A Species of Mouse-Like Marsupial - Fat-Tailed Dunnart - Term Paper Example

Running Header: Fat Tailed Dunnart Student’s Name: Instructor’s Name: Course Code: Date of Submission: Table of Contents Table of Contents 2 Acknowledgements 3 Abstract 4 Introduction 5 Literature review 6 Habitats, Distribution and Status 6 Diet 7 Life Cycle & Reproduction 8 Anatomy & Research 9 Sickness & Diseases 12 Behavioral Characteristics 12 Threats 13 Conclusion 13 Work Cited 14 List of Figures 17 Acknowledgements I owe several people appreciation, love and gratitude. It would have been impossible to complete this work without their help and encouragement. Special thanks to my supervisor who directed and advised me on how to undertake this work. He encouraged me to think critically for myself. He taught me to work hard for my own gain. He has impacted me with a lot of knowledge needed in this field. I also owe a lot of appreciation to my colleagues and dear friends who gave me a lot of encouragement in my studies and research. They were supportive all the time, and that’s why I owe them respect and gratitude. Sincere thanks goes to my department, which has made my work successful. Several of my classmates rely on its support for their benefit. My department and lectures have made a lot of my research be realized. May God bless you for your support, encouragements and guidance which have made me to come this far. Abstract The fat-tailed Dunnart is scientifically referred as Sminthopsis crassicaudata. It is a small marsupial which is carnivorous. It has a body length of 60-90mm with a tail length of 45-70mm. It has adipose tissue which is detectable and brown in color. Fat-tailed Dunnart is found in various regions of Australia with diversified habitats except in Tasmania region (Menkhorst 67). They prefer staying in open shrub-lands, sparse grasslands and uncultivated farmlands. The only region where they are not found is Tasmania. Fat-tailed Dunnart mostly relies on insects and small amphibians for their meal. One notable aspect about the Fat-tailed Dunnart is that it is nocturnal (Groves 35). It spends most of its day time sleeping while it eats during the night. They are several tests that have been experimented on fat-tailed Dunnart to asses the effects of various factors like of photoperiod, food deprivation and tail removal. Other tests have been done to verify whether amino acids have some percentage of similarity or whether they are identical. Human amino acids are 60 percent identical to those of Fat-tailed Dunnart. Fat-tailed Dunnart is in most cases solitary or alone. They behave different especially females when they have litters because they usually kill male partners (Theresa 15). Carnivores and rainfall usually threatens the life of Fat-tailed Dunnart. Introduction Fat Tailed Dunnart is a species of mouse like marsupial. It is of Dasyuridae family, others in this same family include the Quolls, Tasmanian devil and Little Red Kaluta. Its average body length is 60-90mm with its tail of 45-70mm. its ear is 14-16mm in length with its weight varying between 10-20 grams. Female Dunnart takes an average of 115 days to mature while males take 159 days to maturity. The gestation period is around 14 days. Young ones enter the pouch of their mother and attach themselves to the pouch. The young ones remain in the pouch for at least 70 days after which they are weaned and move to live on their own. The litter size is approximately 7.5 with infant death rate of approximately 33 percent. Dunnart’s average body temperature is roughly 34.85 degrees centigrade. Fat-tailed Dunnart is among the smallest in the carnivorous marsupials. Its tail becomes fat just a few millimeters from the anus up to the tails tip. Fat-tailed Dunnart species is widely distributed across central and southern Australia as well as west of the Great Divide (Stephen 54). Fat-tailed Dunnart differ in behavior and external morphology due to the difference in geographical areas. From the latest investigation, there are over 1000 Dunnart in their colony. Fat-tailed Dunnart are usually nocturnal. They mainly eat insects and lizards. Literature review Habitats, Distribution and Status Fat-tailed Dunnart are found in varieties of habitats. They can be found in open shrub-lands, sparse grasslands and farmlands especially where there is bare land. Unimproved farming has a