Method of Counting Tailbeats of Free-Swimming Fish by Ultrasonic Telemetry Techniques

1976 ◽  
Vol 33 (11) ◽  
pp. 2596-2598 ◽  
Author(s):  
A. B. Stasko ◽  
R. M. Horrall
Keyword(s):  
Swimming Speed ◽  
Doppler Effect ◽  
Continuous Wave ◽  
The Body ◽  
Ultrasonic Telemetry ◽  
Free Swimming ◽  
White Bass ◽  
Ultrasonic Signals ◽  
Morone Chrysops

Rhythmic beats in ultrasonic signals from free-swimming fish fitted with continuous-wave transmitters were noted during tracking of four species. Such signal beats corresponded with visually observed tailbeats of salmon and are presumed to have resulted from a Doppler effect due to undulations of the body and tail. The beats cannot be detected from pulsed transmitters. Tailbeat frequencies of white bass (Morone chrysops) were higher than those of salmon for the same swimming speed in body lengths per second.

Biological and Toxicologtcal Effects of Environmental Contaminants in Fish and Their Eggs

1983 ◽  
Vol 40 (3) ◽  
pp. 306-312 ◽  
Author(s):  
A. J. Niimi
Keyword(s):  
Rainbow Trout ◽  
Organic Contaminants ◽  
Yellow Perch ◽  
Survival Rates ◽  
Lake Ontario ◽  
Smallmouth Bass ◽  
Salmo Gairdneri ◽  
White Bass ◽  
Morone Chrysops ◽  
Contaminant Transfer

Rainbow trout (Salmo gairdneri), white sucker (Catostomus commersoni), white bass (Morone chrysops), smallmouth bass (Micropterus dolomieui), and yellow perch (Perca flavescens) were collected from Lakes Ontario and Erie to examine the relationship between contaminant levels in females and their eggs. Factors such as the percent lipid in the fish and percent of total lipid deposited in the eggs significantly influenced (P < 0.01) contaminant transfer. The percentages of the 9–11 organic contaminants transferred generally showed less variation within a species than the percentages for a substance transferred among the five species examined. This relationship was consistent even though there was over a 10-fold range in contaminant concentrations within a given species. Mercury did not demonstrate this response because the percentage in eggs was low for all species. The levels of PCB monitored in eggs of rainbow trout collected from Lake Ontario suggest that egg and fry survival rates could be affected based on the toxicological evidence from other studies. An examination of the possible effects of spawning on the kinetics of contaminants among these species suggests that relative body concentrations of organic contaminants may be decreased by 5% or be increased by 10%, and mercury levels may be increased by 6–22% following the deposition of eggs. The amount of change varies with species and is influenced by the percent egg weight of body weight, and the rate of contaminant transfer from females to eggs.Key words: toxicology, contaminants, reproduction, Lake Ontario, Lake Erie

Pectoral fin locomotion in the striped surfperch. I. Kinematic effects of swimming speed and body size

1996 ◽  
Vol 199 (10) ◽  
pp. 2235-2242 ◽  
Author(s):  
E Drucker ◽  
J Jensen
Keyword(s):  
Body Size ◽  
Swimming Speed ◽  
Beat Frequency ◽  
Limited Range ◽  
The Body ◽  
Small Fish ◽  
Large Fish ◽  
Pectoral Fin ◽  
Transition Speed ◽  
Speed Up

Swimming trials at increasing velocity were used to determine the effects of steady swimming speed on pectoral fin kinematics for an ontogenetic series of striped surfperch Embiotoca lateralis, ranging from 6 to 23 cm in standard length (SL). The fin stroke cycle consisted of a propulsive period, the duration of fin abduction and adduction, and a 'refractory' period, during which the fin remained adducted against the body. Pectoral fin-beat frequency (fp) measured as the inverse of the entire stride period, as in past studies, increased curvilinearly with speed. Frequency, calculated as the reciprocal of the propulsive period alone, increased linearly with speed, as shown previously for tail-beat frequency of fishes employing axial undulation. Fin-beat amplitude, measured as the vertical excursion of the pectoral fin tip during abduction, increased over a limited range of low speeds before reaching a plateau at 0.35&shy;0.40 SL. Pectoral fin locomotion was supplemented by intermittent caudal fin undulation as swimming speed increased. At the pectoral&shy;caudal gait transition speed (Up-c), frequency and amplitude attained maxima, suggesting that the fin musculature reached a physiological limit. The effects of body size on swimming kinematics differed according to the method used for expressing speed. At a given absolute speed, small fish used higher stride frequencies and increased frequency at a faster rate than large fish. In contrast, the relationship between fp and length-specific speed (SL s-1) had a greater slope for large fish and crossed that for small fish at high speeds. We recommend that comparisons across size be made using speeds expressed as a percentage of Up-c, at which kinematic variables influencing thrust are size-independent.

