Do abiotic and ontogenetic factors influence the diet of a generalist predator? Feeding ecology of the Pacific spiny dogfish (<Emphasis Type="Italic">Squalus suckleyi</Emphasis>) in the northeast Pacific Ocean

Stomach contents from 1221 Pacific spiny dogfish (Squalus suckleyi) were collected from the Gulf of Alaska over 2004–2006 and analyzed to determine predominant prey species. Pacific spiny dogfish in the Gulf of Alaska have a variable diet suggesting that they are generalist feeders. Of the 68.30% of stomachs with prey contents, the most important prey groups based on the percent prey-specific index of relative importance (%PSIRI) were shrimp (27.06%), cephalopods (17.16%), and forage fish (17.11%). Remaining components of the diet were inconsistent. Commercially valuable species, such as salmon, Oncorhynchus spp., and rockfish, Sebastes spp. constituted only 2.37% and 1.51% of the diet of Pacific spiny dogfish, respectively. Diet diversity was not significantly influenced by spatial, temporal or ontogenetic factors; however, trophic level of prey and average prey item weight varied both interannually and with ontogeny. With increasing size, Pacific spiny dogfish incorporate larger prey items into their diet, and diet composition may be driven more by seasonal availability and prey size than any other factors.     

Reproductive tables of predatory phytoseiid mites (<Emphasis Type="Italic">Phytoseiulus persimilis,Galendromus occidentalis</Emphasis>, and <Emphasis Type="Italic">Neoseiulus cucumeris</Emphasis>)

Feeding of predatory mites (Phytoseiulus persimilis, Galendromus occidentalis, and Neoseiulus cucumeris) on different life stages of Tetranychus atlanticus under optimal conditions was studied. Daily and total consumption of prey by predators and selection of prey of different life stages were studied for 5 days and for the entire feeding period. Average daily food consumption [number of individuals] for the entire life period of mature mite females constituted 0.43 females + 5.0 [nymphs and males] + 3.4 eggs of Tetranychus atlanticus in P. persimilis; 0.12 females + 3.70 [nymphs and males] + 3.10 eggs in G. occidentalis; and 0.19 females + 4.10 [nymphs and males] + 3.50 eggs in N. cucumeris. During the entire period of feeding, P. persimilis preferred large individuals and at the postembryonic stages selected prey to a greater extent than G. occidentalis and N. cucumeris (61.8 and 55.1%, respectively). The use of a 5-day express-method is possible for estimation of some biological characteristics of phytoseiids that previously consumed the same food for a long period. In other cases, analysis of characteristics for the entire life period is necessary.     

Carnivorous pitcher plant facilitates its ant prey

Positive species interactions are ubiquitous in natural communities. However, positive species interactions are often overlooked or undetected because they tend to be more context dependent—that is, outcomes of interactions may change from positive to neutral/negative, depending on the ecological contexts in which these take place. It was recently shown that the pitchers of the carnivorous plant, Nepenthes gracilis, trapped more ant prey when found in close proximity to a congener, N. rafflesiana. As pitchers usually succeed in trapping only a fraction of all pitcher visitors, it was proposed that N. rafflesiana feeds ant colonies in its immediate vicinity with its copious nectar secretions. We tested this hypothesis using ex situ experiments. Philidris sp., Crematogaster treubi, and C. ferrarii colonies were reared in the presence or absence of N. rafflesiana plants in enclosed terraria. As such an interaction has the potential of being context dependent, the interaction was tested under high and low feeding conditions. Low feeding conditions resulted in strong declines in ant colony health, but this was mitigated by the presence of N. rafflesiana, although N. rafflesiana had no significant effect on ant colony health under high feeding conditions. This was observed even though pitchers of N. rafflesiana trapped large numbers of ant workers. Our results show that prey facilitation by a predator is possible, at least in eusocial insects like ants, and that prey facilitation conforms to the central prediction of the stress gradient hypothesis in being more positive at higher stress (lower resource) levels.     

