L017. This specimen is around 19 cm TL.

Shrimps like this Macrobrachium brasiliense are abundant in the Rio Xingú.

But other species are present too. This species below seem to be undescribed. I will call it Macrobrachium sp. "Rio Xingú.

We spent many hours in the boats enjoying this ever green scenery.

I caught juveniles and only a few of Leporacanthicus heterodon. It seemed to prefer the shallow fast flowing water with lots of rocks.

If you look closely in this photo you will see a small Leporacanthicus heterodon hiding between the rock formations.

The Pseudancistrus asurini is very common in the river though. I found them everywhere except for the still-water pools. This is how they normaly look as subadult.

One of the fishermen caught this color mutation of a Pseudancistrus asurini. We only caught one fish with this peculiar appearance though.

Pseudancistrus asurini. Hiding under a big rock.

Camouflage is not everything. After a minute we succeeded in catching this beautyful Pseudancistrus asurini. This is a adult specimen.

The flat shape of this species allows them to occupy much more narrow caves than other species at same size. Pseudancistrus asurini varies a lot in coloration and pattern. The yellow tips of their fins disappear as the grow older.

Inspiration for aquascaping is never far away. Nature is the best Aquascaper.

Some Bryconops caudomaculatus trying to escape my camera. A few Moenkhausia heikoi too.

One of the species which I found to be most variable anatomically was Spectracanthicus punctatissimus. Its a common species and I caught hundreds of them. I am still not sure that all the fish I caught belonged to the same species.

Here is another specimen of supposedly the same species Spectracanthicus punctatissimus.

Geophagus argyrostictus is one of the common cichlids in Rio Xingú. Her with Moenkhausia heikoi, Leporinus tigrinus and Tometes kranponhah.

Geophagus argyrostictus here with hundreds of offspring. The parental care of this species seem to stop at an early age. Ater the juveniles reach about 1 cm they don't seem to follow their parents anymore.

Geophagus argyrostictus is easy recognized by the shiny scales around the black spot. Here with Moenkhausia heikoi, Bryconops alburnoides, Brycon pesu and Tometes kranponhah.

Ancistomus feldbergae is a common species here.

I noticed a link between the occurences of Ancistomus feldbergae and this sponge (probably the species Oncosclera navicella). Both species appeared under the same rocks every time in more than 90 video sequences.

Ancistomus feldbergae on the move.

Coatings of algae, bacteria, detritus etc. are covering the rocks and the gravel is the more slow moving parts of the Rio Xingú.

Leporinus maculatus and Leporinus fasciatus often shoals together like this.

A shy Leporinus friderici trying to escape. I never got a good photo of this species.

The most common pleco in Rio Xingu most be the Golden Nugget Pleco Baryancistrus xanthellus. They were everywhere. Even on the dinner plate. Very tasty fish by the way.

This is a juvenile Golden Nugget Pleco Baryancistrus xanthellus. It was not ready to be eaten yet. So I went back to the river.

Larger specimens of Golden Nugget Pleco Baryancistrus xanthellus are less colorful with smaller yellow spots, but have much bigger spikes and odontodes. This is an adult.

Baryancistrus xanthellus was present here in the fast flowing parts of the Rio Xingú.

But also here in the still water Baryancistrus xanthellus thrive.

Baryancistrus xanthellus; The head from above showing exactly why gloves can be a good idea. Especially if you handle a lot of them every day.

Even close up these Golden Nugget Plecos Baryancistrus xanthellus are fascinating fish.

The males of Golden Nugget Pleco Baryancistrus xanthellus are more spiny than females like in most other plecos. They use the spikes to trap the female inside the cave when breeding.

Baryancistrus xanthellus occur in very different temperatures and other water parameters.

The silhouette of the adaptable Baryancistrus xanthellus.

The largest Baryancistrus xanthellus specimens I measured was 36 cm. In general I found a lot of them around 20-30 cm like these. Very common size there.

