The moment the reflection of the morning sun touches the surface of the river you understand why they call it white water; the milky reflection of the silt-laden flow makes you wonder how any aquatic creature navigates a daily existence here. Immediately I understand the necessity of the long whiskers of the Pimelodid catfish and the echolocation used by the river dolphins with their tiny eyes (almost pointless in such a river); I continuously observe for other insights and wonder what lessons are in store on this 10 day journey into the deepest jungles of the Amazon basin. I’ve finally departed and I have the overwhelming realisation that I’ve been waiting for this moment my whole life; I am here, heading to untouched Earth along the mighty Solimões, probably the most famous white water river on Earth; I’m living my dream.
Having travelled from Colombia’s mountainous capital situated under the majesty of Mount Monserrate, we stayed a few days in the tropical city of Leticia in Amazonas state before beginning the first leg of our trip into Brasil. In our group are five fish hobbyists from all over the globe, Marcelo and Enrique of the well known blogging site, Wild Fish Aquarium from Argentina, John, a passionate Australian fish keeper and photographer with a special appreciation of herpetology, Tom, a young fish hobbyist who runs a Berkshire based aquarium maintenance business and Myself. We are assisted by our Brasilian boat owner, Domingo and our guide, Stefen (a Colombian boatman of native ‘Tikuna’ Indian descent). We find ourselves here aside our expedition leader, the ichthyological champion of Amazon exploration, Heiko Bleher.
Leaving from the port at Tabatinga just before sunrise, we eventually reach the Rio Jandiatuba, and as we advance southward along the lower reaches, time and time again we continue to pass illegal gold mining barges which ruthlessly upheave the river bed and banks causing the most devastating erosion and destruction of the habitats. Powerful pumps suck anything and everything from the river and project it over filters in hope of finding the tiniest spec of gold all at the expense of any nearby creature and the health of the surrounding ecosystems. Along the Solimões we even saw whole sections of weakened tree-filled land spontaneously plummet downward into the river, which was shallower than it has ever been; huge dry sand banks of what was formally river bed, now exposed.
We set up camp shortly before nightfall along the first creek where we make some brief collections. Burrowed into the leaves along the bank was this lovely Apistogramma sp. accompanied by several other species including this Red Eyed Tetra as well as other characoids. Even though the sun had not quite left us, the fish were prepared well in advance of the approaching darkness and I observed individual Severums (Heros cf. efasciatus) safely tucked in under fallen branches and large leaves to avoid predation during the night.
In the coming days, the further upward we travel along this extremely meandering river, the wilder the forest becomes, the higher the Ceiba trees stand towering over the canopies in all their magnificence and after more than 130 turns of the river, over 2400km, we are willingly surrounded by uncompromised primary rainforest; and yet we are still to even reach the tributary we wish to explore. Along our supplies, which included fresh fruit, rice, black tea and biscuits among other things, we catch fish daily from the river to eat either as soup or grilled over a fire. In this lost haven, I feel such a natural bond with the surrounding environment, the atmosphere devoid of any unnatural sounds and the nature all around is an incredible feeling which evokes many emotions and instincts. Some of the fish were very tasty as well as beautiful. We stop many times each day to collect fish in various locations and the creeks where we make our collections are significantly different to the main river. Instead of the soft sand banks and white water, they are lined with hundreds of season’s worth of leaf litter; the vast majority of the small and juvenile fish species hide and reside within it. The dry brown leaves and sunken logs are responsible for the acidic black water and it is here, in these habitats where we repeatedly find so many aquarium favourites. On one of our collections in the deep leaf litter which lined the entire bank, we encounter small groups of the hatchet fish, Carnigiella marthae. We also find a lovely young eartheater (Satanoperca papaterra) as well as Pyrrhulina cf brevis, Tyttocharax cf cochui, which immediately after capture is an incredibly bright electric blue colour, a Psectrogaster species (one of the toothless characins) and many shrimp. The water parameters at this creek: pH 6.33, conductivity 36μS and temperature 26.5°C.
At another location also in the lower reaches of the Jandiatuba, we take the opportunity to study an isolated lake completely surrounded by Licania trees, the fruits of which are a very common food source for many fish species. At the waters edge we find a hand-made native Indian canoe (possibly left there for fishing purposes). Not one to miss an opportunity, I took some time to row around the lake studying the habitat closely and experiencing for the first time in my life the wonderful stillness, the serene peacefulness of being in the middle of nowhere surrounded by nothing but nature; only occasionally do I hear the gasp of the Pirarucu (Arapaima gigas) which survive easily in such lakes by using their labyrinth organ to breathe atmospheric oxygen. I observe small groups of 3-4 Mesonauta here, swimming just outside the edges of the partially submerged bushes (visible in the background), as well as individuals and small groups of young Boulengerella cf cuvieri scanning for prey along the surface under the protective shade of the overhanging branches. By the time we finish our collections we are once again in the darkness of night and among the fish collected we find Satanoperca sp., Cichlasoma sp., Mesonauta cf mirificus, Apistogramma sp., Crenicichla sp., Acaronia sp. and Hypselecara sp. as well as smaller fish such as Nannostomus trifasciatus, Hypoptopoma.sp., Iguanodectes cf spilurus, tiny doradids, various Hyphessobrycon, Chilodus and other characoid species.
