Feeding Specialization Research Articles

Mathematical modelling of seasonal migration with applications to climate change

The breeding success of many species depends on the alignment of the period of maximum demand of offspring with a period of food abundance. In this paper, we use piecewise-smooth differential equations to model the variation in the size of a population that has a short interval each year during which successful reproduction is possible. An increase in spring-time temperatures in recent decades has caused these intervals to advance, leading to temporal mismatches between species on different trophic levels. We first consider a one-species model which illustrates the dynamics of a population of specialist feeders over the course of a single breeding season and use it to examine how reproductive success depends on the population's distribution of breeding dates. We then introduce time-dependent switches to extend the model to a broader class of species. Steady-state solutions are used to measure the extent to which a migratory population can sustain itself over long time scales and repeated breeding events. The model's predictions agree with the observed negative effect on population size associated with an advance in the food season if not adequately compensated for by the population. Finally, we discuss how this model can be extended in order to encompass a wider range of ecological systems and to highlight the mechanisms over which climate change may exert an influence.

Differentiated adaptive evolution, episodic relaxation of selective constraints, and pseudogenization of umami and sweet taste genes TAS1Rs in catarrhine primates.

BackgroundUmami and sweet tastes are two important basic taste perceptions that allow animals to recognize diets with nutritious carbohydrates and proteins, respectively. Until recently, analyses of umami and sweet taste were performed on various domestic and wild animals. While most of these studies focused on the pseudogenization of taste genes, which occur mostly in carnivores and species with absolute feeding specialization, omnivores and herbivores were more or less neglected. Catarrhine primates are a group of herbivorous animals (feeding mostly on plants) with significant divergence in dietary preference, especially the specialized folivorous Colobinae. Here, we conducted the most comprehensive investigation to date of selection pressure on sweet and umami taste genes (TAS1Rs) in catarrhine primates to test whether specific adaptive evolution occurred during their diversification, in association with particular plant diets.ResultsWe documented significant relaxation of selective constraints on sweet taste gene TAS1R2 in the ancestral branch of Colobinae, which might correlate with their unique ingestion and digestion of leaves. Additionally, we identified positive selection acting on Cercopithecidae lineages for the umami taste gene TAS1R1, on the Cercopithecinae and extant Colobinae and Hylobatidae lineages for TAS1R2, and on Macaca lineages for TAS1R3. Our research further identified several site mutations in Cercopithecidae, Colobinae and Pygathrix, which were detected by previous studies altering the sensitivity of receptors. The positively selected sites were located mostly on the extra-cellular region of TAS1Rs. Among these positively selected sites, two vital sites for TAS1R1 and four vital sites for TAS1R2 in extra-cellular region were identified as being responsible for the binding of certain sweet and umami taste molecules through molecular modelling and docking.ConclusionsOur results suggest that episodic and differentiated adaptive evolution of TAS1Rs pervasively occurred in catarrhine primates, most concentrated upon the extra-cellular region of TAS1Rs.Electronic supplementary materialThe online version of this article (doi:10.1186/s12983-014-0079-4) contains supplementary material, which is available to authorized users.

Fatty acid signatures and stomach contents of four sympatricLakeTrout: assessment of trophic patterns among morphotypes inGreatBearLake

AbstractSympatric diversification inLakeTrout is generally linked to differences in habitat use (especially depth) as a result of foraging on different prey items. However, extensive sympatric divergence has taken place in the shallow waters (≤30 m) ofGreatBearLake, with multipleLakeTrout morphs varying in head and fin characteristics. To investigate diet partitioning as a potential explanatory mechanism for this diversification, we assessed trophic characteristics and relationships among four sympatric shallow‐water morphs ofLakeTrout via analyses of fatty acids and stomach contents. Fatty acids and stomach contents both identifiedLakeTrout,Cisco andMysisas key prey items inLakeTrout diets. Interestingly, terrestrial invertebrates were also seasonally important among morphs, reflecting temporal variability of available prey in this arctic lake. Some diet partitioning was observed among morphs;Morph 1 was characterised as a generalist,Morph 3 was more benthic‐oriented, andMorphs 2 and 4 were mainly pelagic feeders. Of the latter,Morph 4 was the most specialised, whereasMorph 2 exhibited alternative feeding tactics of benthic cannibalistic and pelagic piscivorous feeding. Our findings demonstrate that complementary dietary methods can elucidate habits of opportunistic feeders, a task that can often be problematic, given their complex and variable diets. Our results add new information and perspectives on the current model ofLakeTrout differentiation, demonstrating niche partitioning based on benthic versus pelagic habitat use and generalist versus specialist feeding tactics.