Younger specimens of Baryancistrus xanthellus like this (Around 15 cm) fish are more colorful. More yellow color in the dorsal and caudal tips.

Even smaller individuals of Baryancistrus xanthellus seem to be very varied in coloration. But often much larger spots and more yellow fin tips.

A young Baryancistrus xanthellus (around 10-12 cm) hiding between the rocks in a fast flowing section of the river.

The Baryancistrus xanthellus is one of the easier species to get close to in the river. They are ofter quite curious if you just stay still you might get a visitor.

I also came across specimens looking like this. At first glance I figured it to be a less colorful mutation of Baryancistrus xanthellus. I saw them in sizes from 5-35 cm all with same greenish color with pale small spots. Local fishermen calls them "verde" (green). I am still not sure if this is perhaps a new species. Looking at the mouth parts of the ones I caught. They looked a little different. But I did not examine it further.

Driftwood is common in some areas. Many of the plecos and snails I saw feeding on these.

DNA samples was taken from many of the species we caught to help ichthyologists determine genetic relations between the different species.

The fast flowing part of the river are often filled with air bubbles rich in oxygen and it hides some very interesting species.

One of the species from the really fast flowing water in and near the waterfalls is what I believe to be Melanocharacidium nigrum. But it might even be Characidium declivirostre or Characidium crandellii. I find it hard to tell from the old describtions.

Melanocharacidium nigrum (possibly Characidium declivirostre or Characidium crandellii) quickly loses their color after capture. On the rock in the background you see a dried out riverweed (Podostemaceae) belonging to the species Castelnavia princeps.

Visibility here is almost not existing. Sometimes you just have to try.

A small cichlid found in the same fast-flowing water is this Teleocichla cinderella.

If you step out of the bubles you will see a lot of fish species hanging out outside the fast stream. Waiting for food items to pass by.

A species which I only found in the fastest flowing parts of the river. Mainly directly in the waterfalls was Panaque cf. armbrusteri. I only saw juveniles like this one.

One af the predators here is this Snakebird Anhinga anhinga.

Also the Black Piranha Serrasalmus rhombeus is a common predator here. Probably one of the most widespread predators of the Amazon.

Roots under water in the rainy season are exposed when dry season comes. This often makes it easier to spot and catch the fish during the drought.

Homo sapiens are making a footprint in this wilderness. Large areas are being turned into plantations.

Platydoras armatulus has a large range. I caught this species in Colombia and Peru as well. The specimens in Rio Xingú are almost completely identical.

The gravel and rocks varies a lot.

This type of melted rock is common here. It varies from black, blue to purple depending on the sunlight.

These rounded stones are also common in the Rio Xingú. Sometimes melted into larger rocks like this one on the left.

Tip a few rocks and you will see many interesting species.

Undescribed species like this Centromochlus sp. Rio Xingú are abundant in this environment.

Mark Henry Sabaj is here keeping track and identifying our catch. For later DNA sampling and marking of the fishes.

A pike cichlid I did not expect to find here was this beautiful Lugubria percna (formerly Crenicichla percna).

I often found Lugubria percna (formerly Crenicichla percna) living together with other species with a simular coloration and pattern and shape. Here itś Teleocichla cinderella and a young Lugubria percna (formerly Crenicichla percna).

A fish with an even more simular coloration and pattern is this undescribed Leporinus sp. "2"

Professor Leandro sousa is doing important preservation work on the Rio Xingú and teaching at the campus of Altamira. His work is crucial for the future of this amazing river.

This is a more common species here a young Green iguana Iguana iguana resting in the sun.

Parancistrus sp. (L332) with a tail-bite made by a Cichla shortly before capture. I scared away the Cichla and the pleco went strait for the nearest rock. Easy catch.

Parancistrus sp. (L332) trying to get away.

A large Parancistrus sp. (L332).

Parancistrus sp. (L332) Perfect coloration for hiding in this habitat.

