scholarly journals THE GAS CONTENT OF THE SWIMBLADDER OF THE ROCK BASS, AMBLOPLITES RUPESTRIS, IN RELATION TO HYDROSTATIC PRESSURE

1942 ◽  
Vol 82 (1) ◽  
pp. 138-153 ◽  
Author(s):  
HOWARD H. ROSTORFER
Keyword(s):  
Hydrostatic Pressure ◽  
Gas Content ◽  
Rock Bass ◽  
Ambloplites Rupestris

scholarly journals River Otter, Lontra canadensis, Food Habits in the Missouri Ozarks

2008 ◽  
Vol 122 (4) ◽  
pp. 303 ◽  
Author(s):  
Nathan M. Roberts ◽  
Charles F. Rabeni ◽  
John S. Stanovick ◽  
David A. Hamilton
Keyword(s):  
Smallmouth Bass ◽  
Lontra Canadensis ◽  
Micropterus Dolomieu ◽  
Widespread Occurrence ◽  
River Otters ◽  
Lepomis Megalotis ◽  
Rock Bass ◽  
Longear Sunfish ◽  
The Mean ◽  
Ambloplites Rupestris

The reintroduction of River Otters (Lontra canadensis) between 1982 and 1992 resulted in widespread occurrence of the species throughout the Missouri Ozarks. This study examined otter diets from the vicinity of two Ozark streams in relation to seasonal and spatial trends. Otter scats (N = 4750) were collected and analyzed from the Osage Fork River and Big Piney River during the summer and winter seasons of 2001 and 2002. During the winter (January-March), fish occurred in 86% of the samples. During the summer (June–August), occurrence of fish dropped to approximately 15% for both rivers. Seven families of fish were identified in the diets, with Centrarchidae being most common regardless of river or season. Within the Centrarchidae, the genus Lepomis (mostly Longear Sunfish, Lepomis megalotis) was most common, with Micropterus (mostly Smallmouth Bass, Micropterus dolomieu) and Rock Bass (Ambloplites rupestris) also well represented. The mean age of Ambloplites consumed (mean = 3.3 years) was consistently older than that of either Micropterus (mean = 2.54 years) or Lepomis (mean = 2.78 years). Crayfish were recovered from a mean of 85.2% of scats in the winter and 99% in the summer. Smaller fish and crayfish were more common from the upper reaches of the streams while larger fish were prevalent in the lower reaches.

Sexual differences in accumulation of mercury in four species of centrarchid fishes

1988 ◽  
Vol 66 (4) ◽  
pp. 944-949 ◽  
Author(s):  
Paul F. Nicoletto ◽  
Albert C. Hendricks
Keyword(s):  
Lepomis Macrochirus ◽  
Mercury Content ◽  
Lepomis Gibbosus ◽  
South Fork ◽  
The South ◽  
Male And Female ◽  
Rock Bass ◽  
Males And Females ◽  
Redbreast Sunfish ◽  
Ambloplites Rupestris

A 3-year study of fish from the South River, and the South Fork of the Shenandoah River, and the Shenandoah River in Virginia revealed significant differences in the muscle mercury content of males and females. Female rock bass, Ambloplites rupestris, redbreast sunfish, Lepomis auritus, pumpkinseed, Lepomis gibbosus, and bluegill, Lepomis macrochirus contained higher levels of mercury than the males of each species. An analysis of these species indicated that sex-related differences in mercury levels were not due to differences in body size but may have been related to the onset of reproduction. For example, mercury levels in 1-year-old male and female redbreast sunfish were not significantly different: females averaged 0.66 μg Hg/g and males averaged 0.63 μg Hg/g. However, at 2 years of age, when redbreast sunfish first reproduce, females contained significantly more mercury than males: females averaged 0.84 μg Hg/g and males averaged 0.60 μg Hg/g. Analysis of the other species yielded similar results.

Epizootiology, pathology, and description of Eustrongylides tubifex (Nematoda: Dioctophymatoidea) in fish

1988 ◽  
Vol 66 (10) ◽  
pp. 2212-2222 ◽  
Author(s):  
Lena N. Measures
Keyword(s):  
Yellow Perch ◽  
Perca Flavescens ◽  
Infected Fish ◽  
Lepomis Gibbosus ◽  
Fourth Stage ◽  
Intermediate Hosts ◽  
Third Stage ◽  
Rock Bass ◽  
Ambloplites Rupestris ◽  
Fish Hosts

In Guelph Lake, a man-made reservoir in Ontario, Canada, prevalence of larval Eustrongylides tubifex in pumpkinseed (Lepomis gibbosus), rock bass (Ambloplites rupestris), and yellow perch (Perca flavescens) was 12.9% and mean intensity ranged from 1 to 1.8. Larvae were encapsulated on the mesentery of fish. Pumpkinseed and yellow perch were the important fish hosts in Guelph Lake as most larvae in these fish were alive. In contrast, 40% of larvae in rock bass were dead and calcified. Third- and fourth-stage larvae from naturally infected fish are described. Larvae in the three species of fish elicited a granulomatous inflammatory reaction. Attempts to transfer third-stage larvae from experimentally infected oligochaetes and third-stage larvae from naturally infected fish to laboratory-reared pumpkinseed were unsuccessful. Fourth-stage larvae from naturally infected fish were transferred successfully to pumpkinseed. Eutropic lakes such as Guelph Lake are particularly suitable enzootic areas because of the abundant populations of tubificid intermediate hosts and the presence of fish hosts such as pumpkinseed and perch. The advanced stage and development of larvae (to the fourth stage) in fish likely represents an adaptation for a parasite that occurs in a migratory host such as Common Mergansers (Mergus merganser), which frequent Guelph Lake for only about 1 month in spring and fall.

Sign in / Sign up

Export Citation Format

Share Document