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PubMed1995

[Swimming-induced asthma].

Swimming is said to have low asthmogeneity especially when compared with other physical activities. Four young athletes who participated in heavy swimming exercise are reported as having symptoms of exercise-induced asthma (EIA). Three of them started to develop the symptoms after several years of training and had no former history of asthma. In the fourth, the asthma was diagnosed in childhood but the EIA-symptoms here exacerbated by swimming. All four experienced more symptoms when the air in the swimming pool was warm, or when there was a strong smell of chlorine. Two of the athletes reported having no symptoms when they swam in outdoor pools and had only minor symptoms, or none at all, when they did other formes of physical exercise, including running. In all four their swimming performance was hampered by their respiratory symptoms. Two of the swimmers improved when they inhaled steroids and adrenerg-beta 2 agonists, and continued their swimming carrier. The cases suggest that an irritant may provoke asthma symptoms in susceptible swimmers. Volatile compounds from chlorination of the pools are suspected as possible irritant agents.

Adolescent↗
PubMed1994

Swimming and grommets: a prospective survey.

AIM: To assess the incidence of otorrhoea after swimming in patients with grommets in situ, and discover whether protecting the ears from water affects this occurrence. METHODS: A group of children with bilateral patent grommets were allowed to swim with head under the water with one ear protected, and the other unprotected from water entry. Using a calendar system, each swim was recorded and each episode of otalgia or otorrhoea occasioning medical consultation was recorded with the outcome of the consultation. RESULTS: Nineteen children completed the survey taking a total of 551 swims with head immersion. One child suffered bilateral otorrhoea one day after a swim. There were three episodes of otalgia sufficiently severe to warrant medical consultation. Two occurred in a protected ear and one in an unprotected ear. On each occasion there was no evidence of infection. CONCLUSIONS: There appears to be a low incidence of otorrhoea during summer in children who swim with grommets in situ. There is no evidence that protecting the ears from water entry confers any benefit as far as preventing infection in concerned.

Adolescent↗
PubMed1994

Effect of swimming exercise and ethanol on rat liver P450-dependent monooxygenases.

The interactive effects of 6 wk of repeated swimming exercise and chronic ethanol consumption (36% of total calories) on the hepatic cytochrome P450-dependent monooxygenase system were studied utilizing four groups of male rats in a 2 x 2 factorial design. The sedentary-control (S/C), sedentary-ethanol (S/E), and swim-control (SW/C) groups received the same amount of food that the swim-ethanol (SW/E) group consumed. The swimming groups were trained to swim for 2 h.d-1, 5 d.wk-1. Significant main effects due to ethanol (P < 0.002) and exercise (P < 0.02) were observed for the enhanced cytochrome P450 content and cytochrome P450 reductase activity, respectively. In addition, significant main effects for ethanol (P < 0.001), exercise (P < 0.0001), and significant interaction effects (P < 0.005) on aniline p-hydroxylase activity and significant main effects for ethanol (P < 0.01), exercise (P < 0.01), and interaction effects (P < 0.04) on 7-ethoxycoumarin o-deethylase activity were observed. Because the SW/C treatment had no effect on any of the measured cytochrome P450 activities and the SW/E treatment enhanced P450 activities much more than the S/E treatment, the main effects observed for exercise are accounted for by the alterations produced by combining swimming with the ethanol treatment. Based on these results, repeated exercise combined with ethanol consumption produces a synergistic increase in ethanol-inducible cytochrome P450-dependent activities.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1994

Swimming and grommets.

BACKGROUND: Traditionally, children with tympanostomy ventilating tubes, or grommets, were advised that water should not enter their ears in order to prevent ear infections. This group of children has been considered somewhat handicapped regarding swimming. We conducted a prospective study to determine if there is a relation between suppurative otitis media and surface swimming in children with grommets. METHODS: Forty-two children with tympanostomy ventilating tubes were included in this study. Of the 42 children, 22 were swimmers and 20 were nonswimmers, who served as the control group. The age range was 3 to 12 years, and there was no difference in the age distribution between the groups. Surface swimming was allowed without earplugs or a bathing cap, although it was mandatory to use polymyxin B-neomycin-hydrocortisone eardrops at bedtime on the day of swimming. No diving was allowed. RESULTS: Three of 22 swimmers and 2 of 20 nonswimmers developed otorrhea. In 4 of the 5 children, the otorrhea was followed by an upper respiratory tract infection. In all cases, a bacterial culture revealed Pseudomonas. The ear drainage was easily controlled with local otic treatment in all the patients. CONCLUSIONS: Taking into consideration the possible risks of infection and bearing in mind the value and joy of swimming to children and parents, families should be reassured that surface swimming does not increase the risk of infection in children with tympanostomy tubes.