positive impact for this species mainly because the habitat created is most suitable for Dunnart’s habitat requirements. Therefore, extensive agriculture is a negative factor to this species survival. Fat tailed Dunnart shelter themselves from extensive heat in small nest made of glass as well as in leaved usually built under rocks, logs and in deep cracks in the soil. These species are adopted well to land clearance changes (Answers.com). Photo 1: Fat-tailed Dunnart in their habitats from Vicnet.net Fat-tailed Dunnart is found in diverse habitats in Australia except in Tasmania. However, it is hard to find them in Western Australia at Kimberley region as well as in Northern Territory like Kakadu Park and Arnhern. They avoid Victoria’s Mallee and Wannon scrub habitats in most cases. The species is also found in samphire and grassy woodlands in northeast of Victoria. The subspecies S. c. crassicaudata is found in Queensland at Epping Forest National Park. Other subspecies like S. c. centralis are found in east of Lake Eyre at Killalpanima. S. c. Ferruginea sub-species are found in South Australia around Lake Eyre. SA Fat tailed Dunnart can be found in several Australian deserts like Gibson and Simpson Desert (Finlayson). Figure 1: Black regions showing Fat-tailed Dunnart Figure 2: Brown regions showing fat-tailed distribution in Australia Dunnart distribution in Australia Diet Fat-tailed Dunnart’s main diet comprises insects such as spider larvae, beetles, termites, locusts, centipedes, scorpions, cockroaches and moths. Other diets include baby mice, lizards and small amphibians. Fat-tailed Dunnart are known to eat more than their weight per every night. It stores excess fat in its tail that is used during the food shortage season. This makes them not to become affected by long winter seasons that may occur. This is mainly due to shortage of some insects in their territory (Department for Environment and Heritage 52). Life Cycle & Reproduction Fat-tailed Dunnart breeds from July to February. Gestation period lasts for 13-15 days. Young ones enter the pouch of their mother and attach themselves to the pouch. The young ones remain in the pouch for at least 70 days after which they are weaned and move to live on their own. The litter size is approximately 7.5 with infant death rate of 33 percent. They have 2 litters per year but the females do not breed in the first year. However, it is possible for a fat-tailed Dunnart to have a litter after every 94 days. Females have an average of 155 days while males have an average of 159 days before they start breeding. The life span of Fat-tailed Dunnart is five years (Renfree 436). Table 1: Postnatal growth and development from Menkhorst Anatomy & Research Fat-tail Dunnart has a tail of tail being 45-70mm. the tail is adapted in such a way that it stores excess fat in it for using during the winter or hot seasons when food becomes scarce. Food is usually converted to fats that are stored in the tail. The tall is long and thick hence being able to store enough fat. This is an excellent adoption for survival (Pat 98). Photo 2: Hand held Fat-tail Dunnart showing the tail from Gibson Desert Nature Reserve There are some effects of photoperiod, food deprivation and tail removal on Dunnart. Brown adipose tissue (BAT) presence in Marsupials is a debatable issue. This is because it attempts to identify unsuccessful mitochondrial uncoupling protein (UCP). Fat-Tailed Dunnart has inter-scapular pad of adipose. It has been revealed that, inter-scapular pad of adipose has characteristic typical of BAT. BAT was confirmed by UCP and Guano-sine Di-phosphate binding detection through immune-blot. UCP expression was increased by exposure to cold. Temperature was reduced from 28 to 15 degrees centigrade; this made body temperature decrease by 1.7 degrees centigrade within 30 minutes. It further decreased by 1 degree centigrade in 90 minutes before stabilizing at lower levels. Temperature was returned to 28 degrees centigrade, this made body temperature increase within 30 minutes and returned to basal within 120 minutes. Once temperature was retained at 15 degrees centigrade with ad Libitum food for approximately 12 days, tail width, oxygen consumption, and body temperature decreased. There was an increase in respiratory quotient which was a clear indication of fat to carbohydrates change. There was no change