Radiata2008(3)e

Herbert Meier & Ingo

Herbert Meier & Ingo Schaefer oxygen through the eggshell. This potential source of error can be easily eliminated by creating proper nesting facilities. What such a nesting spot should look like was described in detail by Schaefer (1984), Meier (2002) and Meier & Schaefer (2003a). However, even if a nesting spot is available and accepted by the female turtles, hatching rates remain unsatisfactory in many cases. There are several possible reasons that need to be taken into consideration in combination: - A causal factor that can be easily rectified may be the physical condition of the breeder specimens. Feeder fish are usually not available in sufficient numbers. More often than not these are cyprinid fish (“carp”) in the widest sense. At the senior author’s, most feeder fish originate from commercial breeding farms and thus from more or less intense keeping conditions, and are available only in frozen form. It has only been since 2001 that defrosted river bass from a low-grade breeding pond has been available for some months every year. Regular supplementation of vitamins should be enough to compensate for possible deficiencies. - The major cause of failure is very likely to be found in the incubation methods, however. As has been outlined in the present contribution, incubation has been successful on, respectively in, a substrate of moss. Lehmann (1987) presumed that the lack of a suitable substrate during artificial incubation might prevent the necessary erosion of calcium in the eggshell and as a consequence disable the embryos to pierce it when they need to hatch. This problem may be augmented during the actual hatching process in that the permeation of oxygen is reduced in eggs that are not “eroded”. Our current state of knowledge suggests that a slightly acidic incubation environment favours successful hatching to a great extent. Major differences have been noted with regard to the incubation period, ranging from a minimum of 167 (Meier this work) to a maximum of 300 days (McCord pers. comm). It is most unfortunate that information on moisture levels of the incubation substrate is scarce and seems to be ranging from relatively dry (Hausmann 1964) to damp (McCord in litt. 2001). In the eyes of the senior author’s, the factor of substrate moisture might play a much greater role than incubation temperature. As to how far substrate moisture might have a catalyst effect, or be a key element to triggering the hatching process, has to be left unanswered for the moment, but is certainly deserving of more attention. This especially as a distinct prolonging effect of a dry incubation substrate on the incubation period has already been noted for the European pond turtle, Emys orbicularis, and Emydura subglobosa subglobosa (Meier & Schaefer 2003a, b). References Barrio-Amorós, C. & Í. Narbaiza (2008): Turtles of the Venezuelan Estado Amazonas. – Radiata (English edition), Lingenfeld, 17 (1): 2-19. Budde, H. (1980): Verbesserter Brutbehälter zur Zeitigung von Schildkrötengelegen. – Salamandra, Frankfurt/M., 16 (3): 177-180. Bundesministerium für Ernährung, Landwirtschaft und Forsten (1997): Gutachten über Mindestanforderungen an die Haltung von Reptilien vom 10. Jan. 1997. Sonderausgabe der DGHT. – Rheinbach, 77 pp. Drajeske, P. W. (1982): Captive breeding of the mata mata turtle (Chelus fimbriatus). – 6. Ann. Rep. Symp. Captive Propagation Husbandry, 28.-31. July. — (1983): Husbandry and Captive Reproduction of the Matamata, Chelus fimbriatus 36 RADIATA 17 (3), 2008

The Matamata, Chelus fimbriata (Schneider). – Bull. Chicago Herpetol. Soc., Chicago, 18 (3-4): 73-81. von Fischer, J. (1884): Das Terrarium, seine Bepflanzung und Bevölkerung – ein Handbuch für Terrarienbesitzer und Tierhändler. – Frankfurt/M. (Verlag von Mahlau und Waldschmidt), 384 pp. Hausmann, P. (1964): Zucht der Matamata. – DATZ, Stuttgart, 17 (12): 369-371. Heinroth, O. (1943): Geglückte Zucht der Matamata, Chelus fimbriatus im Berliner Aquarium. – Zool. Garten (N. F.), Jena, 15: 251-254. Iverson J. B. (1992): A revised checklist with distribution maps of the turtles of the world. – Richmond (priv. print.), 318 pp. Kabisch, K. (1997): Ein ungewöhnlich großer Knochenpanzer von Chelus fimbriatus (Schneider, 1783). – Sauria, Berlin, 19 (1): 45-46. Klingelhöffer, W & C. Scherpner (1959): Terrarienkunde Bd. IV, Schlangen, Schildkröten, Panzerechsen. – Stuttgart (A. Kernen), 379 pp. Krause, H.-J. (1998): Handbuch Aquarienwasser. Diagnose, Therapie, Aufbereitung. – Ruhmannsfelden (bede-Verlag), 128 pp. Lehmann, H. (1987): Hypothetische Überlegungen zur Schlupfproblematik von künstlich inkubierten Gelegen südamerikanischer Schildkrötenarten der Familie Chelidae. – Salamandra, Bonn, 23 (2/3): 73-77. Lemell, P., C. Lemell, P. Snelderwaard, M. Gumpenberger, R. Wochesländer & J. Weisgram (2002): Feeding patterns of Chelus fimbriatus (Pleurodira: Chelidae). – J. Experim. Biol., Washington DC, 205: 1495-1506. Meier, H. (2002): Experiences in the Construction of a large Basin for Tropical Turtles. – Radiata (English edition), Haan, 11 (1): 18-21. — (2004): Erfahrungen bei der Eiablage und der Inkubation von Macrochelodina rugosa. – Sacalia, Stiefern, 3 (2): 13-23. — & I. Schaefer (2003a): Experiences and observations of Chelus fimbriatus, the maintenance in terrarium and successful reproduction. – Radiata (English edition), Lingenfeld, 12 (2): 3-20. — & I. Schaefer (2003b): Additional remarks on the breeding of Chelus fimbriatus. – Radiata (English edition), Lingenfeld, 12 (4): 15-24. Müller, M. (1996) Handbuch ausgewählter Klimastationen der Erde. –Forschungsstelle Bodenerosion der Universität Trier Mertesdorf (Ruwertal), 400 pp. Nietzke, G. (1977): Die Terrarientiere Band I. – Stuttgart (Eugen Ulmer), 342 pp. Nöllert, A. (1987): Schildkröten. – Hannover (Landbuch Verlag), 190 pp. Pawley, R. (1969): Observations on the reaction of the Mata Mata turtle to ultra-violet radiation. – Int. Zoo Yearbook, London, 9 (1): 31-32 Pritchard, P.C.H. (1979): Encyclopedia of turtles. – Neptune (T.F.H. Public.), 895 pp. — & P. Trebbau (1984): The turtles of Venezuela. – Ithaca (Soc. Study Amphib. Reptiles), 403 pp. RADIATA 17 (3), 2008 37