URL : http://www.aquarticles.com/articles/travel/Newman_Peruvian_Amazon.htmlTraveling to the Amazon to collect aquarium fishes is rapidly becoming common place among avid home aquarists. Established tour companies and experienced fish collecting guides in countries such as Peru and Brazil, are making what was once thought of as impossible, the adventure of a lifetime. To experience the Amazon firsthand had been a dream of mine since buying my first cichlid, Pterophyllum scalare, in a local aquarium store some twenty-two years ago. Finally, in April/May of 1993, I had the opportunity to collect cichlids for two weeks in the Peruvian Amazon. The trip took place during the high water or flood season. The first week was spent on the live-aboard boat, the Delfin, traveling south from Iquitos to the Rio Ucayali drainage, and the second week at the jungle camp, Amazon Camp, located on the Rio Momon, a tributary of the Rio Nanay, about a 45 minute boat ride from Iquitos. I should note that this trip was not organized specifically for fish collecting but rather as a natural history trip for a variety of interested people.
Obviously, before going to the Amazon to bring back live fishes, some preparation was in order. A logical place to start, I thought, was to talk to people who had already done this. The advice centered around the types of habitats and collecting methods most likely to yield the target species and the logistics of holding and transporting live fish. Additional information regarding species and habitats was obtained from Kullander's monograph, "Cichlid fishes of the Amazon River Drainage of Peru" (1986) I must confess, that although we had made a list of species to collect, my interests were Satanoperca.
Collecting Equipment
In order for us to sample most habitats, we took several sturdy aquarium dip nets, two cast nets and a small beach seine. The tour company provided the most useful net we used, a long-handled (2m-long) dip net. The beach seine net was of limited use in most places due to the abundance of submerged tree branches and other forest "litter." We did however, get the opportunity to use the tour company's beach seine in a couple of spots. During a brief stop at a small village on the Rio Ucayali, we seined a beach area (actually, the beach was the 'front lawn' of the village) and despite the grasses and small shrubs, netted hundreds of Brochis sp. and Dianema sp. We were also able to seine the lawn area of Amazon Camp, dragging the net over the submerged grass in several feet of water produced mainly characins, although there were also juvenile Mesonauta sp. and Heros sp. Probably the best advice was to forget about the standard Styrofoam fish box, as numerous accounts assured us of the fragility of these boxes when subjected to airport handling. Instead, the large (60 litre) plastic coolers used for camping were used. The durable coolers made great "suitcases" for the travel down, filled with old clothes for trading, then served as holding tanks during the collecting and finally, as fish transport boxes for the travel home. We also took plenty of plastic fish bags of various sizes for collecting and packing the fish for the trip home. Bait buckets were taken for collecting during the jungle hikes. Also, some very basic water testing equipment was taken to test pH and temperature at the collecting sites.
Collecting
The first week aboard the Delfin enabled us to visit a variety of habitats; inundated forests, flooded rivers and permanent forest streams. Angling from the Delfin, during brief stops along the way, produced a variety of characoids and silurids (Serrasalmus, Tetragonopterus, Charax, Triportheus, Curimata and Callophysus). In the flooded forest, the increased water depth and the abundance of submerged vegetation made collecting with nets impractical. From the small runabout boats, using hook and line, only characoids and silurids were caught in the flooded forest. On several occasions, we explored the flooded forest at night in a three to four person dug-out canoe looking for Pterophyllum scalare by flashlight. As we paddled among the trees, gently brushing against the branches, small ants would fall into the water, getting eaten only seconds later by marble hatchetfish (Carnegiella sp.). Unfortunately, we did not collect any P. scalare in the flooded forest, although the experience of the flooded forest at night was fascinating.
On an excursion into a small flooded river bordered by inundated forest, fish were seen splashing at the surface near some partially submerged trees and shrubs. The crew told us they were P. scalare, one of our target species for collecting. We boarded a small aluminum boat equipped with an outboard engine and motored over to the site. The noise of the engine caused the fish to swim frantically towards the surface, then skip along the water, possibly the escape response for this species. Between the three aquarists in the boat we managed to dip net eight P. scalare. Within a few seconds, the remaining fish disappeared into the murky water among the flooded trees and shrubs.
