FISHES OF THREE BOLIVIAN RIVERS: DIVERSITY, DISTRIBUTION AND CONSERVATION BARRY CHERNOFF, ANTONIO MACHADO-ALLISON, PHIL WILLINK, JAIME SARMIENTO, SORAYA BARRERA, NAERCIO MENEZES and HERNAN ORTEGA he forested lowlands of most Amazonian tributaries remain poorly explored. Lists of freshwater fishes do not exist for more than one or two of the major arms of the Amazon, a feature that was prominently absent from an otherwise remarkable work on the fishes and fisheries of the Rio Madeira (Goulding, 1981). In Bolivia there have been attempts to bring together information for Amazonian streams (e.g., Lauzanne et al., 1991). More recently, a well documented fauna from the Rio Gaupore/Itenez was provided by Sarmiento (1998). Lauzanne et al. (1991) recorded 389 species of freshwater fishes from the Bolivian Amazon to which Sarmiento (1998) added an additional 21 species bringing the total to 410 species. This work reports upon the ichthyological results of the first AquaRAP carried out in a relatively small area of the upper Rio Orthon. Two teams of ichthyologists surveyed aquatic habitats in the rivers Tahuamanu and Manuripi and their tributaries over 17 days in 1996. Amazingly, 313 species of fishes were recorded. This value includes a spectacular number of new records for Bolivia and several species new to science, including a new piranha, genus Serrasalmus. The purpose of this contribution is to: (i) make known the gen- eral ichthyological results, including a breakdown by sub-basin; (ii) compare the diversity with those of other South American regions and discuss any distributional aspects of the data; (iii) discuss the economic and conservation importance of the results (iv) consider threats to the species richness; and (v) to propose recommendations for conservation. Methods Two teams, three-four persons each, made collections between 4 and 21 September, 1996. The teams were usually isolated and worked in different tracts of the Upper Rio Tahuamanu for the first five days. Eighty-five collection stations were established, each receiving a unique, sequential field number. The field stations were enumerated separately for each group, identified as P1 and P2. At each station, longitude and latitudes were registered from hand held GPS units. At each field station a number of ecological variables corresponding to a description of the habitat were recorded. These included the shore, substrate, type of habitat (e.g., river, lake, flooded area, etc.) as well as the water type. The classification of water type (black, white, turbid) was checked with the results obtained by the limnology group. Fishes were collected using a variety of nets and netting techniques. Each group was equipped with seines (5m x 2m x 1.25cm, 5m x 2m x .63cm, 1.3m x .7m x .37cm), dip nets and experimental gill nets (40m x 2m, monofilament, with five 8m panels, mesh size from 1.25cm to 6.25cm). Team 2 pulled an otter trawl (mouth 3m wide) with two 15kg doors where the depth of the water was >2m over sandy or muddy stretches in a manner modified from that described by Lopez-Rojas et al. (1984). Additionally, one of the river pilots threw a 2m cast net in some deeper lakes or cochas. Fishes were preserved in buffered 10% formalin solution. All specimens captured at the same place and time were maintained separately from all other collected specimens. Larger specimens were tagged individually using fine wire and punched cardboard tags and either placed in large liquidpacks containing formalin with other specimens or were skeletonized, soaked in 40% isopropanol and dried. All material was wrapped and shipped to Chicago for sorting, identification and enumeration in the Division of Fishes, Department of Zoology, Field Museum of Natural History (FMNH). Fifty percent of the specimens are housed in the Museum of Natural History, La Paz, Bolivia; the remaining specimens were shared among the partici- KEY WORDS / Fhises / Diversity / Distribution / Conservation / Bolivia / Barry Chernoff and Phil Willink: Field Museum of Natural History, 1400 Lake Shore Dr. Chicago, Illinois 60605-2496, USA. email: chernoff@fmnh.org Antonio Machado-Allison: Laboratorio de Ictiología, Instituto de Zoología Tropical, Universidad Central de Venezuela, Caracas, Venezuela and Field Museum of Natural History. e-mail: amachado@strix.ciens.ucv.ve Jaime Sarmiento and Soraya Barrera: Museo Nacional de Historia Natural, La Paz, Bolivia. Naercio Menezes: Museu de Zoologia, Universidade de São Paulo, São Paulo, Brasil. Hernan Ortega: Museo de Historia Natural (UNMSM), Lima, Perú. SEP 2000, VOL. 25 Nº 6 0378-1844/00/06/273-11 $ 3.00/0 273 pating institutions: FMNH; Museu Zoologia do Universidade do São Paulo, Brazil; Museo de Historia Natural San Marcos, Perú and Museo de Biología de la Universidad Central de Venezuela. The identifications were made in a careful but relatively rapid fashion. General works such as Eigenmann and Myers (1929) or Gery (1977) were used but preference was always given to systematic revisions (e.g., Vari, 1992; Mago-Leccia, 1994) and recent species descriptions (Stewart, 1985) if available. In many cases specimens were compared to types or historic material referenced in the literature and housed at FMNH. However, some identification to the level of species or even genus was not possible. To do so would represent a less than scholarly approach to the taxonomy. Instead we rely upon morphospecies – the number of distinguishable entities present in our samples. This bears the assumption that such discernable entities or morphospecies are putative taxonomic entities (i.e., species). We were careful to check for sexual and ontogenetic differences. All specimens were examined critically and identified to their lowest taxonomic level (Table I). Another issue inheres in the appropriate selection of taxa across lists in order to judge new additional or new records. We chose a conservative approach and did not include all of the taxa that we had collected. We eliminated from comparison about 5% of those taxa whose identifications were ambiguous or unknown in our list and in published lists. So for example, if Hemigrammus sp. or H. sp. 1 occurred in both lists, it was not counted as a similarity or a difference because there is no way to ascertain that the taxonomic designations represent the same biological entity. However, Gephyrocharax sp. occurs in our list but only G. chapare is reported by either Lauzanne et al. (1991) or Sarmiento (1998). In this case we count the G. sp. as a new record because we compared our material to G. chapare and it is different. The possible error in this latter case is identical to the possible errors in a list containing misidentified species bearing specific epithets or not. Collecting Stations Eighty-five collections were taken in the Tahuamanu and Manuripi river basins from the on the border with Perú downstream to Puerto Rico (Figures 1 and 2). The entire region was divided into the following five subregions based on habitat diversity: Upper, Middle and Lower Tahuamanu, Upper and Lower Nareuda, and the Manuripi. 