Research on feeding habits and stomach fungi in Eothenomys miletus from Hengduan mountain regions

Eothenomys miletus(E.miletus)is one of the rodent species found in Yunnan,and it has caused significant harm to local agricultural production.In this study,we aimed to investigate the differences in feeding habits and stomach fungi of E.miletus across different areas in the Hengduan mountain regions.By exploring the main factors affecting the feeding habits and fungi of E.miletus,this study provides a theoretical basis for the prevention and control of this species.We collected E.miletus specimens from five regions,namely Deqin,Xianggelila,Lijiang,Jianchuan,and Ailaoshan.We measured their feeding habits and the types of fungi in their stomachs using high-throughput sequencing technology.The results showed that E.miletus primarily fed on Poaceae,Oxalidaceae,Asteraceae,and Fabaceae.Food diversity of E.miletus in Ailaoshan and Jianchuan was significantly lower than in the other three regions.As for stomach fungi,Ascomycota and Basidiomycota were the absolute dominant sectors.Changes in the diversity of fungi in different regions were consistent with changes in food diversity.The diversity of fungi in Ailaoshan and Jianchuan regions was lower than in the other three regions.These findings suggest that the feeding habits of E.miletus in different regions were affected by plant species,which,in turn,affects the diversity of fungi in their stomachs.

Nestling discrimination and feeding habits during brooding of Chestnut Thrushes

Background:Nestling discrimination and feeding habits during brooding are important factors affecting host selec-tion of parasitic birds.Some host birds can avoid being parasitized by discriminating their nestlings or feeding food not suitable for parasitic nestlings.Thrushes are common medium-sized birds with widespread distribution and an open nesting habit,but they are rarely parasitized.It remains controversial whether this is due to feeding habits and/or nestling discrimination.Methods:In this study,we tested the nestling discrimination ability and feeding habits of Chestnut Thrushes(Turdus rubrocanus)which is distributed in China’s multi-cuckoo parasitism system.Their nestling discriminability and feeding habits during brooding were studied by cross-fostering experiments and video recording to examine evolutionary restrictions on nestling discrimination and whether feeding habits are consistent with the growth of cuckoo nestlings.Results:Our results indicate that Chestnut Thrushes using earthworms as the main brooding food can feed and maintain cuckoo nestlings and show no nestling discrimination.Conclusions:The present study confirms that feeding habits cannot be regarded as the main factor affecting Chestnut Thrushes being rarely parasitized by cuckoos but suggests that egg rejection is likely to limit the evolution of nestling discrimination in thrushes.

Comparative analysis of the intestinal tract microbiota and feeding habits of five sympatric flycatchers

Gut microbiota and host interactions co-evolve and develop into stably adapted microbial communities and play vital roles in maintaining the health of organisms.Diet is supposed to be an important driver of differences in gut microbiota,but previous studies would commonly use literature depictions,which are essential but inaccurate,to explain the effects of diet on the gut microbiota of wild birds.In this study,we collected intestinal samples from five sympatric flycatchers to compare the gut microbial differences using bacterial 16S rRNA genes from Illumina MiSeq platform.Over 1,642,482 quality-filtered sequences from 1816S rRNA libraries were obtained and distinct compositions and diversities of gut microbiota were found in five flycatchers.Their gut microbiota is mainly from the four bacterial phyla of Proteobacteria,Firmicutes,Actinomycetes,and Bacteroidetes,but at the genus level showed a significant difference.Functional predictions revealed that the metabolic capacity of the gut microbiota of five flycatchers is greatly distinguished at KEGG level 3.And multiple food fragments showed a significant correlation with gut microbiota.Besides,the significant differences in the specific composition of the diets of the five insectivorous flycatchers indicated the differentiation of dietary niches.The study of the gut microbiota and feeding habits of sympatric flycatchers would increase the understanding of the gut microbial diversity of wild birds,and also improve our cognition of the co-evolution and co-adaptation within the host gut microbiota relations.