Oak-insect herbivore interactions along a temperature and precipitation gradient

The interactions between herbivorous insects and their host plants are expected to be influenced by changing climates. Modern oaks provide an excellent system to examine this assumption because their interactions with herbivores occur over broad climatic and spatial scales, they vary in their defensive and nutritional investment in leaves by being deciduous or evergreen, and their insect herbivores range from generalists to highly specialized feeders. In this study, we surveyed leaf-litter samples of four oak species along an elevation gradient, from coastal northern California, USA, to the upper montane woodlands of the Sierra Nevada, to examine the relationship between climatic factors (mean annual temperature and precipitation) and oak herbivory levels at multiple scales; across all oak species pooled, between evergreen and deciduous species and within species.Overall, temperature and precipitation did not appear to have a significant effect on most measures of total herbivore damage (percent leaves damaged per tree, percent leaf area removed and average number of feeding damage marks per leaf) and the strongest predictor of herbivore damage overall was the identity of the host species. However, increases in precipitation were correlated with an increase in the actual leaf area removed, and specialized insects, such as those that make leaf mines and galls, were the most sensitive to differences in precipitation levels. This suggests that the effects of changing climate on some plant–insect interactions is less likely to result in broad scale increases in damage with increasing temperatures or changing precipitation levels, but is rather more likely to be dependent on the type of herbivore (specialist vs. generalist) and the scale (species vs. community) over which the effect is examined.

How Do You Keto? Survey of North American Pediatric Ketogenic Diet Centers

We surveyed ketogenic diet centers in North America about their practices surrounding the ketogenic diet. An internet survey was disseminated via REDCap(©) to North American ketogenic diet centers identified from the Charlie Foundation and Ketocal(©) websites. Fifty-six centers responded. In addition to physicians, nurses and dieticians, ketogenic teams included social workers (39%), feeding specialists (14%), educational liaisons (4%), psychologists (5%), and pharmacists (36%). A child attending school (2%), non-English speaking family (19%), single-parent family (0%), and oral feeding (6%) were rarely considered barriers. Overall, the diet was considered the first or second (0%), third or fourth (67%), fifth or sixth (29%), and last resort treatment (4%) by centers. It was considered the first or second treatment for GLUT1 disease (86%) and third or fourth for Dravet (63%), West (71%), and Doose (65%) syndromes. Ketogenic diet is no longer a last resort option. Traditional barriers do not influence its use.

Palate Variation and Evolution in New World Leaf-Nosed and Old World Fruit Bats (Order Chiroptera)

Two bat families, the leaf-nosed (Phyllostomidae) and fruit bats (Pteropodidae), have independently evolved the ability to consume plant resources. However, despite their similar ages, species richness and the strong selective pressures placed on the evolution of skull shape by plant-based foods, phyllostomids display more craniofacial diversity than pteropodids. In this study, we used morphometrics to investigate the distribution of palate variation and the evolution of palate diversity in these groups. We focused on the palate because evolutionary alterations in palate morphology are thought to underlie much feeding specialization in bats. We hypothesize that the distribution of palate variation differs in phyllostomids and pteropodids, and that the rate of palate evolution is higher in phyllostomids than pteropodids. The results suggest that the overall level of palate integration is higher in adult populations of pteropodids than phyllostomids but that the distribution of palate variation is otherwise generally conserved among phyllostomids and pteropodids. Furthermore, the results are consistent with these differences in palate integration likely having a developmental basis. The results also suggest that palate evolution has occurred significantly more rapidly in phyllostomids than pteropodids. These findings are consistent with a scenario in which the greater integration of the pteropodid palate has limited its evolvability.