274 Figure 1. General Map of the Rio Orthon Basin, showing the Collecting Stations on the Manuripi ( ) and Lower Tahuamanu (+) rivers (11º8-10'S to 67º33'W) The Rio Nareuda is a major tributary of the Rio Tahuamanu. The gear effort used to make the 85 field stations, were as follows: seine = 73; trawl = 6; gill net = 5; cast net = 2. This adds up to 86 because one station P2-04 included both gill net and seine collections. The gill nets were usually set for several days. Because no striking differences were noted for day and night samples within the gill nets, they were recorded as single stations. Due to low water conditions during the time of the field sampling, motors had only limited use in the Upper Tahuamanu and could not be used in the Rio Nareuda except for in the vicinity of its confluence with the Rio Tahuamanu. During the first portion of the expedition team 1 worked in the Upper Tahuamanu and also in the lower end of the Rio Muymanu whereas team 2 collected in the Upper Nareuda as well as in a number of small streams (garapés) that drained independently into the Tahuamanu. The Upper Tahuamanu and the Upper Nareuda systems as well as their tributaries were surrounded by terra firme. For the middle portion of the expedition, both teams were camped together but team 1 focused upon the Lower Nareuda down to its mouth in the Rio Tahuamanu. Team 2 collected upstream and downstream from this confluence to just below the village of Filadelfia; this region is referred to as Middle Tahuamanu. Conditions in the Middle Tahuamanu were such that trawling was accomplished successfully. For the last period both teams camped on the Rio Manuripi upstream from Puerto Rico. Though both groups worked independently, they covered the same territory in the Rio Manuripi as well as in the Lower Tahuamanu, just above its mouth in the Rio Manuripi. River conditions permitted trawling. Results and Discussion Diversity and distribution: General The species richness of fishes was spectacular. A total of 313 species were captured and identified. Because an additional 5% that could not be identified unambiguously were discarded from further evaluation, the actual number of species in the entire region is even greater. The fishes (Table I) included members of all trophic or activity groups, ornamentals (e.g., Abramites hypselonotus), food fishes (e.g., Pseudoplatystoma fasciatum), as well as miniatures (Scoloplax cf. dicra, <20 mm SL) and large fishes (e.g., Prochilodus cf. nigricans, Doras cf. carinatus, >200 mm SL). Together Lauzanne et al. (1991) and Sarmiento (1998) record 410 species from all rivers within the Bolivian Amazon. The 313 species of fishes, therefore, represents a fauna greater than 76% of the number of species previously reported from all other Amazonian tributaries within Bolivia. The number of fishes discovered in a relatively small section of the Tahuamanu and Manuripi rivers is more than three times that reported for the entire BeniMadre de Dios basin (n=101, Lauzanne et al., 1991), more than 1.3 times that reported for the Río Guaporé/Itenez (n=246, Sarmiento et al., 1998) and almost equal to (96%) that found over the entire Río Mamoré basin (n=327, Lauzanne et al., 1991). Furthermore, Santos et al. (1984) reported 300 species from the lower Río Tocantins of Brazil; SEP 2000, VOL. 25 Nº 6 Figure 2. General Map of the Tahuamanu River Basin, showing the Collecting Stations on the Upper Nereuda ( ), Lower Nereuda ( ), Upper Tahuamanu ( ) and Middle Tahuamanu ( ) (11º1825'S to 68º45'-69º02'W) Stewart et al. (1987) reported 473 species in the Napo River Basin of Ecuador; Goulding et al. (1988) reported 450+ species from the Río Negro Basin of Brazil and Machado-Allison et al. (2000) listed 136 species from the Río Cuyuní basin in Venezuela. In each of these latter cases, the areas surveyed exceed vastly that of the Tahuamanu-Manuripi region sampled in the rapid assessment. It is important to consider that the number of species reported for both the Guapore/Itenez and Mamoré drainages included headwater habitats that usually contain fishes with restricted distributions. Even in the Upper Tahuamanu and Upper Nareuda, there were few habitats, perhaps the two garapés, that could correspond to headwater-like conditions. Because of the paucity of knowledge concerning the distributions of the freshwater fishes of South America, it is difficult to state with any certainty the degree of endemism represented in samples from the upper Río Orthon. However, we have apparently uncovered not only a region with exceptional species richness but a region with an exceptional number of new records for Bolivia (Table I). Using the conservative approach discussed above, we document 91 species not previously recorded from Bolivia. Of the 91, 45 species include taxa with some questions associated with their exact name as well as include a number of new species (e.g., the new characid, Hysteronotus sp. 1). The newly SEP 2000, VOL. 25 Nº 6 documented fauna increases the total number of species inhabiting the Bolivian Amazon by ca. 22% to 501 and increases the total for all of Bolivia (using the previous total in Sarmiento, 1998) 16% to 641 species. The significance of the Tahuamanu and Manuripi rivers for the Bolivian ichthyofauna is now clear. This limited region contains 62.5% of all fish species known from the Bolivian Amazon and 48.8% of all fishes known from Bolivia. Furthermore, the 91 species found in the Tahuamanu and Manuripi rivers that are not yet known elsewhere in Bolivia represent within-country “endemism” values of 18% and 14% relative to the ichthyofaunas for the Bolivian Amazon and Bolivia, respectively. Based upon the relatively sparse information published for the ichthyofauna of Bolivia, of regions with more than 50 species, only Lake Titicaca has a higher within-country “endemism” percentage. No other region within Bolivia is currently known to contain as high a percent of the Amazonian or total country fauna. The impressive values reported for the Río Guapore/ Itenez basin within the Parque Nacional Noel Kempff reported upon by Sarmiento (1998) must now be adjusted downwards due to the new species totals. The adjusted values are well below those of the Tahuamanu and Manuripi rivers. Potentially, the impressive nature of the Tahuamanu-Manuripi ichthyofauna could be tempered if, in fact, it was representative of a more widespread fauna within Bolivia. The most obvious possibility is that we used trawls to sample the bottom communities for the first time within Bolivian freshwaters. If the 91 novel records were largely due to trawl samples then the lists would not really be comparable. That is, we might expect to find similar bottom communities in other regions; the uniqueness of the Tahuamanu-Manuripi region would diminish even though its overall diversity would remain