Freshwater Turtles (freshwater + turtle)

Distribution by Scientific Domains


Selected Abstracts


Phylogeny of the Eurasian freshwater turtles of the genus Mauremys Gray 1869 (Testudines), with special reference to a close affinity of Mauremys japonica with Chinemys reevesii

JOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 4 2002
M. Honda
Phylogenetic relationships of the freshwater turtles of the genus Mauremys and representatives of several other batagurid genera were inferred from variations in 863 base positions of mitochondrial 12S and 16S rRNA genes. Results strongly suggested the non-monophyly of Mauremys by indicating the closest affinity of Mauremys japonica with Chinemys reevesii, the type species of the genus Chinemys. Recent morphological analyses of the batagurid genera suggested that Mauremys is a basal stock of the subfamily Geoemydinae, whereas Chinemys is a member of the subfamily Batagurinae as supported by several putative synapomorphs with other batagurine genera. It is thus probable that the morphological character states used to define Mauremys actually represent symplesiomorphy, and that morphological character states shared between Chinemys and other batagurine genera have resulted from convergence. Also, our results did not support a sister-group relationship between Mauremys annamensis and Mauremys mutica, which has been implicitly or explicitly assumed by a number of previous authors on the basis of morphological data. Instead, M. annamensis was indicated to be closest to Mauremys iversoni, a species assumed to be most divergent among the East Asian Mauremys by previous authors. Phylogenie der eurasischen Su¨ßwasserschildkro¨ten der Gattung Mauremys Gray 1869 (Testudines), mit besonderem Hinweis auf eine enge A¨hnlichkeit von Mauremys japonica mit Chinemys reevesii. Die phylogenetischen Beziehungen zwischen den Süßwasserschildkröten der Gattung Mauremys und Vertretern einiger anderer bataguriner Gattungen wurde aus den Unterschieden an 863 Positionen der 12S-und der 16S-rRNA-Gene des Mitochondriengenoms ermittelt. Die Ergebnisse weisen sehr stark darauf hin, daß die Gattung Mauremys wegen der starken Ähnlichkeit zwischen M. japonica und Chinemys reevesii nicht monophyletisch sein kann. Neue morphologische Analysen der batagiurinen Gattungen ließen vermuten, daß Mauremys einen basalen Ast der Unterfamilie Geomydinae darstellt, während Chinemys zur Unterfamile Batagurinae gehört, was aus den anzunehmenden Synapomorphien mit anderen batagurinen Gattungen gestützt wird. Es ist daher auch wahrscheinlich, daß die zur Beschreibung von Mauremys verwendeten morphologischen Merkmalszustände eher Plesiomorphien darstellen und daß die morphologischen Merkmalsausprägungen, die Chinemys und anderen batagurinen Gattungen gemeinsam sind, auf Konvergenz beruhen. Unsere Ergebnisse unterstützen auch nicht eine Schwestergruppen-Beziehung zwischen M. anamensis und M. mutica, was direkt oder indirekt von einer Zahl von früheren Untersuchern auf Grund morphologischer Daten angenommen wurde. Statt dessen erwies sich M. anamensis am engsten verwandt mit M. iversoni, einer Art, die von früheren Autoren als am stärksten divergent zu den ostasiatischen Mauremys-Arten angesehen wurde. [source]


Impact of recreational power boating on two populations of northern map turtles (Graptemys geographica)

AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 1 2010
G. Bulté
Abstract 1.Recreational power boating is growing in popularity in North America. This activity is known to have lethal and sub-lethal effects on aquatic wildlife and freshwater turtles may be particularly sensitive to this activity. 2.This study reports on patterns of traumatic injuries inflicted by powerboat propellers to northern map turtles (Graptemys geographica) from two sites differing in boat traffic intensity in Ontario, Canada. 3.The relative vulnerability of turtles was assessed, in light of seasonal patterns in boat traffic, as a function of sex- and age-specific movement patterns, habitat use, and basking behaviour obtained by radio-telemetry. Population viability analyses (PVA) were also conducted to evaluate the potential demographic consequences of mortality induced by powerboats. 4.The prevalence of propeller injuries was two to nine times higher in adult females than in adult males and juvenile females. Patterns of movement, habitat use, and aquatic basking indicated that adult females are more exposed to collisions with boats. PVA showed that boat-induced mortality in adult females could lead to rapid population extinction if the risk of mortality when hit by a boat is greater than 10%. 5.The results of this study showed that recreational power boating is a serious threat to northern map turtles, even under moderate boat traffic. The need to adopt measures restricting boat traffic in areas important to turtles is discussed. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Comparison of sympatric freshwater turtle populations from an urbanized Sydney catchment

AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 7 2008
Shelley Burgin
Abstract 1.Australian freshwater turtles are widely distributed throughout the continent, and in each river catchment there are at least two taxa. In south-eastern Australia Chelodina longicollis and forms of Emydura macquarii co-habit within a waterway, although they have been shown to partition habitat within the water column in non-urban bodies of water. Limited comparative data are available for the urban populations. 2.Within urban Sydney C. longicollis (eastern long-necked turtle) and Emydura macquarii dharuk (Sydney short-necked turtle) share habitat. However, in contrast with non-urban studies of C. longicollis and other sympatric E. macquarii taxa, it was observed that the population profile of the two species was similar at all sites, and that C. longicollis were present in greater numbers than E. m. dharuk. 3.The continued degradation of preferred habitat, low recruitment, and potential competition from introduced turtles place both species in a precarious position. 4.The shallow, impounded waterways of the regulated urban bodies of water align more closely with the preferred habitat of C. longicollis than with that of forms of E. macquarii, which prefer deeper flowing waters or large wetlands adjacent to rivers. Emydura m. dharuk may be at greatest risk of extinction in urban areas. 5.Across urban Sydney, the low numbers of E. m. dharuk compared with C. longicollis may be due to the lack of mobility of E. m. dharuk such that individuals tend to be stranded in sub-optimal habitat. In contrast, C. longicollis has a greater propensity for overland movement, and a preference for the ,new habitat' resulting from urban impacts on the associated waterways, and thus appears to be able to utilize these modified urban waters more successfully. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Reducing the mortality of freshwater turtles in commercial fish traps

AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 1 2005
M. B. Lowry
Abstract 1.Mortality of air-breathing vertebrates has been recognized for some time as a significant risk in Australian inland fisheries. There has often been conflict between the desires of fishers to maximize catches of their target species and the implementation of effective methods to reduce nontarget bycatch. 2.Two trials were conducted to evaluate the effectiveness of modifications to fish traps designed to prevent the capture of freshwater turtles (Emydura macquarii) and to facilitate their release. The first study evaluated the use of 100 mm exclusion rings to prevent turtles entering eel traps. The second study assessed two configurations of a carp trap designed to release the accidental catch of turtles. 3.Eel traps fitted with 100 mm exclusion rings significantly reduced the turtle bycatch, with no significant difference being observed between mean size of eels captured in traps fitted with exclusion rings and traps without rings. 4.The trials on the modified carp trap confirmed that they effectively retained carp and released a majority (77%) of turtles over a 4 h period. Turtles retained in the carp traps were significantly longer than those that found their way out of the trap. 5.This study demonstrates the different approaches that can be taken to achieve a reduction in non-target bycatch associated with traps, and illustrates the importance of exploiting both the physical and behavioural differences of the target and non-target species in order to develop appropriate gear designs that effectively restrict the entry, or facilitate the release, of bycatch species. Copyright © 2004 John Wiley & Sons, Ltd. [source]