Prey Types Research Articles

Diet and feeding strategy of the common silver-biddy, Gerres oyena (Forsskål 1775) in the seagrass beds of Karang Congkak Island, Kepulauan Seribu National Park

Diet and feeding ecology studies are a principal tool to understand the functional role of fish within their habitat. Like most coastal habitats, seagrass meadow provides food and refuge for many biotas. Karang Congkak Island is a small uninhabited island situated in the northern part of the Kepulauan Seribu National Park and surrounded by a seagrass ecosystem. The current study aims to analyze diet composition changes and trophic attributes of the common silver-biddy, Gerres oyena, in the seagrass ecosystem of the Karang Congkak Island. The research was carried out monthly from March to September 2018 by towing the beach seine net. Data analysis includes diet composition, niche breadth, and feeding strategy. During the study period, 1,196 individuals of G. oyena were captured, and most of them were juveniles. Fifty-nine types of prey were documented and arranged into six groups, namely phytoplankton, algae, zooplankton, zoobenthos, crustaceans, and unidentified material. G. oyena shows an ontogenetic change, from zooplanktivore to crustacivore and zoobenthivore. Moreover, this species has a TROPH value ranging from 3.00-3.31 and is categorized as omnivorous that tend to feed on animals. The interpretation of prey-specific abundance and niche breadth confirms that this species developed specialized and generalized feeding strategies.

Feeding Selectivity in Anuran Species from a Tea Cultivation Area of Barak Valley, Assam, India

The stomach content was studied in adults of Kaloula pulchra, Leptobrachium smithi, Sivirana leptoglossa, and Fejervarya spp., which were encountered in the Rosekandy tea estate of Cachar. All the anuran species found were carnivorous and eighteen prey types were identified consisting of arthropods and mollusks from the anuran stomach-flush samples. Significant positive correlations were observed in the snout-vent length and the gape size of the anuran species with the length, width and height of their prey types. Insects of Hymenoptera and Coleoptera were consumed most frequently. Prey selections were based on the microhabitats and the habits of different anuran species. Adults of Hymenoptera were the relatively abundant prey type to all the anurans, but species like Kaloula pulchra and Sylvirana leptoglossa also showed selective feeding on termites (Isoptera).

Consequences of Evolving Limbless, Burrowing Forms for the Behavior and Population Density of Tropical Lizards

We quantified functional traits (escape strategy, sprint speed and predatory performance) and population density across 10 lizard species representing morphotype stages in the acquisition of burrowing snake-like morphotypes (BSLM), from Brazil. We used phylogenetic mixed models to test if: (a) morphotype and substrate affects flight strategy and speed, (b) BSLM species more effectively access different potential prey types than lacertoid species, when in syntopy, and (c) morphotype is correlated with population abundance and habitat use in a way expected from the output of the previous experiments. BSLM rigidly relied on burrowing as flight strategy, while syntopic lacertoid species changed their strategy according to the substrate. In addition, sand had opposing effects on sprint speed depending on morphotype, making lacertoids run more slowly and BSLM faster. Even though BSLM were overall slower than lacertoids, they were equally effective hunters of challengingly fast prey, and better hunters of underground prey. In their shared habitats, prey is most abundant in the superficial layer of leaf litter, although a large fraction is found beneath this layer, under bushes. Experimental results support the observed higher importance of sand for BSLM’s density and the higher importance of vegetation for lacertoids’ density. Finally, although BSLM species reached the highest population densities among the studied species, a systematic effect of morphological evolution on the abundance of limbless lizards remains elusive.

Success-biased social learning in a one-consumer, two-resource model

Previous analyses have predicted that social learning should not evolve in a predator–prey system. Here we examine whether success-biased social learning, by which social learners copy successful demonstrators, allows social learning by foragers to evolve. We construct a one-predator, two-prey system in which foragers must learn how to feed on depletable prey populations in an environment where foraging information can be difficult to obtain individually. We analyze two models in which social learning is success-biased: in the first, individual learning does not depend on the resource dynamics, and in the second model it depends on the relative frequency of the resource. Unlike previous results, we find that social learning does not cause predators to over-harvest one type of prey over the other. Furthermore, increasing the probability of social learning increases the probability of learning a successful foraging behavior, especially when individually learned information tends to be inaccurate. Whereas social learning does not evolve among individual learners in the first model, the assumption of resource-dependent learning in the second model allows a mutant with an increased probability of social learning to spread through the forager population.

A method to predict overall food preferences.

