Analysis of Stomach Contents of Dugongs From Queensland.

1982 ◽  
Vol 9 (1) ◽  
pp. 55 ◽  
Author(s):  
H Marsh ◽  
PW Channells ◽  
GE Heinsohn ◽  
J Morrissey
Keyword(s):  
Quantitative Analysis ◽  
Stomach Contents ◽  
Seagrass Beds ◽  
Epiphytic Algae ◽  
Island Area ◽  
Generic Composition ◽  
Torres Strait

Quantitative analysis of samples of the stomach contents of 95 north Queensland dugongs, Dugong dugon, (63 from the Townsville area, 30 from the Mornington Island area and 2 from the Torres Strait area) and one dugong from south Queensland indicates that the diet of most consisted almost entirely of seagrasses of all available genera. Halodule was found in 95% of stomachs, followed by Halophila (89%). Cymodocea (61%) and Thalassia (39%). Seagrass rhizomes were present in all stomachs examined including that of a newborn calf. The generic composition of the stomach contents probably reflects that of the seagrass beds in the areas where the dugongs were captured and is not necessarily indicative of discrimination in selecting food. Non-epiphytic algae occurred in 51% of the stomachs, usually in small amounts. When seagrasses were abundant, dugongs appeared to eat algae often but only in very small amounts (<2% of food volume). Dugongs do not appear to be well adapted to utilize algae as food and probably usually consume them incidentally with seagrasses. Many of the dugongs which drowned in the shark nets near Townsville in the year after a cyclone had severely damaged the seagrass beds in the area, had eaten more of the seagrasses Cymodocea and Thalassia, less of the seagrasses Halodule and Halophila, and more algae than animals which died in other years.

scholarly journals Marsh Rice Rat, Oryzomys palustris, Predation on Forster's Tern, Sterna forsteri, Eggs in Coastal North Carolina

2003 ◽  
Vol 117 (4) ◽  
pp. 654
Author(s):  
John H. Brunjes ◽  
W. David Webster
Keyword(s):  
North Carolina ◽  
Stomach Contents ◽  
Nesting Success ◽  
Small Islands ◽  
Island Area ◽  
Harbor Island ◽  
Cedar Island ◽  
Marsh Rice Rat ◽  
Oryzomys Palustris

Nesting success of Forster’s Terns (Sterna forsteri) was examined on two small islands in the Cedar Island area of North Carolina. Forster’s Terns laid an average of 2.1 eggs per nest (n = 50) on Chainshot Island and 2.1 eggs per nest (n = 43) on Harbor Island in clutches that consisted of 1 to 3 eggs. On Chainshot Island every egg (n = 107) was lost to predation. On Harbor Island, 72 of 92 eggs were preyed upon. A trapping program, initiated on both islands, yielded 32 Marsh Rice Rats (Oryzomys palustris). Stomach contents of 23 rats were inspected, with 92.3% from Chainshot Island and 70% of the stomachs from Harbor Island containing yolk and feathers of Forster’s Terns.

Ecology of Botany Bay. II. Aspects of the Feeding Ecology of the Fanbellied Leatherjacket, Monacanthus chinensis (Pisces : Monacanthidae), in Pisidonia australis Seagrass Beds in Quibray Bay, Botany Bay, New South Wales

1979 ◽  
Vol 30 (3) ◽  
pp. 387 ◽  
Author(s):  
MJ Conacher ◽  
WJR Lanzing ◽  
AWD Larkum
Keyword(s):  
New South ◽  
Gut Contents ◽  
Seagrass Beds ◽  
Labile Carbon ◽  
Epiphytic Algae ◽  
Food Items ◽  
South Wales ◽  
Carbon Compounds ◽  
14C Labelling ◽  
Tide Height

