Osmoregulation in Sea Water of Hatchling Emydid Turtles, Callagur borneoensis, from a Malaysian Sea Beach

Salinity of the coastal nesting environment and its association with body size in the estuarine pig‐nosed turtle

“…Coastal nesting is also observed in other freshwater and estuarine turtles such as Malaclemys terrapin (Burger & Montevecchi, ), Trachemys scripta venusta (Pritchard & Trebbau, ; Moll, ), Callagur borneoensis (Dunson & Moll, ), Podocnemis expansa (Portal, Luz & Medonça, ), Pelochelys bibroni (Rhodin, Mittermeier & Hall, ) and Trionix triunguis (Pritchard, ). According to Moll & Moll (), different survival strategies to cope with the unusual requirements of sea nesting sites will be employed by different populations and species, depending on ecological circumstances.…”

“…The synchronization of the nesting time with the optimal period of the year is crucial for the turtle's reproductive success and hatchling fitness (Doody et al, 2004). In the case of female turtles nesting in estuarine areas, they may also rely on a second temporal factor, which is related to periods of fresh water runoff generated by heavy rainfall (Dunson & Moll, 1980). In large rivers, tidal salinity fluctuation allows periods of exposure to salinity levels below 50% seawater, which is sufficient for rehydration and foraging (Davenport & Wong, 1986;Kinneary, 1993Kinneary, , 1996.…”

Functional and morphological plasticity of crocodile (Crocodylus porosus) salt glands

“…Indeed, several species of marine reptiles (e.g. sea snake Pelarmis platurus, estuarine turtles Callagur borneoensis and Malaclemys terrapin and Crocodylus acutus) are thought to also maintain water balance without the need to drink seawater (Dunson, 1982;Dunson and Moll, 1980;Dunson and Robinson, 1976;Evans and Ellis, 1977;Robinson and Dunson, 1976). Taplin (Taplin, 1985) provided data on the relative salt loads of saline water food items of C. porosus in the Liverpool/Tomkinson River System, northern Australia, which showed that the Na + content of these items ranged from ~55 to ~215·mmol·Na + ·kg -1 ·body·mass (the mean Na + content of food items fed to crocodiles in the present study was 145·mmol·kg -1 ·body·mass).…”

Sea water drinking as a homeostatic response to dehydration in hatchling loggerhead turtles Caretta caretta

“…The only measurements of Na turnover in marine turtles, C. caretta and Chelonia mydas, reveal extremely high turnover rates relative to those reptiles known not to drink sea water (Evans, 1973;Kooistra and Evans;. The published data available do not, therefore, provide very strong support for the following assertions: very low rates of Na influx are characteristic of all marine reptiles (Dunson and Moll, 1980); sea snakes and sea turtles gain their water from food alone (Dunson, 1969(Dunson, , 1974; fasting marine snakes have very low rates of Na influx and efflux (Dunson, 1978); or for the broad conclusion that the drinking of sea water is not an important osmoregulatory mechanism in any of the estuarine or marine reptiles (Minnich, 1982).…”

“…While this appears likely, especially given the lizard's ability to maintain water balance in captivity on a diet of fish alone, the conclusion must be treated with some caution in the absence of any data on integumental Na and water permeability and gross water and electrolyte turnover rates. More reliable evidence comes from demonstrations that the sea snake, Pelamis platurus, the estuarine turtles, Callagur borneoensis and Malaclemys terrapin, and the estuarine/marine crocodile, Crocodylus acutus, are in negative water balance when unfed in sea water and have Na turnover rates too low to reflect any significant ingestion of sea water (Dunson, 1982;Dunson and Moll, 1980;Dunson and Robinson, 1976;Evans and Ellis, 1977;Ellis, 1980;Robinson and Dunson, 1976). The third line of evidence is that, in the estuarine snakes Cerberus rhynchops, Nerodia fasciata compressicauda and N.f.…”