exceptional. However, this scenario did not obtain. The trawls captured 53 species (17% of the total) but only 15 species were captured in trawls exclusively. Of these, 10 were new records for Bolivia (Table I). Thus, 81 of the 91 species newly reported for Bolivia were captured by traditional means used commonly in ichthyological sampling. We have no doubt that more careful sampling as exemplified in the Guapore/Itenez by Sarmiento (1998) and in the Tahuamanu-Manuripi by the AquaRAP team will lead to increasing the number of taxa found within Bolivia and will increase knowledge of the distribution patterns of the fishes. Nonetheless, it seems unlikely that the unique character of the Tahuamanu-Manuripi fauna will loose its uniqueness. In fact with continued sampling, the ichthyofauna of the Tahuamanu-Manuripi region will continue to rise and the number of species new to Bolivia will be expected to increase. We base this assumption upon the species accumulation curves (Figure 3). The rate of accumulation of species new to the expedition had not diminished; the graph (Figure 3) displays no asymptote. During the last six days, even with both groups working the same region of the Manuripi, we increased the known fauna by 63 species. Species were being added at a rate of 10.5 species per day. The total capture and accumulation rates were remarkably similar for each of the two collecting teams (Figure 3). Each group captured more than 200 species that were often complementary. By the end of the sampling period, the species collected by the groups differed as much as 50% which maintained the steep slope of the total accumulation curve. These data are evident in the differences of species captured by the two teams when they were both sampling in the Río Manuripi. The teams captured a total of 220 species in the Río Manuripi. Individually they netted 179 and 169 species based upon 17 and 18 collections, respectively. However, only 128 species were common to both sets of col- 275 lections, from which Simpson´s Index of Similarity is 75.7%. Thus, the additional effort increased the collected fauna by 62 species, or by 28.2% Analyses of these data argue strongly that continued collecting will increase the size of the fauna known from the Tahuamanu-Manuripi region. Because the species that represent new records for Bolivia comprise more than 29% of all species captured, we expect that continued collecting will continue to uncover new records for the country as well. These data continue to exemplify that the Upper Orthon Basin is extremely diverse and may prove more diverse than even the Rio Mamore basin, which has received vastly more collecting effort. The biogeographic relationships of the Tahuamanu-Manuripi region are difficult to ascertain, again because of how little that we know in general. There does seem to be a mix of taxa representing three distinct distributional elements. The first comprises widespread amazonian lowland species from the north and the east of the Madeira basin: e.g., Serrasalmus rhombeus, Schizodon fasciatum, Anodus elongatus, Microschemobrycon geisleri, Cetopsorhamdia fantasia, Pimelodus cf. altipinnis, Tatia altae, Electrophorus electricus, and Rhabdolichops caviceps. The second incorporates species found almost exclusively in black waters of the Guapore/Itenez system that derive from the Brazilian Shield: e.g., Hypopygus lepturus, Carnegiella strigata, Aphyocharax alburnus, Hemigrammus cf. unilineatus, Pyrrhulina australe, Nannostomus trifasciatus, Potamorrhina latior, Tatia aulopygia, Corydoras hastatus, Cichla monoculus, and Aequidens cf. tetramerus. The third describes those species in the small garapés that are most head-water like habitats: e.g., Hysteronotus sp., Brachychalcinus copei, Bryconamericus cf. caucana, Creagrutus sp., Cyphocharax spiluropsis, Piabucus melanostomus, Tyttocharax tambopatensis, Corydoras trilineatus, Imparfinis stictonotus, and Otocinclus mariae. The discussions above show the nature of the uniqueness of the ichthyofauna of the Tahuamanu-Manuripi river basins. A relatively small region contains 62.5% of all the freshwater species known from the Bolivian Amazon. The fauna comprises 91 species that have never been recorded from Bolivia – a feature which does not seem to be an artifact of sampling or collecting methods. The region seems to contain an assemblage of fishes that may uniquely combine widespread Amazonian species, with blackwater Brazilian shield species in addition to head water species. Because we 276 Figure 3. Species accumulation curves for fishes collected in the rios Tahuamanu, Nareuda, and Manuripi, Pando, Bolivia, 4-21 September, 1996. Symbols: Group 1 (squares), Group 2 (triangles), and combined (X). never reached the asymptote of the species accumulation curve, the number of species represented in this region is predictably larger than we can document at present. Furthermore, because the number of new records comprises 29% of the fauna of this region, it is reasonable to expect new records as well. All of this leads to the conclusion that within Bolivia, the upper Rio Orthon basin must be considered as a potential hot spot for the species richness of freshwater fishes. Conservation efforts are needed to preserve the unique character of this fish fauna. At a secondary level, more field studies are needed to finish documenting the ichthyofauna of this amazing region. Economic importance Many of the fishes found in the Upper Rio Orthon basin are valuable as commercial resources for food and for the ornamental fish industry. We present a short discussion in order to stimulate immediate research both into the potential of these resources to provide an economic alternative to other activities that damage the environmental character of the region. During the AquaRAP we employed local fishermen who were subsistence fishermen throughout the year and who fished commercially during the seasonal migrations. We also witnessed truck-side fish sales in Cobija and in Filadelfia and saw the following species for sale: Pygocentrus nattereri, Pseudoplatystoma fasciatum, Prochilodus nigricans, Curimata spp., Hydrolycus pectoralis, Plagioscion squamosissimus, Mylossoma duriventre, and Myleus sp. We were told by the fishermen that the fishes of highest commercial value were the tiger catfish, Pseudoplatystoma, and the serrasalmines including both the piranhas and the pacus. In our samples, we caught many other species that are either consumed for subsistence or caught for sales according to our guides. That list included the following: Anodus elongatus, Cichla cf. monoculus, Cochliodon cf. cochliodon, Crenicichla spp., Duopalatinus sp., Hemisorubim platyrynchos, Hoplias malabaricus, Hoplosternum thoracatum, Hypostomus spp., Leiarius marmoratus, Leporinus spp., Myleus sp., Pimelodus spp., Pristobrycon sp., Rhamdia sp., Schizodon fasciatum, Sorubim lima, and Triportheus angulatus. In that list the “spp.” refers to a number of species