Design and Operation of a Small Trawling Apparatus for Use with Dugout Canoes

López-Rojas, Héctor; Lundberg, John G.; Marsh, Edie

doi:10.1577/1548-8659(1984)4<331:daooas>2.0.co;2

Cited by 27 publications

(26 citation statements)

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“…This situation contrasts with records from other neotropical freshwater ecosystems cha racterized by the dominance of characoid fishes ( Lowe-McConnel 1975Lowe-McConnell & Howes 1981). Similar results have been reported for the benthic fish communities of the Apure River (Provenzano & Castillo 1984 ;Provenzano et al 1984 a, b, c) and of the Orinoco River Delta (Lôpez-Rojas et al 1984 ;Ramos et al 1982). In the lower Orinoco River, Lôpez-Rojas et al (1984) distinguis hed two fish assemblages ; one assemblage in the deepest sections of the main channel dominated by Gymnotiformes, and another one in adjacent shal lower areas dominated by high richness of characoid fishes.…”

Section: Discussionsupporting

confidence: 83%

“…Similar results have been reported for the benthic fish communities of the Apure River (Provenzano & Castillo 1984 ;Provenzano et al 1984 a, b, c) and of the Orinoco River Delta (Lôpez-Rojas et al 1984 ;Ramos et al 1982). In the lower Orinoco River, Lôpez-Rojas et al (1984) distinguis hed two fish assemblages ; one assemblage in the deepest sections of the main channel dominated by Gymnotiformes, and another one in adjacent shal lower areas dominated by high richness of characoid fishes. In the Guaritico River, however, characoids specially the « piranhas » (Pygocentrus and Serrasalmus) represent accessory species.…”

Section: Discussionsupporting

confidence: 83%

“…Collections were made with a trawling fishing apparatus adapted to dugout canoes according to the design made by Lôpez-Rojas et al (1984). Each trawling lasted for 10 min, covering a mean distance of 147 m., at depths ranging from 2-10 m (Table 1).…”

Section: Methodsmentioning

confidence: 99%

“…During the expedition, a trawling apparatus was designed to sample in shallower areas. The results of the efficiency of this gear were published by Lôpez-Rojas et al (1984). Similar collections (2) fish fauna associated with the bottom of the river in order to make comparisons with other similar systems ; 2) to quantify the abundance, biomass, and catch per unit effort (CPUE) determined for the first time by means of the apparatus designed by Lôpez-Rojas et al (1984).…”

Section: Introductionmentioning

confidence: 99%

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Composition, abundance and biomass of the benthic fish fauna from the Guaritico river of a Venezuelan floodplain

Lasso¹,

Castroviejo²

1992

Ann. Limnol. - Int. J. Lim.

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Section: Discussionsupporting

confidence: 83%

Section: Discussionsupporting

confidence: 83%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Composition, abundance and biomass of the benthic fish fauna from the Guaritico river of a Venezuelan floodplain

Lasso¹,

Castroviejo²

1992

Ann. Limnol. - Int. J. Lim.

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“…The order Gymnotiformes comprises some 148 nominal species ascribed to 28 genera and five families, and is distributed from Mexico to Argentina (Albert 2001). Gymnotiforms occur in almost every lowland aquatic habitat and often represent a dominant component of the fish fauna, especially in floodplains (Crampton 1996(Crampton , 1998a and deep river channels (Lopez-Rojas et al 1984;Lundberg et al 1987). Specialized electric organs in these fishes produce an electric organ discharge (EOD) that creates an electric field in the surrounding water, and this field is subsequently detected by arrays of electroreceptors on the body surface (reviewed by von der Emde 1997).…”

Section: Introductionmentioning

confidence: 99%

Oxygen consumption in weakly electric Neotropical fishes

et al. 2003

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Weakly electric gymnotiform fishes with wave-type electric organ discharge (EOD) are less hypoxia-tolerant and are less likely to be found in hypoxic habitats than weakly electric gymnotiforms with pulse-type EOD, suggesting that differences in metabolism resulting from EOD type affects habitat choice. Although gymnotiform fishes are common in most Neotropical freshwaters and represent the dominant vertebrates in some habitats, the metabolic rates of these unique fishes have never been determined. In this study, O(2) consumption rates during EOD generation are reported for 34 gymnotiforms representing 23 species, all five families and 17 (59%) of the 28 genera. Over the size range sampled (0.4 g to 125 g), O(2) consumption of gymnotiform fishes was dependent on body mass, as expected, fitting a power function with a scaling exponent of 0.74, but the O(2) consumption rate was generally about 50% of that expected by extrapolation of temperate teleost metabolic rates to a similar ambient temperature (26 degrees C). O(2) consumption rate was not dependent on EOD type, but maintenance of "scan swimming" (continuous forwards and backwards swimming), which is characteristic only of gymnotiforms with wave-type EODs, increased O(2) consumption 2.83+/-0.49-fold (mean+/-SD). This suggests that the increased metabolic cost of scan swimming could restrict gymnotiforms with wave-type EODs from hypoxic habitats.

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Temporal fish community responses to two cascade run‐of‐river dams in the Madeira River, Amazon basin

et al. 2017

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We examined responses from shore fish assemblages and bottom channel fish assemblages before and after 2 cascade run‐of‐river dams in the Madeira River, in the Amazon. Those dams were installed in a river corridor where historical factors, represented by the presence of the Teotônio and Jirau falls, were the best predictors of the fish fauna assemblage composition. Jirau and Santo Antônio were the first dams constructed with Kaplan horizontal bulb turbines in the Amazon. These bulb turbines have the ability to operate by forming small reservoirs known as run‐of‐river, which should minimize impacts on fish assemblages. Overall, there were major short‐term impacts in shore fish assemblages by increasing species richness, abundance, and biomass in experimental catches. Shore fish assemblages dissimilarities before and after the dams' closure were also noticed and were related to an increase in water temperature and dissolved oxygen. However, the historical factor represented by Teotônio Fall is still the best predictor of fish assemblage dissimilarities, combined with effects of dams' closure. Bottom channel fish assemblage dissimilarities can be explained only by dams closure and are related especially to changes in fish species abundance inside the reservoirs. Our study revealed an increase in native opportunistic fish species and changes in fish assemblage structure at local scale. Kaplan horizontal bulb turbines employed in run‐of‐river dams seem to be less deleterious than vertical axis turbines typically used in accumulation reservoirs, and should be preferred in the face of burgeoning new hydroelectricity development plans for rivers across the Amazon basin.

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Design and Operation of a Small Trawling Apparatus for Use with Dugout Canoes

Abstract: This paper describes a light trawling apparatus fitted to a dugout canoe and provides an example of results of using this gear in the Orinoco River Delta, Venezuela. This simple, manually operated apparatus can be especially useful in basic survey work on bottom fishes in remote areas.

Cited by 27 publications

References 0 publications

Composition, abundance and biomass of the benthic fish fauna from the Guaritico river of a Venezuelan floodplain

Composition, abundance and biomass of the benthic fish fauna from the Guaritico river of a Venezuelan floodplain

Oxygen consumption in weakly electric Neotropical fishes

Temporal fish community responses to two cascade run‐of‐river dams in the Madeira River, Amazon basin

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