Kinematics and efficiency of steady swimming in adult axolotls (Ambystoma mexicanum)

1997 ◽  
Vol 200 (13) ◽  
pp. 1863-1871 ◽  
Author(s):  
K D'Août ◽  
P Aerts
Keyword(s):  
Swimming Speed ◽  
High Speed ◽  
Natural Habitat ◽  
Total Body Length ◽  
Ambystoma Mexicanum ◽  
The Body ◽  
Entire Body ◽  
Amplitude Profile ◽  
Wide Range ◽  
Tail Tip

The kinematics of steady swimming at a wide range of velocities was analysed using high-speed video recordings (500 frames s-1) of eight individuals of Ambystoma mexicanum swimming through a tunnel containing stationary water. Animals in the observed size range (0.135&shy;0.238 m total body length) prefer to swim at similar absolute speeds, irrespective of their body size. The swimming mechanism is of the anguilliform type. The measured kinematic variables &shy; the speed, length, frequency and amplitude (along the entire body) of the propulsive wave &shy; are more similar to those of anguilliform swimming fish than to those of tadpoles, in spite of common morphological features with the latter, such as limbs, external gills and a tapering tail. The swimming speed for a given animal size correlates linearly with the tailbeat frequency (r2=0.71), whereas the wavelength and tail-tip amplitude do not correlate with this variable. The shape of the amplitude profile along the body, however, is very variable between the different swimming bouts, even at similar speeds. It is suggested that, for a given frequency, the amplitude profile along the body is adjusted in a variable way to yield the resulting swimming speed rather than maintaining a fixed-amplitude profile. The swimming efficiency was estimated by calculating two kinematic variables (the stride length and the propeller efficiency) and by applying two hydrodynamic theories, the elongated-body theory and an extension of this theory accounting for the slope at the tail tip. The latter theory was found to be the most appropriate for the axolotl's swimming mode and yields a hydromechanical efficiency of 0.75&plusmn;0.04 (mean &plusmn; s.d.), indicating that Ambystoma mexicanum swims less efficiently than do anuran tadpoles and most fishes. This can be understood given its natural habitat in vegetation at the bottom of lakes, which would favour manoeuvrability and fast escape.

Mechanisms of helical swimming: asymmetries in the morphology, movement and mechanics of larvae of the ascidian Distaplia occidentalis

2001 ◽  
Vol 204 (17) ◽  
pp. 2959-2973 ◽  
Author(s):  
Matthew J. McHenry
Keyword(s):  
Body Shape ◽  
Three Dimensional ◽  
The Body ◽  
Hydrodynamic Theory ◽  
Helical Motion ◽  
Body Rotation ◽  
Oblique Angle ◽  
Free Swimming ◽  
Three Point Bending ◽  
And Control

SUMMARY A great diversity of unicellular and invertebrate organisms swim along a helical path, but it is not well understood how asymmetries in the body shape or the movement of propulsive structures affect a swimmer’s ability to perform the body rotation necessary to move helically. The present study found no significant asymmetries in the body shape of ascidian larvae (Distaplia occidentalis) that could operate to rotate the body during swimming. By recording the three-dimensional movement of free-swimming larvae, it was found that the tail possessed two bends, each with constant curvature along their length. As these bends traveled posteriorly, the amplitude of curvature changes was significantly greater in the concave-left direction than in the concave-right direction. In addition to this asymmetry, the tail oscillated at an oblique angle to the midline of the trunk. These asymmetries generated a yawing moment that rotated the body in the counterclockwise direction from a dorsal view, according to calculations from hydrodynamic theory. The tails of resting larvae were bent in the concave-left direction with a curvature statistically indistinguishable from the median value for tail curvature during swimming. The flexural stiffness of the tails of larvae, measured in three-point bending, may be great enough to allow the resting curvature of the tail to have an effect on the symmetry of kinematics. This work suggests that asymmetrical tail motion is an important mechanism for generating a yawing moment during swimming in ascidian larvae and that these asymmetries may be caused by the tail’s bent shape. Since helical motion requires that moments also be generated in the pitching or rolling directions, other mechanisms are required to explain fully how ascidian larvae generate and control helical swimming.

