Morphometric data on the intestines of the platypus Ornithorhynchus anatinus and the short-beaked echidna Tachyglossus aculeatus (original) (raw)
Related papers
2009
Outcomes Eighteen echidna were obtained for analysis (5 M:13 F), ranging in weight from 1118 to 5517 g. Mean body fat content was 542±419 g/kg bodyweight (not detectable in one animal) by DXA and 407.9±64.9 g/kg by chemical analysis. FFM were 2559±1004 g/kg and 2737±966 g/kg and BMC 89.3±34.5 g/kg and 90.3±38.5 g/kg for chemical analysis and DXA respectively. The two methods of analysis were highly correlated for all three measurement variables (r c = 0.85 fat , 0.94 FFM and 0.70 BMC) with biases of 23 % for fat (LOA ± 64%, although the bias was not constant but proportional to fat mass), 6.7% (LOA ± 37%) for FFM and-1.1% (LOA ± 62%) for BMC. Conclusion Body composition of echidna can be measured by DXA, a method applicable to live, albeit anaesthetised, animals. The wide LOA indicate, however, that the methods cannot be used interchangeably. P03 Adolescent females using common weight control techniques show biochemical evidence of reduced nutrition
Journal of Morphology, 2016
Jaculus jaculus (Lesser Egyptian jerboa) and Paraechinus aethiopicus (Desert hedgehog) are small mammals which thrive in desert conditions and are found, amongst others, in the Arabian Peninsula. J. jaculus is omnivorous while P. aethiopicus is described as being insectivorous. The study aims to describe the gastrointestinal tract (GIT) morphology of these animals which differ in diet and phylogeny. The GITs of J. Pereira 2 jaculus (n=8) and P. aethiopicus (n=7) were weighed, photographed, and the length, basal surface areas and luminal surface areas of each of the anatomically distinct gastrointestinal segments were determined. The internal aspects of each area were examined and photographed while representative histological sections of each area were processed to wax and stained using haematoxylin and eosin. Both species had a simple unilocular stomach which was confirmed as wholly glandular on histology sections. P. aethiopicus had a relatively simple GIT which lacked a caecum. The caecum of J. jaculus was elongated, terminating in a narrow cecal appendix which contained lymphoid tissue on histological examination. The internal aspect of the proximal colon revealed distinct V-shaped folds. Stomach content analysis of J. jaculus revealed mostly plant and seed material and some insects, whereas P. aethiopicus samples showed plant material in addition to insects, indicating omnivorous feeding tendencies in areas where insects may be scarce.
Field biology of the platypus (Ornithorhynchus anatinus): historical and current perspectives
Philosophical Transactions of the Royal Society B: Biological Sciences, 1998
The ¢eld biology of the platypus, Ornithorhynchus anatinus, was ¢rst studied by a number of expatriate biologists who visited the Australian colonies to collect specimens in the 1800s. Their work was followed in the early to mid-1900s by a group of resident natural historians and later by an increasing number of academic biologists. All of these workers contributed signi¢cantly to the current understanding of the ¢eld biology of this unique Australian species. The platypus occupies much the same general distribution as it did prior to European occupation of Australia, except for its loss from the state of South Australia. However, local changes and fragmentation of distribution due to human modi¢cation of its habitat are documented. The species currently inhabits eastern Australia from around Cooktown in the north to Tasmania in the south. Although not found in the west-£owing rivers of northern Queensland, it inhabits the upper reaches of rivers £owing to the west and north of the dividing ranges in the south of the state and in New South Wales and Victoria. Its current and historical abundance, however, is less well known and it has probably declined in numbers, although still being considered as common over most of its current range. The species was extensively hunted for its fur until around this turn of this century. The platypus is mostly nocturnal in its foraging activities, being predominantly an opportunistic carnivore of benthic invertebrates. The species is homeothermic, maintaining its low body temperature (32 8C), even while foraging for hours in water below 5 8C. Its major habitat requirements include both riverine and riparian features which maintain a supply of benthic prey species and consolidated banks into which resting and nesting burrows can be excavated. The species exhibits a single breeding season, with mating occurring in late winter or spring and young ¢rst emerging into the water after 3^4 months of nurture by the lactating females in the nesting burrows. Natural history observations, mark and recapture studies and preliminary investigations of population genetics indicate the possibility of resident and transient members of populations and suggest a polygynous mating system. Recent ¢eld studies have largely con¢rmed and extended the work of the early biologists and natural historians.
Journal of morphology, 2016
Jaculus jaculus (Lesser Egyptian jerboa) and Paraechinus aethiopicus (Desert hedgehog) are small mammals which thrive in desert conditions and are found, among others, in the Arabian Peninsula. Jaculus jaculus is omnivorous while P. aethiopicus is described as being insectivorous. The study aims to describe the gastrointestinal tract (GIT) morphology of these animals which differ in diet and phylogeny. The GITs of J. jaculus (n = 8) and P. aethiopicus (n = 7) were weighed, photographed, and the length, basal surface areas, and luminal surface areas of each of the anatomically distinct gastrointestinal segments were determined. The internal aspects of each area were examined and photographed while representative histological sections of each area were processed to wax and stained using haematoxylin and eosin. Both species had a simple unilocular stomach which was confirmed as wholly glandular on histology sections. Paraechinus aethiopicus had a relatively simple GIT which lacked a ca...