within the genus that are eaten. Interestingly, the following armored catfishes are consumed in the Río Madeira basin of Brazil (Goulding, 1981) but were rejected as a source of food by our fishermen: Doras cf. carinatus, Pseudodoras niger, and Liposarcus disjunctivus. Our discussions with local fishermen including others in Puerto Rico indicated that the commercial food fisheries are burgeoning in the Tahuamanu and Manuripi rivers. It was not SEP 2000, VOL. 25 Nº 6 possible to obtain from our fishermen or from the truck-side sellers the annual totals for weight or value of the catch. However, the notion of increasing annual landings would not seem to make sense relative to the local populations that we encountered and interviewed for two reasons: i) the population of Pando while increasing is doing so slowly; and ii) the Bolivian residents have largely settled the region from cattle rearing areas or from La Paz and do not have strong traditions of fish consumption. Most of their demand is for premium species, tiger catfishes and pacus, species that are delicate in flavor. Apparently, much of the catch is exported across the border to Brazil and this exportation appears to be unregulated. Sarmiento (1998) also noted a similar pattern of unregulated exportation of several tons per month with a slightly increasing demand from populations living along the Río Itenez. Peres and Terbourgh (1995), Goulding (1980, 1981) and Goulding et al. (1988) document not only the importance of rivers in structuring human settlements throughout Amazonia but also the increasing dependence of humans on aquatic resources for sustenance. At this time we cannot document the size of species specific harvests that are sustainable for the future. There is no accurate data on the nature of fish migration into the Tauhuamanu-Manuripi region. Many of the commercially important species such as the curimatids and prochilodontids move out of tributaries and forest habitats into the main rivers to spawn at the beginning of the flooding cycle (Goulding, 1981). While many of the larger catfishes migrate upstream to spawn and apparently ascend the cataracts in the upper Madeira into Bolivian waters (Goulding, 1981). The only relevant data that we collected was that the abundance of the most favored species was relatively low (see Machado-Allison et al. 1999, on the abundance and distribution). Even though it was the dry season and at relatively low water, there were still many suitable habitats for these species. The gill net samples did not yield the quantity of individuals for the commercially important species that would indicate bountiful populations, even though our fishermen guided us to their favorite areas (with monetary exchange for the catch). In our experience from similar habitats in other regions of the Amazon and Orinoco river basins where fish populations are apparently healthy, the commercially important species are reasonably well represented in gill net samples even in the dry seasons. We only suggest caution. And we recommend that the stocks must be surveyed SEP 2000, VOL. 25 Nº 6 immediately both within the Upper Río Orthon as well as downstream toward the Río Madeira. Statements such as that by Walters et al. (1982) advocating across the board increase in fisheries are premature in advance of the data on native stocks. Economic potential also exists for the establishment of a harvestbased ornamental fishery. The extreme number of species, the number of cochas and inundated flooded habitats makes the Tahuamanu-Manuripi regions especially attractive. These habitats are easily collected while serving as natural critical rearing habitats for ornamental fishes. The ornamental fishes ranged from the common (e.g., Moenhausia sanctofilamenae, Hemigrammus ocellifer) to ornamentals that are more highly prized, including the folowing: Astronotus crassipinnis, Apistogramma spp., Aequidens spp., Satanoperca cf. acuticeps, Eigenmannia spp., Apteronotus albifrons, Gymnotus carapo, Hypopygus lepturus, Heptapterus longior, Imparfinis stictonotus, Microglanis sp., Brachyramdia martae, Chirocerus eques, Scoloplax cf. dicra, Peckoltia arenaria, Parotocinclus sp., Otocinclus mariae, Hypostomus spp., Ancistrus spp., Agamyxis pectinifrons, Acanthodoras cataphractus, Brochis splendens, Corydoras spp., Bunocephalus spp., Dysichthys spp., Nannostomus trifasciatus, Pyrrhulina spp., Carnegiella spp., Tyttocharax spp., Poptella compressa, Phenacogaster spp., Prionobrama filagera, Metynnis luna, Paragoniates alburnus, Iguanodectes spilurus, Hemigrammus spp., Hyphessobrycon spp. Hysteronotus spp., Aphyocharax spp., and Leporinus spp. The most important areas within the region surveyed for the ornamental fishes are the Upper Río Nareuda and the Río Manuripi (Machado-Allison et al., 1999). In some cases, trapped interior flooded forest lakes can be harvested entirely because these ephemeral environments either dry out completely or become anoxic. However, in the more permanent habitats the reproductive and population biologies of the ornamental fishes must be studied in order to support a sustainable enterprise. Critical habitats We identified a number of critical habitats that are required for continued survival of freshwater fishes and maintenance of the spectacular biodiversity. These are the same habitats that support the growth and reproduction of economically valuable species. The habitats are described in detail in Machado-Allison et al., (1999). However, they fall into three main classes: i) flooded areas; ii) small tributaries; and iii) main channels. The flooded areas comprise the most critical and highly endangered areas, including the varzea (flooded forest), cochas, swamps, forest lakes, etc. These areas provide nursery grounds for perhaps 66% of the species that we captured (Goulding, 1980, 1981, Amazon; Lowe-McConnell, 1987 Amazon-Guianas; MachadoAllison, 1990, 1993 Orinoco). Furthermore, many species, including the pacus, feed on the fruits and nuts, including the Brazil nuts, dropped by the plants into the water (see Goulding, 1980, 1981, Machado-Allison, 1990, 1993). Goulding (1981) characterizes the Brazilian portion of the Rio Madeira as having a relatively narrow flood plane and margin. This is certainly true for the rivers Tahuamanu, Muymanu, Nareuda and Manuripi in the areas that we surveyed. Given such a narrow flood plain there is little buffer between logging and ranching activities and these critical flood zones. Extended development from Puerto Rico, Filadelfia and Aceradero threaten this flood plain zone. In the Upper Tahuamanu and Upper Nareuda there were many smaller streams (garapés) and tributaries with both black and white water conditions. These smaller habitats are highly threatened by deforestation and cattle ranching. A number of the garapés crossing the main road and on cattle ranches are completely denuded of riparian vegetation. Furthermore, one team walked through dense forests into