Food resource partitioning of the <Emphasis Type="Italic">Mustelus lunulatus</Emphasis> and <Emphasis Type="Italic">Mustelus henlei</Emphasis> (Elasmobranchii: Carcharhiniformes)

The feeding habits and trophic ecology of Mustelus lunulatus and Mustelus henlei in the central coast of the Colombian Pacific were evaluated and compared to determine whether there was trophic niche overlap or resource partitioning between these two sympatric shark species. A total of 59 prey items were identified and grouped into 10 taxonomic categories. Mustelus lunulatus fed in large proportion on Stomatopoda and Brachyura, whereas M. henlei fed almost exclusively on Teleostei. Dendrobranchiata, Cephalopoda, Anomura and Polychaeta complemented the diets of both species. There were significant differences in diet between the two species, and there was an ontogenetic diet shift in Mustelus lunulatus, with Stomatopoda being the main prey item of juveniles and Brachyura the main prey item of adults. Dietary overlap (by sex and size) was low between species, but it was high for each species, with significant overlap between juveniles and adults of M. lunulatus and M. henlei, and between males and females of M. henlei. There were differences in the trophic levels of the species, sexes and sizes. This study suggests there is food resource partitioning, and differing ecological function of the two Mustelus species in the food web of the study area.     

Feeding ecology of the Kızılırmak toothcarp, <Emphasis Type="Italic">Aphanius marassantensis</Emphasis>: ontogenetic shift and seasonal diet variation

We studied the feeding ecology of an endemic cyprinodontid fish, Aphanius marassantensis (K?z?l?rmak Toothcarp), with special emphasis on seasonal and ontogenetic diet shift. The dietary composition revealed an omnivorous diet with great seasonal and ontogenetic variation. Cladocera and Calanoid Copepods (Diaptomus sp.) dominated the diet in Spring and Summer, whereas the food items of plant origin e.g. filamentous algae and diatoms were the most important components in Autumn and Winter. An ontogenetic diet shift was also demonstrated. While the feeding of juveniles was based mostly on planktonic organisms, adult individuals preferred larger prey taxa, such as Gammarus sp. and Gastropods. There was no significant sex-related variation in feeding with the exception for the volume of gut content. The investigation on the feeding strategy of A. marassantensis suggested a generalised feeding pattern with some specialised individuals. This generalist feeding habits may account for the well-established population of this species in a big reservoir under coexistence of two non-native fish species, Pseudorasbora parva and Atherina boyeri.     

Effects of Dietary <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> on Growth Performance,Digestive Enzymes and Gut Morphology of <Emphasis Type="Italic">Litopenaeus vannamei</Emphasis>

A 15-day feeding trial was conducted to investigate the effect of dietary Lactobacillus plantarum on growth performance, digestive enzyme activities and gut morphology of juvenile Pacific white shrimp, Litopenaeus vannamei (initial body weight = 7.96 ± 0.59 g). Four microbound diets were formulated to contain fermentation supernatant (FS), live bacteria (LB), dead bacteria (DB), and cell-free extract (CE) of L. plantarum. Results indicated that final weight was significantly higher in FS, DB, and CE group in comparison to the control group (P < 0.05). The maximum weight gain rate (WGR) and specific growth rate (SGR) of the CE diet group were significantly higher than that of other groups (P < 0.05). The FCR of CE diet group was lower than that of the control, LB, DB, and FS diets groups (P < 0.05). The highest digestive enzyme activities (amylase, lipase, and pepsin activity) in the hepatopancreas and gut of shrimp were observed in the CE diet group. Histological study revealed that dietary CE diet could significantly increase the enterocytes height of shrimp. The administration of cell-free extract of L. plantarum could effectively improve the growth performance of L. vannamei via the improvement of digestive enzyme activities and the enterocytes height of shrimp. The results of this study will be essential to promote application of probiotics in shrimp aquaculture.     

Behavioural interactions between the lizard <Emphasis Type="Italic">Takydromus tachydromoides</Emphasis> and the praying mantis <Emphasis Type="Italic">Tenodera aridifolia</Emphasis> suggest reciprocal predation between them

The Japanese lacertid lizard Takydromus tachydromoides and the praying mantis Tenodera aridifolia are sympatric generalist predators feeding on similar prey. To confirm reciprocal predation between them, we observed the behavioural interactions between the lizards and the mantises of different sizes in a laboratory condition. The lizards caught small mantises (from first to fifth instars), but sometimes escaped from large mantises (from sixth instar to adult). Large mantises occasionally showed catch responses to the lizards. The lizards sometimes caught the mantis without a tongue-flick response (sampling of chemical cues), and they sometimes did not catch the small mantises showing immobile or cryptic responses that prevent visual detection. These results suggested the primary role of vision on recognition of the mantis as a prey. The lizards spent a longer time to approach larger mantises. The time from orienting to catch was longer when the lizards showed tongue-flick responses. The lizard also spent a longer time before deciding to escape from the mantis than to catch it. Biological significance of these differences in timing was discussed.     

