Cladocères de quelques corps d'eaux du bassin moyen de l'Orénoque (Vénézuéla)

Rey, J.; Vasquez, E.

doi:10.1051/limn/1986013

Cited by 34 publications

(24 citation statements)

References 20 publications

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“…M. minuta accounted for almost 60 9?o of the mean cladoceran abundance in all lakes. In general, species richness and mean abundance of cladocerans was relatively low as previously reported by Rey and Vâsquez (1986).…”

Section: Orsinerasupporting

confidence: 75%

Composition, abundance and biomass of zooplankton in Orinoco floodplain lakes, Venezuela

Vasquez¹,

Rey

1992

Ann. Limnol. - Int. J. Lim.

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Zooplankton samples were collected over a 21-month period in five fioodplain lakes of the Orinoco River in order to establish zooplankton species composition, abundance patterns, and biomass and their relationships with the patterns of inundations and lake morphometry. 60 rotifer taxa were identified. This group was generally more abundant than copepods and cladocerans (mean : 73,4 % of total zooplankton). spinulosum. Most frequent and abundant zooplankton species were euplanktonic with a dominance of filter feeders and microphagous detritivores. Mean zooplankton density in all lakes ranged from 340 ind./l to 3 486 ind./l. Biomass ranged from 71,1 ^g.l (dw) to 432,8 ^g/l. Rotifers accounted for 64,7 % of the total mean zooplankton biomass in three lakes while copepods accounted for 57,8 % of the biomass in two lakes. Both density and biomass were markedly seasonal with highest mean values at low waters. Mean density in the lakes was 100 times higher than in the Orinoco main stem. Lakes with highest variabilities in surface area and water depths showed highest zooplankton densities. The type of connection (direct or indirect) established between the lakes and the major source of the water also seemed important to interpret the productivity of fioodplain lakes.

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Section: Orsinerasupporting

confidence: 75%

Composition, abundance and biomass of zooplankton in Orinoco floodplain lakes, Venezuela

Vasquez¹,

Rey

1992

Ann. Limnol. - Int. J. Lim.

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“…The record from Mexico is an animal that shows small differences with European A. karelica (e.g., postabdomen armature). A. karelica in Rey and Va´squez (1986) from Venezuela is closest to the Mexican specimens, with similar postabdomen armature (longer distal teeth on postanal margin and basal spine longer than in European A. karelica), which we think belong to the same taxon. These populations may represent a different species from true A. karelica.…”

Section: Distribution and Biologymentioning

confidence: 59%

“…karelica in Idris and Fernando (1981). Non A. karelica in Rey and Va´squez (1986). Non A. prope karelica in Maiphae et al (2005).…”

Section: Alona Karelica Stenroos 1897 (Alona Pulchella Group)mentioning

confidence: 99%

“…karelica is known from the (northern) Neotropics. Specimens have been mentioned from Venezuela and Mexico (Rey and Va´squez, 1986;Elı´as-Guttie´rrez et al, 2008). In this region, confusion with A. bromelicola is possible.…”

Section: Distribution and Biologymentioning

confidence: 99%

“…Records of A. cf. karelica exist from outside the Palaearctic, from Neotropics and even East Asia (e.g., Idris and Fernando, 1981;Rey and Va´squez, 1986;Elı´as-Gutie´rrez et al, 2008). We included specimens from Mexico (coll.…”

Section: Introductionmentioning

confidence: 99%

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Three rare European “Alona” taxa (Branchiopoda: Cladocera: Chydoridae), with notes on distribution and taxonomy

Damme

Elías‐Gutiérrez

Dumont

2011

Ann. Limnol. - Int. J. Lim.

