Abundance, depth distribution, diet composition and growth of perch (Perca fluviatilis) and burbot (Lota lota) larvae and juveniles in the pelagic zone of Lake Constance

Abstract

Abstract— Surveys of larval and juvenile fish in the pelagic zone were made in Lake Constance between April and July 1994 with a plankton net. Perch (Perca fluviatilis) and burbot (Lota lota) were caught persistently, while other species were found only occasionally. Perch and burbot coexisted in the pelagic zone; both species were found first in mid‐May, reached peak density in June, and disappeared from the pelagic zone in late July. However, the abundance of perch was much higher than that of burbot. Perch were distributed mainly near the surface, whereas burbot were more abundant at the deeper strata of 5 and 10 m, exhibiting habitat segregation. Perch fed mainly on copepods and positively selected them during their first month of life, and afterwards, they consumed principally on Daphnia, while burbot fed mainly on copepods and positively selected them throughout the study period. Perch grew significantly faster than burbot, and the mean lengths of perch were about 3 times greater than that of burbot in July. The results demonstrate that perch and burbot were the main species of pelagic larvae in Lake Constance between May and July, and that the two species differed somewhat in depth distribution, diet composition and growth.

Spatial and temporal distribution of landlockedGalaxias maculatusandGalaxias platei(Pisces: Galaxiidae) in a lake in the South American Andes

“…In Lake Gutierrez, Galaxias free embryos and larvae avoid the surface waters during the daytime, and were captured at depths of 7.5 to more than 30 m. This distribution may be attributed to temperature (Wang & Appenzeller 1998), ultraviolet radiation (Hunter & Taylor 1982;Crowder & Crawford 1984;Beland et al 1999), food availability, and/or predation risk. However, temperature is unlikely to be a determining factor, as the same distribution pattern was found when the lake was mixed.…”

Lake‐wide distributions of temperature, phytoplankton, zooplankton, and fish in the pelagic zone of a large lake

“…At the time of our campaign, the most abundant fish in the pelagic zone of Lake Constance were larval burbot (L. lota) feeding almost exclusively on zooplankton (Wang and Appenzeller 1998), whereas perch (P. fluviatilis) had not yet experienced peak hatching at that time in 2007 (W. N. Table 5. Linear models with zooplankton density (as backscattering strength, dB) as independent variable and fish density (ind 3 1000 m 23 ) as response variable.…”

“…The lower signal threshold of integrated SED was set to 280 dB, including small echoes from young-of-the-year fish as well as echoes from larger individuals. At this time of the year the pelagic fish community in Lake Constance is dominated by larval burbot Lota lota, perch Perca fluviatilis (Wang and Appenzeller 1998), and age 1+ lake whitefish (C. lavaretus; Appenzeller 1998).…”

Hydroacoustic observations of surface shoaling behaviour of young-of-the-year perch Perca fluviatilis (Linnaeus, 1758) with a towed upward-facing transducer

“…Wang and Appenzeller (1998) found perch in the open water of Lake Constance until the end of July, where they inhabited the epilimnion during day and night. During their pelagic stage they first feed on rotifers and small copepods and switch to large copepods and Daphnia with increasing gape size (Wang, 1994).…”