in food intake while body weight increased in the first day before going back to baseline on the third day and thereafter it remained stable. This shows how Fat-Tailed Dunnart changes substrate utilization so as to maintain balance of energy as well as composition of the body. All this happen without necessary increasing food consumption rate or metabolic rate (Fritz & Baidinitte 340; Shannon & Peter A5). According to research that has been done to identify the percentage of identity in amino acids. It included several vertebrates like human beings and Dunnart. Table 2 shows the percentage of identical residues that are shared between various species over entire protein length. They reveal that Dunnart Opn4 is 57-60 percent identical to that of mouse, chicken, and human. However, it is only 38 percent to lizard (Bennet, Breed, Hayman & Hope 210; Susana & Julia 2791). Table 2: Percentage amino acid identity across sequence of various vertebrate Sminthopsis crassicaudata (Fat tailed Dunnart) has a tail that contains 25 percent of total body fat. Both Dunnart genders were put in captivity on a long day of 8 hours of darkness and 16 hours of light. There were also kept for 15 hours in darkness and 9 hours in light. Feeding patterns with short day and long day photoperiods were measured under ad Libitum food supply. Others were exposed to 24 and 36 hours of food deprivation conditions. Feeding happened on dark conditions. Food intake reduction was not associated with any decrease in tail thickness or body weight. With 24 and 36 hours fast, food intake was increased in subsequent 24 hours by up to 100 percent. Nevertheless, there was no consequence on either photoperiod or gender. After 36 hours of fasting, width of the tail was seen to decrease in all groups. Constant-food supply under dark conditions had an effect on the tail thickness, it increased significantly. The body weight also decreased in all animals after fasting (Australian wildlife Research). Tail removal in Fat-tailed Dunnart has also been researched extensively. Removal of the tail resulted to fall in body weight. However, this was recovered after three weeks. Their body fats contents was 30 percent more than those which had tails. The food intake rate had no considerable increase. This was evidence that some fat moves to the tail. Sickness & Diseases Fat-tailed Dunnart has fleas and mites that affect their skin after biting their skins. The most common flea is referred as Ornithonyssus bacoti. Other diseases are respiratory infections that occur especially during the rainy season (John 55; Vicnet.net). Behavioral Characteristics Fat-tailed Dunnart is in most cases partially solitary. It stays alone during the breeding season except the mating period. Small clusters of not more than 10 Dunnart huddle together during the night when sleeping. This happens when it is chilly and more warmth is required. They prefer resting at logs, burrows and sheltered location. Fat-tailed Dunnart is nocturnal; they are active during the night time. Fat-tailed Dunnart spend up majority of their daytime sleeping. Females are not receptive to the males after giving birth to a litter. Females with litters kill females housed together with them. Fat-tailed Dunnart have extremely poor thermoregulatory abilities like several other marsupials. This is a suggestion that females with litters may be solitary and territorial in their natural habitat. Fat-tailed Dunnart enter into a thermo-regulatory mutualism with the Mus musculus during colder months. Natural inactivity incidences are extremely low during winter with mixed species aggregations being incredibly common (Jessica A4). Threats Fat-tailed Dunnart are usually threatened by several factors in their habitats. Their population is usually affected by rainfall. They decrease significantly during the rain seasons, this mainly because they live in dried rivers and lakes cracks. Immense floods usually carry them thus drowning them to death. Hyenas and other carnivores are threats to these small creatures. They are also targeted by big snakes who hunt for them in their hide outs (Clive & Rory 3). Conclusion Fat-tailed Dunnart are one of the smallest marsupial animals that are not very common. It is rarely found in other regions in the globe. This species should be nurtured and looked after before their extinction. They are essential animals especially in research areas and other aspects of bio-diversity. Their life cycle is one of the simplest among animals. Fat-tailed Dunnart have some common aspects with human beings that are almost equal in percentage like the case of amino acids. They have some funny behaviors when it comes to socializing and doing their activities. Fat-tailed Dunnart is an animal that draws attention of many scholars and researches because of their peculiar lifestyle. Work Cited Answers.com. Fat-tailed Dunnart. 