Diet of alewives, Alosa pseudoharengus and blueback herring, A. aestivalis (Pisces: Clupeidae) in Minas Basin, Nova Scotia, a turbid, macrotidal estuary

Abstract

SynopsisStomach contents of anadromous alewives, Afosa pseudohurengus and blueback herring, A. aestivalis, obtained from brush weir and drift net collections in Minas Basin, N.S., were examined. Diets showed much overlap in terms of resource use, but the dietary importance of major prey categories differed substantially between species. Alewives favoured larger, more benthic prey (e.g. amphipods, mysids and crangonids), while blueback herring appeared to concentrate their feeding on microzooplankters (e.g. calanoid copepods, cypris larvae and molluscan veligers). Interspecific differences in diet composition are largely attributed to the planktivorous feeding habits of small (81-155 mm fork length) blueback herring. Differences in prey suggest that alewives utilize a particulate feeding strategy while blueback herring are predominantly filter-feeders. Although competition for food in the Basin seems unlikely since high secondary production yields a superabundance of prey, differences in feeding behaviour between younger, smaller individuals of both species could be a means of avoiding competitive interactions in an environment where there are space/ access limitations imposed by the tidal cycle.

Feeding Interactions between Fishes in a Coastal Ecosystem in the Southern Gulf of St. Lawrence, Atlantic Canada

“…). In contrast, Rainbow Smelt ate large amounts and Alewives consumed moderate amounts of seven‐spine bay shrimp (Stone and Daborn ; Lecomte and Dodson ; this study), which is consistent with the near‐bottom distribution of these two fishes during daylight hours. It is unclear why Alewives and Rainbow Smelt differed so greatly in their consumption of seven‐spine bay shrimp given that the stomach samples often came from fish collected in the same fishing sets.…”

“…Three pelagic species (American Shad, Atlantic Herring, and Atlantic Mackerel) only consumed small amounts of seven-spine bay shrimp, consistent with the shrimp remaining close to the bottom during daylight hours (Heck et al 1989;Joseph et al 2006;Brown et al 2014). In contrast, Rainbow Smelt ate large amounts and Alewives consumed moderate amounts of seven-spine bay shrimp (Stone and Daborn 1987;Lecomte and Dodson 2005; this study), which is consistent with the near-bottom distribution of these two fishes during daylight hours. It is unclear why Alewives and Rainbow Smelt differed so greatly in their consumption of seven-spine bay shrimp given that the stomach samples often came from fish collected in the same fishing sets.…”

“…; Debertin et al., in press). Similarly, the few published reports of Alewife marine diets (Stone and Daborn ; Smith and Link ) have described a diet dominated by euphausiids, mysids, and benthic organisms (e.g., Corophium amphipods and seven‐spine bay shrimp), unlike the diet observed in the present study.…”

Régime Alimentaire De La Grande Alose Alosa Alosa (Linné, 1766) Et De L’alose Feinte Alosa Fallax (Lacépède, 1803) Dans Le Golfe De Gascogne.

“…fallax se différencient. La plupart des études sur les habitudes alimentaires des espèces qui coexistent dans un même espace assume que la compétition est évitée par la consommation de proies différentes (STONE et DABORN, 1987). La disponibilité en proies potentielles présentes dans les aires de chasse, corrélées aux adaptations éco-éthologiques que les aloses peuvent manifester lors de la collecte de leur nourriture, sont à l'origine de la composition des régimes alimentaires observés.…”

Feeding chronology and habits of Alosa spp. (Clupeidae) juveniles from the lower Hudson River estuary, New York

“…Crecco & Blake (1983) found that shad and herring larvae competed for a cladoceran during one period in their development, but that competition was likely reduced by selection of different sized prey, a consequence of differences in mouth morphology. Stone & Daborn (1987), working in a polyhaline estuary, found that, at age 1, alewives were more dependent upon benthic prey and herrings upon plankton; older alosids had more similar diets as benthic prey predominated.…”