The Herpetological Journal

pp.159-166

Authors: Adrian Hailey And P. M. C. Davies

Abstract: Absorption efficiency of viperine snakes feeding on goldfish increased slightly with temperature, the rate of digestion increased greatly. Digestion was partial at 15°C and sometimes followed by regurgitation: at 10°C all prey were regurgitated. Prolonged basking in N. maura in the field probably serves to increase the speed of digestion. The metabolic cost of maintaining a high body tern perature (T_b) during digestion is equivalent to 4 percent of the energy of the prey.
The level and time course of raised oxygen consumption (V0₂) following feeding on fish varied with Tb, being large and short lived (2 days) at 35°C, small but long lasting (10 days) at 15°C. The total energy cost of this raised V0₂ accounted for 28 per cent of the energy in the food. V0₂ during maximal activity after feeding at 35°C was greater than that of post-absorptive snakes, indicating that the capacity for oxygen exchange does not limit the active metabolic rate of N. maura. There was no depression of oxygen consumption during hibernation.
Food consumption could not be satisfactorily estimated from the proportion of snakes (a) found handling prey or (b) with prey in the stomach. Data on metabolic costs, reproductive effort and growth are combined to give an energy budget for N. maura. The energy turnover was about a third of that predicted from studies of lizards. Snake and lizard energy budgets differ in the ratio production/assimilation; this was 0.41-0.57 in four snakes, and 0. I 3-0.18 in six lizards. Snakes have lower energy turnover, but allocate a greater proportion of this to reproduction and growth.

pp.167- 169

Authors: Carmen Diaz-paniagua

Abstract: The distribution in ponds of five species of anuran larvae has been studied in relation to the aquatic vegetation. According to the vegetal species composition, ponds have been classified in five zones. The innermost zone in which little or no vegetation grows was poorly frequented by tadpoles, which were mainly distributed throughout the other more vegetated zones. Some preferences for a specific zone have been found for several species.

pp.170-175

Authors: Rosamund F. Birse And John Davenport

Abstract: The effects of temperature within the range 20°C to 30°C, on rate of passage of material through the gut were studied in juvenile captive loggerhead turtles ( Coretta caretta). Total gut clearance time (TGCT) decreased with increasing temperature (Q₁₀ = 1 .6). The difference in value of TGCT was greater between 20°C and 25°C, where it fell by 33 hours, t han between 25°C and 30°C. where it decreased by 6 hours. At 25°C and 30°C the satiation rat ion amounted to 3. 73 per cent body weight; at 20°C the value was only 0.92 per cent. It was calculated that appetite would return to satiation level at a faster rate at 20°C than at 25°C or 30°C.
Food was retained in the oesophagus of juvenile loggerhead turtles for up to one hour after feeding.

pp.175- 177

Authors: Paul A. Verrell

Abstract: Part ial clearance of the terrestrial vegetation surrounding a pond in southern England resulted in a significant decrease in the size of the smooth newt ( Triturus vulgaris) population breeding there, relative to a n earby, intact pond. This finding supports the suggestion of Beebee (1981) that the terrestrial habitat surrounding a pond is an important determinant of t hat pond 's suitability for amphibians.

pp.177-180

Authors: Gad Degani And Hani Hahamou

Abstract: ln this study we examined the adaptation of the enzyme Aldolase from frogs and toads to different temperatures and to hyperosmotic media of 400-1000mOsm/Kg of urea or NaCl . Maximum enzyme activity was found between 200-400m0sm/Kg NaCl, both in enzymes from green toads and from marsh frogs. However, a bove 500m0sm/Kg, the activity of enzymes from green toads was significantly higher than the activity of enzymes from marsh frogs. The activity of aldolase from green toads decreased very slowly as the media concentration of urea increased. However, the activity of aldolase from marsh frogs decreased rapidly under the same conditions. The maximum activity of aldolase from both frogs and toads was at 25°C. The activity of aldolase from green toads was significantly higher than the activity of aldolase from marsh frogs when measured only at high temperatures (35°C). Th e results of this study support the idea that the biochemical systems of terrestrial amphibia are tolerant to hyperosmotic media

pp.181-185

Authors: Mohamed K. Al-Sadoon

Abstract: Aerobic and anaerobic metabolic rates were determined at temperat u res between 20°C and 35°C for the viviparous lizard, Lacerta vivipara. Both parameters were found to be maximal around the preferred body temperature (30°C) with a low thermal temperature dependence a bove PBT. It is noted that L. vivipara does not need a large rate of anaerobic support and aerobic metabolism could supply the energy needed for activity.

pp.185-194

Authors: Adrian Hailey And P. M. C. Davies

Abstract: Viperine water snakes were studied by mark-recapture in a small river in Eastern Spain from 1981 to 1983, a period of drought. Observed growth rates between captures were low and highly variable. Growth rings were counted in skull bones; narrow rings could not be found, and the observed rings were probably from periods of faster growth or normal growth before the drought. The rings predict that males and females reached maturity in their third and fifth years, respectively. The effect of drought was greater on growth than on reproduction. Movements of snakes captured several times at long intervals suggest that the home ranges of mature males and females were I 70m and 250m of river, respectively, although some individuals moved I km between years. A review of published data showed that widely foraging grass and garter snakes have greater displacements between captures than the more sedentary water snakes.
There were estimated to be 1 060 and 390 adult males and females in the main study area, which was a 2km length of river which included most of the permanent unpolluted water in the river system. Annual survival of adult snakes remaining within the study area was estimated as 0.53 ± 0. 16 and 0. 71 ± 0.25 in males and females, respectively. A simple model of the dynamics of this population was developed from results on survival, recruitment, growth and fecundity, as a hypothesis for further study. The model suggested that: I) There was dispersal of adult males but not adult females - this was supported by the population size structure in peripheral areas where mature females were scarce and which were probably stocked by dispersal. 2) The n um ber of adult males and females was stable or increasing, and juvenile survival of about 0.65 year- I would be necessary for total population stability.

pp.194-198

Authors: Donald G. Broadley

Abstract: Examination of most oft he available material of Gerrhosaurus major indicates t hat only two geographical races should be recognised, the typical form (with grandis Boulenger as a synonym) in eastern Africa and G. m. bottegoi Del Prato (with zechi Tornier as a synonym) ranging from northern Somalia west to Ghana. In the last revision of the genus, Loveridge ( 1942) recognised four races, but did not realise that the name bottegoi was applicable to the dark form which he called zechi. The range of variation in the typical form includes all the material t hat Loveridge assigned to bollegoi and grandis.

pp.199-201

Authors: J. Alan Holman

Abstract: The Swanton Morley Ipswichian site yielded fossils of Bufo bufo, Rana arvalis arvalis, Rana temporaria, Rana sp. indet ., Emys orbicularis, and Natrix natrix. This is the first British fossil record of Rana arvalis arvalis which today occurs in the European low countries adjacent to England. A second continental form, Emys orbicularis, has previously been reported from the site. The nearest to Swanton Morley t hat these herpetological species could be found living to get her today would be in the Mecklenburg District of northern East Germany.

pp.202-204

Authors: Richard Shine