14 July 2001. 8 April 2010. http://www.answers.com/topic/fat-tailed-dunnart Australian wildlife Research. An Ecological Study of sminthopsis crassicaudata (marsupialia: Dasyuridae). Sydney, Australia: Wildlife Research management and conservation, 1996. Bennet John, Breed Wiger, Hayman Decker and Hope Riyer. “Reproduction and genetical studies with a laboratory colony of the dasyurid marsupial Sminthopsis crassicandata”. Sminthopsis crassicaudata 37, (1991): 207-222. Clive Chesson and Rory Hope. “Austrilian Marsupials.” Captive breeding and maintenance of the fat- tailed Dunnart 8.4 (1995): 2-4. Department for Environment and Heritage. Parks of the Riverland. Berri, Australia: Authority of the Wildlife conservation.2009. Finlayson. Fat-tailed Dunnart. 2 Nov. 2008. 8 April 2010. http://www.freebase.com/view/en/fat- tailed_dunnart Fritz Geiser & Baidinitte Vike. “Biomedical and Life Science.” Seasonality of torpor and thermoregulation in three Dasyurid marsupials 157.3 (1987): 335-344. Gibson Desert Nature Reserve. Fat-tailed Dunnart (sminthopsis crassicaudata. 23 August 2003. 8 April 2010. http://members.iinet.net.au/~foconnor/mammals/species/sminthopsis_crassicaudata.htm Groves, C. Mammal species of the World. New York, NY: Johns Hopkins University Press, 2005. Jessica Strachan. “Cone visual pigments of the Australian Marsupials, the stripe-faced and fat- tailed Dunnart: sequence and inferred spectral properties.” Herald Sun (Melbourne) 5 April 2005: A4. John, Fakal. “Mammals of Australia.” sminthopsis crassicaudata 1 (1998): 52-55. Menkhorst, Peter K. Australasian Marsupial & Mammals of Victoria. London: Oxford press, 1995. Pat, Slater. First Field Guide to Australian Mammals. Melbourne: Steve Parish Publishing, 2000. Renfree Mobber, Shaw Giky and Fletcher Tucker. “Evidence for the essential role of prostaglandians for parturition in a marsupial”. Reproduction and Fertility of Tall- tailed Dunnart 102, (1994): 433-446. Shannon Simspon and Peter Frappell. “Metabolic and Ventilatory changes upon exposure to hypoxia and hypercapnia in neonatal fat-tailed dunnarts (Sminthopsis crassicaudata).” Mosman Daily (Sydney) 14 Feb. 2009: A5. Stephen, Jackson M. Australian mammals: biology and captive management. Michigan: CSIRO Publishing, 2003. Susana Pires and Julia Shand. “Isolation and Characterization of melanopsin (opn4) from the Australian marsupial.”Sminthopsis crasssicaudata (fat-tailed Dunnart) 274 (2007): 2791-2799. Theresa Sylvester. “Fat-Tailed Dunnart: Facts and Information.” Sminthopsis Crassicaudata 2 (2009): 12-16. Vicnet.net. Fat tailed Dunnart- Sminthopsis crassicaudata. 18 Sept. 2003. 8 April 2010. http://mc2.vicnet.net.au/home/msov/shared_files/Dunnart_Fact_Sheet.pdf List of Figures Photo 1: Fat-tailed Dunnart in their habitats from Vicnet.net. Fat tailed Dunnart- Sminthopsis crassicaudata. 18 Sept. 2003. 8 April 2010. http://mc2.vicnet.net.au/home/msov/shared_files/Dunnart_Fact_Sheet.pdf Photo 2: Hand held Fat-tail Dunnart showing the tail by Gibson Desert Nature Reserve. Fat-tailed Dunnart (sminthopsis crassicaudata. 23 August 2003. 8 April 2010. http://members.iinet.net.au/~foconnor/mammals/species/sminthopsis_crassicaudata.htm Figure 1: black regions showing Fat-tailed Dunnart Figure 2: brown regions showing fat-tailed distribution in Australia Dunnart distribution in Australia From Theresa Sylvester. “Fat-Tailed Dunnart: Facts and Information.” Sminthopsis Crassicaudata 2 (2009): 12-16. Table 1: Postnatal growth and development from Menkhorst, Peter K. Australasian Marsupial & Mammals of Victoria. London: Oxford press, 1995. Table 2: Percentage amino acid identity across sequence of various vertebrate Melanopsins from Susana Pires and Julia Shand. “Isolation and Characterization of melanopsin (opn4) from the Australian marsupial.”Sminthopsis crasssicaudata (fat-tailed Dunnart) 274 (2007): 2791-2799. Read More