Authors: Miguel Tejedo

Authors: Richard Clark

Authors: Patrick T. Gregory , Karl W. Larsen And Daniel R.Farr

Authors: John Davenport, Tat Meng Wong And John East

Abstract: The emydid river terrapin Batagur baska (colloquially known as the tuntong) lives in rivers and estuaries of S.E. Asia. The species is omnivorous, but predominantly herbivorous from the hatchling stage onwards. Young river terrapins (3-4 months; 140-200 g body wt) from a headstarting programme in western Malaysia were studied. Appetite on a plant diet (kangkong; Ipomoea aquatica: Convolvulacea) was extremely high ( 16% body wt d^-1 on fresh wt basis); river terrapins spend long periods of browsing, using the double serrations of the upper beak to cut up plant material. The serrations also function in ratchet like fashion to allow large leaves to be progressively moved into the oesophagus without the turtle losing contact with the food. Batagur baska readily eats water hyacinth (Echornia crassipes), a plant which often chokes tropical waterways. River terrapins fed on trash fish move a meal through the gut more quickly (total gut clearance time, TGCT = 5 days) than do those fed upon kangkong (TGCT = 6 days). The gut features a large stomach, a small intestine of moderate length but large diameter and a capacious large intestine. The gut does not sort material. Assimilation efficiency on a diet of fish (mean assimilation of dry mass = 9 1 .6%, of energy (joules) = 90.5%, of protein = 97.4%) is much greater than on a diet of kangkong (43.2%, 38.6% and 66.0% respectively). [t is recommended that headstarted animals are regularly fed on fish to improve growth rates. River terrapins readily eat plant material in salinities between 0 and 1 9.8%0, but refuse to eat in water of 23. 1 %0 or more, presumably to avoid the incidental drinking of water with a higher ionic content than their blood.

Authors: Francisco J. Saez, Benito Fraile, Mary Paz De Miguel And Ricardo Paniagua

Abstract: The response of the different germ cell types and glandular tissue of the testis to low temperatures (4°C) and long photoperiods ( 16L:8D) was studied in the marbled newt (Triturus marmoratus) by histologic quantitative methods in the three periods of the annual cycle: quiescence (January-March), germ cell proliferation up to round spermatids (April-June), and spermiogenesis (July-September). Together with each group of cold-exposed newts, another group was maintained at mild temperature (20°C) over the same long photoperiod. At the beginning and end of each period, initial and final wild controls were collected. In the quiescent period, only spermatogonial proliferation was observed in the initial and final controls as well as in the cold-exposed newts. The newts kept at 20°C developed spermatogenesis up to the round spermatid level. At the end of the germ cell proliferation period, the final controls showed round spermatids; the newts exposed to 20°C developed complete spermatogenesis; and the newts maintained at 4°C only presented spermatogonial proliferati_on. At the end of the spermiogenesis period, the final controls and the newts kept at 20°C showed complete spermatogenesis and developed glandular tissue whereas the newts exposed to 4°C only had round spermatids and had no glandular tissue. Present results suggest that although low temperature does not affect spermatogonium proliferation it impedes both the subsequent steps in spermatogenesis and the development of glandular tissue.

Authors: John Davenport And Tat Meng Wong

Abstract: Black-rayed softshell turtles (Amyda cartilaginea) from Malaysia were shown to be capable of extracting oxygen from water by a combination of cutaneous and buccopharyngeal respiration. Given access to air as well as water they consumed a mean 81 ml 0₂ g^·1h^-1; when submerged and respiring aquatically the uptake fell to a mean value of 21 ml 0₂ g^·1h^·1 (ratio 3.86:1 ). Behavioural data show that the turtles cannot survive indefinitely by aquatic respiration alone as they incur an oxygen debt, even when inactive. Scope for activity is substantially reduced, even when air becomes available, until the oxygen debt is repaid. Buccopharyngeal respiration is a normal feature of behaviour, and is not used solely during prolonged submergence. The turtles pump some 40-80 ml water min-' through the pharynx at 30ºC. Turtles display dilated cutaneous blood vessels when they are submerged for long periods.

Authors: Mark Wilkinson

Abstract: Previous workers have suggested that uraeotyphlid caecilians are probably oviparous with direct development. Contrary to these suggestions Uraeotyphlus oxyurus has a larval stage with typically larval morphological features including a lateral line system, 'spiracles', and labial folds. Two larvae and one metamorphic specimen of U. oxyurus are described and aspects of their morphologies compared to that of adult Uraeotyphlus, the larvae of other caecilians and to that of aquatic adults of the Typhlonectidae. Gut contents indicate that the larva of this species is not a highly abbreviated non-feeding life history stage.

Authors: Gordon H. Rodda

Abstract: Boiga irregularis is a nocturnal, primarily arboreal, rear-fanged colubrid that is believed to have eliminated most of the native forest vertebrates on the island of Guam. On Guam it usually eats birds, rats, and lizards, including both day and night active species. To determine where the snakes forage, I tabulated 398 sightings of foraging snakes, recording their perch height, perch diameter, and perch plant species. These measures were compared to the places where searchers look for snakes, as well as the heights and perches where likely prey items are seen. Snakes were seen less often than would be expected based on search effort at heights from 2-5 m above ground. The modal height for foraging snakes was less than 0.5 m and they exhibited no preference for perch diameter. To determine how the snake locates its prey I watched 26 snakes for a total of 1 9.45 hours using a night-vision device. Both active search and ambush foraging modes were evident, with many snakes using both tactics within an evening. The postures adopted by immobile snakes suggest that they could detect the odor tracks of geckos. I also observed one medium-sized snake consume a sleeping adult columbid bird, which it found by active search.

Authors: M. S. Khan

Abstract: New material of Gymnodacrylus from Chitral, Pakistan has been compared with that already in museums. Gymnodacrylus walli which has been synonomized with G. stoliczkai by several authors was found to be a valid species. G. Walli is redescribed, with notes on its habitat.