Animals↗
PubMed1993

Relationships among swimming performance, body composition and somatotype in competitive collegiate swimmers.

Relationships were determined between sprint swimming performance and estimates of body composition and somatotype components in competitive collegiate swimmers. Forty-three women and 31 men underwent anthropometric and hydrodensitometric measurements at the beginning of a competitive season. There were significant partial correlations (swim stroke was partialed out) between swimming performance (time in a competitive 100-yard swim of each swimmer's major competitive stroke) and height (-0.466, p < 0.01), the mesomorphic (0.404, p < 0.01) and ectomorphic (-0.398, p < 0.01) components of somatotype, percent body fat (0.351, p < 0.05), and fat-free weight (-0.332, p < 0.05) among the women, but no significant correlations among the men. Twenty-three of the women and 21 of the men were also measured and timed at the end of the competitive season. Again, there were significant (p < 0.01) partial correlations (season and stroke were partialed out) between swimming performance and height (-0.766), fat-free weight (-0.657), body weight (-0.437), and the ectomorphic (-0.441) and mesomorphic (0.392, p < 0.01) components of somatotype in women, but no significant correlations among the men. These findings indicate that measurements of body composition and somatotype may be predictors of swimming performance in women but not in men.

Adipose Tissue↗
PubMed1998

[The effect of SDS, sodium dodecyl sulfate, on the metabolism and swimming capacity of Cyprinus carpio].

Synthetic agents are important sources of pollution in Brazil, especially in the large urban centers. Of these, SDS has been largely employed as a reference substance in toxicity tests with aquatic organisms. Studies on the effect of this substance on the physiology and behavior of fish are scanty. In this study the metabolism and swimming capacity of Cyprinus carpio, at a given swimming velocity (10.15 cm/sec), were analyzed in relation to acute exposition to different concentrations of SDS (1 ppm, 5 ppm, 10 ppm). The metabolism and swimming capacity of a fish are the product of many integrated complex physiological processes that can be directly related to variations in environmental conditions. The results show that oxygen consumption increases while swimming capacity decreases with increasing concentrations of SDS in all size classes studied. At the highest concentration employed (10 ppm), swimming capacity was reduced 5 times and oxygen consumption increased 2.8 times in relation to the control. In general, the pollutant effects on swimming activity are more pronounced in smaller fish whereas the effects on oxygen consumption is more pronounced in larger ones.

Analysis of Variance↗
PubMed1998

Swimming kinematics and respiratory behaviour of Xenopus laevis larvae raised in altered gravity.

We examined the respiratory behaviours and swimming kinematics of Xenopus laevis tadpoles hatched in microgravity (Space Shuttle), simulated microgravity (clinostat) and hypergravity (3 g centrifuge). All observations were made in the normal 1 g environment. Previous research has shown that X. laevis raised in microgravity exhibit abnormalities in their lungs and vestibular system upon return to 1 g. The tadpoles raised in true microgravity exhibited a significantly lower tailbeat frequency than onboard 1 g centrifuge controls on the day of landing (day0), but this behaviour normalized within 9 days. The two groups did not differ significantly in buccal pumping rates. Altered buoyancy in the space-flight microgravity tadpoles was indicated by an increased swimming angle on the day after landing (day1). Tadpoles raised in simulated microgravity differed to a greater extent in swimming behaviours from their 1 g controls. The tadpoles raised in hypergravity showed no substantive effects on the development of swimming or respiratory behaviours, except swimming angle. Together, these results show that microgravity has a transient effect on the development of locomotion in X. laevis tadpoles, most notably on swimming angle, indicative of stunted lung development. On the basis of the behaviours we studied, there is no indication of neuromuscular retardation in amphibians associated with embryogenesis in microgravity.

Animals↗
PubMed1998

Prepulse inhibition of the Tritonia escape swim.