In every sweep of our nets we were able to find tiny specimens which included many juveniles, as well as some fully grown fish of exceptionally small size; for example, this juvenile needle fish and these adult Nannostomus cf. eques. The water parameters at this location: pH 5.80, conductivity 14μS, temperature 29°C.
New Species of Corydoras? We also found what appears to be a new species of Corydoras. It most closely resembles Corydoras lamberti however; the closest recorded populations of C. lamberti are found over 800km east just north of the Lago Rimanchi in Peru. We will have to wait and see. Every night after collecting fish, we made an excuse to find other interesting species of the terrestrial variety living in the jungle and this night was no different. We found many insects and arachnids like this Avicularia, Amphibians such as this tree frog and on this night we even found a young caiman (Caiman crocodilus).
A really special moment which I will never forget was a brief encounter along a creek deep in the rainforest, where I came across a young female Basiliscus sp. (Jesus Christ Lizard). As we navigated up the creek, which was quite difficult due to the many fallen trunks, I went to hold the closest branch to stabilise myself and at first, did not even see this extremely well camouflaged lizard sitting on a thin branch. We introduced ourselves politely and I wished her luck on her journey before letting her go. A very special and precious moment for me. A Special Discovery
Heading into the oxbow lake through its tiny connection with the main Jandiatuba river
Particularly noteworthy from the trip was a discovery made along the lower reaches of the Jandiatuba by Marcelo Fernandez, Enrique Soler and I. Hidden deep inside the leaf litter only at the mouth of a small blackwater creek we found several specimens of what is now a newly documented occurrence of the Neon Tetra (Paracheirodon innesi) within its distribution range.
Marcelo, Enrique and I collecting Paracheirodon innesi at the mouth of the creek where it met the lake.
Their preferred locale was at the mouth of the creek where the tannin stained water met the ‘mixed water’ of the adjoining lake. While the three of us remained at the mouth to see what we could find, the others ventured into the creek for a kilometre or so and surprisingly found no Neons there. This indicated that the specimens we found may indeed be living only in the mixed white and black waters of the attached lake; this is quite unheard of for this species as they tend to be found in black or clear waters (or mixtures thereof) and this lakes composition had a considerable white water influence from its connection to the Jandiatuba. Along with the Neons and also tucked away inside the leaf litter we find cichlids such as Crenicichla sp, Apistogramma sp, Mesonauta cf mirificus accompanied by Nannostomus, Hyphessobrycon sp and other characoids as well as young Hoplias sp; The water parameters at the mouth of the creek: pH 6.25, conductivity was 16 µS and temperature 30°C.
Bit off more than it could chew? In the lake itself, we come across a large unidentified stingray hovering in the shallows and as our boat approaches we realise that it is no longer alive. It has severe bite marks on its disc but on closer inspection we see that it had died as a result of consuming a large Prochilodus found stuck in its mouth.
When we saw this in the shallows, I knew it was too good to be true. I had a thought in my mind that it might have died from choking, but to find it true was both surprising and very sad.
Heiko stands next to the unidentified stingray showing its size
As part of my job researching and formulating diets at my company C.E. Fish Essentials, I am obliged to have a great deal of knowledge of the natural dietary components of many ornamental fish species and baring in mind that the typical food items of stingrays from the Solimoes region include fish of up to and around 8cm total length, this large Prochilodus is a very ambitious meal at 20-25cm long; A reflection of the opportunistic nature of many fish during the food abundance which occurs when many fish species are restricted to smaller areas as water recedes throughout the dry season. Equally insightful, and a consistent feature of the creek biotopes we explored is the invaluable presence of the leaf litter, not only for its contribution to the water chemistry but as a protective haven for small and juvenile fish species. This is something which is underestimated by the average hobbyist, even the ‘leafiest’ of aquaria may only include a few leaves and these are usually scattered across the substrate, but the reality of the daily existence of almost all the smaller species we captured, is that they spend most of their time during the dry season exploring the dense protective labyrinth of millions of leaves along the river bank discarded year on year by the overhanging trees. Had we not plunged our nets far into the leaves to catch them, we most certainly would not have seen the fish at all; without these leafy retreats, many of these species would not be able to survive predation. After more than two decades of fish keeping, over half of which (around 15 years now) has been dedicated to biotope aquariums, it is not until experiencing the ecosystemic nature of the habitats and observing the behaviours and adaptations of the fish first hand, that I could truly grasp why each species dwells where it does and the relationship between the fish and their biotopes is the way it is; an obvious example being the wonderfully leaf-like appearance of this eye-catching Leaf fish (Monocirrhus polyacanthus). After spending so much time immersed in the jungle, there is an overpowering understanding of the symbiotic essence of Amazonia. The way each species or genus neatly fits into its own niche, sometimes a very limited and often very specific place, just as its relatives have done in the same way for thousands of years, provides invaluable insight for any fish keeper ready to build a home for them. I see the hours spent creating perfect artistic aquascapes and wonder what we could achieve if the time was spent building a biotope for the contentment of the fish rather than the hobbyist. I guess if I could bring any one thing back, it would be inspiration, to see more passion for nature reflected in our aquariums, not just love for the fish or their pretty colours, but for the biotopes which made them that way.