Showing papers by "Peter A. Jumars published in 2015"
TL;DR: Polychaetes are common in most marine habitats and dominate many infaunal communities and now include osmotrophic siboglinids as well as sipunculans, echiurans, and myzostomes, which molecular genetic analyses have placed within Annelida.
Abstract: Polychaetes are common in most marine habitats and dominate many infaunal communities. Functional guild classification based on taxonomic identity and morphology has linked community structure to ecological function. The functional guilds now include osmotrophic siboglinids as well as sipunculans, echiurans, and myzostomes, which molecular genetic analyses have placed within Annelida. Advances in understanding of encounter mechanisms explicitly relate motility to feeding mode. New analyses of burrowing mechanics explain the prevalence of bilateral symmetry and blur the boundary between surface and subsurface feeding. The dichotomy between microphagous deposit and suspension feeders and macrophagous carnivores, herbivores, and omnivores is further supported by divergent digestive strategies. Deposit feeding appears to be limited largely to worms longer than 1 cm, with juveniles and small worms in general restricted to ingesting highly digestible organic material and larger, rich food items, blurring the macrophage-microphage dichotomy that applies well to larger worms.
444 citations
TL;DR: These prey families were found to be impor- tant to a wide variety of both juvenile and adult fishes from Cape Hatteras to the Scotian Shelf, and fish biosamplers revealed significant spatial shifts in prey in early spring.
Abstract: Mobile crustacean prey, i.e. crangonid, euphausiid, mysid, and pandalid shrimp, are vital links in marine food webs. Their intermediate sizes and characteristic caridoid escape responses lead to chronic underestimation when sampling at large spa- tial scales with either plankton nets or large trawl nets. Here, as discrete sampling units, we utilized in- dividual fish diets (i.e. fish biosamplers) collected by the US National Marine Fisheries Service and North- east Fisheries Science Center to examine abundance and location of these prey families over large spatial and temporal scales in the northeastern US shelf large ecosystem. We found these prey families to be impor- tant to a wide variety of both juvenile and adult dem- ersal fishes from Cape Hatteras to the Scotian Shelf. Fish biosamplers further revealed significant spatial shifts in prey in early spring. Distributions of mysids and crangonids in fish diets shoaled significantly from February to March. Distributions of euphausiids and pandalids in fish diets shifted northward during March. Of multiple hypotheses for these shifts, prey migration is most strongly supported. Rather than only the classic ontogenetic shift from feeding on shrimp to piscivory, of the 25 identified diet shifts in fish predators, 12 shifts were toward increased shrimp feeding frequency with increasing body length.
10 citations