Spatial distribution and interaction of four species of the catfish genus Hypostomus Lacépède with bottom of Rio São Francisco, Canindé do São Francisco, Sergipe, Brazil (Pisces, Loricariidae, Hypostominae)

Abstract

The large catfishes, genus Hypostomus Lacépède, are common species in almost all freshwater environments of South America. The behavior of specimens from the species Hypostomus alatus, Hypostomus francisci, Hypostomus cf. wuchereri, and Hypostomus sp., from the region downstream from the Xingó Hydroelectric Power Dam, located in Canindé do São Francisco on the Rio São Francisco, were observed. Morphological characters collected from preserved specimens were also studied in the laboratory, in order to shed light on interactions between those fishes and the river bottom. In addition, the formulation of Gatz (1979) was applied to better explain the environmental interactions of Hypostomus species. This study revealed that the fishes utilize their suckers, through a mouth equipped with an oral disk, as well as the pectoral, pelvic, and caudal fins areas, to interact with the rocky river-bottom. The comb-toothed inferior mouth of the Hypostomus showed itself able to grasp green algae on the river bottom. With the help of the oral disk and sucker mouth, which anchor the fishes, in conjunction with the arched design of pectoral and pelvic fin spines, they are also able to remain upright while exploring this substratum. In addition, their large, concave caudal-fin is associated with fast locomotion over short distances. This combination of characteristics allow these fish to live on the bottom of large South American rivers.

Habitat use by two species of Hypostomus (Pisces, Loricariidae) in southeastern brazilian streams

“…Several hypostomins are known for a closer association with fast flowing environments where they display a bottom-dwelling behavior, feeding on attached algae (Garavello & Garavello 2004). Although Hypostomus ancistroides is considered a typical stream species (Castro & Casatti 1997), the occupation of faster mesohabitats seems not a pattern for it in this study.…”

Fish fauna from Sapucaí-Mirim River, tributary of Grande River, upper Paraná River basin, Southeastern Brazil

“…Some of the medium sized species also need free impoundment river flow for their biological activities, as do the Loricariidae fishes. It is noteworthy that approximately 13% of the species belong to the genus Hypostomus, known to inhabit preferentially rocky bottom (Garavello & Garavello 2004) and turbulent water environments, as found in the middle stretch studied in Sapucaí-Mirim River basin. Medium-sized species of other fish groups also indicate that Sapucaí-Mirim furnishes shelter for fish that require riverine environmental conditions, as do the anostomids of genus Leporinus and Schizodon, the serrasalmid Myleus tiete (Eigenmann & Norris, 1900) and catfishes of the genus Pimelodus.…”

Use of food resources and resource partitioning among five syntopic species of Hypostomus (Teleostei: Loricariidae) in an Atlantic Forest river in southern Brazil

“…These differences, in part, result from the different attachment mechanisms they display. These attachment mechanisms ensure that the individuals can maintain their position [while feeding] and result in the differential occupation of lotic systems by the various species (Buck & Sazima 1995, Garavello & Garavello 2004, PaGotto et al 2011). In addition, the differences in the morphology and functional versatility (Schaefer & lauder 1986 of the ventrally oriented feeding apparatus, which bear teeth that touch the substrate from which algae and other food items are scraped, are also relevant to resource partitioning, since these morphological differences result in different ways of obtaining food (delariva & aGoStinho 2001).…”