a number of forest streams and neither captured nor saw any fishes, crustaceans or aquatic insects in crystal clear water with sand bottoms. These streams were downstream from a ranch that was recently cleared and burned. We could only speculate that ashes which are toxic to aquatic organisms or pesticides poisoned these streams. These upper areas are highly diverse. We captured 168 species in the Upper Tahuamanu and the Upper Nareuda; slightly more than half of all the species we discovered. Seventy-one species were found to inhabit both the Upper Tahuamanu and Upper Nareuda but 30 species were found only in these upper regions. These upper regions contain habitats that are similar to headwater areas with a unique and diverse fauna. These are among the most threatened habitats due to logging, deforestation and ranching. The main river channels are not habitats that are usually focused upon. However, as pointed out above, the principal channels also contain a diverse 277 fauna with a number of unique or rare elements (e.g., Cetopsorhamdia fantasia). The Río Tahuamanu above Filadelfia contains a number of rocky outcrops, including some small rapids (cachoeras) and shallow regions with many downed logs. In the dry season the area near Aceradero was almost un-navigable because of the tree trunks and rapids. Such regions are prime candidates for spawning areas of the commercially important, large, pimelodid catfishes (e.g., Pseudoplatystoma fasciatum, Leiarius marmoratus, Barthem and Goulding, 1997). As development continues towards the Peruvian border pressure may be exerted on the river channelization to permit shipment of supplies or equipment up river. Conclusions and Recommendations The region of the Río Tahuamanu-Río Manuripi, upper Río Orthon basin, Pando, Bolivia is a potential hotspot for the diversity of freshwater fishes. A total of 313 species were discovered in the region of which 91 species represented new records for Bolivia. This region contains 62.5% of the fishes found in the Bolivian Amazon and 48.8% of the species found in the entire country. Based upon our analyses of the number of new records and the species accumulation curve (Figure 3), we predict that the number of fish species within this region will increase with continued sampling. The region is further distinguished because the ichthyofauna comprises a unique assemblage of species. There are three distinct biogeographical elements as follows: i) widespread lowland Amazonian elements from the north and east; ii) Brazilian Shield elements from the Río Guapore/Itenez; and iii) headwater elements. Because this region is a potential hotspot for freshwater fishes we are concerned that a plan be implemented to conserve this unique and valuable resource. The region should be managed in a sustainable way that will protect the biodiversity. We recommend that zones of critical habitats with varzea, cochas, main channels and upland areas should be created that will protect the biodiversity. Rather than the formation of a park, authorities may want to consider multiple use zones with some habitats restricted for modification. Because the region has a narrow floodplain, special care should be taken to minimize the impact on this important habitat. We recommend that development of a management plan include educational programs concerning the ecological relationships between the 278 flora and fauna and the habitats that support their survival and life histories. Protection of aquatic resources is critical not only from the standpoint of conserving biodiversity but also for protecting a critical resource for the people who live in the region. Many of the fishes are currently used for subsistence or commercial fishery and have a high value. The ornamental fishes also have a very high value. ACKNOWLEDGEMENTS The expedition that produced the data reported upon was part of the Aquatic Rapid Assessment Program (AquaRAP) of Conservation International and the Field Museum. We would like to express our gratitude, for their help in the organization, planning, and execution of the fieldwork, to Kim Awbrey, Adrian Forsythe, Lois “Lucho” James, Debra Moskovits, Guillermo Rioja, and Tatyana Wachter. Leeanne Alonso and two anonymous reviewers provided excellent suggestions for improving the manuscript. We are grateful to Mary Anne Rogers and Kevin Swagel for their help with processing and distributing the collections of fishes. Funding for fieldwork was generously provided by the W. Alton Jones Foundation and the Marshall Field Funds, Department of Zoology, Field Museum. For their support of AquaRAP we thank the 3-M Corporation, J. Fahn, L. Lee, D. and J. Shores, and Environmental and Conservation Programs and the Department of Zoology, the Field Museum. Partial support of research at the Field Museum was also provided by a Bass Fellowship to AMA. REFERENCES Barthem R, Goulding M (1997) The Catfish Connection : Ecology, Migration, and Conservation of Amazon Predators. Biology and Resource Management in the Tropics Series, Columbia University Press, New York. Eigenmann CH, Myers GS (1929) The American Characidae. Memoirs of the Museum of Comparative Zoology, Harvard, 43 (Part 5): 429-574. Gery J (1977) Characoids of the World. T.F.H. Publications, New Jersey. 672 pp. Goulding M (1980) The Fishes and the Forests: Explorations in Amazonian Natural History. University of California Press, Los Angeles. 280 pp. Goulding M (1981) Man and Fisheries on an Amazon Frontier. Dr. W Junk. The Hague, 132 pp. Goulding M, Carvalho ML, Ferreira EG (1988) Rio Negro: rich life in poor water: Amazonian diversity and foodchain ecology as seen through fish communities. SPB Academic Publishing, The Hague, Netherlands. 200pp. Lauzanne L, Loubens G, Le Guennec B (1991) Liste commente des poissons de l’Amazonie bolivienne. Rev. Hydrobiol. Trop. 24: 6176. Lopez-Rojas H, Lundberg JG, Marsh E (1984) Design and operation of a small trawling apparatus for use with dugout canoes. North American Journal of Fisheries Management, 4: 331-334. Lowe-McConnell RH (1987) Ecological Studies in Tropical Fish Communities. Cambridge University Press. Machado-Allison A (1990) Ecología de los peces de las áreas inundables de los Llanos de Venezuela. Interciencia 15(6): 411-423. Machado-Allison A (1993) Los Peces de los Llanos de Venezuela: Un Ensayo sobre su Historia Natural. CDCH-UCV, Caracas. 143 pp. Machado-Allison A, Chernoff B, Willink P, Sarmiento J, Barrera S, Menezes N, Berth T (1999) Diversity and Abundance of Fishes and Habitats in the Río Tahuamanu and Río Manuripi Basins (Bolivia). Acta Biol. Venez. 19(1): 17-50. Machado-Allison A, Chernoff B, Royero-León R, Mago-Leccia F, Velásquez J, Lasso C, López-Rojas H, Bonilla-Rivero A, Provenzano F, Silvera C. (2000) Ictiofauna de la Cuenca del Río Cuyuní en Venezuela. Interciencia 25(1): 13-21. Mago-Leccia F (1994) Electric Fishes of the Continental Waters of America. Biblioteca de la Academia de Ciencias Físicas, Matemáticas y Naturales, Volumen XXIX, Caracas, Venezuela. 