Most natural ecosystems contain animals feeding on many different types of food, but it is difficult to predict what will be eaten when food availabilities change. We present a method that estimates food preference over many study sites, even when number of food types vary widely from site to site. Sampling variation is estimated using bootstrapping. We test the precision and accuracy of this method using computer simulations that show the effects of overall number of food types, number of sites, and proportion of missing prey items per site. Accuracy is greater with fewer missing prey types, more prey types and more sites, and is affected by the number of sites more than the number of prey types. We present a case study using lion (Panthera leo) feeding data and show that preference vs prey size follows a bell-curve. Using just two estimated parameters, this curve can be used as a general way to describe predator feeding patterns. Our method can be used to: test hypotheses about what factors affect prey selection, predict preferences in new sites, and estimate overall prey consumed in new sites.

Metabarcoding analysis of different portions of the digestive tract of scorpions (Scorpiones, Arachnida) following a controlled diet regime shows long prey DNA half‐life

AbstractMolecular analysis of gut content is one of the widest used methods to investigate diet in arthropods. Stomach content analysis in some arthropods is particularly difficult, e.g., in arachnids, because they have external digestion and a low foraging frequency. Scorpions have a particularly low feeding frequency, and their diet information is scarce. In this work we explore a DNA metabarcoding approach to detect prey DNA in Vietnamese forest scorpions (Heterometrus laoticus) under a controlled diet regime. A different type of prey (crickets, mealworms, and cockroaches) was offered once every 3 weeks for a total of 9 weeks. To assess the most suitable part of the digestive system and extraction method to use for molecular diet analysis, we separately analyzed three different portions of the digestive tract of scorpions (mid‐gut, hepatopancreas, and hindgut) using two different extraction methods (salt‐out method and a customized beads‐based protocol). We calculated the detectability half‐life of the prey DNA for each digestive tract section. We detected all three targeted prey items, showing that in scorpions multiple predation events can be distinguished in the same specimen within its last 9 weeks of foraging activity. The hepatopancreas was the portion of the digestive tract that provided the best prey detection and the longest DNA detectability half‐life (51 days), followed by the mid‐gut (22 days) and the hindgut (16 days). We found no significant difference between the extraction methods used. However, the salt‐out method was less effective in some of the PCRs and is therefore not recommended for molecular diet analysis.

Quantity over quality? Prey-field characteristics influence the foraging decisions of little penguins (Eudyptula minor).

Quantifying prey characteristics is important for understanding the foraging behaviour of predators, which ultimately influence the structure and function of entire ecosystems. However, information available on prey is often at magnitudes which cannot be used to infer the fine-scale behaviour of predators, especially so in marine environments where direct observation of predator–prey interactions is rarely possible. In the present study, animal-borne video data loggers were used to determine the influence of prey type and patch density on the foraging behaviour of the little penguin (Eudyptula minor), an important predator in southeastern Australia. We found that numerical density positively influenced time spent foraging at a patch. However, when accounting for calorific value in density estimates, individuals spent longer at dense patches of low-quality prey. This may reflect a trade-off between capture effort and calorific gain as lower quality prey were captured at higher rates. During the breeding season, foraging trip distance and duration is constrained by the need to return to the colony each day to feed offspring. The results of the study suggest that, under these spatio-temporal constraints, little penguins maximize foraging performance by concentrating efforts at larger quantities of prey, irrespective of their calorific quality.

Foraging microhabitat selection of Spoon-billed Sandpiper in the Upper Gulf of Mottama, Myanmar

Spoon-billed Sandpiper ( Calidris pygmaea ) is Critically Endangered, declining 9% per year since 2009; although important wintering sites have been identified, little is known about why particular sites are selected. The Gulf of Mottama, Myanmar, supports perhaps 60% of the global population in winter. Our objective was to identify macrohabitat and microhabitat characteristics of Spoon-billed Sandpiper foraging locations. We considered 1) location (relative to distance to the main channel of the gulf), 2) temporal patterns (relative to the tide cycle), 3) physical substrate characteristics and 4) possible food sources. Spoon-billed Sandpipers were observed at 26 foraging locations during the study (November 2019-March 2020). The sandpipers were found more frequently on mixed sand-mud substrate, similar to over-wintering sites in Bangladesh, and while it is likely that the mixed sand-mud substrate was generally further from the main channel than the pure sand substrate, presumably due to tidal action, we found no evidence that Spoon-billed Sandpiper locations were associated with the tide cycle. Logistic regression models indicated that foraging locations were associated with shallow surface puddles, compared to random locations. The mixed sand-mud substrate supported more polychaetes relative to crabs or insect larvae, the three most common prey types in our 442 benthos samples used to assess prey availability. Our results reinforce the point that Mottama needs to be protected as an intact functioning estuary and key site for Spoon-billed Sandpiper and other threatened shorebirds. Although we have identified some characteristics of foraging sites associated with Spoon-billed Sandpiper at Mottama, we still lack understanding as to whether and how potential prey is driving site selection and how these characteristics vary among wintering sites.