Species‐specific habitat use of wing‐moulting waterbirds in response to temporary flightlessness

The choice of the moulting habitat is of paramount importance for wing‐moulting waterbirds that have to cope with a flightless period of several weeks. However, some species might have more restricted habitat requirements during moult than others, for example due to a highly specialized feeding ecology. The moult‐related habitat use of five species (Gadwall Anas strepera, Red‐crested Pochard Netta rufina, Common Pochard Aythya ferina, Tufted Duck Aythya fuligula, Coot Fulica atra) was compared at a European inland moulting site that offered a variety of water bodies characterized by different levels of nutrient concentration, water depth, shoreline vegetation density and disturbance. To determine location‐ and species‐specific densities, birds were regularly counted throughout the moulting seasons of 2010 and 2011. In 2011, additional data on Gadwalls were used to assess differences in requirements between the flightless phase of moult and the periods before and after. Furthermore, habitat choice of 38 tagged Gadwalls was compared among two to four successive years. During the moulting season, all species showed clear preferences for specific levels of nutrient content, suggesting an active choice of suitable food sources in both food specialists and generalists. Species showing the strongest attachment to shallow water (Gadwall and Coot) were most sensitive to human disturbance and increasing water depths, and species averse to diving (Gadwall) used ponds with dense shore vegetation while flightless. For Gadwalls, habitat conditions rather than nutrient supply became increasingly important during the flightless phase. Average return rates of 59 and 54% were recorded for male and female Gadwalls, respectively, and the repeated use of familiar locations could be demonstrated in the majority of returning birds (65%). Familiarity with the habitat apparently plays an important role and may enable individuals to compensate for suboptimal conditions at the moulting site.

Frugivorous weevils are too rare to cause Janzen–Connell effects in New Guinea lowland rain forest

Abstract:A community of frugivorous weevils was studied by quantitative rearing of 57 weevil species represented by 10485 individuals from 326 woody plant species in lowland rain forest in Papua New Guinea. Only fruits from 35% of plant species were attacked by weevils. On average, weevils were reared from only 1 in 33 fruits and 1 kg of fruit was attacked by 2.51 individuals. Weevil host specificity was relatively high: 42% of weevil species fed on a single plant genus, 19% on a single plant family and only 16% were reared from more than one family. However, monophagous specialists represented only 23% of all reared individuals. The average 1 kg of fruits was infested by 1.84 individuals of generalist weevils (feeding on allogeneric or allofamilial host species), 0.52 individual of specialists (feeding on a single or several congeneric species), and 0.15 individual of unknown host specificity. Large-seeded fruits with thin mesocarp tended to host specialist species whereas those with thick, fleshy mesocarp were often infested with both specialists and generalists. Weevils tended to avoid small-seeded, fleshy fruits. The low incidence of seed damage (3% of seeds) suggests that weevils are unlikely to play a major role in regulating plant populations via density-dependent mortality processes outlined by the Janzen–Connell hypothesis.

Unsuspected functional disparity in Devonian fishes revealed by tooth morphometrics?

The shape of features involved in key biological functions, such as teeth in nutrition, can provide insights into ecological processes even in ancient time, by linking the occupation of the morphological space (disparity) to the occupation of the ecological space. Investigating disparity in radiating groups may provide insights into the ecological diversification underlying evolution of morphological diversity. Actinopterygian fishes initiated their radiation in the Devonian, a period characterized by the diversification of marine ecosystem. Although a former morpho-functional analysis of jaw shape concluded to conservative and poorly diversified morphologies in this early part of their history, fish tooth disparity evidenced here an unsuspected diversity of possible functional significance in the pivotal period of the Late Devonian (Famennian). All teeth being caniniforms, some were stocky and robust, in agreement with expectations for active generalist predators. More surprisingly, elongated teeth also occurred at the beginning of Famennian. Their needle-like shape challenges morpho-functional interpretations by making them fragile in response to bending or torsion. The occurrence of both types of fish teeth during the beginning of the Famennian points to a discrete but real increase in disparity, thus testifying a first burst of feeding specialization despite overall conservative jaw morphology. The disappearance of these needle-like teeth in the Late Famennian might have been related to a relay in dental diversity with abundant co-occurring groups, namely conodonts and chondrichthyans (sharks).

Grass-fly larvae (Diptera, Chloropidae): Diversity, habitats, and feeding specializations

The fly family Chloropidae belongs to the higher Diptera series Acalyptratae. It is distributed worldwide and globally comprises 200 genera and about 3000 species in 4 subfamilies: Oscinellinae, Siphonellopsinae, Rhodesiellinae, and Chloropinae. In the fossil record, Chloropidae are known since the Oligocene, with 2 genera found in Baltic amber: one extinct, the other recent. The family includes several important agricultural pests (frit flies, gout flies, Meromyza, seed pests) which injure corn. The feeding preferences of chloropid larvae vary strongly: there are saprophages in the broad sense, true phytophages using both woody and grassy plants (mainly monocots), predators on egg masses of insects and spiders, as well as on scale insects and aphids, and ectoparasites of frogs. Among the 100 families of monocots (Liliopsida), only 11 include species serving as food plants for chloropid larvae. The greatest diversity of habitats and feeding types is observed in the subfamily Oscinellinae. The most advanced subfamily Chloropinae includes mostly phytophagous larvae. A possible scenario of ecological evolution within the family is briefly discussed.