Presenting a weak stimulus just before a strong, startle stimulus reduces the amplitude of the ensuing startle response in humans and other vertebrates. This phenomenon, termed "prepulse inhibition" (PPI), appears to function to reduce distraction while processing sensory input. To date, no detailed neural mechanism has been described for PPI. Here we demonstrate PPI in the marine mollusk Tritonia diomedea, which has a nervous system highly suitable for cellular analyses. We found that a 100 msec vibrotactile prepulse prevented the animal's escape swim response to a closely following 1 sec tail shock. This inhibition was highly transient, with a significant effect lasting just 2.5 sec. These findings indicate that the Tritonia escape swim response undergoes a form of PPI phenomenologically similar to that observed in vertebrates. Further tests showed that the vibrotactile stimulus had no inhibitory effect if applied after tail shock, while the animal was preparing to swim, but it acted to terminate swims once they were actively under way. As a first step toward a cellular analysis of PPI, we recorded from neurons of the swim circuit in a semi-intact preparation and found that the vibrotactile stimulus used in the behavioral experiments also prevented the tail shock-elicited swim motor program. These results represent the first explicit demonstration of PPI in an invertebrate and establish Tritonia as a model system for analyzing its physiological basis.

Action Potentials↗
PubMed1998

Comparative kinematics and hydrodynamics of odontocete cetaceans: morphological and ecological correlates with swimming performance.

Propulsive morphology and swimming performance were compared for the odontocete cetaceans Delphinapterus leucas, Orcinus orca, Pseudorca crassidens and Tursiops truncatus. Morphological differences were apparent among the whales. The general body contour and low-aspect-ratio caudal flukes of D. leucas indicated that this species was a low-performance swimmer compared with the other species. Propulsive motions were video-taped as animals swam steadily in large pools. Video tapes were analyzed digitally using a computerized motion-analysis system. Animals swam at relative velocities ranging from 0.4 to 2.4 body lengths s-1. The stroke amplitude of the flukes decreased linearly with velocity for D. leucas, but amplitude remained constant for the other species. Tail-beat frequencies were directly related to relative swimming velocity, whereas the pitch angle of the flukes was inversely related to relative swimming velocity. Unsteady lifting-wing theory was used with regression equations based on kinematics to calculate thrust power output, drag coefficients and propulsive efficiency. Compared with other species, O. orca generated the largest thrust power (36.3 kW) and had the lowest drag coefficient (0.0026), whereas T. truncatus displayed the largest mass-specific thrust power (23.7 W kg-1) and P. crassidens had the highest efficiency (0.9). D. leucas did not swim as rapidly as the other species and had a comparatively higher minimum drag coefficient (0.01), lower mass-specific thrust power (5.2 W kg-1) and lower maximum efficiency (0.84). Minimum drag coefficients were associated with high swimming speeds, and maximum efficiencies corresponded with velocities in the range of typical cruising speeds. The results indicate that the kinematics of the propulsive flukes and hydrodynamics are associated with the swimming behaviors and morphological designs exhibited by the whales in this study, although additional factors will influence morphology.

Animals↗
PubMed2001

Swimming characteristics of magnetic bacterium, Magnetospirillum sp. AMB-1, and implications as toxicity measurement.

To develop a novel toxicity measurement system using the persistent swimming property of magnetic bacteria along an externally applied magnetic field, certain characteristics of Magnetospirillum sp. AMB-1 cells were examined, including their growth pattern, motility, magnetosensitivity, swimming speed, and cell length distribution. In addition, the effect of toxic compounds on the swimming speed was assessed relative to application as a toxicity sensor. With an inoculum of 1.0 x 10(8) cells/mL, the cells reached the stationary phase with a concentration of about 5 x 10(8) cells/mL after 20 h, under both aerobic and anaerobic conditions. The distribution of the cell length did not vary significantly during the growth period, and both aerobically and anaerobically growing cells showed a similar cell length distribution. Although the cells showed similar growth patterns under both conditions, the anaerobically grown cells exhibited higher motility and magnetosensitivity. Actively growing cells under anaerobic conditions had an average swimming speed of 49 microm/s with a standard deviation of 20 microm/s. When the anaerobically growing cells were exposed to various concentrations of toxic compounds, such as 1-propanol and acetone, the swimming speed decreased with an increased concentration of the toxic compound. Accordingly, the relationship between swimming speed and toxicity can be used as an effective quantitative toxicity measurement; furthermore, the relative sensitivity of the proposed system was comparable to Microtox, which is commercially available.