Change in prey genotype frequency rescues predator from extinction.

Indirect evolutionary rescue (IER) is a mechanism where a non-evolving species is saved from extinction in an otherwise lethal environment by evolution in an interacting species. This process has been described in a predator–prey model, where extinction of the predator is prevented by a shift in the frequency of defended towards undefended prey when reduced predator densities lower selection for defended prey. We test here how increased mortality and the initial frequencies of the prey types affect IER. Combining the analysis of model simulations and experiments with rotifers feeding on algae we show IER in the presence of increased predator mortality. We found that IER was dependent on the ability of the prey to evolve as well as on the frequency of the defended prey. High initial frequencies of defended prey resulted in predator extinction despite the possibility for prey evolution, as the increase in undefended prey was delayed too much to allow predator rescue. This frequency dependency for IER was more pronounced for higher predator mortalities. Our findings can help informing the development of conservation and management strategies that consider evolutionary responses in communities to environmental changes.

Use of marine vs. freshwater proteins for egg‐laying and incubation by sea ducks breeding in Arctic tundra

AbstractUnderstanding dietary nutrient sources is fundamental to conserving sensitive species, especially as climate change alters food web dynamics. Migratory species that depend on both marine and terrestrial habitats face unique challenges, as the locations and quality of resources in the two realms may respond quite differently to environmental changes, with potential for spatial and temporal carryover effects. For sea ducks (Mergini) that winter at sea but move inland to breed, body size may determine their capacity to store nutrient reserves for later use in alternative habitats. We assessed ultimate sources of protein for reproduction in four sea duck species in northern Alaska: smaller‐bodied Long‐tailed Ducks and Steller's Eiders (Clangula hyemalis and Polysticta stelleri), and larger‐bodied Spectacled and King Eiders (Somateria fischeri and Somateria spectabilis). To assess the relative use of local freshwater foods vs. marine protein for both egg production and body maintenance of incubating females, we measured stable isotopes of carbon and nitrogen in egg membranes, red blood cells, marine and freshwater invertebrates, and vegetation. For egg production, isotope mixing models indicated that proteinaceous egg membranes of all four species were derived mostly (89%–95%) from freshwater foods on the breeding grounds, with broad individual variation in specific prey types selected by the larger species. For incubation, isotopes in red blood cells indicated that body maintenance of females also relied mainly (87%–91%) on freshwater foods in Long‐tailed Ducks and Steller's Eiders. However, incubating Spectacled and King Eiders obtained only about 60% of their protein from freshwater foods and the remainder from marine‐derived body tissues. The latter strategy allows the larger‐bodied species to incubate almost continuously, whereas the smaller species must take more frequent incubation breaks and generally incur higher rates of predation on eggs. Thus, depending on body size, cross‐seasonal effects of feeding conditions in marine habitats may strongly influence population processes well after the birds move to inland nesting sites. Although conservation programs on land and sea are often researched, planned, and administered by different agencies and organizations, our results emphasize the need to coordinate marine and land‐based efforts for species that integrate conditions across both environments.

Influence of food quality on larval growth of Atlantic bluefin tuna (Thunnus thynnus) in the Gulf of Mexico

AbstractLarval abundances of Atlantic bluefin tuna (ABT) in the Gulf of Mexico are currently utilized to inform future recruitment by providing a proxy for the spawning potential of western ABT stock. Inclusion of interannual variations in larval growth is a key advance needed to translate larval abundance to recruitment success. However, little is known about the drivers of growth variations during the first weeks of life. We sampled patches of western ABT larvae in 3–4 day Lagrangian experiments in May 2017 and 2018, and assessed age and growth rates from sagittal otoliths relative to size categories of zooplankton biomass and larval feeding behaviors from stomach contents. Growth rates were similar, on average, between patches (0.37 versus 0.39 mm d−1) but differed significantly through ontogeny and were correlated with a food limitation index, highlighting the importance of prey availability. Otolith increment widths were larger for postflexion stages in 2018, coincident with high feeding on preferred prey (mainly cladocerans) and presumably higher biomass of more favorable prey type. Faster growth reflected in the otolith microstructures may improve survival during the highly vulnerable larval stages of ABT, with direct implications for recruitment processes.