The Physics of Ultrasound

2018 ◽  
Author(s):  
Gerry van Rensburg ◽  
Andrew Smith ◽  
Ben O’Brien
Keyword(s):  
Continuous Wave ◽  
Imaging Modality ◽  
Doppler Frequency ◽  
Daily Practice ◽  
The Body ◽  
Ultrasound Images ◽  
Plain Language ◽  
Color Flow ◽  
Continuous Wave Doppler ◽  
Physical Principles

Clinical ultrasound has attained significant importance for the practising anesthesiologist. Its applications reach far and wide in anatomic and physiologic diagnosis, and it is a powerful adjunct for guiding interventional procedures. This article describes the physical principles that allow for the generation of ultrasound, its transmission and reflection from within the body, and generation of the ultrasound images used in daily practice. We not only review definitions of important technical terms but also provide synonyms in plain language, as jargon often presents a barrier to grasping basic and fundamental principles. Furthermore, we review the mathematical and physical principles that facilitate the generation of Doppler modes, such as pulsed wave, continuous wave, color flow. Clinically safe practice requires that all data be interpreted in the light of the technology’s shortcomings; we additionally review the common pitfalls and artifacts encountered in the use of this imaging modality. This review contains 16 figures, 1 table, and 5 references. Keywords: attenuation, continuous wave Doppler, Doppler, frequency, imaging artefacts, physics, pulsed-wave Doppler, ultrasound

scholarly journals Acute Stress Causes Skin Ulceration in Striped Bass and Hybrid Bass (Morone)

1998 ◽  
Vol 35 (2) ◽  
pp. 102-107 ◽  
Author(s):  
E. J. Noga ◽  
S. Botts ◽  
M.-S. Yang ◽  
R. Avtalion
Keyword(s):  
Striped Bass ◽  
Acute Stress ◽  
Infectious Agent ◽  
Distal Portion ◽  
The Body ◽  
Similar Response ◽  
Morone Chrysops ◽  
Skin Ulceration ◽  
Serious Infections ◽  
Stromal Tissue

Exposure of striped bass ( Morone saxatilis) and hybrid bass ( M. saxatilis female x Morone chrysops male) to an acute (2-hour) confinement stress caused skin ulceration on the fins but not on the body of all confined fish. Striped bass displayed more severe lesions than did hybrid bass. Histologically, lesions had varying degrees of epithelial erosion and ulceration, which was most severe at the distal portion of the fins. Ulceration was associated with dermal and hypodermal edema and necrosis of the remaining stromal tissue and tips of bone in the fin rays. No hemorrhage or thrombosis was present to suggest any obvious vascular derangement. No evidence was found for either trauma or an infectious agent initiating the lesions. Injecting fish with epinephrine caused a similar response, although the degree of ulceration was less severe. These findings may explain why many opportunistic skin pathogens can rapidly develop into serious infections in fish.

Synchronous changes in length at maturity across four species of Lake Erie fish with different harvest histories

2021 ◽  
Author(s):  
Davíð Gíslason ◽  
Robert L. McLaughlin ◽  
Beren W Robinson
Keyword(s):  
Yellow Perch ◽  
Lake Erie ◽  
Large Scale ◽  
White Perch ◽  
Water Levels ◽  
White Bass ◽  
Morone Chrysops ◽  
Harvest Intensity ◽  
Ecosystem Changes ◽  
Post Hoc

Decreases in size at maturation in harvested fish populations can reduce productivity and resilience. Delineating the causes for these changes in maturation is challenging. We assessed harvest and large-scale ecosystem variability as causes for changes in maturation in four Lake Erie fishes. Regulated harvests of Yellow Perch (Perca flavescens) and Walleye (Sander vitreus) are greater than unregulated harvests of White Perch (Morone americana) and White Bass (Morone chrysops). Our assessment considered cohort data from 1991-2012 for each species. We used a conceptual model of harvest-induced plasticity to show that changes in female length at 50% maturity (L50) were unrelated to harvest intensity in all species. We then demonstrated that changes in female L50 among cohorts were synchronous across species. Post-hoc analysis of variables capturing year-to-year variation in climatic and lake conditions suggested L50 was larger when water levels were near the norm for the study period and smaller at low and high levels. We conclude that changes in L50 were most strongly related to ecosystem changes unrelated to harvest intensity.

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