scholarly journals Морфогенез органа нюху східної довгошийої черепахи (Chelodina longicollis)

2021 ◽  
pp. 66-71
Author(s):  
Daryna Shkabura ◽  
Yaroslav Stepanyuk
Keyword(s):  
Chelodina Longicollis

Вивчення розвитку нюхового аналізатора рептилій є дуже важливим в еволюційному та порівняльно-анатомічному аспектах. Нюховий аналізатор різних рептилій має суттєві відмінності в будові. У ящірок та змій нюховий аналізатор анатомічно розділений на основну та додаткову (вомероназальну) системи. Нюховий орган черепах має відмінні риси організації. У більшості черепах в нюховому органі відсутнє морфологічне розмежування основного нюхового та вомероназального органа.У роботі описано ключові стадії розвитку структур нюхового органа східної довгошийої черепахи (Chelodina longicollis). Нюховий орган складається з присінка, власне нюхової порожнини та носоглоткового каналу, який відкривається в ротову порожнину хоанами. Носова порожнина розмежована вузькою ділянкою несенсорного епітелію на дорсальну частину, яка вистелена нюховим епітелієм, та вентральну, яка вистелена вомероназальним епітелієм. Вентральна частина носової порожнини утворює медіальне впячування, що значно збільшує об’єм вомероназального епітелію. Нюховий епітелій має чисельні залози Боумена, які відсутні у вомероназальному епітелії. Протока латеральної нюхової залози впадає на межі переходу присінка в носову порожнину та зволожує основний нюховий епітелій, який найбільше контактує з повітрям. Доказом наявності вомероназальної системи у черепахи слугує наявність вомероназального нерва, окремі волокна якого йдуть від вентральної частини носової порожнини до медіальної поверхні нюхової цибулини.

Arterial O₂ Homeostasis during Diving in the Turtle Chelodina longicollis

1989 ◽  
Vol 62 (3) ◽  
pp. 668-686 ◽  
Author(s):  
Warren Burggren ◽  
Allan Smits ◽  
Barbara Evans
Keyword(s):  
Chelodina Longicollis

An XX/XY sex microchromosome system in a freshwater turtle, Chelodina longicollis (Testudines: Chelidae) with genetic sex determination

2006 ◽  
Vol 14 (2) ◽  
pp. 139-150 ◽  
Author(s):  
Tariq Ezaz ◽  
Nicole Valenzuela ◽  
Frank Grützner ◽  
Ikuo Miura ◽  
Arthur Georges ◽  
...  
Keyword(s):  
Sex Determination ◽  
Freshwater Turtle ◽  
Chelodina Longicollis

Food abundance and diet variation in freshwater turtles from the mid-Murray River, Australia

2018 ◽  
Vol 66 (1) ◽  
pp. 67 ◽  
Author(s):  
Kristen Petrov ◽  
Jessica Lewis ◽  
Natasha Malkiewicz ◽  
James U. Van Dyke ◽  
Ricky-John Spencer
Keyword(s):  
Green Algae ◽  
Prey Availability ◽  
Foraging Strategies ◽  
Freshwater Turtles ◽  
Food Items ◽  
Filamentous Green Algae ◽  
Invertebrate Diversity ◽  
Murray River ◽  
Specialist Species ◽  
Chelodina Longicollis

Consumers usually respond to variations in prey availability by altering their foraging strategies. Generalist consumers forage on a diversity of resources and have greater potential to ‘switch’ their diet in response to fluctuations in prey availability, in comparison to specialist consumers. We aimed to determine how the diets of two specialist species (the eastern long-necked turtle (Chelodina longicollis) and the broad-shelled turtle (Chelodina expansa) and the more generalist Murray River short-necked turtle (Emydura macquarii) respond to variation in habitat and prey availability. We trapped and stomach-flushed turtles, and compared their diets along with environmental variables (turbidity, macrophyte and filamentous green algae cover, and aquatic invertebrate diversity and abundance) at four wetlands in north-central Victoria. Diets of E. macquarii differed from those of both Chelodina species, which overlapped, across all four sites. However, samples sizes for the two Chelodina species were too small to compare among-wetland variation in diet. Dietary composition of E. macquarii was variable but did not differ statistically among sites. Emydura macquarii preferentially selected filamentous green algae at three of the four sites. Where filamentous green algae were rare, total food bolus volume was reduced and E. macquarii only partially replaced it with other food items, including other vegetation, wood, and animal prey. Many turtles at these sites also had empty stomachs. Thus, filamentous green algae may be a limiting food for E. macquarii. Although E. macquarii has previously been described as a generalist, it appears to have limited ability to replace filamentous green algae with other food items when filamentous green algae are rare.