Dietary Specialization and Habitat Shifts in a Clade of Afro-Asian Colubrid Snakes (Colubridae: Colubrinae)

Speciation through niche divergence often occurs as lineages of organisms colonize and adapt to new environments with novel ecological opportunities that facilitate the evolution of ecologically different phenotypes. In snakes, adaptive diversification may be driven by the evolution of traits relating to changes in their diets. Accordingly, habitat-mediated differences in prey available to ancestral snakes as they colonized and occupied novel dynamic landscapes are likely to have been a strong selective agent behind the divergence and radiation of snakes across the globe. Using an ancestral reconstruction approach that considers the multivariate nature of ecological phenotypes while accounting for sampling variation between taxa, we explored how diet and macro-habitat use coevolved across a phylogeny of 67 species of Afro-Asian colubrine snakes. Our results show that the most recent common ancestor of this clade was likely a dietary generalist that occupied tropical forests in Asia. Deviations from this generalist diet to a variety of specialist diets each dominated by the utilization of single prey types repeatedly occurred as ancestral colubrines shifted from tropical forests to savanna and grassland habitats across Africa. We additionally found that dietary specialist species were on average smaller in maximum length than dietary generalists, congruent with established predator-size, prey-diversity dynamics in snakes. We speculate that adaptive divergence in ancestral colubrines arose as a result of a selective regime that favored diets comprised of terrestrial prey, and that partitioning of different prey types led to the various forms of dietary specialization evident in these lineages today. Our findings provide new insights into the ecological correlates associated with the evolution of diet in snakes, thereby furthering our understanding of the driving forces behind patterns of snake diversification.

Blood-red colour as a prey choice cue for mosquito specialist predators

Specialist predators are innately and distinctively proficient at targeting specific prey types. This is enabled by behavioural, perceptual and cognitive mechanisms that can only be understood using carefully designed experiments. Evarcha culicivora is an East African jumping spider that feeds on vertebrate blood acquired indirectly by actively targeting blood-carrying female mosquitoes as preferred prey. Here we asked whether these spiders use the colour red to identify this prey. In Objective 1, we used spectrophotometry to document the changing redness of mosquitoes in the first 17 h following blood meals. In Objective 2, we used vision-based choice tests to document how E. culicivora's preference for blood-carrying mosquitoes changes over time (using an interval comparable to that in Objective 1). We found the strongest preference for blood-carrying mosquitoes during the first 6 h after those mosquitoes had fed on blood and that this time interval corresponded to when mosquitoes exhibit the reddest coloration. Based on this, we then took mosquitoes that had never fed on blood and manipulated their colour using a blend of red food dye to make them appear blood-fed (i.e. by matching their spectral properties to mosquitoes that had fed on blood within the previous 6 h). We also created grey-dyed mosquitoes that matched the spectral properties of those that had never fed on blood. In Objective 3, there was no evidence of E. culicivora visually discriminating between our red-dyed mosquitoes and blood-carrying mosquitoes; this indicates that, to E. culicivora, our red-dyed mosquitoes appropriately resembled blood-carrying mosquitoes. Finally, in Objective 4, we show that E. culicivora consistently preferred red-dyed mosquitoes over grey-dyed mosquitoes, supporting the hypothesis that E. culicivora uses some aspect of red coloration to identify their preferred prey. We discuss how these findings relate to cognitive processes, colour-based communication and sensory exploitation.

Insularity and Aridity as Drivers of Mandibular Disparity in Thylamys elegans (Waterhouse, 1839) from Populations of the Atacama Desert, Chile.

