Is the High Cost of Body/Caudal Fin Undulatory Swimming due to increased Friction Drag or Inertial Recoil?

1992 ◽  
Vol 162 (1) ◽  
pp. 157-166 ◽  
Author(s):  
PAUL W. WEBB
Keyword(s):  
Lepomis Macrochirus ◽  
Large Body ◽  
Energy Losses ◽  
Bluegill Sunfish ◽  
Friction Drag ◽  
Body Depth ◽  
Surface Areas ◽  
Wetted Surface Area ◽  
Undulatory Swimming ◽  
Inertial Energy

Deep-bodied fish, such as the bluegill sunfish {Lepomis macrochirus), are considered to have relatively larger wetted surface areas for their size than fusiform fish. On the basis of the boundary layer thinning hypothesis attributing high power requirements of undulatory swimming to enhanced friction drag, power (=drag) coefficients should be higher for such fish. Areas are typically normalized with total length, L, as L2 for comparison among species. Bluegill had a wetted surface area of 0.65 L2, compared with areas of about 0.41 L2 for trout of similar mass. However, absolute areas and volume2/3 of bluegill and trout were similar. Power requirements and power coefficients calculated from kinematics during steady swimming were lower for bluegill sunfish than for cruisers, such as trout, and power coefficients were also lower than those of accelerators, such as tiger musky. Large body depth also damps inertial recoil arising from the side force generated largely by the tail. Inertial energy losses appear to be more important contributors than friction to mechanical power requirements.

scholarly journals A case of diquat poisoning in pigs

2019 ◽  
Vol 64 (No. 11) ◽  
pp. 505-511
Author(s):  
Z Siroka ◽  
M Svoboda ◽  
Z Svobodova ◽  
I Nagl
Keyword(s):  
Toxic Substance ◽  
Large Body ◽  
Skin Lesions ◽  
Acute Poisoning ◽  
Pathological Examination ◽  
Tissue Destruction ◽  
Large White ◽  
Surface Areas ◽  
Stomach Fundus ◽  
White Foam

Diquat is a bipyridyl compound which belongs to the group of herbicides. Its activity is based on the liberation of the superoxide anion radical and, subsequently, hydrogen peroxide, leading to tissue destruction by oxidative stress. Acute poisoning is associated with high mortality within several hours to a few days. The reported case of poisoning occurred on a commercial farm. The fattening pigs of the Landrace and Large White breeds were affected. The pigs were kept on a deep litter. Reglone (active ingredient diquat dibromide, 200 g/l) was used on the farm fields to desiccate the clover crop. The dry clover straw was harvested and stored for approximately a month and then used as a litter. In total, 50 pigs were affected. The onset of the poisoning was very fast. Within eight hours after the litter administration, 20 animals died. The only clinical sign seen was severe haemorrhagic dermatitis. The pathological examination revealed acute superficial haemorrhagic dermatitis on the belly, the snout and the ears of the affected pigs. Hyperaemia of the tonsils, pharynx and oesophagus was diagnosed, as well as a pronounced hyperaemia of the stomach fundus. In the distal part of the trachea, there was a dense, white foam. The lungs were congested, with focal emphysema. The liver was slightly hyperaemic. The histological examination revealed a massive haemostasis in liver and diffuse acute polymorphonuclear hepatitis. The other organs were without changes. The examination revealed acute poisoning caused by the large body surface areas contacting with a toxic substance. The pigs that survived were immediately removed to a non-contaminated area. The changes on their skin were not so extensive compared to the dead ones. Within 5–7 days after the exposure to diquat, the skin lesions healed.

scholarly journals Boldness and behavioral syndromes in the bluegill sunfish, Lepomis macrochirus

2009 ◽  
Vol 20 (2) ◽  
pp. 231-237 ◽  
Author(s):  
Alexander D.M. Wilson ◽  
Jean-Guy J. Godin
Keyword(s):  
Lepomis Macrochirus ◽  
Behavioral Syndromes ◽  
Bluegill Sunfish

Effect of water temperature on stomach evacuation rates, and estimation of daily food intake of bluegill sunfish (Lepomis macrochirus Rafinesque)

1990 ◽  
Vol 68 (3) ◽  
pp. 591-595 ◽  
Author(s):  
D. J. Booth
Keyword(s):  
Food Intake ◽  
Water Temperature ◽  
Field Experiments ◽  
Lepomis Macrochirus ◽  
Stomach Contents ◽  
Bluegill Sunfish ◽  
Field Methods ◽  
Daily Food Intake ◽  
Evacuation Rate ◽  
Daily Food

Field experiments were conducted over the summer of 1983 to determine food-evacuation rate and measure stomach fullness of bluegill sunfish (Lepomis macrochirus). A combination of these data gave estimates of daily food intake of fish. Fish were captured and held in large holding pens in Lake Opinicon, Ontario, Canada, and periodically subsampled over 24 h to monitor changes in mean weight of stomach contents. Stomach-evacuation rates obtained in this way increased significantly with water temperature over the range 10–25 °C. However, variation in stomach-evacuation rate was considerable, reducing the utility of water temperature as a predictor of stomach-evacuation rate. It is suggested that the simple field methods employed here to estimate stomach evacuation and food intake are more useful in the estimation of daily ration than the more commonly employed laboratory-based methods.

Locomotor hyperactivity induced in the bluegill sunfish, Lepomis macrochirus, by sublethal concentrations of DDT

1977 ◽  
Vol 55 (7) ◽  
pp. 1077-1081 ◽  
Author(s):  
Erik G. Ellgaard ◽  
J. Coller Ochsner ◽  
J. Keith Cox
Keyword(s):  
Locomotor Activity ◽  
Tap Water ◽  
Lepomis Macrochirus ◽  
Quantitative Description ◽  
Control Fish ◽  
Bluegill Sunfish ◽  
Locomotor Hyperactivity ◽  
Sublethal Concentrations

A quantitative description of the effects of sublethal concentrations of DDT on the locomotor activity of the bluegill sunfish, Lepomis macrochirus, is presented. DDT-elicited hyperactive locomotor responses at all the concentrations examined (0.008, 0.01, 0.02, 0.04, 0.06, 0.08, 0.1, and 0.2 parts per billion (ppb)) and the degree of such responses were concentration dependent. Maximal effects at each concentration were observed within 8 days after addition of DDT to the environment. At their maxima, fish at 0.008 ppb were 1.3 times as active as control fish, whereas fish at 0.2 ppb were 3.0 times as active as controls. The effects of DDT on locomotor activity were not reversed even after the fish were transferred back into tap water for 2 weeks.

Nitrogen Excretion and Protein Consumption of the Bluegill Sunfish (Lepomis macrochirus)

1971 ◽  
Vol 28 (3) ◽  
pp. 449-451 ◽  
Author(s):  
J. Savitz
Keyword(s):  
Mathematical Description ◽  
Lepomis Macrochirus ◽  
Specific Dynamic Action ◽  
Nitrogen Excretion ◽  
Bluegill Sunfish ◽  
Protein Consumption ◽  
Dynamic Action ◽  
Excretion Rates

Nitrogen excretion rates increase with an increase in protein consumption levels. A mathematical description of this relation was formulated from the data. Estimates of the effect of specific dynamic action on nitrogen excretion were also calculated.

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