Why do juvenile fourhorn sculpin, Triglopsis quadricornis , appear in the pelagic habitat at night?
- Myoxocephalus quadricornis
- Glacial relicts
- Migratory behavior
- Lake Vättern
- 1) Institute of Freshwater Research, S-178 93, Drottningholm, Sweden
- 2) Department of Zoology, Section of Animal Ecology, University of Uppsala, Uppsala, Sweden
- 3) Department of Zoology, University of Stockholm, Stockholm, Sweden
Synopsis: Challenging the generally accepted view of the fourhorn sculpin Triglopsis quadricornis as a cold-stenothermal and true benthic species, novel findings of juveniles in the pelagic habitat of Lake Vättern, Sweden, have been examined and critically evaluated. Young-of-the-year and small-sized, sexually mature individuals, ranging 27–45 and 82–110 mm in total length, were recorded in nocturnal trawl catches from pelagic midwater in August. The sculpin had fed extensively on both benthic and semi-pelagic crustaceans, including large cyclopoid copepods, Mysis relicta, Pallasea quadrispinosa, Monoporeia affinis, Gammaracanthus lacustris, and Saduria entomon. Based on an extensive literature review a series of ecological and evolutionary reasons for a pelagic behavior of this profundal coldwater fish is suggested. Nocturnal, semi-pelagic feeding, and consecutive, thermotactic, vertical migrations up in midwater as shown by Wurtsbaugh & Neverman (1988) in order to maximize energy intake after feeding, are possible adaptations of these juvenile sculpin for minimizing size-dependent mortality due to intra- and interspecific predation and competition from other deepwater fishes.
- 1 - sciences appliquees, technologies et medecines
- 2 - sciences biologiques et medicales
- 3 - sciences biologiques fondamentales et appliquees. psychologie
- 4 - ethologie animale
- 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Aquatic Science
- 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Ecology, Evolution, Behavior and Systematics