scholarly journals Applying and refining DNA analysis to determine the identity of plant material extracted from the digestive tracts of katydids

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6808 ◽  
Author(s):  
Laurel B. Symes ◽  
Nicole L. Wershoven ◽  
Lars-Olaf Hoeger ◽  
Jessica S. Ralston ◽  
Sharon J. Martinson ◽  
...  
Keyword(s):  
Plant Material ◽  
Dna Analysis ◽  
Feeding Habits ◽  
Time Of Day ◽  
Barro Colorado Island ◽  
Gut Contents ◽  
Neotropical Forest ◽  
Amplification Success ◽  
Significant Difference ◽  
Primer Sets

Background Feeding habits are central to animal ecology, but it is often difficult to characterize the diet of organisms that are arboreal, nocturnal, rare, or highly mobile. Genetic analysis of gut contents is a promising approach for expanding our understanding of animal feeding habits. Here, we adapt a laboratory protocol for extracting and sequencing plant material from gut contents and apply it to Neotropical forest katydids (Orthoptera: Tettigoniidae) on Barro Colorado Island (BCI) in Panama. Methods Our approach uses three chloroplast primer sets that were previously developed to identify vegetation on BCI. We describe the utility and success rate of each primer set. We then test whether there is a significant difference in the amplification and sequencing success of gut contents based on the size or sex of the katydid, the time of day that it was caught, and the color of the extracted gut contents. Results We find that there is a significant difference in sequencing success as a function of gut color. When extracts were yellow, green, or colorless the likelihood of successfully amplifying DNA ranged from ~30–60%. When gut extracts were red, orange, or brown, amplification success was exceptionally low (0–8%). Amplification success was also higher for smaller katydids and tended to be more successful in katydids that were captured earlier in the night. Strength of the amplified product was indicative of the likelihood of sequencing success, with strong bands having a high likelihood of success. By anticipating which samples are most likely to succeed, we provide information useful for estimating the number of katydids that need to be collected and minimizing the costs of purifying, amplifying, and sequencing samples that are unlikely to succeed. This approach makes it possible to understand the herbivory patterns of these trophically important katydids and can be applied more broadly to understand the diet of other tropical herbivores.

The Ecology of the Eastern Water Rat Hydromys Chrysogaster at Griffith, N.s.w.: Food and Feeding Habits.

1978 ◽  
Vol 5 (1) ◽  
pp. 59 ◽  
Author(s):  
P Woollard ◽  
WJM Vestjens ◽  
L Maclean
Keyword(s):  
Plant Material ◽  
Feeding Habits ◽  
Starch Content ◽  
South Australia ◽  
Stomach Contents ◽  
Freshwater Mussel ◽  
Time Of Day ◽  
Gut Contents ◽  
South Wales ◽  
Hydromys Chrysogaster

The eastern water rat, Hydromys chrysogaster, lives in inland waters, estuaries, sea beaches and islands from Queensland to South Australia and Tasmania. It is adapted to semiaquatic life and changes in its molar teeth may be an adaptation to diet of crustaceans and molluscs. The present study was of 408 stomach contents and 316 contents of caecum with rectum, collected in New South Wales in 1970-73 from permanent Typha swamp. From elsewhere there were 12 other stomach and 11 gut contents and live rats were observed. At any time of day but particularly in evenings the rats swam along the bank or between logs or reed clumps, foraging and catching fish. Captive rats crushed small mussels and left large mussels to open by exposure. Diet varied with season and included crustaceans, mostly the yabbie, a crayfish (Cherax destructor), spiders, all Araneida with one identified as of the suborder Pisauridae, a fishing spider. Insects were the main food and were eaten in all seasons, and included larvae, nymphs and adults. Only 1% of rats had the freshwater mussel Veksurio ambiguus but the flesh was difficult to identify and empty shells were often found. Fish were eaten all the year, and were found in up to 35% of rats in autumn and winter; fish may be underestimated because flesh is not easily recognised and hard parts are not much eaten. Several species of fish, mostly introduced, were identified, their ages estimated from their scales, and length was calculated to be up to 36 cm. Frogs and macquaria tortoise (Emydura macquarii) were eaten. Birds were eaten all the year and were in up to 10% of stomachs in winter. Personal communications are quoted, from persons having seen H. chrysogaster capture large adult birds including duck and mutton bird (Puffinus tenuirostris). Captive rats were able to open cracked hen's eggs but left intact eggs. Plant material was eaten as food and possibly also in stomachs of prey. For 3 rats half the starch content was plant; 3 other stomachs had 5, 40 and 50% plant material, Azolla fuliculoides. Differences in diet with age are described. H. chrysogaster was an adaptable and opportunist feeder, making use of transient plenty of insects, exploiting plagues among other species and using plants during shortage of food. They may control introduced pests such as perch, or control yabbies in irrigation ditches.