Most of the collecting was done in the flooded main river channel near the bank and in the forest streams flowing over "terra firma." In the main river near the bank, many cichlids were caught using either a dip net or castnet. The castnet was not the easiest net to throw properly, but once shown how by the locals it became a very efficient tool. During the daylight hours in this habitat, Biotodoma cupido were caught using a castnet from the shore, while Hypselacara temporalis, Apistogramma eunotus and Crenicichla sp. were taken close to the bank by small dip net, standing in the river. Only Crenicichla sp. were caught using hook and line near the bank in the flooded river. At the start of the second week, with the help of the native guides, we learned that some species of cichlids spend the night hours in the shallow water near the bank of the flooded river. They probably use this habitat, at least in part, to avoid predation by the many species of nocturnal predatory catfish that search the river bed at night. Admittedly, up to this point, I had been a little disappointed by the fact that we had not caught any Satanoperca. On the second night at Amazon Camp, I was lying in my bunk trying to soothe an inconveniently located heat rash, when Alex, one of the "fish guys," came to my room and explained that the Peruvian crew had caught a Satanoperca , directly in front of the camp! Fishing in front of the camp became part of our daily evening routine. Using a sturdy, long-handled dip net near the river bank at night, we were able to collect Laetacara thayeri, L. flavilabrus, Crenicara punctulatum and the green-bronze Satanoperca. According to Kullander (1986), Satanoperca jurupari is the only species of Satanoperca known to occur in Peru, despite slight biotypic shape and color differences found in some populations. This species lacks the white opercular spotting characteristic of S. leucosticta, the species it is most often confused with in the hobby.
On both weeks of the trip, optional day and night guided jungle hikes were offered. During the hikes, when the group encountered a forest stream, the fish guys were able to collect for a short time while the others explored the area or rested. The forest streams, which in many areas had greatly undercut banks, were effectively sampled using a sturdy, long-handled, fine mesh dip net. The mesh size was very important as most of the fish caught in this habitat tended to be quite small. In a short distance, a stream could vary between 0.3m and 2m across and from O.lm to 1.5m in depth. The stream beds consisted of whitish-grey fine sand and abundant forest litter, logs, sticks and leaves. There were no rooted or floating aquatic plants, most likely due, at least in part, to abundant forest cover and stream velocity. Wading in the streams with the dip net was the only way to sample them properly. We wore wetsuit boots to avoid foot injury, but an old pair of hightop running shoes or sneakers would also work.
Most of the fish were caught by placing the dip net against the side of the stream at the bottom, then quickly lifting the net, keeping it against the bank. Not many fish were caught on the bottom of the streams because of the forest litter. In the forest streams we caught Nannostomus, Nannobrycon, Carnegiella, juvenile Colossoma, abundant small tetras, several silurids including a loricariid, Hoplosternum, Rivulus, Apistogramma , Aequidens tetramerus , Bujurquina and a freshwater crab.
Keeping and Transporting the Fish
There were enough fish people with coolers that during collecting, fishes were grouped according to size, to avoid predation, and held in the coolers without the need to bag them It was important to keep the coolers in the shade as direct sunlight could dramatically increase the temperature of the water. Several daily water changes were done to maintain water quality and no effort was made to feed the fish. We made great efforts to only keep what we could transport safely and house comfortably upon our return. Also, to make the transport easy, we collected only small or juvenile fish when possible. Most of the fishes were photographed and released.
Arrangements were made, through the tour operator, with a tropical fish exporter in Iquitos to pack our fish with oxygen for the two day trip back to Vancouver, Canada. We dropped our fish off at the exporter the day before our flight to Miami. Early the next morning, we went to the exporter to help and oversee the packing of our fish. The fish were carefully packed with oxygen in plastic bags, with only two to three fish per bag, then placed in the coolers. The exporter also gave us a "permit" to take the fish out of Peru. All this cost a small sum which was divided between the three fish guys.