1-Propanol↗
PubMed1993

Antimalarial drugs inhibit calcium-dependent backward swimming and calcium currents in Paramecium calkinsi.

The antimalarial drugs, quinacrine, chloroquine, quinine, primaquine, and mefloquine, share structural similarities with W-7, a compound that inhibits calcium-dependent backward swimming and calcium currents in Paramecium. Therefore, we tested whether antimalarial drugs also inhibit backward swimming and calcium currents in P. calkinsi. When the Paramecium is depolarized in high potassium medium, voltage-dependent calcium channels in the ciliary membrane open causing the cell to swim backward for 30 to 70 s. Application of calcium channel inhibitors, such as W-7, reduce the duration of backward swimming. In 0.05 mM calcium, quinacrine, mefloquine, quinine, chloroquine, primaquine and W-7 all reduced the duration of backward swimming. These effects were seen in sodium-containing and sodium-free high potassium solutions as well as sodium-free depolarizing solutions containing potassium channel blockers. In these low calcium solutions, backward swimming was inhibited by 50% at concentrations ranging from 100 nM to 30 microM. At higher calcium concentrations (1 mM or 15 mM), the effects of the antimalarials and W-7 were reduced. The effects of quinacrine and W-7 were tested directly on calcium currents using the two microelectrode voltage clamp technique. In 15 mM calcium, 100 microM quinacrine and 100 microM W-7 reduced the peak calcium current by 51% and 42%, respectively. Thus, antimalarial drugs reduce calcium currents in Paramecium calkinsi.

Animals↗
PubMed1995

Comparison between a two-layer discontinuous Percoll gradient and swim-up for sperm preparation on normal and abnormal semen samples.

PURPOSE: This work was to compare the effects of Percoll gradient and swim-up treatments for sperm preparation on the percentage of progressive motility, recovery of motile sperm, removal of debris, percentage of normal forms according to strict criteria, and movement characteristics of sperm using computer-assisted velocity analysis. RESULTS: In total, 50 semen samples from 50 patients were tested and divided into two groups: a normal group (n = 27) with normal parameters and an abnormal group (n = 23) with abnormal parameters. The results in both the normal and abnormal groups revealed that the sperm concentration in the Percoll samples was significantly greater than that in the swim-up samples. Although the percentage of progressive motility was greater in the swim-up samples than in the Percoll samples, the number of motile sperm, reflecting the percentage of motile sperm recovery, was till greater in the Percoll samples. The debris of semen was equally removed by both methods and the percentage of normal forms was also similar in the samples treated according to these two procedures. Both curvilinear velocity (VCL) and straight-line velocity (VSL) of sperm were significantly greater in the swim-up samples than in the Percoll samples. Sperm from the swim-up procedure also showed a greater mean amplitude of lateral head displacement than that from the Percoll gradient procedure, but the distinction was insignificant. CONCLUSION: The Percoll gradient technique, by recovering more motile sperm, may be applied to prepare oligospermic samples. The swim-up method may become the standard choice to prepare normal semen which could obtain sufficiently motile sperm, due to its simplicity and recovered sperm with superior motility.

Centrifugation, Density Gradient↗
PubMed1995

Effect of bovine sperm separation by either swim-up or Percoll method on success of in vitro fertilization and early embryonic development.

