Three-Dimensions Prey Reaction Fie e Coho Sa Oncorhynchus kisutch
نویسنده
چکیده
Filmed observations of the feeding behaviour of juvenile coho salmon (Oncorhynchers kisutch) cruising i n a large aquarium were used t o determine the three-dimensional shape s f their reaction field, and t o estimate the cross-sectional area of the effective volume searched for prey (scanning area). Reaction distance was greatest above the horizontal visual plane and ahead of the transverse visual plane, and this corresponds t o the feeding behaviour of fish observed in the wild. The scanning area for a given size s f prey was obtained by plott ing all captures as projections on the transverse plane. This distribution of points was then divided into a series of concentric bands characterized by prey attack probabilities, which were then used as weighting factors in the final caiculation of the scanning area. Our results and techniques are discussed in relation t o previous studies of fish reaction fields, and a simple method of estimating scanning area for salmonids is suggested.
منابع مشابه
Influence of Movement by Coho Salmon (Oncorhynchus kisutch) Parr on Their Detection by Common Mergansers (Mergus merganser)
A common reaction in juvenile salmonids that detect predators is to decrease activity. To test whether there is a survival advanrage to reduced movement under such circumstances, juvenile coho salmon (Oncorbyncbus kisrrtcb) were placed with common mergansers (Mergus merganser) under laboratory conditions that precluded crypsis. Mergansers were more likely to attack fish that moved than fish tha...
متن کاملThe effects of water depth on prey detection and capture by juvenile coho salmon and steelhead
We used three-dimensional video analysis of feeding experiments to determine the effects of water depth on prey detection and capture by drift-feeding juvenile coho salmon (Oncorhynchus kisutch) and steelhead (0. mykiss irideus). Depth treatments were 0.15, 0.30, 0.45 and 0.60 m. Mean prey capture probabilities for both species were constant across all treatments (coho = 0.51, steelhead = 0.39)...
متن کاملPrey selectivity and diel feeding chronology of juvenile chinook (Oncorhynchus tshawytscha) and coho (O. kisutch) salmon in the Columbia River plume
We studied salmon feeding selectivity and diel feeding chronology in the Columbia River plume. Juvenile chinook and coho salmon were caught by trawling at 2–3 h intervals throughout a diel period on three consecutive days (21–23 June 2000) at stations located 14.8 and 37 km offshore from the mouth of the Columbia River. A total of 170 chinook salmon were caught at the inshore and 79 chinook and...
متن کاملLow-level copper exposures increase visibility and vulnerability of juvenile coho salmon to cutthroat trout predators.
Copper contamination in surface waters is common in watersheds with mining activities or agricultural, industrial, commercial, and residential human land uses. This widespread pollutant is neurotoxic to the chemosensory systems of fish and other aquatic species. Among Pacific salmonids (Oncorhynchus spp.), copper-induced olfactory impairment has previously been shown to disrupt behaviors relian...
متن کاملComparative mapping reveals quantitative trait loci that affect spawning time in coho salmon (Oncorhynchus kisutch)
Spawning time in salmonids is a sex-limited quantitative trait that can be modified by selection. In rainbow trout (Oncorhynchus mykiss), various quantitative trait loci (QTL) that affect the expression of this trait have been discovered. In this study, we describe four microsatellite loci associated with two possible spawning time QTL regions in coho salmon (Oncorhynchus kisutch). The four loc...
متن کامل