Four species of arboreal folivore show differential tolerance to a secondary metabolite.

The marsupials that eat Eucalyptus in south-eastern Australia provide an example of animals with similar niche requirements occurring sympatrically. They certainly differ in size, ranging from about 1 kg in the greater glider (Petauroides volans) and the closely related common ringtail possum (Pseudocheirus peregrinus), to 4 kg (common brushtail possum, Trichosurus vulpecula) and up to 15 kg in the koala (Phascolarctos cinereus). All species, however, may eat considerable amounts of eucalypt foliage, often favouring the same species, and thus appear to compete for food. In order to better understand the degree of competition for food, we measured feeding by the greater glider in response to increasing concentrations of a specific group of eucalypt plant secondary metabolites (PSM), the sideroxylonals, and then compared it to results published for the other species. The greater glider was more resilient than the other species to increasing concentrations of sideroxylonals. We suggest this allows gliders to feed on leaves from the eucalypt subgenus, Symphyomyrtus, while its small size and gliding ability allow it to feed where koalas cannot, on the young leaves on top of the canopy. In contrast, the common ringtail possum is well adapted to feeding from species of the subgenus Eucalyptus, which do not produce sideroxylonals but contain less available nitrogen (AvailN) than do the symphyomyrtles. These 'nutritional niches' segregate the forest and along with other factors, such as generalist and specialist feeding strategies and differences in body size and requirements for shelter, presumably minimise competition between the marsupial species.

Ecological factors contributing to variability of persistent organic pollutant bioaccumulation within forage fish communities of the Detroit River, Ontario, Canada.

Understanding variability of contaminant bioaccumulation within and among fish populations is critical for distinguishing between the chemical and biological mechanisms that contribute to food web biomagnification and quantifying contaminant exposure risks in aquatic ecosystems. The present study examined the relative contributions of chemical hydrophobicity (octanol-water partition coefficient [KOW ]) and habitat use as factors regulating variability in polychlorinated biphenyl (PCB) congener bioaccumulation in 3 lower trophic level cyprinid species across spatial and temporal scales. Bluntnose minnows (Pimephales notatus), spottail shiners (Notropis hudsonius), and emerald shiners (Notropis atherinoides) were sampled at 3 locations in the Detroit River, Ontario, Canada. Variability in PCB concentration was evaluated with respect to several factors, including chemical hydrophobicity, site, season, species, and weight using sum of squares and Levene's test of homogeneity of variance. Individual variability in bioaccumulated congener-specific residues depended on chemical hydrophobicity with mid- and high-range KOW congeners (log KOW >6.0), demonstrating the highest amount of variance compared with low KOW congeners. Different feeding strategies also contributed to the variance observed for mid-range KOW congeners among species. In the present study, benthic feeding specialists exhibited lower variance in PCB concentrations compared with the 2 generalist species. The results indicate that chemical hydrophobicity and feeding ecology not only contribute to differences in the biomagnification potentials of fish, but also regulate between-individual variation in PCB concentrations both across and within fish species.

Physiological aspects of the development of mastication in early childhood (LB63)

The development of feeding skills is a complex process influenced by four main factors: (1) Anatomy, (2) Neurophysiology, (3) Environment, (4) Society and culture. Feeding skills are therefore investigated by two fields of science: the behavioral science of feeding and the biomechanics of feeding (e.g. chewing and swallowing), with a particular emphasis on the first approach.Food intended to be fed to infants and toddlers are currently recommended based on motor and eating skills described by Speech Language Pathologists (SLPs) and feeding specialists. The biomechanical characterization of mastication and its development has been less addressed, even though it could bring a new insight in the design of developmentally appropriate food.In this work, we focus on the development of mastication in infants and toddlers. We aim to describe changes in the oral physiology (e.g. bone and muscle structure, teeth and soft tissues) of infants and toddlers, and its relationship to mastication abilities. Finally, we reviewed previous works on the effect of the food consistency on children’s mastication abilities and on their level of texture acceptance.Recommending products that are adapted to children’s mastication during weaning could facilitate their acceptance of new textures and support the development of healthy eating habits.

