Fish Swimbladder Research Articles

The permeability to oxygen and the guanine content of the swimbladder of a physoclist fish,Pollachius virens

Moreau (1876), Bohr (1894), and Fänge (1953) are among those authors who have demonstrated that the swimbladder walls of certain fish are highly impermeable to gases. This property assists in the maintenance of high partial pressures of gases in the swim-bladder and enables physoclist fish to use the swimbladder as a buoyancy mechanism, often at great depth. It has been shown experimentally that the swimbladder contains a high percentage of oxygen (Fänge, 1953; Kanwisher & Ebeling, 1957) and that this percentage increases with depth in most fish (Scholander & Van Dam, 1953; Scholander, 1954). Diffusion of gas through a tissue increases with increasing partial pressure difference across the tissue (Krogh, 1919). This may be as high as 10–20 atm in inshore gadoids such as the saithe,Pollachius virens(L.) or 50–60 atm in mesopelagic fish (Kanwisher & Ebeling, 1957). Thus low permeability to oxygen is required if the swimbladder is to be used as a buoyancy mechanism at any depth.

Swim-bladder surfactants of Amazon air-breathing fishes

Minimum surface tension and phospholipid composition of fish lung and swim-bladder wash and tissue extract were determined on an obligate water breather, Hoplias malabaricus, two species of facultative air breathers, Hoplerythrinus unitaeniatus and Erythrinus erythrinus, and two species of obligate air breathers, Arapaima gigas and Lepidosiren paradoxa. In addition, lung tissue slices were incubated with [1-14C]acetale and [1-14C]palmitate.All lung and swim-bladder wash lipid extracts showed a minimum surface tension of 20–25 dyn/cm (1 dyn = 10 μN). The principle phospholipid of all species is phosphatidylcholine; no phosphatidylglycerol was detected in any sample.The two obligate air breathers had higher rates of incorporation of isotope in tissue slices than facultative air breathers and nonair breathers. This observation correlates well with the greater vascular supply to their lungs.The phospholipid patterns of these fishes are significantly different from those of mammals. We speculate that these lipids recovered from saline wash may not be important in the maintenance of lung stability. Perhaps their function is keeping water from leaking into the lung and swim bladder.

Membrane biosynthesis in swimbladders of deep sea fishes Coryphaenoides acrolepis and Antimora rostrata

1. 1. Excised tunica interna from the swimbladder of an abyssal fish ( Coryphaenoides acrolepis) incorporated acetate-1- 14C and squalene-4- 3H into membrane lipids, cholesterol, phosphatidyl ethanolamine, phosphatidylcholine, cardiolipin, and to a lesser extent sphingomyelin. 2. 2. Ultrastructural study of the tunica interna of the swimbladder of another abyssal fish ( Antimora rostrata) revealed large cytoplasmic vacuoles lined and filled with “bilayer” membrane. 3. 3. The membrane-lined vacuoles in the tunica interna cells may be an assembly point for the biosynthesis of the gram quantities of pure “bilayer” membrane found on the interior of the swimbladder.

Vegetalising factor extracted from the fish swimbladder and tested on presumptive ectoderm ofTriturus embryos.

Vegetalising factor was isolated from swimbladder of crusian carp (Carassius auratus) by solubilishing with 8 M urea the precipitate obtained after digesting the swimbladder with collagenase. The urea-soluble fraction vegetalised isolated presumptive ectoderm ofTriturus gastrula and produced both undifferentiated mesodermal and endodermal cells. Brief heating of the fraction changed its capacity to produce organised mesodermal tissues, such as notochord and somite, and the frequency of induction of undifferentiated cells was reduced. By inserting the urea-soluble fraction into the blastocoel of an early gastrula, embryos without epidermis were obtained. Some of the embryos consisted of undifferentiated mesodermal and endodermal cells, but in the remaining ones small fragments of notochord, small numbers of somites and pronephros developed, enclosed by endodermal cells.

Fish swimbladder: an excellent mesodermal inductor in primary embryonic induction

Swimbladder of the crucian carp, Carassius auratus, was found to be better as a vegatalizing tissue than other tissues, such as guinea-pig bone marrow, when presumptive ectoderm of Triturus gastrulae was used as reacting tissue. Swimbladder usually induced assemblies of highly organized mesodermal tissues, such as notochord, somites and pronephric tubules, some of which were covered by mesodermal epithelium without any epidermal covering. A special character of the effect of swimbladder was the rather frequent induction of solid balls of undifferentiated cells, which were identified as mesodermal or mesodermal and probably endodermal. These findings show that swimbladder has a strong and fast spreading vegetalizing effect on the responding presumptive ectoderm.

