Life-history characteristics of Pseudoplatystoma metaense (Teleostei: Siluriformes: Pimelodidae) from the northwestern Orinoco River Basin

Abstract

The tiger shovelnose catfish (Pseudoplatystoma metaense) identified in literature prior to 2007 as P. tigrinum is the most important catfish species in the Orinoco River fishery, because of its abundance and high market price. The aim of this study was to obtain age, growth and population parameters of the of tiger shovelnose catfish. A total of 2,183 catfish, were sampled during 1996-2003 from the commercial fishery of the northwestern Orinoco River Basin in Venezuela, and were aged by examination of otoliths. Validation of otolith annuli was achieved with marginal increment analysis. Results suggest that, the opaque and translucent zones of otoliths were formed once per year. Length-weight relation and the von Bertalanffy growth model parameters were used to evaluate growth and other population parameters. A strong link between the annual flood pulse and opaque zone formation was confirmed in tiger shovelnose catfish. The total mortality (Z) and natural mortality (M) were estimated. Based in the reference points for optimal and limit fishing mortality rates (F opt and F limit ) this species is exploited above optimum levels. We thus recommend a closed fishing season during their seasonal reproduction, and establishment of a system of fish refuges to help sustain the population.

A dinâmica do desembarque pesqueiro pelos registros dos intermediários do Mercado Cai n’água em Porto Velho-RO

“…As pescarias da Amazônia são dominadas por Characiformes migratórios, espécies de pequeno a médio comprimento com alta capacidade de repor estoques (Isaac et al, 2012), característica que não se observa na maioria dos peixes de importância comercial da família Pimelodidae, ordem Siluriformes (Sant'Anna, 2014;Pérez & Fabré, 2018;Souza et al, 2019). O que reforça a necessidade do monitoramento continuado deste incremento do esforço de pesca sobre as espécies da família Pimelodidae no rio Madeira.…”

Reproductive life-history strategies in a species-rich assemblage of Amazonian electric fishes

“…Outside the gymnotiforms, the life history strategy most commonly reported in Neotropical fishes is iteroparity. Examples of species which live for multiple years and exhibit multiple breeding seasons include Arapaima gigas [102, 103], Colossoma macropomum [104], some migratory pimelodid catfishes [67, 105], Pygocentrus nattereri [62], and Calophysus macropterus [106]. Predominantly two-year lifespans have been reported in Poecilia reticulata [107] and Symphysodon haraldi [88] (although both species live and breed for longer in aquaria), but we are unaware of other Neotropical species reported to have two-year life histories.…”

“…Finally, we performed marginal increment analysis (MIA) to validate annual formation of opaque bands, i.e. true annular growth increments (annuli), in otoliths following Campana [58], Lessa et al [65], Lin and Tzeng [66], and Perez and Fabre [67]. The ‘marginal increment ratio’ is a measure used to determine the timing of opaque band formation.…”

“…When the ratio is at its maximum, the most recent opaque band is furthest from the edge of the otolith, and when the ratio is at its minimum, the most recent band is close to the edge (and thus recently formed). Therefore, if an opaque band is to be presumed a true annulus (resulting from a period of slower growth), the marginal increment ratio should be at a minimum only once per year (just after formation) and is expected to approximate a sinusoidal pattern through the year in individuals sampled from a single location [58, 65–67].…”

Length–weight relationships of fishes from western Caribbean freshwater drainages of Venezuela

“…This is true for most freshwater fishes of Venezuela, which has a considerable richness of freshwater fishes, but where reports about LWRs are scarce and centered on few species, usually with importance in continental fisheries in the Lake Maracaibo and Orinoco River basins (e.g. Urdaneta & Pasquier, ; Pérez & Fabré, ). LWRs are essential tools for the monitoring and conservation of fish populations, because they allow us to increase the effectiveness of management strategies, whether for control (e.g.…”