206 pp + Tables. Peres CA, Terborgh JW (1995) Amazonian nature reserves: an analysis of the defensibility status of existing conservation units and design criteria for the future. Conservation Biology 9: 34-45. Santos GM, Jegu M, Merona B (1984) Catalogo de peixes comerciales do baixo Tocantins. Electronorte/CNPq/INPA, Manaus. 83pp. Sarmiento J (1998) Ichthyology of Parque Nacional Noel Kempff Mercado. Pp. 168180, Appendix 5. In: Killeen TJ, Schulenberg TS (eds.) A biological assessment of Parque Nacional Noel Kempff Mercado. RAP Working Papers 10, Conservation International, Washington, D.C. Stewart DJ (1985) A new species of Cetopsorhamdia (Pisces: Pimelodidae) from the Río Napo Basin of Eastern Ecuador. Copeia 1985: 339-344. Stewart DJ, Barriga R, Ibarra M. Ictiofauna de la cuenca del Río Napo, Ecuador Oriental: lista anotada de especies. Revista del Politécnico 12: 9-63. Vari RP (1992) Systematics of the Neotropical characiform genus Curimatella Eigenmann and Eigenmann (Pisces: Ostariophysi) with summary comments on the Curimatidae. Smithsonian Contributions to Zoology, 533, 48pp. Walters PR, Poulter RG, Coutts RR (1982) Desarrollo Pesquero de la Región Amazónica en Bolivia. London: Tropical Products Institute, Overseas Development Agency. SEP 2000, VOL. 25 Nº 6 TABLE I FISHES FROM THE BOLIVIAN AMAZONIAN REGION (Explanation of localities and sources of information at end of table) TAXA Bolivia Noel Bolivian Madre Itenez AquaRAP Kempff Amazon de (or Mercado Dios Guapore) Rajiformes Potamotrygonidae Potamotrygon cf. hystrix Potamotrygon motoro Potamotrygon cf. motoro Potamotrygon sp. Potamotrygonidae sp. Lepidosireniformes Lepidosirenidae Lepidosiren paradoxa Clupeiformes Clupeidae Pellona castelnaeana Pellona flavipinnis Engraulidae Anchoviella cf. carrikeri ** Engraulidae sp. 1 Engraulidae sp. 2 Characiformes Anostomidae Abramites hypselonotus Anostomus cf. gracilis Anostomus cf. plicatus Anostomus proximus Anostomus taeniatus Laemolyta sp. ** Leporinus cf. cylindriformis Leporinus fasciatus Leporinus cf. fasciatus Leporinus friderici Leporinus cf. friderici Leporinus cf. nattereri ** Leporinus pearsoni Leporinus striatus Leporinus trifasciatus Leporinus sp. nov. (amazonensis) Rhytiodus argenteofuscus Rhytiodus lauzannei Rhytiodus microlepis Schizodon fasciatum Characidae Acestrorhynchus altus Acestrorhynchus falcatus Acestrorhynchus falcirostris Acestrorhynchus guianensis Acestrorhynchus heterolepis Acestrorhynchus microlepis Acestrorhynchus cf. minimus Acestrorhynchus sp. Aphiodite cf. grammica Aphyocharax alburnus Aphyocharax dentatus Aphyocharax paraguayensis Aphyocharax pusillus ** Aphyocharax rathbuni Aphyocheirodon sp. nov. Astyanacinus cf. moori Astyanacinus multidens Astyanax abramis Astyanax cf. abramis Astyanax bimaculatus Astyanax cf. daguae Astyanax fasciatus Astyanax lineatus Astyanax cf. mucronatus Astyanax sp. Astyanax sp. 1 Astyanax sp. 2 Brachychalcinus copei Brycon cephalus Brycon erythropterus Bryconacidnus ellisi Bryconamericus bolivianus Bryconamericus cf. caucanus ** Bryconamericus cf. pachacuti ** P - - P P P P P - P P P - P P - - - - P P P P P P P - - P P P P - P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P - P P P P P P P P P P P P P P P P P P P P P P P P P - P P P P - P P P P P P P P - SEP 2000, VOL. 25 Nº 6 TAXA Bolivia Noel Bolivian Madre Itenez AquaRAP Kempff Amazon de (or Mercado Dios Guapore) Bryconamericus cf. peruanus Bryconamericus cf. peruanus Bryconamericus sp. Bryconops cf. alburnoides Bryconops cf. caudomaculatus Bryconops melanurus Bryconops sp. Catoprion mento Chalceus erythrurus Chalceus macrolepidotus Characidium bolivianum Characidium cf. fasciatum Characidium sp. 1 Characidium sp. 2 Charax gibbosus Cheirodon fugitiva ** Cheirodon piaba Cheirodon sp. 1 Cheirodon sp. 2 Cheirodon spp. Cheirodon sp. Cheirodon stenodon Cheirodontinae sp. Cheirodontinae sp. Cheirodontinae sp. 1 Cheirodontinae sp. 2 Cheirodontinae sp. (gr. Aphyodite) Clupeacharax anchoveoides Colossoma macropomum Creagrutus beni Creagrutus sp. 1 Creagrutus sp. 2 Creagrutus sp. 3 Ctenobrycon spilurus Cynopotamus amazonus Cynopotamus gouldingi ** Engraulisoma taeniatum ** Eucynopotamus biserialis ** Eucynopotamus sp. 1 Eucynopotamus sp. 2 Galeocharax gulo Gephyrocharax chapare Gephyrocharax sp. Gnathocharax steindachneri Gymnocorymbus ternetzi Gymnocorymbus thayeri Hemibrycon sp. Hemigrammus cf. bellottii Hemigrammus lunatus Hemigrammus cf. marginatus Hemigrammus cf. megaceps ** Hemigrammus ocellifer Hemigrammus cf. pretoensis ** Hemigrammus sp. Hemigrammus? sp. Hemigrammus cf. tridens Hemigrammus unilineatus Hemigrammus cf. unilineatus Holobrycon pesu Hyphessobrycon agulha ** Hyphessobrycon cf. anisitsi ** Hyphessobrycon bentosi Hyphessobrycon cf. bentosi Hyphessobrycon callistus Hyphessobrycon cf. gracilior ** Hyphessobrycon cf. herbertaxelrodi Hyphessobrycon cf. heterorhabdus Hyphessobrycon cf. minimus Hyphessobrycon cf. scholzei Hyphessobrycon serpae Hyphessobrycon? sp. Hyphessobrycon cf. tucunai Hysteronotus sp. 1 ** Hysteronotus sp. 2 ** Iguanodectes spilurus Jobertina lateralis Knodus breviceps Knodus cf. caquetae ** P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P - P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P - P P P P P P P - P P P P P P P P P P P P - 279 TABLE I (continued) FISHES FROM THE BOLIVIAN AMAZONIAN REGION (Explanation of localities and sources of information at end of table) TAXA Bolivia Noel Bolivian Madre Itenez AquaRAP Kempff Amazon de (or Mercado Dios Guapore) Knodus cf. gamma ** Knodus cf. heterestes ** Knodus cf. moenkhausii Knodus sp. Knodus sp. Knodus sp. 1 Knodus sp. 2 Knodus cf. victoriae ** Markiana nigripinnis Megalamphodus megalopterus Megalamphodus sp. Megalamphodus sp. Metynnis argenteus Metynnis hypsauchen Metynnis cf. hypsauchen Metynnis cf. lippincotianus Metynnis luna ** Metynnis cf. maculatus 1 Metynnis cf. maculatus 2 Microschemobrycon geisleri ** Microschemobrycon hasemani Moenkhausia cf. chrysargyrea ** Moenkhausia colletti Moenkhausia cf. colletti Moenkhausia cf. comma ** Moenkhausia cf. cotinho Moenkhausia dichroura Moenkhausia grandisquamis Moenkhausia jamesi Moenkhausia cf. jamesi Moenkhausia cf. lepidura Moenkhausia cf. lepidura Moenkhausia cf. megalops ** Moenkhausia oligolepis Moenkhausia sanctaefilomenae Moenkhausia sp. 1 Moenkhausia sp. 2 Moenkhausia sp. 3 Moenkhausia sp. 4 Moenkhausia sp. 5 Moenkhausia sp. 6 Moenkhausia sp. 7 Moenkhausia sp. 8 Moenkhausia sp. Myleus sp. Myleus cf. rubripinnis Myleus tiete Mylossoma aureum Mylossoma duriventris Odontostilbe cf. fugitiva Odontostilbe hasemani Odontostilbe piaba ** Odontostilbe paraguayensis ** Odontostilbe sp. 1 Odontostilbe sp. 2 Odontostilbe sp. Parecbasis cyclolepis Paragoniates alburnus Phenacogaster cf. microstictus ** Phenacogaster cf. pectinatus ** Phenacogaster sp. 1 Phenacogaster sp. 2 Phenacogaster sp. 3 Phenacogaster? sp. Phenacogaster sp. Phenacogaster sp. Piabucus melanostomus