Energetics and foraging behaviour of the Platypus Ornithorhynchus anatinus
2002
In this work, behavioural field studies and metabolic studies in the laboratory were conducted to elucidate the extent of adaptation of the platypus Ornithorhynchus anatinus to its highly specialised semiaquatic lifestyle. Energy requirements of platypuses foraging, resting and walking were measured in a swim tank and on a conventional treadmill using flow-through respirometry. Foraging behaviour and activity pattern of platypuses in the wild were investigated at a sub-alpine Tasmanian lake where individuals were equipped with combined data-logger-transmitter packages measuring foraging activity or dive depth and ambient temperature. Energy requirements while foraging in the laboratory were found to depend on water temperature, body mass and dive duration and averaged 8.48 W kg-1. Mean rate for subsurface swimming was 6.71 W kg-1. Minimum cost of transport for subsurface swimming platypuses was 1.85 J N-1m-1 at a speed of 0.4 m s-1. The metabolic rate of platypuses resting on the water surface was 3.91 W kg-1 while minimal RMR on land was 2.08 W kg-1. The metabolic rate for walking was 8.80 and 10.56 W kg-1 at speeds of 0.2 and 0.3 m s-1, respectively. Minimal cost of transport for walking was predicted to be 2.13 J N-1m-1 at a speed of 1.7 m s-1. A formula was derived, which allows prediction of power requirements of platypuses in the wild from measurements of body mass, dive duration and water temperature. Activity patterns of platypuses in the wild were highly variable. Forty percent of the platypuses studied showed patterns, which deviated considerably from the nocturnal pattern generally reported for the species. Some animals showed diurnal rhythms while others temporarily followed the lunar cycle. Foraging trips lasted for an average of 12.4 h of continuous foraging activity per day (maximum: 29.8 hours). There were significant differences in diving behaviour between sexes and seasons. Activity levels were highest between August and November and lowest in January. While foraging, platypuses followed a model of optimised recovery time, the optimal breathing theory. Mean dive duration was 31.3 seconds with 72 % of all dives lasting between 18 and 40 seconds. Mean surface duration was 10.1 seconds. Mean dive depth was 1.28 m with a maximum of 8.77 m. Up to 1600 dives per foraging trip with a mean of 75 dives per hour were performed. Only 15 % of all dives were found to exceed the estimated aerobic dive limit of 40 seconds indicating mainly aerobic diving in the species. Total bottom duration per day was proposed as a useful indicator of foraging efficiency and hence habitat quality in the species. In contrast to observations made earlier in rivers, temporal separation was found to play a vital role for social organisation of platypuses in the lake system that was investigated. It is suggested that high intra-specific competition as well as limited burrow sites and a limited number of at the same time highly productive foraging locations were responsible for this observation. Mean burrow temperature in the wild was 17.5 and 14.2 degrees C in summer and winter, respectively, and was fairly constant over the platypus's resting period. In the cooler months, burrow temperature was up to 18 degrees C higher than ambient air temperature. By combining both field and laboratory data, a time-energy budget for the platypus was created. Mean field metabolic rate was 684 kJ kg-1 day-1 and was significantly higher in the winter months. Mean food requirement was 132 g fresh matter kg-1 day-1. Feeding rates were 68 % higher in winter than in summer. While platypuses in the swim tank were found to expend energy at only half the rate of semiaquatic eutherians of comparable body size, cost of transport at optimal speed as well as field metabolic rates were in line with findings for eutherians. These patterns suggest that locomotor efficiency of semiaquatic mammals might have reached a limit for energetic optimisation. The semiaquatic lifestyle seems to pose comparable energetic hurdles for mammals regardless of their phylogenetic origin.
The diet of the platypus Ornithorhynchus anatinus was studied by examination of material collected from the cheek pouches of animals captured while foraging in streams in Kangaroo Valley, NSW, Australia. Platypuses consumed benthic invertebrates from 55 families in 16 orders, with virtually no prey being derived from the terrestrial environment. We also sampled invertebrates in pool, riffle and stream edge habitats to identify where prey were obtained. Invertebrates in the diet were most similar to those collected along stream edges and in pools compared with the faster-flowing riffles, suggesting that platypuses focused their foraging activities largely in these deeper water habitats. Although there was no seasonality in the assemblage structure of macroinvertebrates, the diet of platypuses varied between seasons, notably between winter and summer, suggesting that some dietary selectivity is seasonal. Dietary differences between the sexes were not detected. Overall, our results suggest that some dietary selection occurs in the platypus with respect to both foraging habitat and season. Seasonal selectivity may reflect different metabolic demands on platypuses at different times of the year. In contrast, habitat selectivity may reflect difficulty of prey access and risk of prey escape in fast-flowing riffles, higher energy costs and risk of predation associated with exploiting this habitat, and prey avoidance responses that are more rapid in the shallow riffles than in the deeper water pools and stream edges. These alternatives await evaluation by future research.