Simple SummaryThe following article studied the environment influence between island and mainland in an endemic marsupial from Chile the mouse-opossum Thylamys elegans (Waterhouse, 1839). Its important to understand that the isolated habitat could affect the pattern of morphological evolution in organism due to millions of years of being separated from the mainland. In this re-search we used two methodologies to study those effects in the mandible of this marsupial, first a biomechanical methodology which was used to correlate it with the diet, and a second called ge-ometric morphometrics which combine the geometry and biology to identify the principal changes in the morphology. Our results showed that Island populations have more disparity in the mor-phology in comparison to the mailand differences that could be related to the arid environment and other characteristic of the island. Concluding that one of the possible reason of the evolutionary history of this Chilean mouse-opossum was processes of natural selection by a process of coloniza-tion of island after vicariance denominated founder effect.Island ecosystems differ in several elements from mainland ecosystems and may induce variations related to natural selection and patterns of adaptation in most aspects of the biology of an organism. Thylamys elegans (Waterhouse, 1839) is a marsupial endemic to Chile, distributed from Loa River to Concepción. Historically, three subspecies have been described: Thylamys elegans elegans, Thylamys elegans coquimbensis and Thylamys elegans soricinus. For this research, two morphometric approaches and a biomechanical model were used to compare the mandible shapes and biomechanics between two Chilean mouse opossum populations belonging to different subspecies: one from the coastal desert of Chile (T. e. coquimbensis) and the other from the central inland region (T. e. elegans). Additionally, mandibles of insular populations found in the Reserva Nacional Pinguino de Humboldt (RNPH)), from which the subspecies association is unknown, were also included. The results showed that insular populations have differences in mandibular shapes, sizes and biomechanical characteristics compared to continental populations, which may be related to environmental variables like aridity and vegetation cover, prey type, insularity effects and/or the founder effect on micromammals, apart from vicariance hypotheses and other selective pressures.

Provisioning behavior of male and female Loggerhead Shrikes

The unique predatory, caching, and impaling behaviors of shrikes (Laniidae) may provide these unusual passerines with alternative provisioning strategies compared to other songbirds, but few studies have determined the impact these unique behaviors have on provisioning rates. Our objectives were to compare the provisioning behavior of male and female Loggerhead Shrikes ( Lanius ludovicianus), and determine how their provisioning behavior was influenced by nestling age. The provisioning behavior of six pairs of Loggerhead Shrikes was videotaped from 15 April to 15 August 2004–2007 in Garrard and Madison counties, Kentucky, USA. For each nest visit by a shrike, the sex of the visiting adult, number of prey items delivered, size of prey, type of prey, and the duration of the nest visit were recorded. Adults made 2169 visits to nests, with males (49%) and females (51%) making similar numbers of visits. Males and females differed in time spent at nests, with males spending less time at nests per visit (mean = 12.0 s, N = 1062) than females (77.0 s, N = 1107). Feeding rates did not differ between the sexes, but feeding rates did increase with nestling age. The size of prey delivered to nestlings also tended to increase with nestling age. Invertebrates comprised 65% of the identified prey items, and cached items made up the remaining 35%. Although many passerine species increase provisioning rates as nestling demand increases, the caching behavior of shrikes may allow adults to reliably increase both feeding rates and prey size as nestling age and demand increase as well as act as buffers when prey availability declines. The caching behavior of shrikes provides them with parental provisioning strategies not available to non-caching songbirds.

Alien versus Alien: The American mink, Neovison vison, as an indicator of invasive crayfish presence in the environment

Invasive animal species pose a significant threat to native biocenoses. For the management of invasive species, it is important to know their distribution. We aimed to investigate the potential use of American mink (Neovison vison) scats as a bioindicator of the presence and density of invasive crayfish Faxonius (Orconectes) limosus (Rafinesque, 1817) in the watercourses. The structure and seasonal dynamics of the mink’s diet were studied in western Belarus. The dietary composition of the American mink showed great similarities across different types of watercourses (rivers and drainage channels). The basic diet consisted of rodents, amphibians, and fish. The crayfish’s presence in the samples during the warm season was negatively dependent on all the other main prey groups, but mostly on aquatic insects. During the cold season the relations were weaker, and crayfish was negatively associated mostly with birds in the samples. The percentage of crayfish in scats collected during the warm season was correlated with crayfish density, which indicated that with higher crayfish densities, the mink more often used this type of prey. However, the regression model was only a moderate fit. Droppings collected during both seasons can indicate the presence of crayfish in the environment. We conclude that the American mink’s diet can be a good indicator of invasive crayfish presence and their density in the environment. However, estimating crayfish density based on the mink’s diet may deviate from the trend during years of low water level, therefore, it is necessary to first assess precipitation during the season.

