Diet of Iheringichthys labrosus (Siluriformes, Pimelodidae) in the Ibicuí River, Southern Brazil

Abstract

ABSTRACT. The diet of the benthic-feeding fish Iheringichthys labrosus (Lütken, 1874) was analyzed. Samples were taken bimonthly from December 1999 to January 2002, in three sites of the Ibicuí River, a tributary of Uruguay River basin (Rio Grande do Sul, Brazil). In each sampling point the specimens were collected in lentic and lotic environments. Gillnets and trammel nets were examined every 6 hours (6h, 12h, 18h and 24h). Diet description was based on the frequency of occurrence and the volume of each food item to obtain the Alimentary Index (IAi). The average stomach fullness was adopted to detect variations in the feeding activity according to the season, the circadian rhythm and the environment. Chironomids were the most important food item, followed by mollusks, and feeding activity was highest in summer, during daylight (6h and 12h), and in the lotic environment of the second sampling point.

Rapid ecological assessment of benthic indicators of water quality: a successful capacity-building experience for Brazilian postgraduate students in ecology

“…The taxonomic richness of these organisms was relatively low in comparison with the results of other studies based on a similar approach (Callisto et al, 2002b;Tupinambás et al, 2007). For more reliable and conclusive data on these parameters, a much larger sample of fish would be required, in particular of benthophagous species, which were not collected in the present study and would increase the inventory of aquatic insects (Fagundes et al, 2008).…”

Iheringichthys labrosus (Siluriformes: Pimelodidae) in the Piquiri River, Paraná, Brazil: population structure and some aspects of its reproductive biology

“…The high capture of I. labrosus recorded in the Piquiri River in the evening does not seem to be associated with the feeding habit of this species. According to Fugi (1993) and et al (1996), I. labrosus in the upper Paraná River floodplain shows greater feeding activity at dawn and during the diurnal period, a finding also reported by Fagundes et al (2008) in the Ibicuí River in southern Brazil. Thus, the largest capture observed in the evening may be related to other factors, such as physical and chemical conditions of the water, and shelter availability, among others, which were not examined in this study.…”

“…The reproduction of I. labrosus was studied by Silva (1995) in the Camargos Reservoir and Santos et al (2004) in the Funas Reservoir, both in state of Minas Gerais, Brazil. The diet of I. labrosus was studied by Fugi (1993), Fugi et al (1996) and Abes et al (2001) in the Upper Paraná River, and Fagundes et al (2008) in the Ibicuí River. However, in spite of its increasing importance in commercial fishery, studies on the population dynamics and reproductive biology of I. labrosus in the Piquiri River are nonexistent.…”

Feeding habits and morphometry of Iheringichthys labrosus (Lütken, 1874) in the Uruguay River (Uruguay)

“…The maximum total length reported for this species is 33.4 cm (Fagundes et al, 2008). Iheringichthys labrosus shows no parental care behaviour and reproduces along the year, with multiple spawning reproductive peaks synchronized with rainy season (Santos et al, 2006).…”