Biological sound scattering in the oceans: A review

An Office of Naval Research‐sponsored conference was held in November 1975 to determine approaches to predicting volume reverberations based upon physicochemical, biological, acoustic, and modeling considerations. Review papers were presented in plenary session for each disciplinary area, after which working groups were convened to assess current understanding, review problems, and prepare recommendations. This paper is the substance of the review given in plenary session on biacoustic aspects of sound scattering. Biological backscattering is frequency dependent, and varies with depth, time of day, season, and area. Both resonant and nonresonant scattering effects are involved. Gas‐filled swimbladders of mesopelagic fishes dominate resonant effects, especially at frequencies below about 30 kHz, although these fishes and many others may contribute as well to nonresonant, geometric scattering, depending upon acoustic wavelength. At higher frequencies (40–300 kHz), various zooplankton groups are discernible using single‐frequency sources. Column scattering‐strength spectra over the range from about 1–20 kHz show definite patterns and variations which are relatable to oceanographically and biologically defined regions in the oceans.

The permeability to oxygen of the swimbladder of the mesopelagic fish Ceratoscopelus maderensis

The permeability to oxygen of the swimbladder of physoclistous fish is important because of the usually high oxygen content of the bladder. The oxygen permeability and guanine content of the swimbladder wall of the mesopelagic myctophid Ceratoscopelus maderensis (Lowe) were measured. The oxygen permeability was 0.0672 cm3 μm/atm min cm2 and the guanine content was 73 μg/cm2. Attention is drawn to the high rates of gas loss which would occur from a swimbladder with these characteristics and the problems of maintaining the gas content, especially at depth.

Lipid synthesis by Antimora rostrata, an abyssal codling from the Kona coast

1.1. Antimora rostrata was collected from 2000 m in depth using the free vehicle technique off the Kona coast, Hawaii. Four of its tissues were excised to study lipid synthesis at different pressures and oxygen tensions.2.2. Acetate-1-14C was incorporated chiefly into phospholipids in swimbladder, intestine, and gill. Acetate-1-14C was primarily incorporated into triglycerides in the liver. This reflects the lipid composition of these tissues.3.3. The swimbladder and gill had the highest metabolism of the four tissues.4.4. Triglyceride synthesis was inhibited by pressure in all four tissues studied. High pressure enhanced phospholipid and fatty acid synthesis.5.5. Oxygen enhanced the synthesis of cholesterol from acetate-1-14C and squalene-4-3H. This suggests that the synthesis of high cholesterol concentrations in the swimbladder lipids is facilitated by the presence of hyperbaric oxygen in the swimbladders of abyssal fishes.

Clathrate hydrate of oxygen: does it occur in deep-sea fish?

Oxygen exists in the swimbladder of some deep-sea fish at partial pressures that are more than twice the hydrate equilibrium pressure in water. Observations suggest that no hydrate forms to depths of 3500–4000 m. At greater depths, gas secretion may not occur because of the formation of hydrate.

Predictions of volume scattering strengths from biological trawl data

A volume reverberation model which utilizes fish distribution data has been developed to permit quantitative predictions of depth−dependent scattering strengths. The model was evaluated by using coincident acoustic volume scattering measurements and biological trawl data collected in the Mediterranean Sea. Biological specimens were collected at discrete depths with an Isaacs−Kidd midwater trawl. Each fish collected was identified and sized, and its acoustic cross section calculated by utilizing regression equations relating fish species, length, and swimbladder volume at frequencies near swimbladder resonance, or equations relating fish length to acoustic cross section at frequencies far above resonance. Scattering strengths for each species were then determined, indicating dominant species at each trawl depth for 1/3−octave frequency bands between 2.5 and 20 kHz. The acoustic data were obtained with surface−vented explosive sources and a shallow onmidirectional hydrophone. These data were processed to yield integrated column strength versus depth profiles, which were then numerically differentiated to produce scattering strength versus depth profiles for each frequency band. Comparison of the model predictions to the scattering strength profiles showed good agreement at the higher frequencies, with the agreement decreasing with frequency below 6.3 kHz. Subject Classification: 30.30, 30.40.

