Mitochondria-rich cells in gills and skin of an African lungfish, Protopterus annectens

Sturla, Maddalena; Masini, Maria Angela; Prato, Paola; Grattarola, Carla; Uva, Bianca Maria

doi:10.1007/s004410000341

Cited by 50 publications

(35 citation statements)

References 21 publications

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“…The aforementioned presence of MR cells in both the dorsal and ventral skin of P. annectens (Sturla et al 2001) is in accord with these data. Because MR cells are also present in amphibian skin (Ehrenfeld et al 1989), our data complement the morphological findings of Sturla et al (2001Sturla et al ( , 2002 and their prediction of a "convergence of strategies" of osmoregulation and ionoregulation between lungfish and amphibians.…”

Section: Ion Uptake Continues In Airsupporting

confidence: 88%

“…Few studies have examined the skin of lungfish (e.g., Kitzan and Sweeney 1968;Sturla et al 2001Sturla et al , 2002. Graham (1997) reported that supradermal capillary density in P. annectens was comparable with the density in many frogs, in which the critical role of the skin for water uptake is firmly established (for reviews, see Toledo and Jared 1993;Jørgensen 1997).…”

Section: Extrabranchial Route(s) Of Water Exchangementioning

confidence: 99%

“…Inspection of the electron micrographs and immunohistochemistry of the skin and gills of P. annectens (Sturla et al 2001) suggests the MR cells are fewer in number and size compared to teleosts (Perry 1997;Marshall 2002). These observations, combined with the lungfish's reduced gill (Laurent et al Burggren and Johansen 1986), suggested that P. dolloi would have low basal rates of ion uptake.…”

Section: Ion Uptake Continues In Airmentioning

confidence: 99%

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The African Lungfish (Protopterus dolloi): Ionoregulation and Osmoregulation in a Fish out of Water

Wilkie

Morgan

Gálvez

et al. 2007

Physiological and Biochemical Zoology

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Although urea production and metabolism in lungfish have been thoroughly studied, we have little knowledge of how internal osmotic and electrolyte balance are controlled during estivation or in water. We tested the hypothesis that, compared with the body surface of teleosts, the slender African lungfish (Protopterus dolloi) body surface was relatively impermeable to water, Na ϩ , and Cl Ϫ due to its greatly reduced gills. Accordingly, we measured the tritiated water ( 3 H-H 2 O) flux in P. dolloi in water and during air exposure. In water, 3 H-H 2 O efflux was comparable with the lowest measurements reported in freshwater teleosts, with a rate constant (K) of 17.6% body water h Ϫ1 . Unidirectional ion fluxes, measured using 22 Na ϩ and 36 Cl Ϫ , indicated that Na ϩ and Cl Ϫ influx was more than 90% lower than values reported in most freshwater teleosts. During air exposure, a cocoon formed within 1 wk that completely covered the dorsolateral body surface. However, there were no disturbances to blood osmotic or ion (Na ϩ , Cl Ϫ ) balance, despite seven-to eightfold increases in plasma urea after 20 wk. Up to 13-fold increases in muscle urea (on a dry-weight basis) were the likely explanation for the 56% increase in muscle water * Corresponding author. Address for correspondence: Department of Biology, Wilfrid Laurier University, 75 University Avenue West, Waterloo, Ontario N2L 3C5, Canada; e-mail: mwilkie@wlu.ca. content observed after 20 wk of air exposure. The possibility that muscle acted as a "water reservoir" during air exposure was supported by the 20% decline in body mass observed during subsequent reimmersion in water. This decline in body mass was equivalent to 28 mL water in a 100-g animal and was very close to the calculated net water gain (approximately 32 mL) observed during the 20-wk period of air exposure. Tritiated water and unidirectional ion fluxes on air-exposed lungfish revealed that the majority of water and ion exchange was via the ventral body surface at rates that were initially similar to aquatic rates. The 3 H-H 2 O flux declined over time but increased upon reimmersion. We conclude that the slender lungfish body surface, including the gills, has relatively low permeability to water and ions but that the ventral surface is an important site of osmoregulation and ionoregulation. We further propose that an amphibian-like combination of ventral skin water and ion permeability, plus internal urea accumulation during air exposure, allows P. dolloi to extract water from its surroundings and to store water in the muscle when the water supply becomes limited. Physiological and Biochemical Zoology