Notice that only the small specimens of Parancistrus sp. (L332) have the thin white markings in the dorsal and caudal fin. Like in this photo below.

Parancistrus sp. (L332) is a very common species in Rio Xingú. Catch!

And release! Parancistrus sp. (L332).

The cracks between the rocks in this tower is hiding place for many species.

Guess a pleco. Yes you are right Baryancistrus chrysolomus.

A very young Baryancistrus chrysolomus I caught in an area with still and cloudy water.

A larger specimen of Baryancistrus chrysolomus. Again caught in still and cloudy water in another area. Notice the spots which appear when they get stressed out.

Baryancistrus chrysolomus in a crack between the rocks

When the fish try to escape they stir up the bottom and everything is cloudy. This Baryancistrus chrysolomus escapes under a big rock.

This video below shows Squaliforma emarginata (L011, L108, L116) Red Fin Thresher Pleco, Peckoltia vittata (L015) Candy Striped Pleco, Baryancistrus chrysolomus (L047) Magnum Pleco and Ancistrus sp. (L255) Spotted Medusa Pleco

Large rocks creates hiding places for the big fish.

Who says pleco caves are not present in their natural habitat? This brick is commonly use in Brazil and some end up in the river like this one.

Parancistrus nudiventris is very abundant is big parts of the Rio Xingú.

Parancistrus nudiventris in itś natural habitat

Julian Dignall (Jools) with a large Parancistrus nudiventris.

Parancistrus nudiventris and a few Bryconops alburnoides.

This is actually a young specimen of Parancistrus nudiventris.

This is one of my favorite species of this region. I found Parancistrus nudiventris in both fast flowing streams and in still water like this one.

Beautiful large male specimen of Parancistrus nudiventris.

Another interesting species is this Leopolds Stingray Potamotrygon leopoldi. I found them mostly on rocky bottom. They are fast swimmers and seemed to prefer the super fast flowing waters in the smaller waterfalls.

The flow here was so fast that I had problems just standing with me feet locked in between some big rocks. Leopolds Stingray Potamotrygon leopoldi had no problems maneuvering in these violent currents

I noticed Potamotrygon leopoldi feeding on these snails in the photo below. The rough ones seem to be Doryssa starksi and the smoother more elongated ones seem to be Doryssa heathi.

I encountered what to me looked like around 7 species of snails which all seemed to belong to the same genus (Doryssa). In this pictures most seem to be Doryssa starksi. A juvenile Ancistrus sp. (L100) also present in this photo.

The next three photos are from the same waterfall. First one is above water. The riverweed (Podostemaceae) is most likely a Mourera sp. The flowers are above the surface in the sides of this picture. They are ready to produce fruits.

Below you can see the riverweed (Podostemaceae) growing all the way down the waterfall. I observed more than 15 species of fish feeding on these unique aquatic plants. They most be a very important part of this ecosystem.

I have submerged the camera and you see the leaves of the riverweed (Podostemaceae). Rio Xingu has about 200 species of aquatic macrophytes. Most are endemic to the river and some riverweeds even to a single waterfall.

Here you see three of the fish species which I observed feeding on a certain riverweed (Podostemaceae) probably the species Castelnavia princeps. The fish are Moenkhausia heikoi, Tometes kranponhah and Leporinus tigrinus.

I also noticed Brycon pesu and Leporinus fasciatus feeding on the same riverweed (Podostemaceae). Leporinus fasciatus was chewing off pieces and Brycon pesu was collecting the leftovers.

Leporinus maculatus and Hypomasticus julii are two other species I observed taking part of this feeding habit.

The Teleocichla preta is easily distinguished from the other species in the genus by it's dark coloration.

Leporinus tigrinus is one of the most beautyful species in the Rio Xingú in my opinion.

They are also very curious. Dont move and you will get a visit from Leporinus tigrinus.