scholarly journals Rainy Season Food Availability for Anurans of Kimboza Forest Reserve, Tanzania

2021 ◽  
pp. 15-25
Author(s):  
Nsajigwa Emmanuel Mbije ◽  
Asha Kamungu
Keyword(s):  
Food Availability ◽  
Rainy Season ◽  
Diet Composition ◽  
Feeding Habits ◽  
Gut Contents ◽  
Generalist Predators ◽  
Forest Reserve ◽  
Significant Difference ◽  
To Come ◽  
Prey Items

Amphibians are mostly considered to be generalist predators. Some species have a narrow diet or even specialize on certain prey categories. An assessment of the feeding habits of anuran species of Kimboza forest reserve, Tanzania was conducted during rainy season between March 2017 and June 2017. Through a visual encounter survey, 93 species were captured and analyzed for gut contents. About 462 prey items were identified the most abundant component being Isoptera and Hymenoptera. There was no significant difference (P > 0.05) in the anurans’ diet (composition or diversity or preferences) among different habitats of the forest (along boundaries and within the forest) but significant difference (P < 0.05) was found between the upper Stratum and the lower Stratum of the forest. The study provides a preliminary estimation of the actual diet of anurans and establishes a general feeding pattern for these species for the management of the Kimboza forest reserve. The study recommends the intensification of similar assessments in the nearby forest areas to come up with a complete description of the feeding habits for management purposes.

Utilizing next-generation sequencing to identify prey DNA in western North Atlantic grey seal Halichoerus grypus diet

2020 ◽  
Vol 655 ◽  
pp. 227-240
Author(s):  
KR Flanders ◽  
ZH Olson ◽  
KA Ono
Keyword(s):  
Next Generation Sequencing ◽  
Feeding Habits ◽  
Atlantic Menhaden ◽  
Halichoerus Grypus ◽  
Frequency Of Occurrence ◽  
Grey Seal ◽  
Next Generation ◽  
Significant Difference ◽  
Generation Sequencing ◽  
Seal Diet

Increasing grey seal Halichoerus grypus abundance in coastal New England is leading to social, political, economic, and ecological controversies. Central to these issues is the foraging ecology and diet composition of the seals. We studied grey seal feeding habits through next-generation sequencing of prey DNA using 16S amplicons from seal scat (n = 74) collected from a breeding colony on Monomoy Island in Massachusetts, USA, and report frequency of occurrence and relative read abundance. We also assigned seal sex to scat samples using a revised PCR assay. In contrast to current understanding of grey seal diet from hard parts and fatty acid analysis, we found no significant difference between male and female diet measured by alpha and beta diversity. Overall, we detected 24 prey groups, 18 of which resolved to species. Sand lance Ammodytes spp. were the most frequently consumed prey group, with a frequency of occurrence (FO) of 97.3%, consistent with previous studies, but Atlantic menhaden Brevoortia tyrannus, the second most frequently consumed species (FO = 60.8%), has not previously been documented in US grey seal diet. Our results suggest that a metabarcoding approach to seal food habits can yield important new ecological insights, but that traditional hard parts analysis does not underestimate consumption of Atlantic cod Gadus morhua (FO = 6.7%, Gadidae spp.) and salmon Salmo salar (FO = 0%), 2 particularly valuable species of concern.

