Food resource partitioning between stream-dwelling Arctic charr Salvelinus alpinus (L.), Atlantic salmon Salmo salar L. and alpine bullhead Cottus poecilopus Heckel, 1836: an example of water column segregation

Abstract

We assessed the food resource partitioning of three fish species (Arctic charr, Atlantic salmon and alpine bullhead) living in sympatry in a subarctic river.

The role of Salvelinus in contemporary studies of evolution, trophic ecology and anthropogenic change

“…Juveniles of riverine anadromous Arctic charr show a clear food segregation with other fish species (Atlantic salmon and alpine bullhead, Cottus poecilopus) living in sympatry (Sánchez-Hernández et al, 2016). In competition with these other species Arctic charr showed the greatest capacity to forage at the water surface, eating mainly surface prey (terrestrial and emerged aquatic insects).…”

“…In contrast, the other species consumed largely benthic resources. The vertical segregation may be important for coexistence of sympatric species, facilitating food resource partitioning (Sánchez-Hernández et al, 2016). Similarly, resource partitioning in food, space and time appears to dominate in other fish communities where Arctic charr are present.…”

“…habitat alterations. While the high niche plasticity of Arctic charr seems essential for their coexistence with competitively superior fish species (Sandlund et al, 2016;Sánchez-Hernández et al, 2016), the adaptive ability of Arctic charr is not limitless.…”

Seasonal variations in food resource partitioning among four sympatric gudgeon species in the upper Yangtze River

“…In the present study, the four studied gudgeon species have similar feeding apparatus and all prefer to utilize the same aquatic invertebrate (Zeng & Liu, 2011). Numerous studies have demonstrated that seasonal fluctuation in food resource availability may affect the trophic relationships among sympatric fish species (Sánchez-Hernández et al, 2016Gray et al, 1997). Therefore, it is possible that the high prey availability in spring enables fish species to share the same food resources, and hence the observed high diet overlap (Gabler & Amundsen, 2010 (Hammerschlag, Ovando, & Serafy, 2010;Jardas, Santic, & Pallaoro, 2004;Tyler, 1971;Gray et al, 1997).…”

“…Noteworthy, food resource partitioning patterns among sympatric fish species may change obviously across seasons, according to the seasonal variations in food availability, including food diversity and food abundance (Prejs & Prejs, 1987;Sánchez-Hernández et al, 2016;Sánchez-Hernández, Gabler, & Amundsen, 2017;Gray et al, 1997). Some researchers found that co-occurring species may specialize following their species-specific resource preferences when food resource become limited and the overlap will decrease (Gabler & Amundsen, 1999;Robinson & Wilson, 1994;Schoener, 1971;Gray et al, 1997).…”