Piaractus brachypomus Poptella compressa ** Poptella orbicularis Prionobrama filigera Pristobrycon sp. ** Prodontocharax melanotus Pseudocheirodon sp. Pygocentrus nattereri Roeboides affinis Roeboides cf. descalvadensis Roeboides myersii 280 P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P - P P P P P P P P P P P P - P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P TAXA Bolivia Noel Bolivian Madre Itenez AquaRAP Kempff Amazon de (or Mercado Dios Guapore) Roeboides cf. myersii Roeboides sp. 1 Roeboides sp. 2 Roeboides sp. 3 Roeboides sp. Roestes molossus Salminus affinis Salminus brasiliensis Serrasalminae sp. Serrasalmus compressus Serrasalmus eigenmanni Serrasalmus elongatus Serrasalmus hollandi Serrasalmus cf. hollandi Serrasalmus marginatus ** Serrasalmus rhombeus Serrasalmus sp. Serrasalmus sp. Serrasalmus spilopleura Stethaprion crenatum Tetragonopterinae sp. 1 Tetragonopterinae sp. 2 Tetragonopterus argenteus Tetragonopterus cf. chalceus Thayeria boehlkei Triportheus albus Triportheus angulatus Triportheus culter Triportheus sp. Tyttocharax madeirae Tyttocharax sp. nov. Tyttocharax tambopatensis ** Vesicatrus sp. nov. Xenurobrycon polyancistrus P P P P P P P P P P P P P P P P P P - P P P P P - P P P P P P P P P P P P P P P P P P P P P P P P P P P - P P P P P P P P P P P P P P P - Curimatidae Chilodus punctatus Curimata roseni Curimata vittata Curimatella alburna Curimatella dorsalis Curimatella immaculata Curimatella meyeri Curimatopsis macrolepis Cyphocharax notatus Cyphocharax plumbeus Cyphocharax cf. plumbeus Cyphocharax sp. Cyphocharax sp. nov. Cyphocharax spilura Cyphocharax cf. spilura Cyphocharax spiluropsis Cyphocharax cf. spiluropsis Eigenmannina melanopogon Potamorhina altamazonica Potamorhina laitior Psectrogaster curviventris Psectrogaster essequibensis Psectrogaster rutiloides Steindachnerina bimaculata Steindachnerina binotata Steindachnerina dobula Steindachnerina hypostoma Steindachnerina guentheri ** Steindachnerina leucisca ** Steindachnerina sp. Steindachnerina sp. P P P P P P P P P P P P P P P - P P P P P P P P P P P P P P P P P P P P P P P P P P P - P P P P P P P - P P P P P P P P P P P P P P P P - Cynodontidae Cynodon gibbus Hydrolycus cf. armatus Hydrolycus pectoralis ** Hydrolycus scomberoides Rhaphiodon vulpinus P P P - P P P P P P P P P P - Erythrinidae Erythrinus erythrinus Erythrinus sp. - P P - - - SEP 2000, VOL. 25 Nº 6 TABLE I (continued) FISHES FROM THE BOLIVIAN AMAZONIAN REGION (Explanation of localities and sources of information at end of table) TAXA Bolivia Noel Bolivian Madre Itenez AquaRAP Kempff Amazon de (or Mercado Dios Guapore) Hoplias malabaricus Hoplerythrinus unitaeniatus P - P P P P P - P - Gasteropelecidae Carnegiella marthae Carnegiella myersi Carnegiella schereri Carnegiella strigata Gasteropelacus sternicla Thoracocharax securis Thoracocharax stellatus P P P P P P P - P P P P P - P - Hemiodontidae Anodus elongatus ** Hemiodopsis cf. microlepis Hemiodopsis semitaeniatus Hemiodopsis unimaculatus Parodon cf. carrikeri P - - P P P P P - P P P - Lebiasinidae Nannostomus sp. Nannostomus harrisoni Nannostomus trifasciatus Nannostomus unifasciatus Pyrrhulina australe Pyrrhulina brevis Pyrrhulina vittata P P P P P P P P - P P P - P P P Prochilodontidae Prochilodus nigricans Prochilodus cf. nigricans Prochilodus sp. 1 Prochilodus sp. 2 P - - P P P P - P P - Siluriformes Ageneiosidae Ageneiosus brevifilis Ageneiosus cf. caucanus ** Ageneiosus dentatus Ageneiosus madeirensis Ageneiosus sp. Ageneiosus sp. Ageneiosus ucayalensis Tympanopleura sp. Tympanopleura sp. P P P - - P P P P P P P P - P P Aspredinidae Amaralia sp. Bunocephalus coracoideus ** Bunocephalus sp. 1 Bunocephalus sp. 2 Bunocephalus sp. 3 Bunocephalus sp. Bunocephalus sp. 1 Bunocephalus sp. 2 Bunocephalus sp. 3 Dysichthys bifidus ** Dysichthys cf. aleuropsis ** Dysichthys cf. amazonicus ** Dysichthys cf. depressus ** Xiliphius cf. melanopterus ** P P P P P P P P P P - P P P P - - P - Astroblepidae Astroblepus longiceps Astroblepus sp. - - P P - - Auchenipteridae Auchenipterichthys thoracatus Auchenipterus nigripinnis Auchenipterus nuchalis Auchenipterus cf. nuchalis Centromochlus cf. heckelii ** Centromochlus sp. 1 Centromochlus sp. 2 Entomocorus benjamini Epapterus dispilurus Parauchenipterus striatulus Pseudotatia? sp. P P P P - P P P P P P P P P - P P - P P P P P - SEP 2000, VOL. 25 Nº 6 TAXA Bolivia Noel Bolivian Madre Itenez AquaRAP Kempff Amazon de (or Mercado Dios Guapore) Tatia altae ** Tatia aulopygia Tatia cf. intermedia Tatia cf. perugiae ** Tatia sp. Trachelyopterus coriaceus Trachelyopterus cf. galeatus Trachelyopterus cf. galeatus Trachelyopterus maculosus P P P P - P P P - P P P P - - Callichthyidae Brochis britskii Brochis multiradiatus Brochis splendens Callichthys callichthys Corydoras acutus Corydoras aeneus Corydoras armatus Corydoras bolivianus Corydoras geryi Corydoras hastatus Corydoras cf. latus Corydoras cf. loretoensis ** Corydoras cf. napoensis ** Corydoras punctatus Corydoras sp. Corydoras sp. Corydoras sp. 1 Corydoras sp. 2 Corydoras trilineatus ** Dianema longibarbis Hoplosternum littorale Megalechis thoractus P P P P P P P P P P P P P P P P - P P P P P P P P P P P P P P P P P P - P P - Cetopsidae Cetopsis sp. Hemicetopsis candiru Pseudocetopsis plumbeus Pseudocetopsis sp. Pseudocetopsis sp. P - - P P P P - - Doradidae Acanthodoras cataphractus ** Acanthodoras spinosissimus Agamyxis flavopictus Agamyxis pectinifrons ** Amblydoras hancockii Amblydoras cf. hancockii Anadoras cf. grypus ** Anadoras weddellii Astrodoras asterifrons Doras cf. carinatus ** Doras eigenmanni Doras fimbriatus Doras punctatus Doras sp. Hemidoras microstomus ** Megalodoras irwini Opsodoras humeralis Opsodoras cf. humeralis Opsodoras stubelii Opsodoras cf. stubelii Opsodoras sp. 1 Opsodoras sp. 2 Platydoras costatus Pseudodoras niger Pterodoras granulosus Trachydoras atripes Trachydoras cf. atripes Trachydoras paraguayensis Trachydoras cf. paraguayensis P P P P P P P P P P P P P P - P P - P P P P P P P P P P P P P P P P P P P - P P P P P - Helogenidae Helogenes marmoratus - P - - - Hypophthalmidae Hypophthalmus edentatus Hypophthalmus marginatus - - P P P - - 281 TABLE I (continued) FISHES FROM THE BOLIVIAN AMAZONIAN REGION (Explanation of localities and sources of information at end of table) TAXA Bolivia Noel Bolivian Madre Itenez AquaRAP Kempff Amazon de (or Mercado Dios Guapore) Loricariidae Ancistrus cf. bolivianus Ancistrus cf. megalostomus Ancistrus sp. 1 Ancistrus sp. 2 Ancistrus sp. 3 Ancistrus sp. 4 Ancistrus sp. Ancistrus sp. Ancistrus cf. temminckii Aphanotorulus frankei Aphanotorulus unicolor ** Cochliodon cf. cochliodon ** Cochliodon sp. 1 Cochliodon sp. 2 Crossoloricaria sp. ** Farlowella acestrichthys Farlowella cf. oxyrryncha ** Farlowella sp. 1 Farlowella sp. 2 Farlowella sp. Farlowella sp. 1 Farlowella sp. 2 Glyptoperichthys lituratus Glyptoperichthys punctatus Hemiodontichthys acipenserinus Hypoptopoma joberti Hypoptopoma sp. Hypoptopoma