Selective predation by reintroduced juvenile Lake sturgeon (<Emphasis Type="Italic">Acipenser fulvescens</Emphasis>) in Ft. Loudoun reservoir,Tennessee (USA)

Following water quality and minimum flow improvements to the impounded Tennessee and Cumberland Rivers, juvenile lake sturgeon (Acipenser fulvescens) have been restocked annually since 2000. Our goal was to seasonally assess foraging mode of this recovering population in Ft. Loudoun Reservoir in the Upper Tennessee River. During 2014–15, individuals were captured using trot-lines in a 13-km reach that supports the greatest density of lake sturgeon. We used colonic flushing and gastric lavage techniques to obtain diet. We took systematic benthic sediment grabs along multiple transects throughout the reach and opportunistically deployed rock cages filled with hard substrates to assess potential prey that colonize hard surfaces. Foraging modes of lake sturgeon were determined by comparing relative abundances of invertebrate taxa in the gut contents (6581 invertebrates) of 28 fish to the relative abundances of the same invertebrate taxa collected from the resource base (1667 invertebrates). Proportional similarity, Levin’s niche breadth, and Manly’s index were used to assess the degree of prey selectivity. Lake sturgeon fed selectively on a narrow range of available prey consisting mostly of larval chironomids (93% composition by number during warm season, 96% during cool season), some genera of which they prey upon selectively, primarily Chironomus sp., but to a lesser extent Procladius, Ablabesmyia, Coelotanypus, and Cryptochironomus spp. Meanwhile, other abundant taxa in the resource base were avoided, such as Oligochaetes, Hexagenia mayflies, and the chironomid Glyptotendipes. Our results illustrate that assessing seasonally available prey from habitat utilized by lake sturgeon is important when investigating diet preference.     

Strategies of resource partitioning between two sympatric puffer fishes in a tropical hypersaline estuary,Brazil

The strategies of food partitioning among two abundant estuarine puffer fishes, Sphoeroides greeleyi (Gilbert, 1900) and Sphoeroides testudineus (Linnaeus, 1758), were investigated in a tropical hypersaline estuary. We examined the stomachs of 946 fishes collected with a beach seine across three zones (upper, middle and lower estuary) along with a salinity gradient. The highest abundances of species were recorded in the upper and middle estuary. The diet was comprised mostly by benthic organisms, mainly Bivalvia, Gastropoda, and Brachyura. However, in a hypersaline estuary, these species develop strategies of resource partitioning in three ways: 1) asymmetry effects; 2) habitat selection; and 3) trade-offs among age classes. Diet variations according to fish age classes indicated that the largest individuals showed a decrease in their consumption of small preys (Amphipods, Copepods, and Ceratopogonidae) and an increase in their consumption of larger preys (Bivalvia and Decapoda). This behavior of switching diet towards larger prey was related to the functional trade-offs in swimming capacity, and feeding mode used to capture prey. The middle and upper estuary are important feeding grounds for puffer fishes, as demonstrated by their influence on prey distributions and habitat type. Diet breadth indicated that S. greeleyi tended to be a generalist, whereas S. testudineus tended to be a specialist. Thus, the strategies of partitioning seem to have importance for puffer fish populations in this hypersaline environment.     

Pitcher plant facilitates prey capture in a sympatric congener

Carnivorous plants avoid below-ground competition for nitrogen by utilizing an alternative nitrogen resource—invertebrate prey, but it remains unclear if sympatric carnivorous plants compete for prey resources. The aim of this study was to investigate if exploitative prey-resource competition occurs between the two sympatric pitcher plant species, Nepenthes rafflesiana and N. gracilis in Singapore. We first investigated if prey-resource partitioning occurs between these two species, and then investigated niche shift in N. gracilis by examining its pitcher contents along an in situ gradient of N. rafflesiana interspecific competition. Our results showed clear evidence of resource partitioning between the two species, but contrary to the expectation of competition, proximity to N. rafflesiana pitchers correlated with higher total prey numbers in N. gracilis pitchers. Our multivariate model of prey assemblages further suggested that N. rafflesiana facilitates N. gracilis prey capture, especially in several ant taxa that are trapped by both species. Concurrently, we found strong evidence for intraspecific competition between N. gracilis pitchers, suggesting that prey resources are exhaustible by pitcher-predation. Our results show that resource partitioning can be associated with facilitative interactions, instead of competition as is usually assumed. Facilitation is more typically expected between phylogenetically distant species, but divergences in resource acquisition strategies can permit facilitation between congeners.     

