Paul E. Ouboter

The fish fauna of Brokopondo Reservoir, Suriname, during 40 years of impoundment

We investigated long-term changes in the fish fauna of Brokopondo Reservoir, Suriname, the first large reservoir (1560 km2) that was created in tropical rainforest. Before closure of the dam in 1964, the fish fauna of Suriname River had 172 species, high diversity and high evenness. The riverine fauna was dominated by small-sized species, but no single species was dominant in numbers. Large catfishes were dominant in biomass. Species were evenly distributed over riverine habitats: rapids, tributaries and main channel. Four years after closure of the dam, only 62 fish species were collected from Brokopondo Reservoir, but the composition of the fish fauna was still changing. The reservoir fauna in 1978 was very similar to the reservoir fauna in 2005, indicating that a stable equilibrium had been reached 14 years after closure of the dam. The reservoir fauna had 41 species, low diversity and low evenness. Most species of Suriname River and its tributaries with strict habitat requirements did not survive in Brokopondo Reservoir. Fish community structure was different among four habitats of Brokopondo Reservoir. The open-water habitat (10 species) was dominated by the piscivores Serrasalmus rhombeus, Acestrorhynchus microlepis and Cichla ocellaris and their prey Bryconops melanurus and two Hemiodus species. B. melanurus fed on zooplankton, Culicinae pupae and terrestrial invertebrates. Hemiodus fed on fine flocculent detritus, demonstrating that the detritus-based food chain was still important in late stages of reservoir development. Serrasalmus rhombeus also fed on peccaries that drowned when swimming across the large reservoir in rough weather. The shore community (27 species) was dominated by seven cichlids, but early stages and juveniles of the open-water species S. rhombeus and B. melanurus also occurred in the shore habitat. Fish biomass in the shore habitat was 66.5±59.9 kg ha-1. The cichlid Geophagus surinamensis and the characid B. melanurus had a lower biomass in Brokopondo Reservoir than in Suriname River. Serrasalmus rhombeus showed reduced body length in Brokopondo Reservoir as compared to riverine populations.

The fish fauna of Suriname

The ichthyofauna of the Neotropics is still badly known. Ecological studies of fish communities are possible, but many species that will be included in these studies are unnamed and can only be indicated by numbers (see for instance Goulding et al 1988). The Surinamese ichthyofauna has been studied by numerous zoologists since Van der Stigchel (1947). During six years of fish collecting, between 1987 and 1993, we (probably) found no species new to science, and only a few that were not mentioned for Suriname before. This indicates a relatively well-known fish fauna (compared to other South American countries), enabling us to make ichthyofaunal comparisons between rivers and river-sections. This chapter will give an impression of the fish fauna of a selection of rivers and river-sections in different parts of the country and consequently with different environmental conditions. The ichthyofauna of the swamps and swamp forests of the Coastal Plain is not included in this study. However, the lotic environment is very dominant in Suriname, and probably few species are exclusively restricted to the standing waters of the Coastal Plain.

Cryptic diversity in Amazonian frogs: Integrative taxonomy of the genus Anomaloglossus (Amphibia: Anura: Aromobatidae) reveals a unique case of diversification within the Guiana Shield

Lack of resolution on species boundaries and distribution can hamper inferences in many fields of biology, notably biogeography and conservation biology. This is particularly true in megadiverse and under-surveyed regions such as Amazonia, where species richness remains vastly underestimated. Integrative approaches using a combination of phenotypic and molecular evidence have proved extremely successful in reducing knowledge gaps in species boundaries, especially in animal groups displaying high levels of cryptic diversity like amphibians. Here we combine molecular data (mitochondrial 16S rRNA and nuclear TYR, POMC, and RAG1) from 522 specimens of Anomaloglossus, a frog genus endemic to the Guiana Shield, including 16 of the 26 nominal species, with morphometrics, bioacoustics, tadpole development mode, and habitat use to evaluate species delineation in two lowlands species groups. Molecular data reveal the existence of 18 major mtDNA lineages among which only six correspond to described species. Combined with other lines of evidence, we confirm the existence of at least 12 Anomaloglossus species in the Guiana Shield lowlands. Anomaloglossus appears to be the only amphibian genus to have largely diversified within the eastern part of the Guiana Shield. Our results also reveal strikingly different phenotypic evolution among lineages. Within the A. degranvillei group, one subclade displays acoustic and morphological conservatism, while the second subclade displays less molecular divergence but clear phenotypic divergence. In the A. stepheni species group, a complex evolutionary diversification in tadpole development is observed, notably with two closely related lineages each displaying exotrophic and endotrophic tadpoles.