The fanbellied leatherjacket, M. chinensis, was found to ingest fresh seagrass as a major part of its diet. Other important food items were gammarid amphipods, carid shrimps and several species of epiphytic algae. All food items were of seagrass bed origin. Microscopic examination of gut contents suggested that seagrass and algae did not appear to be digested by the fish, but 14C-labelling of the plants showed that significant amounts of the labile carbon compounds were removed and assimilated during digestion. The fanbellied leatherjacket was found to feed in the seagrass beds during the day, probably relying on eyesight for detecting food. Variations in tide height did not seem to affect their feeding pattern. The amounts of seagrass, algae, amphipods and shrimps removed by M. chinensis in Quibray Bay were calculated and compared with the availability of each of these foods. Grazing by M. chinensis had little effect on seagrass and algae production rates and standing crops, but probably had a significant influence on carid shrimp and amphipod populations.

scholarly journals Quantitative analysis of nitrate and nitrite contents in vegetables commonly consumed in Delta State, Nigeria

2006 ◽  
Vol 96 (5) ◽  
pp. 902-905 ◽  
Author(s):  
I. Onyesom ◽  
P. N. Okoh
Keyword(s):  
Quantitative Analysis ◽  
Stomach Contents ◽  
Dry Weight ◽  
The State ◽  
Secondary Amines ◽  
Vernonia Amygdalina ◽  
Nitrite Toxicity ◽  
Frequent Consumption ◽  
Nitrate And Nitrite ◽  
Talinum Triangulare

Plasma thiocyanate has been reported to be high among cassava-eating populations such as that in Nigeria because of the cyanide content of cassava. Thiocyanate, which is secreted into the stomach contents of animals, has been demonstrated to catalyse the formation of nitrosamines (potent carcinogens) in the stomach from secondary amines and nitrite. The main source of the nitrite precursor in this environment is vegetables, primarily eaten as the chief supplier of proteins. The present study attempts to analyse the levels of nitrate and nitrite in vegetables commonly grown and consumed in Delta State, Nigeria. The nitrate and nitrite contents in green vegetable (Amaranthus spp.), bitter leaf (Vernonia amygdalina), pumpkin (Telfaria occidentalis) and water leaf (Talinum triangulare) grown in different localities of the state were determined by standard analytical procedures. The results show that those vegetables grown in the industrialised urban centres of the state had higher nitrate (223 (sd 71) mg/kg dry weight; P<0·05) and nitrite (12·6 (sd 1·7) mg/kg dry weight; P>0·05) levels when compared with the same species (188 (sd 77) mg nitrate/kg dry weight and 10·9 (sd 1·1) mg nitrite/kg dry weight) cultivated in less industrialised suburbs. We conclude that frequent consumption of such vegetables whose nitrate and nitrite contents are high by cassava-eating individuals might put them at risk of developing stomach cancer and other possible results of nitrate and/or nitrite toxicity. In order to avoid an outbreak in our communities, appropriate agencies should monitor and regulate the release of chemicals into the environment. In the meantime, the cultivation and consumption of vegetables grown in industrialised areas of the state should be discouraged.

Comparison of the diets of sympatric dugongs and green turtles on the Orman Reefs, Torres Strait, Australia

2005 ◽  
Vol 32 (1) ◽  
pp. 53 ◽  
Author(s):  
Jessica André ◽  
Emma Gyuris ◽  
Ivan R. Lawler
Keyword(s):  
Stomach Contents ◽  
Chelonia Mydas ◽  
Food Resources ◽  
Thalassia Hemprichii ◽  
Green Turtles ◽  
Large Numbers ◽  
Full Explanation ◽  
Feeding Area ◽  
Torres Strait ◽  
Syringodium Isoetifolium

This study investigated the diet of dugongs (Dugong dugon, Dugongidae) and green turtles (Chelonia mydas, Cheloniidae) on the Orman Reefs in Torres Strait, between Australia and Papua New Guinea, where large numbers of these animals live sympatrically. The stomach contents of dugongs and green turtles caught in an indigenous fishery were examined. Dugongs fed exclusively on seagrasses (mainly Thalassia hemprichii, Cymodocea spp. and Syringodium isoetifolium) whereas turtles consumed both seagrasses (especially T. hemprichii and Enhalus acoroides) and algae (mainly Hypnea spp., Laurencia spp. and Caulerpa spp.). The two herbivores showed no overlap in resource use except for the seagrass T. hemprichii, which was abundant in the feeding area. Both species appeared to feed selectively and did not just consume the most available food items. These results are suggestive of partitioning of food resources between dugongs and green turtles but a full explanation requires more detailed, and concurrent, study of the food resources and the animals’ movements.