One of the bigger fish in the river is this Semaprochilodus brama. I did not se any juveniles but adult in great numbers. Behind is a Serrasalmus rhombeus.

Fishing trips at night reveales many interesting species.

Like this crab Sylviocarcinus pictus. These were active at night and easy to spot with the headlight.

Satanoperca jurupari are also present here in Rio Xingú. I caught this species in Colombia, Venezuela and Peru as well. It is a common species in the Amazon.

Another widespread species is this Geophagus altifrons.

They are probably feeding on the juveniles of these shrimps Macrobrachium amazonicum.

Even Hoplisoma benattii formerly Corydoras benattii (C022) were abundant at night. Not particular active though.

The Ancistrus sp. (L100) lose color at night. In the daytime they are completely black with small white spots.

Also amphibians like this Caecilians Potomotyphlus kaupii.

And shy birds like this Pauraque Nyctidromus albicollis.

The night was also spent taking DNA samples and marking fish with tags. Here Mark Henry Sabaj and Leandro Sousa is working. Oliver Lucanus is observing.

I never got a good shot of this Leptorhampdia sp. "Rio Xingú even though it is a common species in the river. But its difficult to observe. They are mostly active at night.

I think this species might be undescribed. Leptorhampdia sp. "Rio Xingu".

Good hiding places like this root can reveal many interesting species.

Ossubtus xinguense is a very unique species. It is endemic to the area. They are often quite shy and not easy to photograph. I surprised this adult fish. Many adults have black spots like this, but not all.

Younger fish of Ossubtus xinguense look a little different. This is a school of young ones.

A young Parancistrus aurantiacus getting a lift and a small meal.

Parancistrus aurantiacus in itś natural habitat. Notice the spots in the dorsal and caudal fins.

One of the larger predatory fish here is this Hoplias aimara.

When viewed from below it is easy to tell apart the different Hoplias species.

Large-billed terns Phaetusa simplex are common birds here. They pick up shrimps and fish fry when the waves from our boat hid the shore.

This shallow water is the habitat of Hoplisoma benattii formerly Corydoras benattii (C022) and Scottish people apparently. Julian Dignall (Jools) trying to capture the behavior of the coryś on video.

Shoals of hundreds of Hoplisoma benattii formerly Corydoras benattii (C022) forages here in this sandy stream. I found them only from around 1 cm to about 15 cm in water level.

Visibility here was perfect. The water was crystal clear. This Hoplisoma benattii formerly Corydoras benattii (C022) was resting with about 50 other specimens in 1 cm of water with the dorsal sometimes disturbing the surface as they moved.

What better place to setup camp. Waking up less than 1 meter from large schoals of Hoplisoma benattii formerly Corydoras benattii (C022). Julian Dignall (Jools), Oliver Lucanus, Pablo Arroyo and Margaret Kalacska getting ready for the night.

Catching them was easy with no hiding places and large quantities of fish in shallow water.

I tried to capture Hoplisoma benattii formerly Corydoras benattii (C022) and the habitat in the same picture from above the surface. If you look thoroughly you can see a specimen in the bottom of the picture.

It was difficult for me to capture the Hoplisoma benattii formerly Corydoras benattii (C022) underwater. because of their excellent camouflage. This is the best shot I got.

The Cocoi heron Ardea cocoi looking for potential prey

One of the fish the Heron might not notice is this Banjo catfish Bunocephalus sp.. It is perfectly camoflaged. Not in this white tray though.

I caught the Bunocephalus sp. in this shallow stream with surprisingly high temperatures. I measured 34,6 degrees C here. Very comfortable having just been swimming in the main river at a 26,3 degrees C.

The classic shape of the Bunocephalus sp. makes it easy to spot for an aquarist. And very easy to catch because it trust its camouflage 100%.

The shallow water in this river might be the reason for the high temperature in this confluence. The waterflow was not that fast and the sun might heat up the water on these solar collecting black rocks.