Genetic structure analysis of mantis shrimp <Emphasis Type="Italic">Oratosquilla oratoria</Emphasis> based on mitochondrial DNA control region sequence

The genetic relationships of mantis shrimp Oratosquilla oratoria between the coastal waters of China and Japan were not well studied. To reveal the genetic differentiation and genetic structure among populations, we collected populations of mantis shrimp O. oratoria from the coastal waters of China and Japan to analyze the mtDNA control region variation. A total of 309 individuals of O. oratoria were collected from 13 localities (11 from China and 2 from Japan) and a segment of mitochondrial DNA control region was sequenced. Three hundred nine haplotypes were defined, yielding a very high haplotype diversity and nucleotide diversity. Two lineages of O. oratoria were revealed and displayed strong differences in the geographical distribution. In the coastal waters of China, the geographic distribution of the two lineages was completely separated by the Yangtze River estuary; however, the lineages showed geographic sympatry in two populations from Japan. Based on the lineage distribution, three groups were defined. There was no significant genetic differentiation among the populations within the three groups, indicating high gene flow within each group. Significant and negative values for Tajima D and Fu’s Fs tests, and mismatch distributions for two lineages indicated population expansion. The present result confirmed that the freshwater outflow from the Yangtze River formed a physical barrier and affected gene exchange. The different distribution patterns of the two lineages in coastal waters of China and Japan indicated that the larvae of O. oratoria were transferred from China to the coastal waters of Japan with a one-way gene flow.     

Experience of plant infestation by the omnivorous arthropod <Emphasis Type="Italic">Nesidiocoris tenuis</Emphasis> affects its subsequent responses to prey-infested plant volatiles

Nesidiocoris tenuis, an omnivorous arthropod, infests plants in either the absence or presence of prey arthropods. We studied whether plant-infestation experience of N. tenuis affected its subsequent prey-finding behavior. We used sesame plants and eggplants as food plants for N. tenuis, and common cutworm (CCW) (Spodoptera litura larvae) as prey. We focused on their olfactory response to CCW-infested sesame plants versus CCW-infested eggplants in a Y-tube olfactometer. When N. tenuis adults experienced the infestation of sesame plants for one day, they preferred volatiles from CCW-infested sesame plants to those from CCW-infested eggplants. By contrast, when N. tenuis experienced the infestation of eggplants for one day, they showed no difference in their preference between the two odor sources. When the duration of the infestation of plants was increased to four days, N. tenuis that had experienced sesame plants showed a reversed response: they preferred CCW-infested eggplant volatiles, while those that had infested eggplants again showed no difference in their preference. Next, we studied the olfactory preference of N. tenuis that had previously infested plants with moth (Ephestia kuehniella) eggs. We found that irrespective of plant species and of duration of experience (either one or four days), N. tenuis adults that had previously experienced one plant species showed a significant preference for volatiles from CCW-infested plants of the same species. The blends of the volatiles emitted from CCW-infested sesame plants and those from CCW-infested eggplants were qualitatively different. Possibility to control the olfactory response of N. tenuis to certain prey-infested plant volatiles by adjusting their feeding history is discussed.     

Contrasting the early life histories of sympatric Arctic gadids <Emphasis Type="Italic">Boreogadus saida</Emphasis> and <Emphasis Type="Italic">Arctogadus glacialis</Emphasis> in the Canadian Beaufort Sea

The early life stages of Boreogadus saida and Arctogadus glacialis are morphologically similar, making it difficult to assess differences in their ecological niche. The present study documented for the first time the early life stage ecology of A. glacialis, compared it to that of B. saida, and identified the factors separating the niches of the two sympatric species. The 10,565 larval gadids collected in the Beaufort Sea from April to August of 2004 and 2008 were identified to species either directly by genetics and/or otolith nucleus size, or indirectly with a redistribution procedure. Between 8.0 and 8.7 % of all gadids were assigned to A. glacialis. Larvae of A. glacialis were longer at hatch and experienced lower mortality rates than those of B. saida. The two species shared similar spatiotemporal and vertical distributions, hatching season, and growth rate. Under the ice, feeding incidence of B. saida was low (14 %) relative to A. glacialis (88 %). At lengths <15 mm, both species specialized on different prey. The diet of fish >15 mm overlapped (Schoener’s index = 0.7), with Calanus glacialis and C. hyperboreus providing >50 % of the carbon intake of both species. The higher mortality in B. saida may be explained by the smaller size at age from hatching to metamorphosis and a lower under-ice feeding incidence. The early larval stage appears to be the key period of niche divergence between the two species.     