scholarly journals Stomach content analysis of a Dugong (Dugong dugon) from South Sulawesi, Indonesia

1993 ◽  
Vol 44 (1) ◽  
pp. 229 ◽  
Author(s):  
PLA Erftemeijer ◽  
Djunarli ◽  
W Moka
Keyword(s):  
Quantitative Analysis ◽  
Coastal Waters ◽  
Stomach Contents ◽  
Dry Weight ◽  
Stomach Content Analysis ◽  
Total Biomass ◽  
Feeding Selectivity ◽  
Individual Female ◽  
South Sulawesi ◽  
Total Dry Weight

A quantitative analysis of the stomach contents of an individual female dugong (Dugong dugon) caught by fishermen in February 1991 in the coastal waters of South Sulawesi, Indonesia, is presented. Of the total dry weight of digesta (about 3.4 kg), 98.9% consisted of seagrass material. Rhizome and root material of smaller pioneering genera (i.e. Halophila, Halodule, Cymodocea) accounted for 71.5% of the total dry weight. Enhalus acoroides dominated among leaf material (about 50%), but its contribution to the total biomass of the stomach contents was only 13.5%. Rhizome material of Enhalus and Thalassia was absent. The amount of sediment in the stomach was negligible. The results are compared with those from similar studies, and the implications for possible feeding selectivity are discussed.

scholarly journals Species composition and distribution characteristic of seaweeds on seagrass beds in Phu Quoc island

2019 ◽  
Vol 19 (4A) ◽  
pp. 229-240
Author(s):  
Nguyen Trung Hieu ◽  
Hoang Xuan Ben ◽  
Mai Xuan Dat
Keyword(s):  
Species Composition ◽  
Seagrass Beds ◽  
Distribution Characteristic ◽  
Epiphytic Algae ◽  
Favorable Environment ◽  
Species Composition And Distribution ◽  
Total Species

Seagrass beds in Phu Quoc are a favorable environment for seaweed development (bottom-living and epiphytic species). The surveys at 18 sites along the coastal line in Phu Quoc island showed that 69 species belonging to 4 phyla of seaweed were recorded on seagrass beds in Phu Quoc island. Among them, there are 27 species of Rhodophytes (comprising 37% of total species), 19 Chlorophytes (28%), 16 Ochrophytes (24%) and 7 Cyanobacteriophytes (11%). We identified 12 species of epiphytic algae including three species on seagrass and nine species on both seagrass and the substratum. The characteristics of substratum may play an important role for diversity and distribution of the bottom-living seaweed. For epiphytic algae on bigger size seagrass, the diversity of epiphytic species on the top of seagrass leaf is higher than on the root and other parts of leaf.

scholarly journals Status Trofik Ikan yang Berasosiasi dengan Lamun (Seagrass) di Tanjung Luar Lombok Timur

2014 ◽  
Vol 14 (2) ◽  
Author(s):  
Abdul Syukur, Yusli Wardiatno Ismudi Muchsin2) dan Mohammad Mukhlis Kamal
Keyword(s):  
Marine Environment ◽  
Trophic Status ◽  
Stomach Contents ◽  
Seagrass Beds ◽  
Ecological Functions ◽  
Carnivorous Fish ◽  
The Family ◽  
Food Fish ◽  
Study Sites