Preliminary Study on Feeding Habits of Anthocidaris crassispina

Abstract Employing experimental-ecological methods, the feeding and vitality of adult Anthocidaris crassispina were investigated. The results showed that A. cras- sispina exhibited an obvious preference on five different seaweeds, with the preference order of Betaphycus gelatinum 〉 Sargassum hemiphyllum 〉 Gelidium amansii 〉 Ulva lactuca 〉 Codium fragile. The daily feed intake of A. crassispina differed among U. lactuca, S. hemiphyllum and B. gelatinum. The feeding was affected by water temperature, seaweed species and body weight. The optimal vitality and feed intake were observed under 23 -27℃, which were inhibited under whether too higher or too lower temperature. Under the optimal temperature for feeding, the daily feed intake of adult A. crassispina assumed an exponentially-decreasing trend with increase of body weight.

Responses of protists with different feeding habits to the changes of activated sludge conditions:A study based on biomass data

Changes of protists, which were categorized into different functional groups primarily according to their feeding habits, in two full-scale municipal wastewater treatment systems experiencing sludge bulking were investigated over a period of 14 months. Protist biomass represented 3.7% to 5.2% of total biomass on average under normal sludge conditions, and the percentage increased significantly （p 〈 0.05） under sludge bulking conditions. The biomass of Chilodonella spp., capable of eating filamentous bacteria, tended to decrease in both systems when sludge bulking occurred, showing that the abnormal growth of filamentous bacteria did not lead to a biomass bloom of this group of protists. On the other hand, the bactivorous protists represented more than 96% of total protist biomass, and the biomass of this group, particularly the attached ciliates, increased significantly （p 〈 0.05） when sludge bulking occurred. The significant increase of the attached ciliates may have possibly facilitated the growth of filamentous bacteria through selectively preying on non-filamentous bacteria and further exacerbated sludge bulking. The redundancy analysis and correlation analysis results showed that the biomass changes of the attached ciliates were primarily related to the sludge volume index and to some extent related to five-day biochemical oxygen demand loading and hydraulic retention time.

Study on the feeding habit and trophic level of main economic invertebrates in the Huanghai Sea

The stomach contents of 14 main invertebrates in the Huanghai Sea are analyzed. The results indicate that: (1) the examined predator species were all omnivore with wide md range, showing no obvious selection for specific fed items, (2) on the basis of their ecological habitat, the predators could be classified into 5 different types, i.e., benthoelagic and planktopelagic animals, nektopelagic and planktopelagic animals, benthopelagic animals, nektopelagic and benthopelagic animals, and nektopelagic animals and (3) the trophic level of the 11 predator species, including Crangon affinis, Palaemon gravieri, Penaeus orientalis, Trachypenaeus curvirostris, Metapenaeopsis dalei, Portunus trituberculatus, Charybdis bimaculata, Oratosquilta oratoria, Sepia andreana, Loligo beka and L. japonica ranged from 2. 30 to 2. 72, belonging to low carnivore (trophic level: 2. 0~ 2. 8), whereas that of the other 3 predator species, including Sepia esculenta, Sepiella maindroni and Todarodes pacificus were in the range of 2. 86~ 2. 97, belonging to mid-carnivore (trophic level: 2. 9 ~3. 4).

Feeding habit and seasonal variation of stomach contents of sand dabs, Pseudopleuronectes yokohamae, in the South Bohai Sea

Sand dabs, an important commercial flatfish in the Bohai Sea, has recently decreased gradually in biomass, resulting from overfishing and marine pollution. Artificial culture and multiplication of sand dabs are essential and practical in China. The present paper examines the food habitof this fish to provide detailed information for its culture and multiplication.