Sadly this is the best picture I got of the Ancistrus sp. (L352). Sometimes the focus area teases me a little. Well at least my hand is sharp in the picture.

Other species like this Spectracanthicus punctatissimus were swimming from the cold water in the main river up this small hot stream with no time to acclimatize. They did not seem to care.

This confirmed to me that radical temperature changes might not be as significant or disastrous when keeping fish in captivity as I once thought. Here the mouth of Spectracanthicus punctatissimus.

As you can see the Spectracanthicus punctatissimus I caught in shallow water as well. Like most of the other Loricariidae species.

This picture is right before capture of the Spectracanthicus punctatissimus in the picture above.

The younger specimens of Spectracanthicus punctatissimus have larger spots than the adults. Here is a young specimen in the picture below.

A beautiful Spectracanthicus punctatissimus appeared under the rock.

Places like Rio Xingú are important to preserve. We can learn a lot from this amazing river.

The Capybara Hydrochoerus hydrochaeris were very shy in this area. This is this best shot I got.

Ancistrus sp. (L100) male hiding between the rocks. But the classic ancistrus silhouette does not fool me.

Ancistrus sp. (L100) captured. A lttle advice: bring gloves. You hands will be full of holes after a week of pleco collecting here.

Rapid color-change is a perfect camouflage. This female Ancistrus sp. (L100) changes color in an instant when it discover my hand.

Deforestation is sadly destroying the habitat like many other places in the world. As populations rise the demand for land grows.

The building of the Belo Monte dam have destroyed large areas of nature too.

Habitat that once was is now flooded and the course of the river is changed. The current is changed. Only the future will tell which influence this will have for all the animals living here. This is the Belo Monte dam.

Areas that was once under water filled with life now looks like this. Dry desert-like and lifeless.

While areas on the other side of the Belo Monte dam like this place does not exist anymore. This area is now flooded. It is now a big still water reservoir.

Habitat like this fast flowing part of the river is home to many endemic species of fish and it is probably one of the areas that suffers the most after the dam has been started.

This Cryptic Racerunner Lizard Cnemidophorus cryptus I spotted in a pile of rocks being used near the Belo Monte dam.

Not very far from there this well hidden Green-backed Heron Butorides striata was looking for an easy meal.

Hopefully places like this will continue to exist in the future.

Spectracanthicus zuanoni is a common species in the Rio Xingú. Notice the dorsal and the adipose fin are attached to each other.

Spectracanthicus zuanoni in itś natural environment. Perfectly camouflaged.

When you try to capture the Spectracanthicus zuanoni you will have to be fast.

Between these two photos is only a blink of an eye. The Spectracanthicus zuanoni is now on alert. With the dorsal fin up ready to make fast turns to escape. Notice the cloud of silt from itś former position.

I found Spectracanthicus zuanoni in fast flowing water and still water in temperatures from 26-34° C.

Spectracanthicus zuanoni feeding on the biofilm a rock.

The pattern varies a lot in Spectracanthicus zuanoni.

Figthing the current while snorkling is sometimes difficult and funny shots occur. Under the surface you see a school of Jupiaba acanthogaster.

Itś a very common tetra that occur in the fast flowing parts of the river. The Jupiaba acanthogaster can climb even the highest waterfalls.In this picture you see a few Moenkhausia heikoi too.

I observed a large school of Jupiaba acanthogaster swimming up the Volta Grande like it was no challenge at all.

Sometimes the Jupiaba acanthogaster occur in large schools and other times they are more scattered and mixed with other species. Leporinus tigrinus and Moenkhausia heikoi photobombing this picture.

The Leporinus fasciatus living in the Rio Xingu is different than the ones I have caught else where. Here they have black caudal, adipose and dorsal fins with yellow ventral fins. The anal fins are both colors. Here with Tometes kranponhah.

Leporinus fasciatus here with a school of Brycon pesu.

Same habitat above water.

Another species very abundant here is Leporinus maculatus here with Moenkhausia heikoi and Hypomasticus julii.