Parasites in Antarctic krill guts inferred from DNA sequences

2019 ◽  
Vol 31 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Alison C. Cleary ◽  
Maria C. Casas ◽  
Edward G. Durbin ◽  
Jaime Gómez-Gutiérrez
Keyword(s):  
Dna Sequences ◽  
High Frequency ◽  
Dna Analysis ◽  
Antarctic Krill ◽  
Euphausia Superba ◽  
Gut Contents ◽  
The West ◽  
West Antarctic ◽  
Wide Range

AbstractThe keystone role of Antarctic krill,Euphausia superbaDana, in Southern Ocean ecosystems, means it is essential to understand the factors controlling their abundance and secondary production. One such factor that remains poorly known is the role of parasites. A recent study of krill diet using DNA analysis of gut contents provided a snapshot of the parasites present within 170E. superbaguts in a small area along the West Antarctic Peninsula. These parasites includedMetschnikowiaspp. fungi,Haptoglossasp. peronosporomycetes,LankesteriaandParalecudinaspp. apicomplexa,Stegophorussp. nematodes, andPseudocolliniaspp. ciliates. Of these parasites,Metschnikowiaspp. fungi andPseudocolliniaspp. ciliates had previously been observed inE. superba, as had other genera of apicomplexans, though notLankesteriaandParalecudina.In contrast, nematodes had previously only been observed in eggs ofE. superba, and there are no literature reports of peronosporomycetes in euphausiids.Pseudocolliniaspp., parasitoids which obligately kill their host, were the most frequently observed infection, with a prevalence of 12%. The wide range of observed parasites and the relatively high frequency of infections suggest parasites may play a more important role than previously acknowledged inE. superbaecology and population dynamics.

Lack of Effect of Exercise Time of Day on Acute Energy Intake in Healthy Men

2010 ◽  
Vol 20 (4) ◽  
pp. 350-356 ◽  
Author(s):  
Katriona J.M O’Donoghue ◽  
Paul A. Fournier ◽  
Kym J. Guelfi
Keyword(s):  
Energy Intake ◽  
Time Of Day ◽  
Treadmill Running ◽  
Short Term ◽  
Exercise Time ◽  
Acute Bout ◽  
Healthy Men ◽  
Significant Difference ◽  
Term Energy ◽  
Successful Weight Loss

Although the manipulation of exercise and dietary intake to achieve successful weight loss has been extensively studied, it is unclear how the time of day that exercise is performed may affect subsequent energy intake. The purpose of the current study was to investigate the effect of an acute bout of exercise performed in the morning compared with an equivalent bout of exercise performed in the afternoon on short-term energy intake. Nine healthy male participants completed 3 trials: morning exercise (AM), afternoon exercise (PM), or control (no exercise; CON) in a randomized counterbalanced design. Exercise consisted of 45 min of treadmill running at 75% VO2peak. Energy intake was assessed over a 26-hr period with the participants eating ad libitum from a standard assortment of food items of known quantity and composition. There was no significant difference in overall energy intake (M ± SD; CON 23,505 ± 6,938 kJ, AM 24,957 ± 5,607 kJ, PM 24,560 ± 5,988 kJ; p = .590) or macronutrient preferences during the 26-hr period examined between trials. Likewise, no differences in energy intake or macronutrient preferences were observed at any of the specific individual meal periods examined (i.e., breakfast, lunch, dinner) between trials. These results suggest that the time of day that exercise is performed does not significantly affect short-term energy intake in healthy men.

Feeding ecology of Symbolophorus californiensis larvae (Teleostei: Myctophidae) in the southern transition region of the western North Pacific

2009 ◽  
Vol 90 (6) ◽  
pp. 1249-1256 ◽  
Author(s):  
Chiyuki Sassa
Keyword(s):  
Transition Region ◽  
North Pacific ◽  
Western North Pacific ◽  
Developmental Stages ◽  
Feeding Habits ◽  
Larval Growth ◽  
Trophic Niche ◽  
Size Class ◽  
Gut Contents ◽  
Wide Range

The feeding habits of myctophid larvae of Symbolophorus californiensis were examined in the southern transition region of the western North Pacific where the main spawning and nursery grounds of S. californiensis are formed. This species is a key component of the pelagic ecosystems of this region, and their larvae attain one of the largest sizes among myctophids. To analyse gut contents larvae, including most life history stages after yolk-sac absorption (3.7 to 22.2 mm body length (BL)), were collected in the upper 100 m layer in 1997 and 1998. Feeding incidence was higher during the day than at night (53.1–92.3% versus 0–5.6%), and daytime feeding incidence increased gradually with larval growth. Larvae fed mainly on copepods of various developmental stages. Larvae of S. californiensis showed an ontogenetic change in their diet: larvae ≤7.9 mm BL (i.e. preflexion stage) fed mainly on copepod eggs and nauplii, while the larvae ≥8 mm BL consumed mainly calanoid copepodites such as Pseudocalanus and Paracalanus spp. In the largest size-class (16–22.2 mm BL), the furcilia stage of euphausiids was also an important prey item. There was an increase in the average prey size with growth in larvae ≤11.9 mm BL, while the number of prey eaten positively correlated with growth in larvae ≥12 mm BL. The trophic niche breadth also increased with larval growth, which would ensure a wide range of available food resources for the larger size-class larvae.