The objectives of these experiments were to characterize separation of frozen-thawed bovine spermatozoa on a Percoll gradient and then to compare sperm separation by either a swim-up or Percoll gradient procedure for the ability of spermatozoa to fertilize oocytes in vitro. The Percoll gradient was a 45 and 90% discontinuous gradient. Initial experiments found that centrifugation of semen on the Percoll gradient for 15 min at 700 g was sufficient to obtain optimal recovery of motile spermatozoa. Most of the nonmotile spermatozoa were recovered at the interface of the 45 and 90% Percoll layers, while the motile spermatozoa were primarily in the sperm pellet at the bottom of the gradient. When frozen-thawed semen from each of 7 bulls was separated by swimup, a mean +/- SEM of 9% +/- 1 of the motile spermatozoa were recovered after the procedure. In contrast, more spermatozoa were recovered after Percoll gradient separation (P < 0.05), with 40% +/- 4 of the motile spermatozoa recovered. The effect of separation procedure on in vitro fertilization found swim-up separated spermatozoa penetrated a mean +/- SEM of 74% +/- 5 of the oocytes, while fewer oocytes were penetrated by Percoll separated spermatozoa at 52% +/- 8 (P < 0.05). There was no effect of the separation procedure on the rates of polyspermy as measured by sperm/penetrated ova, with a mean +/- SEM of 1.25 +/-.09 for swim-up separated spermatozoa and 1.14 +/-.07 for Percoll separated spermatozoa (P>0.05). A carry over of Percoll into the fertilization medium with the Percoll separated spermatozoa was found not the cause for the decreased penetration of oocytes by these spermatozoa. In 2 of 3 bulls tested, the decreased penetration of oocytes by Percoll separated spermatozoa could be overcome by increasing the sperm concentration during fertilization from 1 x 10(6) to 5 x 10(6)/ml. When development of embryos fertilized by either swim-up or Percoll separated spermatozoa was compared for the semen from 2 bulls, a difference in cleavage rate was found in favor of swim-up separated spermatozoa (P < 0.05), but there was no effect of separation procedure on development (Day 7) to the morula + blastocyst or blastocyst stage (P>0.05). The disadvantages of the Percoll procedure could easily be overcome and the procedure was faster and yielded a six-fold greater recovery of motile spermatozoa than the swim-up method.

Journal Article↗
PubMed1987

Semen quality before and after processing by a swim-up method: relationship to outcome of intrauterine insemination.

Twenty-five couples with normal semen analyses and postcoital tests of less than or equal to 3 motile sperm/high-power field were treated by intrauterine insemination (IUI) with sperm prepared by a swim-up method. Eight women conceived (32%). Influence of semen parameters both before and after swim-up, patient age, and duration of infertility on outcome of IUI was assessed with logistic discriminant analysis. The percent motility of sperm after swim-up allowed significant differentiation of pregnant and nonpregnant patients (P = 0.0009). For patients with greater than 79% motility after swim-up, discrimination provided by post-swim-up motility (P = 0.0063) was enhanced by inclusion in the analysis of either total number of motile sperm used for insemination (P = 0.0021) or sperm concentration after swim-up (P = 0.0019), Predictions of nonpregnancy and pregnancy were correct at rates of 93.3 and 70%, respectively. There were no significant differences between semen parameters of conception and nonconception cycles of patients who conceived.

Female↗
PubMed2000

An analysis of swimming performance in the Norway lobster, Nephrops norvegicus L. infected by a parasitic dinoflagellate of the genus Hematodinium.

Various components of swimming performance were measured in uninfected Norway lobsters (Nephrops norvegicus) and compared to animals at different stages of infection by a parasitic dinoflagellate (Hematodinium sp.). Animals showed a progressive decline in overall swimming performance as infection severity increased, with reductions in the number of tail-flips performed, the number of swimming bouts and the total distance travelled by swimming. The velocity of the first (giant-fibre mediated) tail flip and average velocity over the swimming bout were also significantly reduced in infected lobsters. Possible reasons for this decreased swimming performance are suggested and the implications of this for predator avoidance of infected lobsters in the benthic habitat, and for capture of Nephrops by trawl rigs are discussed.

Journal Article↗
PubMed1992

Improvement in semen quality and sperm fertilizing ability after filtration through the L4 membrane: comparison of results with swim up technique.

The L4 filtration membrane was used at our laboratory on 30 semen specimens (19 from suspected subfertile patients and 11 from fertile donors) to assess changes in semen quality after routine sperm washing and swim up versus filtration through the L4 membrane. Of these 30 samples 17 (11 suspected subfertile patients and 6 fertile donors) were chosen to evaluate differences in sperm fertilizing ability between the 2 sperm preparation methods. Liquified specimens were analyzed on a Cell Soft semen analyzer. Semen specimens were divided equally, and 1 aliquot was processed by sperm washing and the swim up technique and the other by filtration. In all subjects the results of semen analysis and the hamster-egg penetration test showed significant improvement in sperm quality and fertilizing ability after filtration through the L4 membrane. Sperm motility was 58% after the swim up technique compared to 79% after filtration (p less than 0.0001) and velocity was 47 mu. per second after the swim up method compared to 52 mu. per second after filtration (p less than 0.048). Penetration rate and penetration index also showed a significant increase after filtration over values for the swim up method. Our results demonstrate that sperm filtration through the L4 membrane provides results superior to those of the traditional swim up technique. Due to significant savings in time associated with its use the L4 membrane can be used during sperm processing for intrauterine insemination and in vitro fertilization procedures.