In the fast flowing parts of Rio Xingu I found Leporellus vittatus. A very fast species. I found them only in and near waterfalls. They only occured individually and often along Hypomasticus julii like in this photo.

I always found Peckoltia vittata in still water pools. Often in the areas where a lot of silt/detritus particles end up. This young fish is on alert.

Habitat above the surface.

This is an adult Peckoltia vittata from same location. Notice the stripes turn into a pattern as they grow older.

The rainforest when need to surface for air.

Somewhere in between young striped fish and adult the Peckoltia vittata looks like this. You can see both the pattern and the stripes.

Peckoltia vittata are hiding in the cracks like most of the other plecos.

I never saw Peckoltia vittata in the open waters unless I tipped a rock and they were escaping like this one.

The state of Pará still have a lot of rainforest left that future generations will have to protect.

I saw two different species of swamp eel in the Rio Xingú. This Synbranchus marmoratus. This is an adult around 80-90 cm.

As a young fish the Synbranchus marmoratus is marbled yellow/dark like this. This fish is around 20-30 cm.

I was surpriced to see the swamp eel Synbranchus marmoratus even in this habitat below.

Another swamp eel I came across here is what I believe to be Synbranchus lampreia. This is an adult around 60-70 cm.

The young Synbranchus lampreia have a lot more spots and smaller spots as you can see on this around 8-10 cm specimen.

The turtle species Podocnemis unifilis has a wide range. I have observed same species in Peru. But it is also common in Rio Xingú.

Adult Baryancistrus xanthellus in the background a school of Leporinus maculatus.

Same place above the surface in the picture below.

Moenkhausia heikoi is a very common species here. I found them mostly in moderate flowing waters.

This photo below shows a typical area I found Moenkhausia heikoi in.

But I also found Moenkhausia heikoi in the backwaters of larger waterfalls like this one.

Moenkhausia heikoi seemed to prefer the shallow water from about 15-100 cm in depth. Here with a young Baryancistrus xanthellus.

In deeper waters they kept close to the rocks like this photo below. I observed Moenkhausia heikoi schools with around 10 individuals up to around a couple of thousands.

Clean sand ripples like these are common in some parts of the Rio Xingú.

Depending on the current sand ripples change and leaves and other particle appear. These become hiding places for juveniles of many different species. This photos was made before the Belo Monte dam was put into use. It might look different here now.

The sand moving according to the water level from dry season to rainy season releases food items/nutrition for many the unique species of fish, amphibians, invertebrates, plants and algae that lives in Rio Xingú.

In my opinion the Rio Xingú deserves the highest rang of protection possible. I have seen many rivers but this one has one of the highest diversity of animal and plant life I have encountered so far.

Bio scrapes of the rock in this picture below.

Later showed a wide range of life in the laboratory microscope.

The density of fish are very high in some areas of the river. I did not expect to get pictures like this. Ossubtus xinguense, Baryancistrus xanthellus and Leporinus fasciatus in the classic rio Xingú melted rock scenery.

Hiding with the Plecos. If the eye sight of a pleco is simular to that of us humans. Then they are not able to see much out of the caves. The bright light makes it impossible to see anything.

I found Retroculus xinguensis mostly near fast water flows. They were present in a large areas of the Rio Xingu. Usually a pretty shy species.

This Retroculus xinguensis slipped right past me though. Beautyful species.

The greenish color of the Retroculus xinguensis makes them easy to spot on both rocky and sandy bottoms. I did not see many juveniles though.

Skull of the Hog-like animal Tayassu pecari. A common mammal in the area.

Creagrutus yudja is a newly described species from the Rio Xingu. I only observed them in the fastest water flows near Volta Grandé. Itś a very fast and active species. Here a specimen and some Bryconops alburnoides.

Creagrutus yudja were almost purple in color when the sun was up. Here is a male and a female. The female (on the right) has a slightly thinner black stripe and less color. Schools were often consisting of about 30 individuals.