High incidence of patients lost to follow-up after venous thromboembolism diagnosis – Identifying an unmet need for targeted transition of care

Vascular ◽  
2021 ◽  
pp. 170853812110209
Author(s):  
Rae S Rokosh ◽  
Jack H Grazi ◽  
David Ruohoniemi ◽  
Eugene Yuriditsky ◽  
James Horowitz ◽  
...  
Keyword(s):  
Emergency Department ◽  
Pulmonary Embolism ◽  
Venous Thromboembolism ◽  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
Time Of Day ◽  
Transition Of Care ◽  
Initial Discharge ◽  
Significant Difference

Objectives Venous thromboembolism, including deep venous thrombosis and pulmonary embolism, is a major source of morbidity, mortality, and healthcare utilization. Given the prevalence of venous thromboembolism and its associated mortality, our study sought to identify factors associated with loss to follow-up in venous thromboembolism patients. Methods This is a single-center retrospective study of all consecutive admitted (inpatient) and emergency department patients diagnosed with acute venous thromboembolism via venous duplex examination and/or chest computed tomography from January 2018 to March 2019. Patients with chronic deep venous thrombosis and those diagnosed in the outpatient setting were excluded. Lost to venous thromboembolism-specific follow-up (LTFU) was defined as patients who did not follow up with vascular, cardiology, hematology, oncology, pulmonology, or primary care clinic for venous thromboembolism management at our institution within three months of initial discharge. Patients discharged to hospice or dead within 30 days of initial discharge were excluded from LTFU analysis. Statistical analysis was performed using STATA 16 (College Station, TX: StataCorp LLC) with a p-value of <0.05 set for significance. Results During the study period, 291 isolated deep venous thrombosis, 25 isolated pulmonary embolism, and 54 pulmonary embolism with associated deep venous thrombosis were identified in 370 patients. Of these patients, 129 (35%) were diagnosed in the emergency department and 241 (65%) in the inpatient setting. At discharge, 289 (78%) were on anticoagulation, 66 (18%) were not, and 15 (4%) were deceased. At the conclusion of the study, 120 patients (38%) had been LTFU, 85% of whom were discharged on anticoagulation. There was no statistically significant difference between those LTFU and those with follow-up with respect to age, gender, diagnosis time of day, venous thromboembolism anatomic location, discharge unit location, or anticoagulation choice at discharge. There was a non-significant trend toward longer inpatient length of stay among patients LTFU (16.2 days vs. 12.3 days, p = 0.07), and a significant increase in the proportion of LTFU patients discharged to a facility rather than home ( p = 0.02). On multivariate analysis, we found a 95% increase in the odds of being lost to venous thromboembolism-specific follow-up if discharged to a facility (OR 1.95, CI 1.1–3.6, p = 0.03) as opposed to home. Conclusions Our study demonstrates that over one-third of patients diagnosed with venous thromboembolism at our institution are lost to venous thromboembolism-specific follow-up, particularly those discharged to a facility. Our work suggests that significant improvement could be achieved by establishing a pathway for the targeted transition of care to a venous thromboembolism-specific follow-up clinic.

