Effect of body size on microhabitat preferences in stream-dwelling fishes

Abstract

Summary Microhabitat preferences of two stream‐dwelling fish assemblages in two different Brazilian habitats of rainforest and semi‐arid vegetation and comparisons within and between species were investigated. Data collection was from June to October 2012 in the Gato Stream within the rainforest, and from April to September 2012 in the Curu Stream within a semi‐arid vegetation. Snorkeling observations and diving sessions along a 200‐m stretch in each stream were performed. In total, 39 diving sessions were made over a total of 55 hr of underwater observations. Microhabitat preferences of the fish were analyzed by comparing resource use by fish species to the resource availability of the streams. Use of the microhabitat differed significantly between fish species within and between assemblages. In addition, there was a higher level of intraspecific variation in the fish assemblage in the semi‐arid area. There was no significant correlation between fish size and microhabitat use, but five species showed a significant correlation between microhabitat use and distance from the stream bank. The findings herein point to highly intraspecific variability in both fish assemblages and highlight the importance of measuring individual differences in microhabitat preferences. Additionally, the versatility described for tropical freshwater fishes confirms the importance of measuring the intraspecific variability of their different ecological traits, and challenges the use of morphology as a predictor of fish ecology.

Daily movement behavior of two Neotropical armored catfish species (Ancistrusaff. cirrhosusValenciennes, 1836 andHypostomus ancistroidesIhering, 1911) at a road-stream crossing culvert

“…Nocturnal activity physiologically depends on light perception and melatonin production (Bayarri et al., ; Veras et al., ), and ecologically depends on the relationship between feeding and safety (Helfman, ; Helfman, Collete, Facey, & Bowen, ; Ramallo et al., ). In the case of shallow streams, fish species with negative phototaxis and/or nocturnal habits, such as those in the Loricariidae family, tend to stay in refugia on the bottom (Manna et al., ) and/or in dark places during periods of high luminosity, and move during nocturnal periods to obtain their ecological requirements (Buck & Sazima, ). Nocturnal movement behavior in the Siluriformes varies temporally, and is a function of luminosity (Buck & Sazima, ; Oldani & Baigún, ); in the species studied here, A. aff .…”

“…Streams are multidimensional open systems that are interconnected to the adjacent terrestrial environment (Bain & Stevenson, ; Ward, ), and are characterized by a high variability and complexity of micro‐habits, expressed by biotic, and abiotic factors (Celestino et al., ; Manna, Resende, & Mazzoni, ). Streams contain a diverse ichthyofauna in the Neotropical region (Gerhard, Moraes, & Molander, ).…”

Environmental conditions promote local segregation, but functional distinctiveness allow aggregation of catfishes in the Amazonian estuary

“…Aggregated species greatly varied in niche axes that promote shared use of space and food: (i) S. parkeri is a large species with caniniform teeth, while A. quadriscutis is a small species with molariform teeth; and (ii) A. rugispinis and C. arenatus are smallsized species that differ in traits related to habitat use, such as eye size and depth of the caudal peduncle. In fishes, ecomorphological differences between phylogenetically close species facilitate coexistence either by trophic (Portella et al 2016, Silva et al 2016 or microhabitat partitioning (Manna et al 2017(Manna et al , 2020. Trophic partitioning may be an important factor underpinning the observed co-occurrence patterns because marine catfishes display high interspecific trophic variation (Mishima & Tanji 1982, Dantas et al 2013, and syntopic species may exhibit trophic specialization (Maitra et al 2020).…”

Trophic structure of coastal freshwater stream fishes from an Atlantic rainforest: evidence of the importance of protected and forest-covered areas to fish diet

“…Many stream fish species require specific conditions and resources and depend on the importation of material from the surrounding forest (Schlosser 1991). Microhabitat preference is closely related to the morphological traits of fishes (Manna et al 2017). In the JIES streams, different micro and mesohabitats that are formed by combinations of substrate types, depths and water velocities (Gonçalves and Braga 2012) can be exploited by fish from different groups.…”