Incubation of eggs of three species of Chelid tortoises, and notes on their embryological development

1968 ◽  
Vol 16 (5) ◽  
pp. 749 ◽  
Author(s):  
J Goode ◽  
J Russell
Keyword(s):  
Individual Differences ◽  
The Other ◽  
Large Individual ◽  
Embryological Development ◽  
Natural Conditions ◽  
Early Embryos ◽  
Incubation Periods ◽  
The Mean ◽  
Main Factors ◽  
Chelodina Longicollis

Incubation periods and nest contents of three species of chelid tortoises in northern Victoria were recorded. Mean incubation period for eggs of Emydura macquari (Cuvier) was 75 days and average number of eggs per nest was 15.7; for Chelodina longicollis (Shaw), 138 days and 10.7 eggs per nest; for Chelodina expansa Gray, normally exceeding 324 days and 15.4 eggs per nest. In abnormal seasons C. expansa hatchlings may emerge from the nest in less than 193 days or more than 522 days after eggs were deposited. Eggs artificially incubated at 30�C consistently develop more quickly than those at lower temperatures under natural conditions. In the field nest temperatures closely approximate the mean daily air temperature. Embryos of C. expansa are tolerant to nest temperatures ranging from 4.9�C minimum to 29.6�C maximum. The other species are subject to variations of about 15 degC with up to 8.5 degC variation being recorded in 1 day. Development of early embryos approximated that recorded for cryptodire tortoises. However, there are large individual differences in the period of incubation needed for specific stages to be reached, especially between embryos of the short-necked and long-necked species of these pleurodire tortoises. It is suggested that differences in the anatomy of their eggs are the main factors in the different incubation periods between short-necked and long-necked species.

Ecological and physiological impacts of salinisation on freshwater turtles of the lower Murray River

2012 ◽  
Vol 39 (8) ◽  
pp. 705 ◽  
Author(s):  
Deborah S. Bower ◽  
Clare E. Death ◽  
Arthur Georges
Keyword(s):  
Saline Lake ◽  
South Australia ◽  
Freshwater Turtle ◽  
Plasma Sodium ◽  
Freshwater Species ◽  
Freshwater Turtles ◽  
Brackish Lake ◽  
Ecological Processes ◽  
Murray River ◽  
Chelodina Longicollis

Context The increasing intensity and extent of anthropogenically mediated salinisation in freshwater systems has the potential to affect freshwater species through physiological and ecological processes. Determining responses to salinisation is critical to predicting impacts on fauna. Aims We aimed to quantify the response of wild-caught turtles from freshwater lakes that had become saline in the lower Murray River catchment. Methods Plasma electrolytes of all three species of freshwater turtle from South Australia were compared among two freshwater sites (Horseshoe Lagoon and Swan Reach), a brackish lake (Lake Bonney) and a saline lake (Lake Alexandrina). Key results Chelodina longicollis, C. expansa and Emydura macquarii from a brackish lake had higher concentrations of plasma sodium and chloride than those from freshwater habitats. However, osmolytes known to increase under severe osmotic stress (urea and uric acid) were not elevated in brackish sites. Turtles from the highly saline lake were colonised by an invasive marine worm which encased the carapace and inhibited limb movement. Conclusions Freshwater turtles in brackish backwaters had little response to salinity, whereas the C. longicollis in a saline lake had a significant physiological response caused by salt and further impacts from colonisation of marine worms. Implications Short periods of high salinity are unlikely to adversely affect freshwater turtles. However, secondary ecological processes, such as immobilisation from a marine worm may cause unexpected impacts on freshwater fauna.

scholarly journals Quantifying Costs of Urbanisation: Wetland Loss and Impacts in a Rapidly Developing Global City