Effect of Diet History on Prey and Pollen Food Choice by Two Lady Beetle Species

Mixed diets of prey and plant-provided foods, such as pollen, have been shown to benefit a wide range of arthropods. However, diet shifting between these two very different food sources remains poorly understood. We hypothesized that previous diet should influence subsequent time allocation between prey and plant food types; to reach a balanced diet, consumers are expected to allocate more time to resources previously lacking in their diet. We tested this hypothesis by observing the foraging choices of larvae of two omnivorous coccinellid species: Coccinella septempunctata L. and Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae), following a diet history of prey, pollen or a mixed diet of both food types. Results showed an asymmetrical tendency of C. septempunctata larvae to complement their previous diet with unfamiliar food: larvae allocated more time to pollen feeding, but not to prey, when each of the foods was previously absent from their diet. Study results have important implications for the use of plant-provided food supplements to enhance biological control by these omnivorous consumers.     

First assessment of the diet composition and trophic level of an assemblage of poorly known chondrichthyans off the central coast of Peru

Although chondrichthyans are conspicuously present in shallow waters, many ecological aspects of neritic species in the Humboldt Current System remain unknown. This study provides a first assessment of the diet of seven commercially exploited and understudied sympatric chondrichthyans inhabiting nearshore habitats off the central coast of Peru: four stingrays (Hypanus dipterurus, Myliobatis peruvianus, M. chilensis, and Urotrygon chilensis), a guitarfish (Pseudobatos planiceps), a smooth-hound shark (Mustelus mento), and a chimaera (Callorhinchus callorynchus). A total of 166 stomachs were examined between 2012 and 2015 and prey items were pooled for the total of years for analysis. Although our analysis did not account for inter seasons variability, our results suggest diet partitioning among species, except for the stingrays’ group. A diet based on soft-bottom polychaetes and fish was shared by H. dipterurus, M. peruvianus, and M. chilensis, while soft-bottom polychaetes and crabs were more important in U. chilensis. The smooth-hound shark and guitarfish exhibited a diet dominated by crabs, and the chimaera consumed mainly hard-bottom mollusks. Foraging habitat estimations distinguished two main habitats of association: Benthic, including the stingray U. chilensis, the chimaera, and the smooth-hound shark; and benthic-demersal, including the guitarfish, and the rest of stingrays. A pattern of feeding specialization was observed for H. dipterurus, P. planiceps, and C. callorynchus. Preliminary trophic level estimations based on diet composition placed these species as secondary consumers. Intraspecific dietary variation was assessed for P. planiceps and H. dipterurus as their sampled sizes allowed meaningful comparisons. The diet of P. planiceps varied from small to large sizes but not for H. dipterurus. No differences were detected on diet composition between males and females in either species. Despite the limited temporal resolution, this study provides the first insights of chondrichthyans predatory activity, suggesting diet partitioning among the species of this assemblage in a nearshore habitat of the central coast of Peru. Enhancing the temporal resolution of this type of studies would improve our knowledge on trophic functioning in the Humboldt Current ecosystem.     

Predation on crown-of-thorns starfish larvae by damselfishes

Examining the functional response of predators can provide insight into the role of predation in structuring prey populations and ecological communities. This study explored feeding behaviour and functional responses of planktivorous damselfishes when offered captive reared larvae of crown-of-thorns starfish, Acanthaster sp., with the aim of determining whether these predators could ever play a role in moderating outbreaks of Acanthaster sp. We examined predatory behaviour of 11 species of planktivorous damselfish, testing: (1) the relationship between predator size and predation rate, both within and among fish species; (2) consumption rates on larvae of Acanthaster sp. versus larvae of a common, co-occurring coral reef asteroid Linckia laevigata; (3) maximal feeding rates upon both Acanthaster sp. and L. laevigata; and (4) functional responses of planktivorous fishes to increasing densities of Acanthaster sp. Consumption rates of crown-of-thorns larvae by damselfishes were independent of predator size; however, there was a significant negative relationship between predator size and consumption rate of L. laevigata, when pooling across all predatory species. Some damselfishes, including Acanthochromis polyacanthus and Amblyglyphidodon curacao, consumed larval Acanthaster sp. at a greater rate than for L. laevigata. Most predatory species (all except A. curacao and Pomacentrus amboinensis) exhibited a Type II functional response whereby the increasing feeding rate decelerated with increasing prey density. In addition to revealing that a wide range of planktivorous fishes can prey upon larvae of Acanthaster sp., these data suggest that planktivorous damselfishes may have the capacity to buffer against population fluctuations of Acanthaster sp. Importantly, predators with Type II functional responses often contribute to stability of prey populations, though planktivorous fishes may be swamped by an abnormally high influx of larvae, potentially contributing to the characteristic population fluctuations of Acanthaster sp.     

