Exploitation Of Food Resources Research Articles

Signatures of convergence in Neotropical cichlid fish.

Convergent evolution of similar phenotypes suggests some predictability in the evolutionary trajectories of organisms, due to strong and repeated selective pressures, and/or developmental constraints. In adaptive radiations, particularly in cichlid fish radiations, convergent phenotypes are commonly found within and across geographical settings. Cichlids show major repeated axes of morphological diversification. Recurrent changes in body patterns reveal adaption to alternative habitats, and modifications of the trophic apparatus respond to the exploitation of different food resources. Here we compare morphologically and genetically two Neotropical cichlid assemblages, the Mexican desert cichlid and the Nicaraguan Midas cichlid, with similar polymorphic body and trophic adaptations despite their independent evolution. We found a common morphological axis of differentiation in trophic structures in both cichlid radiations, but two different axes of differentiation in body shape, defining two alternative limnetic body patterns. Adaptation to limnetic habitats implied regulation of immune functions in the Midas cichlid, while morphogenesis and metabolic functions in the desert cichlid. Convergent phenotypic adaptions could be associated to divergent gene regulation.

Assessing the direct and indirect effects of bigheaded carp (Hypophthalmichthys spp.) on freshwater food webs: A meta‐analysis

Abstract The rapid growth of aquaculture over the last century has led to the widespread introduction of aquatic species to freshwater environments. Bighead carp (Cyprinidae: Hypophthalmichthys nobilis) and silver carp (Cyprinidae: Hypophthalmichthys molitrix), collectively referred to as bigheaded carp, are among the top finfishes produced in aquaculture. These filter feeders possess feeding structures that allow them to efficiently remove plankton and other particles from the water. Unfortunately, when introduced into the wild and outside their historical range, their feeding traits generally result in the exploitation and suppression of phytoplankton and zooplankton, reducing food resources for native invertebrates and vertebrates. We conducted a meta‐analysis of published experiments to examine how bigheaded carp directly and indirectly affect organisms in aquatic food webs to better understand their ecological role within ecosystems. Specifically, we addressed the following questions: (1) What is the overall magnitude and direction of bigheaded carp effects on different aquatic organisms? (2) Do bigheaded carp affect organisms in planktonic and benthic habitats? (3) Are effects similar between bighead carp and silver carp? (4) Are effects consistent among experimental arenas (i.e., mesocosm, ponds)? We detected direct and indirect effects of bigheaded carp across multiple trophic levels. Large zooplankton often exhibited the strongest negative effects, with taxa‐specific differences between carp species. The suppression of zooplankton cascaded down to primary producers, resulting in an increase in phytoplankton (i.e., indirect effect). However, we observed no compensatory increases in rotifers when large zooplankton were reduced. Growth rates of planktivorous native fishes were the slowest when stocked with bigheaded carp. Our results further indicated that egested waste from bigheaded carp appeared to subsidise (i.e., direct effect) some benthic invertebrates such as Chironomidae midges. Effects of carp on zooplankton were generally similar between mesocosms and ponds. Invasive bigheaded carp greatly restructure their surrounding food web, both positively and negatively, through a complex suite of direct and indirect effects. These changes manifested across multiple trophic levels and differing habitats. Our analysis provides a more complete understanding of how these invasive carps change their surroundings by exploiting food resources and transferring materials from planktonic to benthic habitats. Taken together, the suite of direct and indirect effects shows how an invasive species can create imbalances within aquatic ecosystems, often to the detriment of native taxa. Bigheaded carp are invasive in many countries across the globe because of their popularity in aquaculture. Our findings reaffirm the threat these planktivores pose to native freshwater organisms.

Honey bees and mason bees as biological indicators of landscape pesticide loads: Different results but similar conclusions

Agricultural environments, including crop and non-crop areas, often provide important pollen and nectar resources for managed and wild bees. However, these resources may be contaminated with pesticides detrimental to bees and other non-target organisms, including humans. Differences in life-history traits among bee species influence food resource exploitation and pesticide exposure. This study assesses the potential of honey bees (Apis mellifera) and mason bees (Osmia), two bee species with highly contrasting functional traits, as biological indicators of pesticide exposure in 34 Italian agricultural farms. Pollen loads of both species were used to identify pollen species collected and to analyse multi-residue levels of pesticides. Pesticide risk indexes were calculated for honey bees, mason bees and humans. In mason bees, pesticide risk was not influenced by plant diversity. In agreement with their pollen preferences and short foraging ranges, mason bees collected a high proportion of pollen from flowers of the target crop. Conversely, pesticide risk decreased with increasing pollen diversity in honey bees. In agreement with their generalist foraging habits and long foraging ranges honey bees collected a greater diversity of pollen species and a lower proportion of target crop pollen. Although honey bees and mason bees showed similar toxic loads and pesticide composition, at a field scale pesticide risk of one species is not a good indicator of the risk to the other species. Our study confirms that bees in agricultural environments are pervasively exposed to multi-residue pesticide loads. Exposure is conditioned by specific bee traits but is also highly context-dependent.