Diet, Food Intake of Phrynocephalus frontalis (Agamidae) and Its Potential Role in Desert Habitat

We examined the dietary diversity and food intake of Phrynocephalus frontalis, compared the difference of insect diversity in the natural habitats with different lizard densities, and discussed the potential role of this lizard in the desert ecosystem. The results show that： （1） arthropodans of the orders Coleoptera, Hymenoptera and Hemiptera were major dietary components of P. frontalis; （2） coleoptera larvae always formed the predominant component of lizard diets; （3） dietary diversities of P. frontalis were not significantly different between summer and autumn or between the two sexes; （4） the similarity in trophic niches between seasons was 0.756, whereas the similarity in trophic niches between sexes was 0.994; （5） stomach content weight of lizards varied significantly among different seasons, but there was no significant difference in stomach content weight between sexes; （6） insect diversity differed significantly among the groups of the habitat with different degrees of lizard density, and the habitat with moderate lizards density had the highest insect diversity. We infer that P. frontalis prey mainly on insects and change their diet and food intake with season; males and females consumed similar preys in types and weights. As an important predator, P. frontalis could affect the insect community in the arid ecosystem of Hunshandak Desert on the Mongolian Plateau.

Domesticated Feed of Tetrao parvirostris

The digestive characteristics,wild feeding habits and food nutrients of Tetrao parvirostris were analyzed,in order to develop the feed that could meet the nutritional needs of T.parvirostris.

Poverty as a Determinant of Marital Status in the Douala Metropolis of Cameroon

This paper examines how poverty determines people’s marital status and their participation in the desired leading values of the metropolitan city of Douala.We used the quota sampling method in which the number of respondents selected from each division was determined by its population size,and then we divided the various divisions into clusters(neighbourhoods).We employed a systematic sampling method in the clusters in which we started with an nth subject and then selected every twentieth unit after the first.We sampled everyone:the married,divorcees,single and cohabiting people in order to understand how poverty determines their different marital statuses.We discovered that the more prestigious jobs people do,the more they earn and the higher the probability that they are married and either rent or own more expensive homes.Equally,the more people become jobless and have precarious jobs,the higher the rate of divorce,single,separated and cohabitating persons and the higher the probability that they are either dependent or homeless.However,marriage constrains people’s participation in the main values of their society,that is why married people diversify less their meals and leisure activities as compared to separated and engaged persons.

Inferring trophic variation for Antarctic krill(Euphausia superba) in the Antarctic Peninsula from the austral fall to early winter using stable isotope analysis

The Antarctic krill（Euphausia superba） is a key species in the Southern Ocean ecosystem and an important link in the food web of the Antarctic ecosystem. The trophic information for this species during the transition from the austral fall to the winter is important to understand its poorly known overwintering mechanisms. However, the few studies on the topic differ in their results, in terms of both spatial and temporal variables. We investigated the size dependence and monthly and regional variation in δ^（13） C and δ^（15） N values of adult krill in the Antarctic Peninsula, in the austral fall（April to May） and the early winter（June）. We aimed to examine the trophic variations of krill occurred during this period, and the relationship between krill and their feeding environment in the Antarctic marine ecosystem. The following results were obtained：（1） no significant relationship was observed between size and the δ13 C value of krill, but the δ15 N value of krill presented a remarkable association with size;（2）the δ13 C values of krill increased during the austral fall, but no remarkable variation existed at the onset of winter,and the δ15 N values were not significant different during this period;（3） mean δ15 N values of krill differed significantly between the Bransfield Strait and the South Shetland Islands. Our data imply that adult krill present size-, season-, and region-dependent trophic variation during the transition from austral fall to early winter in the Antarctic Peninsula.

Both host and diet shape bacterial communities of predatory mites

Microbial communities,derived from food,ambient,and inner,can affect host ecological adaption and evolution.Comparing with most phytophagous arthropods,predators may have more opportunities to develop specific microbiota depending on the level of prey specialization.To explore how diet sources affect host microbial communities and vary across predator species,we considered 3 types of predators from Phytoseiidae(Acari:Mesostigmata):polyphagous(Amblyseius orientalis Ehara,Neoseiulus barkeri Hughes,and Amblyseius swirski Athias-Henrio),oligophagous(Neoseiulus californicus McGregor),and monophagous(Phytoseiulus persimilis Athias-Henriot)predatory mites.The polyphagous species were fed on 2 types of diets,natural prey and alternative prey.By using 16S rRNA sequencing,we found that diet was the main source of microbiota in predatory mites,while there was no clear pattern affected by prey specialization.Among 3 polyphagous predators,host species had a larger impact than prey on microbial composition.Unlike A.orientalis or N.barkeri which showed consistency in their microbiota,prey switching significantly affectedβ-diversity of bacterial composition in A.swirskii,with 56%of the microbial alteration.In short,our results confirmed the substantial influence of diet on host microbial construction in predatory species,and highlighted species differences in shaping the microbiota which are not necessarily related to prey specialization.