Predictions of volume scattering strengths from biological trawl data

A volume reverberation model which utilizes actual fish distribution data has been developed to permit quantitative predictions of depth-dependent scattering strengths. The model was evaluated using coincident acoustic volume scattering measurements and biological trawl data collected in the Mediterranean Sea. Biological specimens were collected at discrete depths with an Issacs-Kidd midwater trawl. Each fish collected was identified and sized, and its acoustic cross section calculated utilizing regression equations relating fish species, length, and swimbladder volume at frequencies near swimbladder resonance or equations relating fish length to acoustic cross section at frequencies far above resonance. Scattering strengths for each species were then determined, indicating dominant species at each trawl depth for 1/3-octave frequency bands between 2.5 and 20 kHz. The acoustic data were obtained with surface-vented explosive sources and a shallow omnidirectional hydrophone. These data were processed to yield integrated column strength versus depth profiles, which were then numerically differentiated to produce scattering strength versus depth profiles for each frequency band. Comparison of the model predictions to the scattering strength profiles showed good agreement at the higher frequencies, with the agreement decreasing with frequency below 8 kHz. Possible causes of this disagreement are enumerated.

The membranous lining of the swimbladder in deep sea fishes—I. Morphology and chemical composition

1. 1. Cholesterol-rich swimbladder foams from Coryphaenoides (cf. fernandezianus) and Parabassogigas sp. collected from 3400 to 4575 m depth appear as sheets of layered membranes having typical bilayers. 2. 2. Sphingomyelin was the major phospholipid in Parabassogigas swimbladder foam (48.7 and 63.0 per cent) whereas phosphatidylcholine (39.1–44.8 per cent) was the major phospholipid in Coryphaenoides. 3. 3. Although percentages of both cholesterol and phospholipids were lower in Parabassogigas than in Coryphaenoides, the ratio of cholesterol to phospholipid was close to one to one in both fish. 4. 4. Total fatty acid unsaturation in the swimbladder foams was high (71.4–80.5 per cent) despite the presence of hyperbaric oxygen.

Volume backscattering in the Tasman Sea, the Coral Sea, and the Indian Ocean

Acoustic volume reverberation was measured at frequencies from 2.5 to 16 kHz at a number of stations in the Tasman Sea, the Coral Sea, and the north-eastern region of the Indian Ocean. The dependence of volume backscattering strength on time of day, acoustic frequency, and depth beneath the sea surface were investigated. In the Coral Sea and the Indian Ocean, the average diurnal variation increased with decreasing frequency; but in the Tasman Sea the diurnal variation was almost independent of frequency. The volume backscattering strengths generally increase with frequency, but nighttime spectra are usually flatter than daytime spectra. Deep-scattering layers were detected in the three areas at 40% of the daytime stations. Each of these DSL's had a single resonance frequency, 70% of them at 5 or 6 kHz. Most of the DSL's were at depths between 400 and 600 m. The results suggest that the volume reveration was due to backscattering by the swimbladders of mesopelogic fish.

Lactate dehydrogenase and cytochrome oxidase in the swimbladder of fish

1. 1. Activities of lactic dehydrogenase and cytochrome oxidase were investigated in homogenates of gas gland tissue from the swimbladder of 9 species of marine teleosts. Similar analyses were made on skeletal muscle (mainly white fibres) and heart tissue. 2. 2. The gas gland tissue shows a high activity of lactic dehydrogenase. The enzyme is predominantly of the anaerobic type also found in the skeletal muscle, but differs from the aerobic type characteristic of cardiac tissue. 3. 3. The cytochrome oxidase activity is remarkably low in the gas gland tissue. 4. 4. The enzymic pattern of the gas gland tissue seems to be well suited for production of lactic acid at a rapid rate.

Cholesterol and hyperbaric oxygen in swimbladders of deep sea fishes.

WE have found an accumulation of cholesterol within the oxygen-filled swimbladders of some deep sea benthic fishes, which suggests that certain steps in cholesterol biosynthesis and/or degradation are affected by hyperbaric oxygen. The lipid content of these swimbladders included as much as 49 % (dry wt basis) of cholesterol. The lipid included major amounts of unsaturated fatty acids which resist auto-oxidative processes within the swimbladder which contains oxygen at pressures up to 380 atmospheres.

Capillaries in the rete mirabile and in the gas gland of the swim bladder in fishes, <i>Perca fluviatilis</i> L. and <i>Misgurnus fossilis</i> L.

Capillaries in the rete mirabile and in the gas gland of the swim bladder in fishes, <i>Perca fluviatilis</i> L. and <i>Misgurnus fossilis</i> L.