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Section: Ion Uptake Continues In Airsupporting

confidence: 88%

Section: Extrabranchial Route(s) Of Water Exchangementioning

confidence: 99%

Section: Ion Uptake Continues In Airmentioning

confidence: 99%

See 1 more Smart Citation

The African Lungfish (Protopterus dolloi): Ionoregulation and Osmoregulation in a Fish out of Water

Wilkie

Morgan

Gálvez

et al. 2007

Physiological and Biochemical Zoology

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“…Many studies of teleost gills have described the morphological and functional characteristics of gill epithelial cells (Carmona et al, 2004). These cells participate in various functions, such as gas exchange, maintenance of blood acid-base balance and ionic regulation (Brown, 1992;Laurent et al, 1994aLaurent et al, , 1994bMoron & Fernandes, 1996;Fernandes et al, 1998;Goss et al, 1998;Sturla et al, 2001).…”

Section: Discussionmentioning

confidence: 99%

Morphological Studies on the Gills of Puffer Fish (Lagocephalus sceleratus, Gmelin, 1789)

Abumandour

Gewaily

2016

Int. J. Morphol.

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SUMMARY:In the present study, we focused on the morphology of L. sceleratus gills using gross anatomy, scanning electron microscopy as well as light microscopy. Results of this study revealed that the gill openings appeared as simple slits anterior to the pectoral fin without distinct opercular cover. The gill system consisted of three pairs of gill arches carrying two rows of gill rakers on its concave border and gill filaments on its convex border. SEM showed that all surfaces of the gill arch were characterized by the presence of the longitudinal ridges with many taste buds in addition to many spines around the rakers. Histologically, the gill arch was composed of curved bar of hyaline cartilage with slightly elevated area corresponding to the sites of gill rakers. Each filament was formed of a thin central cartilaginous core surrounded by peripheral cartilaginous ma trix and covered by primary epithelial layer with abundant mucous cells. The chloride cells appeared mainly near to the base of secondary lamellae. Each gill filament gave rise to a very large number of secondary lamellae on both sides. The epithelial lining of the secondary lamellae comprised epithelial pavement cells, few mucous cells and pillar cells. The latter interposed the enriched blood capillaries. These findings suggest that L. sceleratus gills have characteristic morphological features that are related to adaptive functions for feeding habits, osmoregulation and respiratory mechanism with in their living environment.

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“…Because most O 2 uptake occurs from the air, branchial ventilation in lungfish need not be constrained by convection requirements for O 2 uptake. Consequently, the gill is ventilated by low volumes of water (Jesse et al, 1967) and this factor, coupled with the low surface area and high bloodto-water diffusion distances of the lungfish gill (Sturla et al, 2001), results in arterial P CO 2 values that are unusually high for fish (~20-30·mmHg) (Lenfant and Johansen, 1968;Perry et al, 2005). Thus, the respiratory status of lungfish is more suitable for using ventilation to regulate acid-base disturbances than is the case for water-breathing fish.…”

Section: Introductionmentioning

confidence: 99%

Mechanisms of acid–base regulation in the African lungfishProtopterus annectens

Gilmour

Euverman

Esbaugh

et al. 2007

Journal of Experimental Biology

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cotransporter) were cloned, and their branchial and renal mRNA expressions were examined prior to and following acid or base infusion. In no case was mRNA expression significantly altered by metabolic acid-base disturbance. These findings suggest that lungfish, like tetrapods, alter ventilation to compensate for metabolic acid-base disturbances, a mechanism that is not employed by waterbreathing fish. Like fish and amphibians, however, extrarenal routes play a key role in metabolic compensation.

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Mitochondria-rich cells in gills and skin of an African lungfish, Protopterus annectens

Cited by 50 publications

References 21 publications

The African Lungfish (Protopterus dolloi): Ionoregulation and Osmoregulation in a Fish out of Water

The African Lungfish (Protopterus dolloi): Ionoregulation and Osmoregulation in a Fish out of Water

Morphological Studies on the Gills of Puffer Fish (Lagocephalus sceleratus, Gmelin, 1789)

Mechanisms of acid–base regulation in the African lungfishProtopterus annectens

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