The barred grunt Conodon nobilis (Perciformes: Haemulidae) in shallow areas of a tropical bight: spatial and temporal distribution, body growth and diet

This study aimed to comprehensively investigate the population biology of Conodon nobilis (Perciformes, Haemulidae) in Caraguatatuba Bight, southeastern Brazil. Monthly trawls were performed from October 2003 through October 2004 in two areas of the bight that are similar to but distant from each other, South and North. For all specimens, the size was measured and the sex and reproductive stage identified. Abundance and size were compared over areas and months. Body growth parameters were parameterized according to the Von Bertalanffy growth function. The stomach contents were identified and quantified. C. nobilis occurred mainly in the North area and showed an erratic pattern of abundance over time. Several cohorts entered in different periods, but very few large and mature individuals were observed. The results indicate a preference for shallow, ocean-influenced habitats and some degree of segregation between young and older individuals. The species showed a distribution consistent with an r-strategist species, with high abundance and a high growth constant (K = 0.68 year−1 and L max = 34.2 cm). Both the relative length of the digestive tube and the prey items indicated a carnivorous feeding habit; mysids were the main item of the diet throughout the study period, indicating that this grunt is a specialist feeder. Other frequently observed items were amphipods and fish fragments. Ingestion of scales is possibly intentional.

Palaeopopulations of Late Pleistocene Top Predators in Europe: Ice Age Spotted Hyenas and Steppe Lions in Battle and Competition about Prey

Late Pleistocene spotted hyenaCrocuta crocuta spelaea(Goldfuss, 1823) and steppe lionPanthera leo spelaea(Goldfuss, 1810) were top predators in Central Europe. The fossil record (2.303 hyena/1.373 lion bones = ratio 3/1) from 106 cave and open air sites demonstrates comparable associations to modern African hyenas/lions resulting in competition about prey and territory. Cannibalism within extinct spotted hyenas is well documented, including two individual skeletons. Those hyenas produced bone accumulations at dens. Feeding specializations on different megamammal groups are demonstrated for Late Pleistocene hyenas whose prey partly overlaps (e.g., cave bears) with those of lions and wolves. At most fossil sites, 1–3% of the lion remains indicate scavenging of lions by hyenas. The larger Late Pleistocene felids focussed on cervids (reindeers specialization during the high glacial = LGM), on bovids (steppe bison/aurochs), and possibly on saiga antelope and on the cave bear, hunting deep in caves during their hibernations and targeting cubs. The cave bear feeding was the target of all three top predators (lions, hyenas, and wolves) in the Late Pleistocene boreal forests which caused deathly conflicts in caves between them, especially with lions/hyenas and herbivorous cave bears that have no modern analogue.

Interventions to Improve Oral Feeding Performance of Preterm Infants

This review presents a summary of our current understanding of the development of preterm infant oral feeding skills, the feeding issues they are facing, and evidence-based approaches that facilitate their transition from tube to oral feeding.The field of infant oral feeding research is understudied as the recognition of its importance truly came about with the increased preterm population and the realization that a large number of these infants are not safe and competent oral feeders. It is understandable that this research has taken a “back seat” to the more immediate concerns of saving these babies’ lives. However, the time has now come when these infants make up a large proportion of patients referred to feeding specialists for unresolved oral feeding problems during their stay in neonatal intensive care units (NICUs) as well as post-discharge. Unfortunately, due to the limited research so far conducted in this domain, available therapies are limited and lack evidence-based support. Fortunately, this growing medical concern is stimulating deeper research interests and funding.It is hoped that the information provided will assist the development of systematic differential diagnostic approaches to address infant oral feeding issues.