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-Taxonomical efforts in freshwater zooplankton are continuously needed for the delineation of species. Even today, confusion exists in correct identification of several European Cladocera because of poor original descriptions and subtle differences in morphology. In this context, we discuss three of the rarest Alona-like Chydoridae in the Palaearctic and their validity. 1) Alona moniezi, only reported once from Vichy area, France, has a male indistinguishable from that of A. elegans Kurz, 1875 while females show characters of A. elegans and of Coronatella rectangula. We provide a description of this taxon, with intermediate morphology and discuss the possibilities of hybridization. 2) Alona karelica is unusual as one of the few eurythermic species of a predominantly stenothermic A. pulchella-group. We discuss Neotropical A. cf. karelica from Mexico as its closest relative. Both show similarities with the semi-terrestrial A. bromelicola from Nicaragua, forming a small A. karelica-section within the A. pulchella-group. 3) A. weltneri is redescribed based on type material and we confirm it as a member of the A. costata-group. We discuss the three taxa and expand their diagnosis. A. weltneri and A. karelica are both found sporadically, and little is known about their ecology. Their scarcity in the Palaearctic may be linked with specialisation to a peculiar habitat and the possibility that these are true relicts.

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The Orinoco river: A review of hydrobiological research

Vasquez¹

1989

Regul. Rivers: Res. Mgmt.

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The Orinoco River is one of the world's longest rivers (2060 km) and in terms of average water discharge (36000 m3 s-') it ranks third. Seventy per cent of its basin (1.1 X 106km2) is found in Venezuela and the rest in Colombia. Due to the uneven distribution of the population toward the northern coastal areas (97 per cent of the population inhabits 55 per cent of the country with only 16 per cent of the surface waters) plans have been carried out to develop resources in the Orinoco Basin. So far these programs include mining (mainly iron and bauxite), oil exploration and extraction from the Orinoco Oil Belt, industry, river transport, and hydroelectric exploitation. Development of the latter has involved the construction of two dams on the Caroni River (the most important blackwater tributary of the Orinoco) and two more are planned on this same river. Hydroelectric projects are also being considered for the Orinoco River. Physicochemical and biological characterization has been regarded as of major importance to establish base-line information to detect and quantify possible alterations in this river which is considered to be in a pristine state. Systematic hydrobiological research has recently been carried out in the river, some of its major tributaries, and floodplain lakes, and a fair amount of knowledge has emerged mainly from its lower section.Phytoplankton studies have revealed the presence of over 400 species of algae. Zooplankton research has identified 116 taxa of rotifers and 58 taxa of cladocerans. In general plankton densities negatively correlate with water level. Diatoms were observed to predominate in the Orinoco River while Cyanophyta predominate in the studied floodplain lakes. Seventeen aquatic macrophyte species have been recorded in the lakes of the Orinoco with high densities of Eichhornia crassipes, Oxycarium cubense, and Puspalurn repens. Rooted emergent and floating-piant cover tends to increase rapidly during high water. Some 318 species and subspecies of fish have been reported for the Orinoco Basin, even though this number is far from complete. Preliminary data have revealed different species associations among relatively close lakes with biornasses ranging between 30 to 900 kg ha-' displaying considerable variations in diversity and species richness. Fisheries along the Orinoco are mainly of a multispecific nature and their overall potential has been estimated as being in the order of 45000 t yr-I.In general, management plans have taken into consideration the multispecific potential of the Orinoco Basin but indicate a lack of sufficient knowledge of the physical, biological, and social aspects involved. Furthermore development plans tend to precede the generation of this basic knowledge, thereby increasing the risks of conflict among the various users of the resources involved.

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Cladocères de quelques corps d'eaux du bassin moyen de l'Orénoque (Vénézuéla)

Cited by 34 publications

References 20 publications

Composition, abundance and biomass of zooplankton in Orinoco floodplain lakes, Venezuela

Composition, abundance and biomass of zooplankton in Orinoco floodplain lakes, Venezuela

Three rare European “Alona” taxa (Branchiopoda: Cladocera: Chydoridae), with notes on distribution and taxonomy

The Orinoco river: A review of hydrobiological research

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