2020 ◽  
Author(s):  
Harriet Gabites ◽  
Ricky-John Spencer
Keyword(s):  
Land Use ◽  
Surface Area ◽  
Social Cohesion ◽  
Green Infrastructure ◽  
Urban Areas ◽  
Wetland Loss ◽  
Urban Environments ◽  
Urban Biodiversity ◽  
Wetland Inventory ◽  
Chelodina Longicollis

AbstractAs cities grow, natural ecosystems decline through conversion to urban environments. Cities are often viewed as biodiversity wastelands, but they can be hotspots of global biodiversity. Urban biodiversity emphasises two fundamentals. First, people living in cities enjoy wildlife and second, there is virtually no planning for species that co-inhabit our cities. If urban biodiversity was a significant part of planning, then we would be far better at integrating green infrastructure into expanding urban environments.Wetlands are among the most important and productive ecosystems in the world. They are the main suppliers of fresh water for human use and provide habitat to critical fauna and flora. In urban areas they are a vital link to nature and social cohesion. Currently, there is an absence of wetland inventory quantifying loss and changes overtime. Hence the broad impacts of urbanisation on wetland loss are difficult to assess.We explored wetland loss and created a wetland inventory for Western Sydney, Australia, one of the world’s fastest growing urban regions. We used satellite imagery to determine wetland number and type, and calculated changes in wetland surface area from 2010-2017. Broad changes to land use were also quantified. We developed species distribution models of a common urban wetland turtle (Chelodina longicollis) that people interact with regularly or have as pets. Chelodina longicollis utilises both aquatic and terrestrial environments, and we determined if changes in distribution were associated with changes in the wetland inventory and urbanisation.Most local government areas (LGA) experienced a decrease in wetland surface area from 2010-2017, ranging from -1% (Cumberland) to -21% (Blacktown). Majority of LGAs experienced a decrease in wetland density, with wetland densities declining by 25% (Blacktown). All LGAs experienced an increase in urban land use, ranging from 3-12%, which was associated with high rates of wetland loss.Changes in turtle distribution over the decade reflects a southern distribution shift away from where wetland losses were concentrated. We estimated that ∼40,000 individual turtles were displaced or killed due to wetland loss and urbanisation.Urbanisation was the leading cause of wetland loss and degradation in Western Sydney between 2010 and 2017. Wetlands provide critical green infrastructure and significant green space for social cohesion in urban areas. Integration of current wetlands, or the creation of functional wetlands, is key for sustainable development of urban landscapes. Urban wetlands (natural and constructed) may provide “biodiversity arks” for endangered species and facilitate community led conservation programs.

Road mortality of the eastern long-necked turtle (Chelodina longicollis) along the Murray River, Australia: an assessment using citizen science

2018 ◽  
Vol 66 (1) ◽  
pp. 41 ◽  
Author(s):  
Claudia Santori ◽  
Ricky-John Spencer ◽  
James U. Van Dyke ◽  
Michael B. Thompson
Keyword(s):  
Citizen Science ◽  
Management Practices ◽  
Habitat Destruction ◽  
Road Mortality ◽  
Freshwater Turtles ◽  
Introduced Predators ◽  
Murray River ◽  
Time Of Year ◽  
Rain Events ◽  
Chelodina Longicollis

Turtles face a variety of threats (e.g. habitat destruction, introduced predators) that are pushing many species towards extinction. Vehicle collisions are one of the main causes of mortality of adult freshwater turtles. To conceptualise the level of threat that roads pose to Australians turtles, we analysed data gathered through the citizen science project TurtleSAT along the Murray River. We recorded 124 occurrences of turtle road mortality, which included all three local species (Chelodina expansa, Chelodina longicollis, and Emydura macquarii). Chelodina longicollis was the most commonly reported species killed on roads. We found that rain and time of year affect the likelihood of C. longicollis being killed on roads: increased turtle mortality is associated with rain events and is highest during the month of November, which coincides with their nesting season. Chelodina longicollis was most likely to be killed on the Hume Highway and roads around major urban centres; therefore, we recommend that governing bodies focus management practices and increase awareness at these locations. The degree of road mortality that we detected in this study requires mitigation, as it may contribute to the decline of C. longicollis along the Murray River.

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