A new marine reptile from the Triassic of China, with a highly specialized feeding adaptation

The Luoping fauna (Anisian, Middle Triassic) is probably the oldest of Triassic faunas in Guizhou-Yunnan area, China. The reptilian assemblage is comprised of ichthyosaurs, a number of sauropterygians (pachypleurosaur-like forms), saurosphargids, protorosaurs, and archosauriforms. Here, we report on a peculiar reptile, newly found in this fauna. Its dentition is fence or comb-like and bears more than 175 pleurodont teeth in each ramus of the upper and lower jaws, tooth crown is needle-like distally and blade-shaped proximally; its rostrum strongly bends downward and the anterior end of its mandible expands both dorsally and ventrally to form a shovel-headed structure; and its ungual phalanges are hoof-shaped. The specializations of the jaws and dentition indicate that the reptile may have been adapted to a way of bottom-filter feeding in water. It is obvious that such delicate teeth are not strong enough to catch prey, but were probably used as a barrier to filter microorganisms or benthic invertebrates such as sea worms. These were collected by the specialized jaws, which may have functioned as a shovel or pushdozer (the mandible) and a grasper or scratcher (the rostrum). Our preliminary analysis suggests that the new reptile might be more closely related to the Sauropterygia than to other marine reptiles.

Setting the Stage for Successful Oral Feeding

To evaluate the impact of implementing the Supporting Oral Feeding in Fragile Infants (SOFFI) program in a tertiary-level neonatal intensive care unit (NICU) on the oral feeding, growth, and length of stay outcomes of a heterogeneous population of medically fragile infants at discharge and feeding and growth outcomes postdischarge at 3 to 5 months postterm. Data related to feeding, growth, and length of stay from a convenience sample of 81 infants recruited pre-SOFFI training were compared with data for 75 infants recruited post-SOFFI training of the NICU staff. Subjects were not excluded on the basis of level of illness or medical diagnoses. To establish comparability of subject groups, infants were assigned scores using the Neonatal Medical Index. At 3 to 5 months postterm, semistructured parent phone interviews related to feeding and growth at home were conducted (n = 128). Post-SOFFI infants born at less than 37 weeks' gestation achieved full oral feedings in significantly fewer days than pre-SOFFI infants (P = .01). Time to achieve full oral feedings was not significantly different in post-SOFFI infants born at 37 or more weeks' gestation. Growth and length of stay were not significantly different at discharge. At follow-up, parents of post-SOFFI infants reported significantly fewer feeding problems overall (P = .01), less arching (P = .003), less vomiting (P = .006), and fewer infants seeing feeding specialists (P = .03). Results of the study support that NICU implementation of the SOFFI feeding program positively influences feeding outcomes before and following discharge.

Early beak development in Argonauta Nodosa and Octopus Vulgaris (Cephalopoda: Incirrata) paralarvae suggests adaptation to different feeding mechanisms

Morphological and morphometric development of the beak of Argonauta nodosa (oceanic species) and Octopus vulgaris (neritic species) paralarvae were analyzed in order to verify whether or not they are determined by distinct life strategies and habitats. Measurements were taken from the upper jaw (UJ) and lower jaw (LJ), compared by the t test to identify-specific differences, and correlated with mantle length (ML) by multiple linear regression to determine overall and relative influences on growth. The jaws of both species were fragile, lightly colored, presented dentition and a slit (division) in the LJ rostrum, and showed considerable variation in general aspect. The hood and lateral walls (UJ) and crest and wings (LJ) showed the highest correlation with paralarval size (ML), and were more developed in A. nodosa than in O. vulgaris of similar size. The rostrum of O. vulgaris seems to be less functional than that of A. nodosa. The presence of beak characteristics from ancestral cephalopod species in the jaws of early paralarvae, namely teeth and a slit in the LJ rostrum, and also the inability of small-sized A. nodosa paralarvae to close the jaws and bite off a piece of prey, seem to be related to the performance of external pre-digestion and suction of body fluids of prey, a specialized feeding mode.

Identification of odorant-binding protein genes expressed in the antennae and the legs of the onion fly, Delia antiqua (Diptera: Anthomyiidae)

The onion fly, Delia antiqua (Meigen), is a pest specialized to the onion, Allium cepa L., and some other Allium plants. Host odorants play an important role in the attraction of D. antiqua adults and stimulation of oviposition in females. Odorant-binding proteins (OBPs) may serve as a first step in the perception of these chemical cues. In this study, to identify all OBP genes expressed in the chemosensory tissues in D. antiqua, RNA-seq analysis was carried out. In addition to the seven OBP genes previously identified, we found eight novel OBPs. Comparisons with Drosophila melanogaster Meigen OBP genes revealed that these 15 D. antiqua OBPs cover the structural variety observed in D. melanogaster OBPs, including Plus C and Minus C OBPs. These results suggest that a relatively large repertoire of chemosensory genes is maintained even in a specialist feeder.