Alterations in energy metabolism associated with the transition from water to air breathing in fish

Abstract

1978. Alterations in energy metabolism associated with the transition from water to air breathing in fish. Can. J. Zool. 56: 730-735. Hoplios malaharicus and Hoplerythrin~rs rrniturniatrrs are two closely related species which live in poorly oxygenated water. The former is an obligate water breather, whereas the latter has the additional capacity to respire atmospheric oxygen through a highly vascularized swim bladder. Hoplcrythrin~rs has greater lipid stores than Hoplitrs and probably places a greater dependence upon this metabolic fuel as an energy source than Hoplios. In contrast with this, Hoplirrs has greater heart and liver glycogen reserves than Hopleryrhrinrrs. Hoplias hearts perfused in vitro with buffer containing cyanide continued to beat eight times longer than Hoplepthrir~rrs hearts. The performance of both types of hearts was markedly increased when glucose was added to the perfusate; however, the Hoplias hearts still continued to function better than the Hoplrrythrinus hearts. It is concluded that the Hoplias heart is better adapted to function anaerobically than the Hoplerythrinlts heart. DRIEDZIC, W. R., C. F. PHLEGER, J. H. A. FIELDS et C. FRENCH. 1978. Alterations in energy metabolism associated with the transition from water to air breathing in fish. Can. J. Zool. 56: 730-735. Hoplias malabaricus et Hoplerythrinus unitaeniatus sont deux especes parentes vivant dans un milieu aquatique peu oxygene. Hoplerythrinus est un poisson a respiration aquatique obliga-toire, alors qu'Hoplias possede la propriete additionnelle de pouvoir respirer I'oxygene atmospherique par le tmchement d'une vessie natatoire tres vascularisee. Hoplerythrinus met plus de lipides en reserve qu'Hoplias et depend probablement plus aussi de ce produit de metabolisme comme source d'energie. Chez Hoplias, en revanche, le coeur est plus gros et les reserves de glycogene hepatique plus importantes. Des coeurs d'Hoplias en perfusion in vitro dans une solution-tampon contenant du cyanure continuent de battre huit fois plus longtemps que les caeurs d'Hoplerythrinus. Du glucose ajoute au perfusat ameliore la performance des deux types de cceurs, mais les coeurs d'Hoplias continuent de fonctionner mieux que ceux d'Hoplerythrinus. Le coeur d'Hoplias semble donc mieux adapt6 a une vie anaerobique que le caeur d3Hoplerythrinus.[Traduit par le journal] Introduction sphere through a highly vascularized swim bladder Hoplias ,nn/nharicus and Huplerythr.inus uni-(Carter and Beadle 193 1). Laboratory studies have tcrerziatus are two closely related fish in the family shown that Hoplerythrinus extracts about 25% of Erythrinidae which differ in one important charac-l t~ oxygen requirement through the swimbladder teristic. Hoplias is an obligate water breather when held in normoxic water, but as the oxygen (Johansen 1970), whereas Hoplerythrinus has the content of the water decreases a greater ~r o~o r t i o n capability of extracting oxygen from the atmo-of the required oxygen is derived from the atmosphere (

The regulation and importance of glucose uptake in the isolated Atlantic cod heart: rate-limiting steps and effects of hypoxia

“…ATP production from extracellular glucose is minimally about 4-fold greater than that from glycogenolysis. These independent biochemical measures are consistent with the finding of glucose-dependent performance, including the current work with cod and studies with other species (Driedzic et al, 1978;Bailey et al, 2000).…”

“…The fish heart, similar to the mammalian heart, has the capacity to utilize glucose as a metabolic fuel under aerobic conditions (Lanctin et al, 1980;Driedzic and Hart, 1984;Sidell et al, 1984;West et al, 1993West et al, , 1994 and is dependent upon the uptake of extracellular glucose to maintain performance under conditions of oxygen deprivation (Driedzic et al, 1978;Bailey et al, 2000) or elevated work (West et al, 1993). Unlike mammal hearts, how glucose uptake is regulated in fish remains unresolved.…”

Effects of extended absence of flooding on the fish assemblages of three floodplain lagoons in the middle São Francisco River, Brazil

“…Ecological attributes of the fishes captured in the 'Curral-de-Vara', 'Cajueiro' and 'Juazeiro' lagoons, São Francisco River, from September, 1994 to March, 1996. Species denomination followed Reis et al, 2003;1: Sato et al (1987), Lamas (1993); 2: Pompeu & Godinho (2003);3: Carter & Beadle (1931), Bastos (1956), Driedzic et al (1978), Hochachka et al (1978), Kramer et al (1978), Acuña & Sanz (1992), Rantin et al (1992), Machado-Allison (1994); N = non-migratory, Y = migratory, U = migratory trait unknown; herb = herbivore, invert = invertivore, detri = detritivore; N = hypoxia intolerant, Y = hypoxia tolerant.…”

“…Tolerance to hypoxic conditions was apparently a determinant for the survival of the species in the Juazeiro lagoon, following the marked reduction of its water volume. Of the seven species that survived, four are capable of breathing atmospheric oxygen (H. unitaeniatus: Driedzic et al, 1978;M. etentaculatus: Carter & Beadle, 1931, Kramer et al, 1978H.…”

“…Hoplosternum littorale, in addition to breathing atmospheric oxygen, shows blood cell modifications that ensure greater efficiency during hypoxia (Acuña & Sanz, 1992). Although not breathing atmospheric oxygen, Hoplias malabaricus tolerates very low oxygen levels, it needs little water convection to breathe (Rantin et al, 1992) and it has a large respiratory gill surface area (Driedzic et al, 1978;Hochachka et al, 1978). Since the trophic position and maximum size of the species are unrelated to their chances of local extinction, the number of locally extinct species in each size class or trophic category may have reflected an inherent characteristic of the fish fauna rather than a predisposition to extinction.…”