Female↗
PubMed2002

Amplified behavioral and endocrine responses to forced swim stress in the Wistar-Kyoto rat.

The Wistar Kyoto (WKY) rat may be a useful model for the study of depressive behavior because they exhibit exaggerated responses to a number of stressors. These studies compared the behavioral and endocrine responses to swimming stress in WKY rats with Sprague-Dawley (SD) rats. In the first experiment, the onset of behavioral immobility and the endocrine stress responses (adrenocorticotropin hormone (ACTH) and corticosterone (CORT)) were examined as the duration of a swimming session was increased. In the second experiment, WKY and SD rats were swum for 15 min, then sacrificed at different intervals after completion of the swim, to examine the time course of endocrine stress responses. The final experiment compared the suppression of ACTH and CORT secretion by dexamethasone of peak diurnal ACTH and CORT levels in WKY and SD rats. Behaviorally, the WKY rats displayed early and prolonged immobility compared to SD rats regardless of the length of the swim stress. Plasma CORT and ACTH increased in WKY and SD rats as the duration of the stressor lengthened. The swim stress (15 min) produced higher levels of ACTH and CORT secretion at the end of the stress interval that persisted after termination of the stressor in WKY compared to SD rats. Peak diurnal CORT levels, but not ACTH levels, were higher in WKY than in SD rats. Dexamethasone suppressed ACTH levels less in WKY than in SD rats. These results indicate that the WKY rat that displays increased behavioral immobility also demonstrates exaggerated secretion of stress hormones during swimming stress, and the results may be due, in part, to reduced sensitivity of glucocorticoid receptors that supply negative feedback to the hypothalamic-pituitary-adrenal axis. The exaggerated behavioral and endocrine stress responses in the WKY rat support its potential usefulness as a model for studying stress-evoked depressive behavior.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

The origin and evolution of the surfactant system in fish: insights into the evolution of lungs and swim bladders.

Several times throughout their radiation fish have evolved either lungs or swim bladders as gas-holding structures. Lungs and swim bladders have different ontogenetic origins and can be used either for buoyancy or as an accessory respiratory organ. Therefore, the presence of air-filled bladders or lungs in different groups of fishes is an example of convergent evolution. We propose that air breathing could not occur without the presence of a surfactant system and suggest that this system may have originated in epithelial cells lining the pharynx. Here we present new data on the surfactant system in swim bladders of three teleost fish (the air-breathing pirarucu Arapaima gigas and tarpon Megalops cyprinoides and the non-air-breathing New Zealand snapper Pagrus auratus). We determined the presence of surfactant using biochemical, biophysical, and morphological analyses and determined homology using immunohistochemical analysis of the surfactant proteins (SPs). We relate the presence and structure of the surfactant system to those previously described in the swim bladders of another teleost, the goldfish, and those of the air-breathing organs of the other members of the Osteichthyes, the more primitive air-breathing Actinopterygii and the Sarcopterygii. Snapper and tarpon swim bladders are lined with squamous and cuboidal epithelial cells, respectively, containing membrane-bound lamellar bodies. Phosphatidylcholine dominates the phospholipid (PL) profile of lavage material from all fish analyzed to date. The presence of the characteristic surfactant lipids in pirarucu and tarpon, lamellar bodies in tarpon and snapper, SP-B in tarpon and pirarucu lavage, and SPs (A, B, and D) in swim bladder tissue of the tarpon provide strong evidence that the surfactant system of teleosts is homologous with that of other fish and of tetrapods. This study is the first demonstration of the presence of SP-D in the air-breathing organs of nonmammalian species and SP-B in actinopterygian fishes. The extremely high cholesterol/disaturated PL and cholesterol/PL ratios of surfactant extracted from tarpon and pirarucu bladders and the poor surface activity of tarpon surfactant are characteristics of the surfactant system in other fishes. Despite the paraphyletic phylogeny of the Osteichthyes, their surfactant is uniform in composition and may represent the vertebrate protosurfactant.

Air Sacs↗