Selective ingestion of detritus by a north temperate omnivorous fish, the juvenile white sucker, Catostomus commersoni

Abstract

SynopsisThe capacity of the juvenile white sucker, Catostomus commersoni, to feed selectively on detritus was examined by analyzing gut contents of fish feeding in a northern Michigan pond and in laboratory aquaria. Suckers selected fine particle detritus. The median length of detritus particles consumed by pond suckers ranged from 26-38 pm for all seasons sampled. Although suckers in the pond ingested invertebrates > 21.5 urn they never ingested detritus particles > 215 urn. Suckers fed pond detritus in laboratory aquaria selectively ingested the fine particle fraction (Kolmogorov-Smirnov test, p < 0.0001). Suckers excluded particles > 220 urn and ingested a median particle size of 54 urn. Amorphous detritus particles comprised 100% of the detritus particles in 93% of the foreguts analyzed. Suckers fed fine particle (< 45 pm) pond detritus in laboratory aquaria rejected the inorganic fraction and selectively ingested organic material with the highest protein and energy content. Ash free dry mass (AFDM) as a percent of dry-mass was 2.6 times greater in the foregut contents than in the detritus (p < 0.001). The amino acid concentration and energy density of the ingested organic matter were 1.9 times higher (p < 0.044) and 1.3 times higher (p < 0.025) than the respective amino acid and energy content of the organic fraction of the detritus. These results indicate that suckers have the capacity to consume selectively fine particle detritus with the highest nutritional value.

Relationship between morphology and diets of six neotropical loricariids

“…The six species of loricariids studied here had well-developed gill rakers when compared with other species of the same family with similar feeding habits, such as Loricaria vetula Valenciennes (=Paraloricaria vetula) and Loricariichthys platymetopon Isbrü cker & Nijssen (Angelescu & Gneri, 1949;Fugi, 1993), yet they were similar to other loricariids such as Loricaria anus Valenciennes (=Loricariichthys anus), Hypostomus plecostomus L. and H. hoplonites Py-Daniel (Py-Daniel, 1984), that feed on small-sized particles by straining ingested food (Bowen, 1983;Verigina, 1990;Ahlgren, 1996). Rhinelepis aspera has a branchial apparatus that is modified and different from that of other species.…”

Sulphur stable isotopes can distinguish trophic dependence on sediments and plankton in boreal lakes

“…We also measured stable S isotopes in fish species that feed, as adults, mainly on detritus and benthic invertebrates ( Catostomus commersoni ; Ahlgren, 1996) or on fish ( Esox lucius ; Skov et al. , 2003).…”

“…4), whereas in Lakes É vain and Fortune bivalves were significantly depleted in 13 C compared to insects, and in Lake Ollier the d 13 C values of bivalves differed from those in Hexagenia but not those of Sialis (significance level of 0.05 for all comparisons; A N O V A A N O V A and Tukey post hoc tests). We also measured stable S isotopes in fish species that feed, as adults, mainly on detritus and benthic invertebrates (Catostomus commersoni; Ahlgren, 1996) or on fish (Esox lucius; Skov et al, 2003). Indeed, stable N isotopes confirmed that C. commersoni is at a lower trophic level than E. lucius in all of our study lakes; that is, mean (±SD) trophic positions of the two species were 2.0 ± 0.3 and 2.7 ± 0.2, respectively, as determined by comparing N isotopic values in fish and in the bivalve P. grandis (Cabana & Rasmussen, 1996).…”

Do wood‐grazing fishes partition their niche?: morphological and isotopic evidence for trophic segregation in Neotropical Loricariidae

“…In both temperate and tropical aquatic systems, diverse and often locally abundant invertebrate and vertebrate detritivores are adept at selectively feeding on the most labile and nutritionally rich fractions of detritus (Arsuffi & Suberkropp 1985; Wallace et al. 1987; D’Avanzo, Alber & Valiela 1991; Maltby 1994; Ahlgren 1996; Wilson et al. 2003).…”

“…In both temperate and tropical aquatic systems, diverse and often locally abundant invertebrate and vertebrate detritivores are adept at selectively feeding on the most labile and nutritionally rich fractions of detritus (Arsuffi & Suberkropp 1985;Wallace et al 1987;D'Avanzo, Alber & Valiela 1991;Maltby 1994;Ahlgren 1996;Wilson et al 2003). Morphic detritus, including coarse particulate organic matter such as allochthonous leaves and wood, is consumed by few fishes in temperate stream systems -some Asian carps (Ctenopharyngodon idella, Hypophthalmichthys nobilis and H. moltrix) being exceptions (Cremer & Smitherman 1980;Prinsloo & Schoonbee 1987) -but is specialized on by diverse assemblages of macroinvertebrates collectively referred to as shredders (Cummins 1973;Peterson & Cummins 1974;Cummins & Klug 1979;Maltby 1994).…”