<Emphasis Type="Italic">Lioptilodes friasi</Emphasis> (Lepidoptera: Pterophoridae) Niche Breadth in the Chilean Mediterranean Matorral Biome: Trophic and Altitudinal Dimensions

Understanding the factors driving the diet breadth of phytophagous insects remains one of the main questions in ecological research. In this study we explored the diet breadth and plant-insect associations in the plume moth Lioptilodes friasi Vargas & Parra (Lepidoptera: Pterophoridae). This phytophagous insect was originally described in association with a single host species, Haplopappus foliosus (Asteraceae), a native shrub of the Chilean Mediterranean matorral. In order to address the breadth of host plant choice, we surveyed other Haplopappus species growing along the elevation gradient of central Chile from sea level to 2600 m. We were able to obtain L. friasi adults from five additional Haplopappus species: Haplopappus chrysantemifolius and Haplopappus decurrens from the coastal zone, Haplopappus multifolius and Haplopappus schumanii from the mid-elevation zone, and Haplopappus scrobiculatus at high elevation. Our results demonstrate that the genus-specialized endophagous herbivore L. friasi has a wider distribution and climatic tolerance than previously described. Its biogeographical range extends from the lowland coastal habitats up to the Andean subnival level. We propose that shared flower phenotypic traits such as morphology and chemical composition may have allowed the colonization of closely related Haplopappus species in central Chile, the expansion of which is limited by the harsh high elevation conditions.     

Feeding patterns of the black-striped pipefish <Emphasis Type="Italic">Syngnathus abaster</Emphasis> in an invaded freshwater habitat

Syngnathus abaster is an euryhaline species, which has penetrated freshwaters in Europe and its range is expanding. The goal was to investigate the feeding patterns of this species in an invaded freshwater habitat, where it first appeared at the beginning of 1990s, with implications for assessing its possible effects on invaded ecosystems. In total, 36 prey items were identified in the diet of S. abaster. The most important prey were zooplanktonic organisms, among which copepods predominated significantly. The second most important prey were cladocerans, represented by 20 species/genera. The diet composition of this species showed clear seasonal dynamics but copepods remained the predominant prey item throughout the year. Significant positive relationships between the abundance of zooplanktonic organisms in the gut contents of S. abaster and their abundance in zooplankton samples were found for copepods and Ceriodaphnia sp. S. abaster showed a significant positive electivity for copepods throughout all months. It also positively selected some large cladocerans, which probably shared the same habitat. S. abaster also consumed fish items including gobiid larvae and its own juveniles, when they were abundant in May and especially in June. The possible effect of S. abaster on native ecosystems may include the shaping of zooplanktonic communities through selective predation on copepods. This species is unlikely to be a serious food competitor for native fish inhabiting European freshwaters, the majority of which are cyprinids. Nevertheless, it can have effects on some native fish through predation on their juveniles, which might share the same habitats.     

Diet Composition of Indian Burrowing Frog <Emphasis Type="Italic">Sphaerotheca breviceps</Emphasis> (Anura: Dicroglossidae) in Uttarakhand Region of Western Himalaya

A study encompassing the food and feeding habits of Indian burrowing frog Sphaerotheca breviceps was carried out in Srinagar Garhwal (n = 27) and Joshimath region (n = 21) of Uttarakhand, Western Himalaya, India to establish their feeding nature and diet composition. Gut content analysis of S. breviceps revealed acceptance of a wide range of insects and other invertebrates as their food. They feed extensively on the ground and litter-dwelling prey animals. There exists a slight deviation in the diets of S. breviceps in respect to localities perhaps due to variation in prey faunal species. Analysis of the food items ingested revealed that the size of the prey animals was ranged from 3 to 56 mm. The diet composition and index of relative importance confirm its insectivorous type of feeding habit. The study indicates that these anurans are primarily predators of nocturnal terrestrial arthropods and act as an important biological agent for controlling the harmful pests and thus help in ecosystem management.