ABSTRAKLamun di lingkungan laut berperan penting dalam proses pembentukan rantai makanandetritus dan herbivora. Penelitian ini bertujuan untuk menentukan status trofik ikanberdasarkan jenis makanan. Contoh ikan diambil pada lima lokasi padang lamun yaitu: GiliKere, Gili Maringkik, Kampung Baru, Lungkak dan Poton Bakau dengan menggunakan minipure seine. Analisis status trofik ikan dilakukan berdasarkan jenis makanan yang ditemukanpada isi lambung. Status trofik dikelompokkan dalam status trofik herbivora, carnivora,planktivora dan omnivora. Status trofik ikan yang ditemukan pada semua lokasi penelitiandidominasi oleh ikan dengan status trofik carnivora sebesar 58,62 %, status trofik herbivorasebesar 17, 64 %, status trofik planktivora 17,64 % dan status trofik omnivora 5,88 %. Ikanyang berasosiasi dengan lamun pada lokasi penelitian sebagian besar untuk mencari makan.Namun demikian jenis ikan dari famili Apogonidae dengan spesies Archamia goni dan familiMonacanthidae dengan spesies Plectorhinchus falvomaculatus menggunakan lamun tidakhanya sebagai tempat mencari makan tetapi juga sebagai tempat untuk memijah, tinggalmassa juvenil dan massa dewasa. Kesimpulan dari penelitian adalah status trofik ikan danbentuk asosiasi ikan dengan lamun sebagai indikator fungsi ekologi lamun yang sangat vitaluntuk ikan dapat survive.Kata Kunci: Lamun, Status Trofik Ikan dan Asosiasi Ikan dengan Lamun.ABSTRACTSeagrass in the marine environment plays an important role in the process of detritus foodchain and herbivores. This study aims to determine the trophic status of fish based on the typeof food. Fish were taken on the five locations seagrass beds: Gili Kere, Gili Maringkik,Kampung Baru, Lungkak dan Poton Bakau by using pure mini seine. Analysis of trophicstatus of fish is done based on the type of food that is found in the stomach contents. Trophicstatus are grouped into trophic status of herbivores, carnivores, omnivores and planktivora.Trophic status of fish found in all study sites are dominated by carnivorous fish with trophicstatus of 58.62%, herbivore trophic status of 17, 64%, trophic status planktivora 17.64% and5.88% omnivorous trophic status. Fish associated with seagrass research sites mostly forforaging. However, the type of fish of the family Apogonidae with Archamia goni and familyMonacanthidae with Plectorhinchus falvomaculatus use seagrass not only as a feeding sitesbut also as a place to spawning, mass live juvenile and adult the mass. The conclusion of the study is the trophic status of fish and fish form of association with seagrass as an indicator ofthe ecological functions that are vital for the fish to survive.Key Words: Seagrass, Trophic Status of Fish and Fish with Seagrass Association.

13C/12C ratios in marine food webs of the Torres Strait, Queensland

1983 ◽  
Vol 34 (5) ◽  
pp. 707 ◽  
Author(s):  
B Fry ◽  
RS Scalan ◽  
PL Parker
Keyword(s):  
Food Webs ◽  
Food Sources ◽  
Important Food ◽  
Epiphytic Algae ◽  
Δ13c Values ◽  
Marine Food Webs ◽  
Seagrass Meadows ◽  
Marine Food ◽  
Torres Strait ◽  
Intertidal Seagrass

During a research cruise in 1979 to the area between New Guinea and northern Australia, 250 samples were collected for measurement of 13C/12C (δ13C) to analyse carbon flow in tropical marine food webs. Plants at the base of food webs could be divided into two groups on the basis of their mean δ13C values: benthic seagrasses (-8.8‰), macroalgae (-12.5‰) and epiphytic algae (-13.3‰) were enriched in 13C (had less-negative δ13C values) when compared to planktonic samples (-21.8‰). Animals collected offshore were enriched in 13C by up to 9.1‰ relative to planktonic samples and seemed to show an increasing 13C enrichment with increasing trophic level. Relative to these offshore specimens, animals collected in intertidal seagrass meadows were usually enriched in 13C by 2-8‰, indicating that 13C-enriched benthic plants are important food sources in grassflats. Unusual 13C- enriched values of -3 to -7‰ among benthic chitons, gastropods and holothurians at one grassbed site suggest that unsampled benthic microalgae are also important sources of food-web carbon in the Torres Strait.

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