Interspecific differences in plasma carotenoid profiles in nestlings of three sympatric vulture species

Carotenoids are diet-based micronutrients important in health and coloration signaling.Related species with similar diets can differ in the kinds and levels of circulating carotenoids,which suggests specific physiological mechanisms to efficiently utilize these micronutrients,regardless of their availability.We explored whether diet and parental provisioning of unusual sources of carotenoids(fresh vegetal matter and vertebrate feces)can explain the occurrence and concentrations of carotenoids in the cinereous vulture Aegypius monachus,griffon vulture Gyps fulvus,and Egyptian vulture Neophron percnopterus nestlings,even when these pigments appear to not be deposited in their integumentary system.A greater diversity of wild prey in diet could be behind the profile of higher concentrations of carotenoids in the Egyptian vulture,the species with carotenoid-dependent coloration during adulthood,while differences in diet composition between cinereous and griffon vultures do not translate to different carotenoid profiles.The carotenoid profile appears to not be related to the ingestion of unusual matter rich in these compounds,although the infrequent occurrence of lycopene and unidentified y-carotene-like compounds suggest that these vultures may be exploiting vegetal matter that left no identifiable unconsumed remains in the nest of Egyptian vultures.The consumption of green plant material by griffon vultures does not result in especially high levels of carotenoids when compared to the carotenoids found in cinereous vultures,which do not consume green plant material.Ungulate feces were not provisioned to Egyptian vulture nestlings,despite the fact they contain carotenoids that adults need for appropriate coloration.Overall,this study indicates that diet differences alone appear insufficient to explain contrasting inter.specific carotenoid profiles,especially since all types of food consumed are considered to be poor in carotenoids,except vegetable matter.We suggest that nestling Egyptian vultures are comparatively efficient in uptaking carotenoids present in low concentrations in food when these compounds are not deposited in their integument,which suggests allocation to other functions.

Diets of Halfbeak Hemiramphus lutkei(Valenciennes,1847)from Karachi Coast,Pakistan

Objective: To investigate the diets of the Lutke’s halfbeak, Hemiramphus lutkei (H. lutkei) to determine the food and feeding habits. Methods:Samples of H. lutkei were collected from the landing sites of Karachi Coast, Pakistan. Total length was measured to the nearest 0.01 cm using digital slide calipers, and total body weight was measured using an electronic balance with 0.01 g accuracy. The dietary composition was determined from gut content examination and analysis was done using frequency of occurrence and numerical methods. To assess the changes in diet with size, H. lutkei were divided into two size groups, Group 1:14-20 cm (n=250) and Group 2:21-25 cm (n=160). Results:The total length and body weight of the sampled specimens ranged from 14 to 25 cm and 10 to 23.5 g, respectively. Out of the studied specimens, 45.12%fish stomachs were found to be empty. Dietary composition revealed daphnia, small fish, isopods, unidentified animal materials, ostracods and unidentified plant materials in the gut contents of Lutke’s halfbeak. Therefore, H. lutkei is omnivore fish feeding on algae, zooplankton, small fishes and different food items of both plant and animal origin. According to the Schoener overlap index (C), there was no significant difference in feeding of the two length groups of H. lutkei (C=0.833). On the other hand, the Shannon-Wiener index showed that the prey diversity of the Lutke's halfbeak in Group 1 was lower (H'=1.545) than that of Group 2 (H'=1.653). Conclusions:This study reports the first description of diets for H. lutkei, which would be useful for the sustainable management of this fishery in the coast of Pakistan and also neighboring countries.