Diet and reproductive success of Great Horned Owl (<i>Bubo virginianus</i>) at its northern breeding limit

We studied the diet and reproductive success of Great Horned Owl (Bubo virginianus) at its northern range limit during an apparent high in the Snowshoe Hare (Lepus americanus) population. We performed diet analyses using images from fixed motion sensor cameras and pellet and prey remains collected at active nests, and gathered data on breeding success through camera and visual observations. Pellet data at 14 nests produced 1277 prey records consisting of 65–95% Snowshoe Hare biomass. Great Horned Owls ate 18 different prey types, with overall biomass consisting of 93% mammal, 7% bird, and less than 1% insects, frogs, and fish. The mean prey mass of 714 g (± 34 SE) was 2–25 times the mean prey mass of studies of this species at more southerly latitudes. Camera observations showed that Great Horned Owls delivered an average of 459 g/chick/d (± 75) throughout nesting. This was significantly (P = 0.005) higher than observations from Alberta, at 328–411 g/chick/d. Pellet/prey remains data showed that Great Horned Owls delivering a higher proportion of hares to their nestlings successfully raised more chicks (χ21 = 6.3, P = 0.012), highlighting the importance of this prey in the population dynamics of Great Horned Owl. In addition, we observed Snowshoe Hare removing pellets beneath nest sites, revealing an apparently undocumented bias to the use of pellet analysis.

Winter diet of Burrowing Owls in the Llano La Soledad, Galeana, Nuevo León, México.

The dietary niche breadth of the Burrowing Owl was determined (Athene cunicularia Molina, 1782) in Llano La Soledad, Galeana, Nuevo Leon in northern Mexico, by considering prey type, numerical percentage, weight, weight percentage, frequency of occurrence percentage, and IRI percentage. The study compared data from three winters (2002–2003, 2003–2004, 2004–2005) by analyzing 358 pellets, identifying 850 prey items. Invertebrates constituted 90% of prey items, which mostly included insects (85%); beetles were the most common insects found in pellets (70%). Vertebrates made up 84% of consumed weight, of which 83% were mammals. Most of the mammals were cricetid rodents (41%). Niche breadth based on the numerical and weight percentage confirmed the Burrowing Owl as a generalist species with mean values per year ranging between 0.65 and 0.82. Additionally, there was a strong association between the weight of rodent species in winter. This association was mainly driven by changes in composition and frequency of these prey species during the second winter, probably caused by high annual rainfall. The second season also showed a statistically significant narrower niche (Ro = 0.96) and the smallest overlap (0.45 vs. 0.76) among the three winters.

Note on feeding relationships of three species of cyprinid fish larvae in Al-Huwaiza marsh, Southern Iraq

Food composition of three cyprinid larvae (Cyprinus carpio, Carassius auratus and Alburnus mosulensis) in Al-Huwaiza marsh has been studied during March and April 2006. The diet of these cyprinid larvae were consist mainly of zooplankton dominated by copepods both adult and larval stages followed by Cladocera Rotifera, aquatic insects and Ostracoda. The food of plant origin also exists and consists of diatoms and filamentous algae. Costello graphical plot showed that these larvae are generalist feeders. This strategy result in lower competition and allow these three species to co-occur in relatively high density in this marsh area. The food similarity between C. carpio and C. auratus was 0.60, between C. carpio and A. mosulensis was 0.44, while it was 0.72 between C. auratus and A. mosulensis. The food overlap analysis showed that C. carpio; C. auratus and A. mosulensis larvae share a wide range of prey types. Competition for food is possible However, direct competition seemed to be avoided to some extent as a result of great food availability in Al-Huwaiza marsh which makes it as a suitable nursery and feeding site for many cyprinid fish.

Contact chemoreception in multi-modal sensing of prey by Octopus.

Octopuses have keen vision and are generally considered visual predators, yet octopuses predominantly forage blindly in nature, inserting their arms into crevices to search and detect hidden prey. The extent to which octopuses discriminate prey using chemo- versus mechano-tactile sensing is unknown. We developed a whole-animal behavioral assay that takes advantage of octopuses' natural searching behavior to test their ability to discriminate prey from non-prey tastes solely via contact chemoreception. This methodology eliminated vision, mechano-tactile sensing and distance chemoreception while testing the contact chemosensory discriminatory abilities of the octopus arm suckers. Extracts from two types of prey (crab, shrimp) and three types of non-prey (sea star, algae, seawater) were embedded in agarose (to control for mechano-tactile discrimination) and presented to octopuses inside an artificial rock dome; octopuses reached their arms inside to explore its contents - imitating natural prey-searching behavior. Results revealed that octopuses are capable of discriminating between potential prey items using only contact chemoreception,as measured byan increased amount of sucker contact time and arm curls when presented with prey extracts versus non-prey extracts. These results highlight the importance of contact chemoreception in the multi-modal sensing involved in a complex foraging behavior.