thoracatum Hypoptopomatinae sp. Hypoptopomatinae sp. nov. ? Hypostomus bolivianus Hypostomus cf. chaparae Hypostomus emarginatus Hypostomus cf. popoi Hypostomus sp. 1 Hypostomus sp. 2 Hypostomus sp. 3 Hypostomus sp. 4 Hypostomus sp. Hypostomus sp. 2 Hypostomus sp. 3 Hypostomus sp. 1 Hypostomus sp. 2 Hypostomus sp. 3 Hypostomus sp. 4 Hypostomus sp. 5 Lamontichthys filamentosus Lamontichthys cf. filamentosus Liposarcus disjunctivus Liposarcus disjunctivus (sp. nov.) Loricaria cf. simillima Loricaria sp. Loricaria sp. Loricariidae sp. Loricariinae sp. Loricariichthys cf. maculatus Loricariichthys sp. Loricariichthys sp. Otocinclus mariae Otocinclus cf. mariae Panaque sp. Panaque sp. n 1 Panaque sp. n 2 Parotocinclus sp. ** Peckoltia arenaria Peckoltia cf. arenaria Planiloricaria cryptodon Pseudohemiodon cf. lamina ** Pseudohemiodon sp. 1 Pseudohemiodon sp. 2 Pseudohemiodon sp. 3 Pseudohemiodon sp. Pseudohemiodon thorectes Pterosturisoma microps Pterygoplichthys sp. Rineloricaria beni Rineloricaria lanceolata 282 P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P - P P P P P P - P P P P P P P P P P P - TAXA Bolivia Noel Bolivian Madre Itenez AquaRAP Kempff Amazon de (or Mercado Dios Guapore) P P P - P - P P P P P - P - Pimelodidae Brachyglanis? sp. ** P Brachyplatystoma filamentosum Brachyplatystoma flavicans Brachyrhamdia martae ** P Callophysus macropterus Cetopsorhamdia phantasia ** P Cheirocerus eques ** P Duopalatinus cf. malarmo ** P Hemisorubim platyrhynchos P Heptapterus longior ** P Heptapterus sp. P Imparfinis bolivianus Imparfinis cochabambae Imparfinis guttatus Imparfinis sp. P Imparfinis stictonotus P Imparfinis cf. stictonotus Leiarius marmoratus P Megalonema platanum Megalonema sp. P Megalonema sp. nov. P Microglanis sp. P Microglanis sp. Paulicea lutkeni Phractocephalus hemioliopterus Pimelodella cf. boliviana ** P Pimelodella cf. chaparae Pimelodella cristata P Pimelodella gracilis P Pimelodella hasemani ** P Pimelodella cf. itapicuruensis ** P Pimelodella mucosa Pimelodella roccae Pimelodella serrata Pimelodella cf. serrata P Pimelodella sp. Pimelodidae sp. P Pimelodidae sp. Pimelodina flavipinnis Pimelodus “altipinnis” ** P Pimelodus altissimus (sp. nov.) ** P Pimelodus armatus ** P Pimelodus cf. blochii P Pimelodus cf. maculatus-blochi Pimelodus ornatus Pimelodus cf. pantherinus ** P Pimelodus sp. 1 P Pimelodus sp. 2 P Pimelodus sp. 3 P Pimelodus sp. 4 P Pinirampus pirinampu Platysilurus barbatus Pseudopimelodus zungaro Pseudopimelodus sp. 1 Pseudopimelodus sp. 2 Pseudoplatystoma fasciatum P Pseudoplatystoma tigrinum Rhamdia quelen Rhamdia sp. P Rhamdia sp. Rhamdia sp. Sorubim lima P Sorubimichthys planiceps - P P P P - P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P - P P P P P P P P P - Trichomycteridae Acanthopoma cf. bondi ** Apomatoceros sp. Gyrinurus batrachostoma - P P - - Rineloricaria cf. lanceolata Rineloricaria sp. Rineloricaria sp. Rineloricaria sp. Scoloplax cf. dicra ** Scoloplax sp. Spatuloricaria cf. evansii Sturisoma nigrirostrum Sturisoma cf. nigrirostrum P - SEP 2000, VOL. 25 Nº 6 TABLE I (continued) FISHES FROM THE BOLIVIAN AMAZONIAN REGION (Explanation of localities and sources of information at end of table) TAXA Bolivia Noel Bolivian Madre Itenez AquaRAP Kempff Amazon de (or Mercado Dios Guapore) P P P P P P - P P P - P P P P P P P P P - P - Gymnotiformes Apteronotidae Adontosternarchus clarkae ** P Adontosternarchus sachsi Apteronotus albifrons P Apteronotus bonapartii P Apteronotus sp. Porotergus cf. gimbeli Porotergus cf. gymnotus Sternarchorhynchus oxyrhynchus Sternarchorhynchus sp. - - P P P P P P P P - P - Electrophoridae Electrophorus electricus ** P - - - - Gymnotidae Gymnotus anguillaris Gymnotus cf. anguillaris Gymnotus carapo Gymnotus cf. coatesi ** P P P P - P P - - P - Hypopomidae Brachyhypopomus brevirostris P Brachyhypopomus cf. brevirostris Brachyhypopomus pinnicaudatus ** Brachyhypopomus sp. P Gymnotiforme Hypopomus cf. artedi Hypopomus sp. 1 Hypopomus sp. 2 Hypopygus lepturus P P P P P P P P - - - Rhamphichthyidae Gymnorhamphichthys hypostomus Rhamphichthys rostratus Rhamphichthys sp. - P - P P P P - - Sternopygidae Distocyclus conirostris Eigenmannia humboldtii Eigenmannia macrops ** Eigenmannia cf. trilineata ** Eigenmannia virescens Rhabdolichops caviceps ** Rhabdolichops troscheli Sternopygus macrurus P P P P P P P P P P Homodiaetus cf. maculatus Homodiaetus sp. Homodiaetus sp. Ochmacanthus cf. alternus ** Ochmacanthus sp. Ochmacanthus sp. Paracanthopoma sp. Plectrochilus sp. Plectrochilus sp. Pseudostegophilus nemurus Trichomycteridae sp. Trichomycterus cf. barbouri Trichomycterus sp. Tridentopsis pearsoni ** Vandellia cirrhosa Vandellia hasemani Cyprinodontiformes Rivulidae Cynolebias sp. Pterolebias sp. Rivulidae sp. Rivulus sp. Rivulus sp. Rivulus sp. P P P P P P P P - P P P - P P - - - TAXA Bolivia Noel Bolivian Madre Itenez AquaRAP Kempff Amazon de (or Mercado Dios Guapore) Beloniformes Belonidae Potamorrhaphis cf. eigenmanni Potamorrhaphis sp. Potamorrhaphis sp. Strongylura sp. P - P - P P - P - Synbranchiformes Synbranchidae Synbranchus marmoratus P P P - P Perciformes Cichlidae Aequidens dorsiger Aequidens sp. 1 Aequidens sp. 2 Aequidens sp. 3 Aequidens cf. paraguayensis ** Aequidens cf. tetramerus Aequidens cf. tetramerus Aequidens viridis Aequidens cf. vittatus Apistogramma inconspicua Apistogramma linkei Apistogramma sp. 1 Apistogramma sp. 2 Apistogramma sp. 3 Apistogramma sp. 4 Apistogramma sp. 1 Apistogramma sp. 2 Astronotus crassipinnis Batrachops sp. Biotodoma cupido Chaetobranchiopsis orbicularis Chaetobranchus flavescens Cichla monoculus Cichla cf. monoculus Cichlasoma boliviense Cichlasoma severum ** Cichlidae sp. Crenicara sp. Crenicara cf. unctulata ** Crenicichla cf. heckeli ** Crenicichla johanna Crenicichla lepidota Crenicichla semicincta Crenicichla sp. 1 Crenicichla sp. 2 Crenicichla sp. Crenicichla sp. Geophagus megasema Heros sp. Heros sp. Laetacara dorsigera Mesonauta festivus Mesonauta cf. insignis ** Microgeophagus altispinosa Satanoperca cf. acuticeps ** Satanoperca jurupari Satanoperca pappatera Satanoperca sp. P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P P - P P P P P P P P P P P P P P P P P P P P P P P - P P P P P P - P P P P P P P P P P P P P P P P P - Eleotridae Eleotridae sp. - - P - - Sciaenidae Pachypops sp. Pachyurus sp. Plagioscion squamosissimus P P - P P P P Pleuronectiformes Soleidae Achirus achirus - P P - - P: Presence; -: Absence of given species; **: Species collected by AquaRAP and believed to be new records for Bolivian Amazon. Locality information for fishes in Noel Kempff Mercado is from Sarmiento (1998). Locality information for fishes in the Bolivian Amazon, Madre de Dios, and Itenez (or Guapore) columns is taken from Lauzanne et al. (1991). Note that Madre de Dios and Itenez (or Guapore) are subsections of the Bolivian Amazon, and that the Bolivian Amazon includes additional basins not indicated in this table. SEP 2000, VOL. 25 Nº 6 283