The role of lactic acid in gas secretion in the teleost swimbladder

1. 1. Existing evidence for the mechanism of gas secretion into the swimbladder of fish suggests that lactic acid is produced by the gas gland tissue in the presence of high oxygen pressure and is responsible for the “single concentrating effect” (Kuhn & Kuhn, 1961) which is multiplied by countercurrent blood flow through the rate mirabile to produce the necessary gas pressure. 2. 2. The catabolism of the gas gland tissue of the vermilion rockfish, Sebastodes miniatus, a species whose ecological depth range extends down to 200 m, has been investigated under O 2 pressures up to 51 atm. Lactic acid was produced by the tissue throughout the range of pressures investigated, and no evidence of a Pasteur effect was found. CO 2 production by the tissue was similar and very low under both O 2 and N 2 and suggested that citric acid cycle enzymes and oxidative phosphorylation systems were very weak in this tissue. 3. 3. The maximum glycolytic rates observed were too low to account for pre- and post-rate differences in lactate concentration observed by other workers, and glycogen levels in the gas gland tissue (0·02 mg/mg dry wt.) could produce the observed arteriovenous differences in lactate for only a few minutes. 4. 4. The essential role of lactic acid in gas secretion was supported by injecting oxamic acid, a competitive inhibitor of lactic dehydrogenase, into the swimbladder of deflated fish; statistically significant differences in control and experimental groups in both amounts and relative percentages of gases secreted were observed.

Volume Back Scattering in the Coral Sea

Volume back-scattering strengths S averaged over three depth intervals are presented for a number of deep water stations in the Coral Sea at frequencies between 2.5–12.5 kHz in 13-oct steps. At daytime stations, mean values for the 1-m S ranged from −95 dB at the low frequencies to −77 dB at 12.5 kHz. On the average in the depth interval 0–1500 m, S was a maximum in the interval 0–450 m at the lower frequencies, but at the higher frequencies S was a maximum in the interval 450–750 m. Deep scattering layers were found at three stations, where significant negative correlations were observed between S and water temperature at a depth of 200 m. At evening stations 1 h before sunset, S was a maximum in the interval 0–750 m and increased with frequency at an average rate of 9 dB/oct. At 1 h after sunset, S was a maximum in the interval 0–450 m and increased with frequency at an average rate of 6 dB/oct. The main temporal increases in S ranged from a maximum of 14 dB at 3.2 and 4 kHz to 4 dB at 12.5 kHz. The increases obtained are consistent with the hypothesis that volume scattering is geared to swimbladders of fish that migrate toward the surface over the sunset.

Lung alveolar cell cytosomes: a consideration of their significance.

An ultrastructural comparison of mammalian, reptilian, and amphibian lung alveolar cells, and avian lung atrial cells reveals that morphologically similar cytoplasmic bodies (cytosomes) occur in these cells. The cytosomes, which appear generally as osmiophilic, lamellae-containing, membrane-bound, round bodies 0.3 to 0.5 μ in diameter, are also similar to bodies occurring in epithelial cells of both physoclistous and physostomatous swimbladders of fishes. Because the function of both lung alveolar and swimbladder epithelial cells is gas-handling, the possibility is raised that the morphologically similar lamellae-containing bodies of these vertebrate cells are functionally identical. One function, suggested by other investigators, is that, in mammalian lungs, these bodies supply a surface-tension lowering material (surfactant). Because several assumptions concerning this proposed function remain unproved, an alternative proposal is speculatively explored. The suggestion is offered that cytosomes contain an antioxidant needed to protect alveolar and swimbladder cells against the toxic effects of the relatively high concentration of oxygen to which these cells are exposed.

A Revision of the Genus Cystidicola Fischer, 1798 (Nematoda: Spiruroidea) of the Swim Bladder of Fishes

The systematics of the species of the genus Cystidicola Fischer, 1798, parasites of the swim bladder of physostomous fishes, is revised. Cystidicola farionis Fischer, 1798, C. cristivomeri White, 1941, and C. stigmatura (Leidy, 1886) Ward and Magath, 1917, are considered to be the only valid species in the world. These three species are redescribed. Cystidicola farionis is morphologically indistinguishable from C. stigmatura but the two species are tentatively regarded as distinct until more data on their biology are available. Cystidicola brevicauda Fujita, 1939, and C. mesopi Fujita, 1940, are not members of Cystidicola but they cannot be assigned to any other genus. Cystidicola lepisostei Hunter and Bangham, 1933, is a member of Cystidicola but should be regarded as a species inquirendae. Cystidicola minuta Rhodhain and Vuylsteke, 1934, and C. serratus (Wright, 1879) Railliet, 1916, are regarded as species inquirendae of the genus Rhabdochona. The literature on numerous other species assigned at various times to Cystidicola is reviewed. The host and geographical distribution of the valid members of Cystidicola are reviewed.