Ciencia Rural, 2010
The present study compared some morphometric parameters of the digestive tract of four teleosts with different feeding habits: traira (Hoplias malabaricus, carnivore), silver catfish (Rhamdia quelen, omnivore), hassar (Hoplosternum littorale, omnivore), and grass carp (Ctenopharyngodon idella, herbivore). The digestive tract was removed from fish collected from nature and fixed for some morphometric analyses, such as: intestinal quotient, intestinal area quotient, vilosity height, digestive somatic index, and hepatosomatic index. Grass carp showed the highest values of intestinal quotient and height vilosity. On the other hand, the intestinal area quotient was higher in traira than in the other species. The intestinal quotient can be used to estimate the feeding habit, and the intestinal area quotient, vilosity height and the relationships between digestive tract length and fish weight or digestive tract weight can provide important additional information to analyze the feeding habits.
Seasonal changes in food selection and nutrition of captive platypuses (Ornithorhynchus anatinus)
Australian Journal of Zoology, 2017
Anecdotal observations of captive platypuses (Ornithorhynchus anatinus) suggest that they show a seasonal preference for particular foods, but this has never been rigorously measured. This study aimed to determine seasonal food preferences and energy consumption of captive platypuses so that better protocols for maintaining platypuses in captivity can be developed. Seven platypuses were fed an ad libitum diet with all food items weighed in and out of tanks. Food items were analysed for energy, fats, carbohydrates, proteins, vitamins and minerals. Platypuses preferred less mobile prey (mealworms, earthworms and fly pupae) over highly mobile prey (crayfish). There was no significant seasonal change in preference for different dietary items, which is more likely to be driven by prey behaviour. Crayfish contributed the largest percentage (mass) consumed and was highly nutritious. While the relative percentage of items in the diet did not change seasonally, the quantity eaten did. The me...
MORPHOMETRICS OF THE ALIMENTARY CANAL OF FIVE INSECT SPECIES IN DIFFERENT FEEDING HABITS
The morphometrics of the alimentary canal (AC) of five insect species viz., Agathocles limbatus (sap feeder), Hemiptera; Apis indica (pollen and nectar feeder), Hymenoptera; Chrysomya megacephala (Omnivorous), Diptera; Oxya chinensis (Herbivorous), Orthoptera, and Periplaneta americana (Omnivorous), Orthroptra were studied. Total lengths of the AC of all five insect species were measured. Length and width of all the parts of the foregut, mid gut and hindgut were also measured by an ocular and a stage micrometer. Percentages of the length of different parts of the AC were calculated for the above mentioned insect species. One way 'Analysis of variance' and "Tukey"s honest significance difference" tests were prepared for multiple comparisons of the results. The longest and the shortest AC were found in Periplaneta americana (68.88 mm ± 6.36) and Apis indica (14.43 ± 1.38 mm), respectively. Crop was absent in A. limbatus and proventriculus was absent in A. limbatus and C. megacephala. Length and widths of each part of the foregut were significantly different (p < 0.05) from each other. The highest percent (19.46) of crop was present in C. megacephala and proventriculus (13.12) was present in O. chinensis. Lengths and widths of each of the parts of the mid gut and hindgut were significantly (p < 0.05) different from each other except the width of the Malpighian tubules. The highest per cent of midgut caeca (15.18) and Malpighian tubules (25.47) were present in O. chinensis.
Short-beaked echidnas (Tachyglossus aculeatus) are myrmecophages, or ant and termite insectivore specialists, and replicating their exact diet in captivity is problematic. Diets for captive animals often incorporate raw meat, eggs and cat food mixed together with water, and vitamin and mineral supplements. These diets have promoted a number of health problems in captive echidnas, such as gastritis, cystitis, gut impaction, obesity, and diarrhea. A manufactured diet was designed and three echidnas from two zoos were transitioned onto this diet to assess the acceptability and digestibility of this diet for echidnas. The new "test" diet was readily accepted by the echidnas with a 1 week transition period. Daily digestible energy intake was 280 kJ kg À0.75 d À1 , similar to another myrmecophagous species. Digestibility values were above 74% for all macronutrients. It was determined that this diet was an acceptable replacement for the previous diets and it was decided that the remaining echidnas at both institutions would be transitioned to the new diet. The diet will also be used for wild echidnas being rehabilitated in the zoo hospitals prior to release and commercially available within Australia. Further data are being collected to assess the use of this diet for seasonal weight management, transitioning hand-reared puggles and effects on gastrointestinal tract health.