At first glance the Amazon kingfisher Chloroceryle amazona living near the Rio Xingú looks simular to the Colombian one.

But as it turns the Amazon kingfisher Chloroceryle amazona living here in Pará has no orange chest as you can see in this photo below.

As far as water parameters go I measured these values in the Rio Xingu; pH: 6,6-7,1, NO3: 4-5 mg/l, GH: 1-2, Temperature: 26,3-34,6° C all measured in a depth between around 30-100 cm.

I did not notice this species until I went through the videos. A beautyful young Leporinus villasboasorum.

The Teleocichla cinderella I found in different habitats. amoung twigs and leaves like here below. Can you see the male?

But also in rocky areas. Teleocichla cinderella seemed to be an adaptable species. This is a young female.

The habitat of Teleocichla cinderella sometimes looks like this photo below.

Teleocichla centrarchus seemed more common in the rocky parts of the river. Often hiding in caves like this below.

A brave Teleocichla centrarchus male patrolling itś territory. In the background Brycon pesu and Brycon sp. "Black adipose".

Teleocichla centrarchus seemed to prefer more current. This was one of the places I found them (photo Below).

Teleocichla monogramma I only found near waterfalls. Often in pools above the falls. Here with Moenkhausia heikoi and Baryancistrus xanthellus.

This large male Teleocichla monogramma is resting on the bottom along side a Baryancistrus xanthellus

Some of the species of catfish were simply to fast. This fellow I never got close to. I found them often among rocks. But I was not able to ID this species because this is the best picture I got and I never caught any of them.

A pair of the Northern crested caracara Caracara cheriway restings on a large rock.

A species I never got close to was Sartor respectus, you can just see the silhouette under the rock here below.

Mark Henry Sabaj trying to capture some young Crenicichla in the shallow waters.

The visibility of the Rio Xingu is variable dependent on the current. Here a large specimen of Brycon falcatus with shoals of Brycon pesu near the surface and Bryconops alburnoides near the bottom.

A better shot of Bryconops alburnoides. Very common species in the Rio Xingú.

Local fishermen passing by in their canoe.

Sometimes I wonder how they pass waterfalls like this.

A lot of fish will gather behind me in the river to shelter from the current and still be in reach of all the food items passing by. Here itś Bryconops alburnoides, Brycon pesu and Leporinus maculatus.

Riverweeds (Podostemaceae) grow in these small waterfalls. They might flower and develop fruits during dry season and even self pollinate. The seeds attach to rocks via biofilm of bacteria. They are important to the ecosystem of the Rio Xingú.

Yet another undescribed species from this amazing river is Brycon sp. "Black adipose". It was often in schools with Brycon pesu like in this picture below. It has a deeper body than the other species present in Rio Xingú.

Brycon sp. "Black adipose" here with Brycon pesu near the surface and some young Tometes kranponhah near the bottom.

Spectracanthicus punctatissimus, Leporinus maculatus, Teleocichla cinderella, Tometes kranponhah and Brycon pesu.

It never ceases to amaze me how most fish can change color in an instant. Here Moenkhausia heikoi in fast flowing water.

Moenkhausia heikoi in a still water pool in a more paler color. Here with Brycon pesu, Tometes kranponhah and Bryconops alburnoides.

Academic Director Dr. Pablo Arroyo from the Department of Geography at McGill University in Canada was 3-D mapping the area.

The Rio Xingú has many interesting species of freshwater crabs as well. This is probably the species Kingsleya ytupora.

This Purple freshwater crab is one of the more common ones in the Rio Xingú (Presumably the species Kingsleya ytupora).

Kingsleya ytupora always ready to fight.

So look out where you put your hands. A Kingsleya ytupora might attack you.

The National Aquarium of Denmark: Den Blaa Planet has supported this work on the Rio Xingú. Conservation, exploration and informing the public about this amazing river.