Seasonal and daily activity patterns in a Canadian population of the prairie rattlesnake, Crotalus viridus viridis

1985 ◽  
Vol 63 (1) ◽  
pp. 86-91 ◽  
Author(s):  
V. P. J. Gannon ◽  
D. M. Secoy
Keyword(s):  
Daily Activity ◽  
Activity Patterns ◽  
High Energy ◽  
Time Of Day ◽  
Energy Demands ◽  
Level Of Activity ◽  
Canadian Population ◽  
Significant Difference ◽  
Gravid Females ◽  
Daily Activity Patterns

The seasonal and daily activity patterns of a Saskatchewan population of Crotalus viridus viridis is presented. Snakes emerged from hibernation in late April and migrated into the surrounding river valley and upland regions in early May. Adult migration preceded that of immature age-classes. Several gravid females occupied a rookery near the hibernaculum during the summer months and remained there until parturition. Females did not occupy this site in successive years and may have a biennial or greater reproductive cycle. Snakes returned to the hibernaculum in early September and remained active until early October. The behaviour of snakes in a field enclosure in response to time of day and body temperature (Tb) was recorded during the spring, summer, and fall. Significant differences in the Tb values of sunning, movement, and shading behaviours were noted. Gravid females were significantly more active in all seasons. However, no significant difference in mean Tb was found between males and females in the field, enclosure study, or laboratory thermal gradient. The observed greater level of activity may reflect the high energy demands of gravid females.

scholarly journals FEEDING HABITS AND HELMINTH PARASITES OF SARDINE (S. PILCHARDUS) AND ANCHOVY (E. ENCRASICOLUS) IN THE ADRIATIC SEA

2015 ◽  
Vol 17 (1) ◽  
pp. 216 ◽  
Author(s):  
B. ZORICA ◽  
V. ČIKES KEČ ◽  
O. VIDJAK ◽  
I. MLADINEO ◽  
D. EZGETA BALIČ
Keyword(s):  
Diet Composition ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Stomach Content Analysis ◽  
Helminth Parasites ◽  
Significant Difference ◽  
Prey Composition ◽  
One Year ◽  
Paratenic Hosts ◽  
Hysterothylacium Aduncum

We examined the stomach contents of two of the most economically and ecologically important small pelagic fish species, the sardine, Sardina pilchardus and the anchovy, Engraulis encrasicolus, obtained monthly from commercial purse-seine catches operating on Croatian fishing grounds during a one-year period (January–December, 2011). Both species generally showed a similar diet, with copepod and decapod larvae as dominant prey groups. The composition of anchovy and sardine stomach contents was not size- or sex-related, but throughout the year, a significant difference in diet composition was observed for each species as well as between species. Two gastrointerstinal helminths; the digenean Parahemiurus merus and nematode Hysterothylacium aduncum, were recorded during the stomach content analysis. Differences in population dynamics between the two parasites are congruent with differences in the prey composition of sardine and anchovy, reflecting fine-tuned interactions in the trophic web between parasites and intermediate or paratenic hosts included in the sardine and anchovy diet.

scholarly journals Hábitos alimentarios de quironómidos (Diptera: Chironomidae) en lagos del páramo de Chingaza, Colombia

2017 ◽  
Vol 66 (1) ◽  
pp. 136 ◽  
Author(s):  
Yulibey Caleño Ruiz ◽  
Carlos Alberto Rivera Rondon ◽  
Hernando Ovalle
Keyword(s):  
Dietary Habits ◽  
Feeding Habits ◽  
Diet Overlap ◽  
Gut Contents ◽  
High Mountain ◽  
Trophic Guilds ◽  
Use Of Resources ◽  
Fine Particulate ◽  
Chironomidae Larvae ◽  
Well Differentiated

Tropical high mountain lakes show unique environmental conditions where chironomids play an important role in ecosystem functioning. The characteristics of these environments could favor diet overlap and therefore a high interspecific competition. This study described the dietary habits of chironomid genera, identified whether the dietary habits were specialized or generalist, and analyzed the diet overlap in the genera. Chironomidae larvae were collected from four lakes of the Chingaza paramo during the dry season, between April and May of 2 016. The feeding habits of larvae were evaluated by analyzing gut contents following standard methods. Each genus was assigned to trophic guilds (carnivore, detritivore and algivore) and the diet overlap was estimated using the Pinka's index. A total of 1 003 individuals were collected and nine genera were identified. Larvae consumed mainly fine particulate organic matter (FPOM), algae, macrophyte fragments, macroinvertebrates, and animal tissues. FPOM was the main feeding resource of detritivores. The analysis of diets showed a high affinity of each genus for a single trophic guild and most of the genera were generalist in the use of resources. For all lakes, high levels of diet overlap were observed among genera and trophic guilds, mainly among detritivores. Our results suggested that Chironomidae larvae of these lakes presented well differentiated trophic habits, and showed a moderate diet overlap within detritivores and carnivores.

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