A new Dendropsophus Fitzinger, 1843 (Anura: Hylidae) of the parviceps group from the lowlands of the Guiana Shield.

Many Amazonian frog species that are considered widely distributed may actually represent polyspecific complexes.. A minute tree frog from the Guiana Shield originally assigned to the allegedly widely distributed Dendropsophus brevifrons proved to be a yet undescribed species within the D. parviceps group. We herein describe this new species and present a phylogeny for the D. parviceps group. The new species is diagnosed from other Dendropsophus of the parviceps group by its small body size (19.6-21.7 mm in males, 22.1-24.5 mm in females), thighs dorsally dark grey with cream blotches without bright yellow patch, absence of dorsolateral and canthal stripe, and an advertisement call comprising trills (length 0.30-0.35 s) composed of notes emitted at a rate of 131-144 notes/s, generally followed by click series of 2-3 notes. Its tadpole is also singular by having fused lateral marginal papillae and absence of both labial teeth and submarginal papillae. Genetic distances (p-distance) are >5.3% on the 12S and >9.3% on the 16S from D. brevifrons, its closest relative. This species occurs from the Brazilian state of Amapá, across French Guiana and Suriname to central Guyana and is likely to also occur in adjacent Brazilian states and eastern Venezuela. This species is not rare but is difficult to collect because of its arboreal habits and seasonal activity peaks.

Mercury Levels in Women and Children from Interior Villages in Suriname, South America

Natural sources of mercury, historical gold mining, and contemporary artisanal and small-scale gold mining (ASGM) activities have led to mercury contamination in Suriname. Our primary objective was to evaluate mercury levels in hair of women and children from interior villages in Suriname where mercury levels in fish are elevated. We also estimated blood levels of mercury using an established mathematical conversion to facilitate comparison with other biomonitoring programs in the United States. Estimated levels of mercury in the blood of participants from Suriname were significantly higher than those in women from a heavy marine fish-consuming population in southeast Louisiana and estimates of the US national average. This includes women from Surinamese villages well upstream of ASGM activities. Since residents in these areas rely heavily on local fish, this is likely the source of their exposure to mercury. The levels in hair are similar to those seen in women from longitudinal studies finding neurological impairments in children exposed pre- and postnatally. Additional biomonitoring and neurodevelopmental assessments are warranted in these areas, as well as other areas of the Suriname. Mercury levels in hair (Suriname) and blood (southeast LA USA) were determined using cold vapor atomic absorption spectroscopy (CVAAS).

Common Names Index

This index presents a list of Common Names that occur in this book on Amphibians of Suriname. The entries are arranged in alphabetical order.Keywords: amphibians; Suriname

Species that may occur in Suriname, but not yet recorded for sure or known from one specimen collected in the far past only

This chapter presents species that may occur in Suriname, but not yet recorded for sure or known from one specimen collected in the far past only. It presents 7 species such as Anomaloglossus Degranvillei, Adelophryne Gutturosa, Eleutherodactylus Johnstonei, Trachycephalus Hadroceps, Caecilia Albiventris, Siphonops Annulatus, and Typhlonectes Compressicaudus.Keywords:Adelophryne Gutturosa; Anomaloglossus Degranvillei; Caecilia Albiventris; Eleutherodactylus Johnstonei; Siphonops Annulatus; Trachycephalus Hadroceps; Typhlonectes Compressicaudus

Gymnophiona Family Caeciliidae

This chapter presents short descriptions, data on the distribution, reproduction and natural history of the species of family Caeciliidae now known for the country. It discusses 5 species such as Caecilia gracilis, Caecilia tentaculata, Microcaecilia rabei, Microcaecilia taylori, and Microcaecilia unicolor under this family.Keywords:Caecilia gracilis; Caecilia tentaculata; family Caeciliidae; Microcaecilia rabei; Microcaecilia taylori; Microcaecilia unicolor

Conservation of Amphibians in Suriname

Suriname has one of the highest forest covers and one of the lowest deforestation rates in the world. Suriname is a country that, relative to its size, is rich in amphibians. It still has a good chance to preserve this natural heritage by the promotion and implementation of a sustainable development, nowadays usually called green economic development. Thirty four species are extremely rare, and known only from five or less localities or specimens. Rare species may be vulnerable. The number of species remaining is 19. Of this group the distribution of 6 species includes at least one protected area, leaving 13 species that are extremely rare or have a very limited distribution and are not protected in Suriname. If the chapter looks at threats for the 34 species that are rare, these are mining, the construction of hydro-electric reservoirs, savanna burning, land degradation, the pet trade and sea-level rise.Keywords:hydro-electric reservoirs; savanna burning; Suriname