At the Iquitos airport upon our departure, a military official requested a "fine" due to recent changes in the laws making our permit invalid! An employee of the tour company bartered our military friend down to $25 US for all three coolers. Considering this a bargain, we happily paid. The rest of the two-day trip home was uneventful, we lost only one fish because of a leaking bag, which we discovered during our layover in Miami, Florida. The fish bags remained unopened for the entire trip home, with the only concern being keeping the coolers at an appropriate temperature for the fish. It is likely that the fish survived the trip home so well because they were packed very lightly and transported in durable containers.
Wild Cichlids in the Aquarium
The species we brought back included Pterophyllum scalare, Satanoperca jurupari, Laetacara thayeri , L. flavilabrus, Crenicara punctulatum , Apistogramma eunotus and Biotodoma cupido, as well as some non-cichlid fishes. The cichlids adjusted to aquarium conditions without much difficulty, although they were understandably more shy than captive reared fish. The Satanoperca in particular, had small pieces of caudal fin missing when collected. This may have been caused by the numerous fish-eating species, Acestrorhynchus, Hydrolycus and Charax, that were caught in the same area, during the day with the castnet. The damaged fin rays grew back in just a few days, but the fish continue to protect their caudal fins by "lifting" them up slightly whenever chased from behind.
The A. eunotus were the first of our Peruvian cichlids to be spawned, with the fry distributed to other interested aquarists. At the time of this writing (March 1995), the only other species beginning to spawn are the S. jurupari. As mentioned above, these fish were juveniles when collected, and take up to two years to become sexually active. The P. scalare seem to have matured, as there are loosely bonded pairs defending territories, but no spawning yet
.
Of considerable interest was the C. punctulatum and the B. cupido. It seems, we may have collected only a single sex of each. According to the hobby literature, all of our C. punctulatum may be females, as they all have red ventral and anal fins. However, we have decided to keep all of them in an effort to observe a reported sex change phenomenon.
According to Zupanc (1988), Ohm, a German zoologist, reported that C. punctulatum are protogynous, meaning females can change into functional males. The report states, that at an age of seven to ten months, the dominant female of the group will grow at a faster rate than the others and begin to lose the red color in the ventral and anal fins. The ventral and anal fins eventually become bluish and the animal continues to grow to the typical size of a male. At the time of this writing, one of the fish has almost lost all the red colour in the anal fin and the ventral fins are becoming very pale. It will be interesting to see what happens over the next several months.
Our B. cupido , which were collected in the same place as the C. punctulatum, may all be males. It has been reposed that the blue markings on the snout and under the eye differentiate the sexes. Males have lines and females, small spots. Aquarists having experiences with Biotodoma suggest this sexual dichromatic characteristic may not apply to all populations or species of Biotodoma. In any event, we plan to keep the fish with the intention of breeding them, if possible.
Acknowledgements
First, I would like to thank Paul Loiselle, Jeff Cardwell, Wayne S. Leibel, Lee Finley and Jim Forshey for their valuable advice. Second, I would like to thank the other members of the trip for making it such a memorable experience. Also, thanks to the interested and enthusiastic fish collectors on the trip: Alex Saunders, Jason Hutchison and Danny Kent. At the start of the second week, I had all of my camera gear (except the unexposed, and most of the exposed film), money, and passport stolen. My sincerest thanks to Christine Fritzsche for lending me her camera and Lisa Mclntosh for financially supporting the remainder of my trip.
References
* Kullander, S. O. , 1986. Cichlid Fishes of the Amazon River Drainage of Peru. Monograph. Swedish Museum of Natural History, Stockholm.
* Zupanc, G. K. , 1988. Fish and Their Behavior. Tetra-Press, Germany.
© Copyright 1995, Lee Newman All Rights Reserved
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