Crepuscular and Nocturnal Activities of Californian Nearshore Fishes, with Consideration of Their Scotopic Visual Pigments and the Photic Environment'

  • N . MCFARLANDP, JAMES R .
  • Published 2004

Abstract

Activities in 27 of the major southern Californian nearshore fish species, w t h emphasis on trophic relationships. were studied between 1972 and 1975 a t Santa Catalina Island. Because these fishes onent pnmari ly by vision, they are strongly influenced by the underwater photic environment, which wedefine with representative spectra. Wecenteron crepuscular and nocturnal events, but also describe daytime events for comparison. The species tha t feed mostly by day include Athennops affrnis, Paralabrax clathratus, Girella nigrrcans, Medialuna calrfornrensrs. Brachyrstrus frenatus, Cymatogaster aggregata, Damalrchthys uacca. Embiotoca jacksonr, Chromis punctiprnnrs. Hypsypops rubtcunda, Halrchoeres semicrnctus, Oxyjulrs calrfomrm, Semrcossyphus pulcher. Alloclinus holderr, Gibbonsra elegans. Heterostrchus mstratus, and Coryphopterus nrcholsc. Those tha t feed mostly a t night include Scorpaena guttata. Sebastes atroutrens, S. sermnordes I subadult), S serriceps, Xenist ius californiensrs. Seriphus polrtus. Umbrina roncador. and Hyperprosopon argentrum. Those tha t show no clear diurnal or nocturnal mode include Lerocottus hrrundo and Pleuronrchthys coenosus. Activity patterns tend to be defined less clearly in the warm-temperate fish communities of California than in fish communities of tropical reefs. Included are the twilight patterns of transition between diurnal and nocturnal modes. which a re considered to be defined by predation pressures. The lesser definition of twl ight patterns in CalifoAia could mean reduced crepuscular predation there, but we believe tha t Californian fishes, too, have evolved under severe threats from crepuscular and nocturnal predators. We suggest this i s evidenced in the spectral sensitivities of their scotopic visual pigments. which cluster around 500 nm-the best position for vision during twilight and a t night in Californian

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Cite this paper

@inproceedings{MCFARLANDP2004CrepuscularAN, title={Crepuscular and Nocturnal Activities of Californian Nearshore Fishes, with Consideration of Their Scotopic Visual Pigments and the Photic Environment'}, author={N . MCFARLANDP and JAMES R .}, year={2004} }