Fish Feeding and Rapid Foraging Behavior Switching by Gray Whales (Eschrichtius robustus) in California

Gray whales (Eschrichtius robustus) evolved to suction feed on benthic invertebrates and typically do not consume adult fish. Yet, these whales are flexible foragers, occasionally skim feeding on planktonic invertebrates and rarely lunge feeding on fish, the latter according to anecdotal accounts. We documented the unusual phenomenon of multiple gray whales predating dense schools of anchovy over a sustained period (22 days) in June 2022 at Pacifica, California, in the Gulf of the Farallones. Analysis of 11,265 photos and 11 video clips (totaling 4 min 16 s) for behavior and whale identification resulted in a total of 165 foraging events by six identified gray whales. Attribution of foraging behavior to the most active individuals was achieved by matching left pectoral fins, visible during lateralized feeding behavior. Whales rolled onto their right sides in 96% of near-surface side-swimming bouts. Another behavior, first photographed here, was dynamic surface lunge feeding by one gray whale. Five gray whales interspersed fish feeding with benthic suction feeding evidenced by sediment streaming: prey type switching was executed rapidly, in less than 1 minute in several instances, the shortest intervals reported for a baleen whale. Similar results were obtained for foraging behavior switching (continuous side-swimming or intermittent lunging) in pursuit of fish. Four photo-identified Pacifica whales were sighted in San Francisco Bay/Gulf of the Farallones, one of which was also matched to the Pacific Coast Feeding Group. Such local and regional connections warrant efforts to determine whether gray whales use this area as a migratory stopover site or for summer foraging, or both. Our observations confirm gray whale behavioral plasticity and opportunistic exploitation of food resources in mid-latitudes, which may enhance their resilience to climate change.

Masticatory habits of the adult Neanderthal individual BD 1 from La Chaise-de-Vouthon (France).

The analysis of dental wear provides a useful approach for dietary and cultural habit reconstructions of past human populations. The analysis of macrowear patterns can also be used to better understand the individual chewing behavior and to investigate the biomechanical responses during different biting scenarios. The aim of this study is to evaluate the diet and chewing performance of the adult Neanderthal Bourgeois-Delaunay 1 (BD 1) and to investigate the relationship between wear and cementum deposition under mechanical demands. The macrowear pattern of BD 1 was analyzed using the occlusal fingerprint analysis method. We propose a new method for the bilateral measurement of the cementum volume along both buccal and lingual sides of the molar root. BD 1's anterior dentition is more affected by wear compared to the posterior one. The macrowear pattern suggest a normal chewing behavior and a mixed-diet coming from temperate environments. The teeth on the left side of the mandible display greater levels of wear, as well as the buccal side of the molar crowns. The cementum analysis shows higher buccal volume along the molar roots. BD1 could have been preferably chewing on the left side of the mandible. The exploitation of various food resources suggested by the macrowear analysis is compatible with the environmental reconstructions. Finally, the greater wear on the buccal side of the molar occlusal surface and the greater volume of cementum in that side of the molar roots offers a preliminary understanding about the potential correlation between dental wear and cementum deposition.

Resilin in Insect Flight Systems

AbstractCompared to wingless insects, pterygote insects profit from numerous wing‐related benefits including a wider distribution range, the exploitation of various food resources and the escape from water‐ or land‐confined predators. In order to maintain the wings´ functionality, the wing design and resistance to material fatigue are of key importance. This is even more essential for survival when considering that wings are used for millions of wing beat cycles but cannot be repaired and do not contain inner muscles so that their aerodynamic performance is mainly based on passive, structure‐based wing deformations. One of the components serving this purpose is the endowment of certain wing components with the elastomeric protein resilin building stable and complex material composites with the tanned cuticle. Resilin endows the respective structures with, e.g., higher flexibility and compliance and enables elastic energy storage. In this study, the occurrence of resilin in the insect flight system is reviewed based on previous studies of several insect orders including Odonata, Orthoptera, Hymenoptera, Coleoptera, Dermaptera, and Diptera, and the function of resilin is discussed with reference to the respective structures.

Phasmid species that inhabit colder environments are less likely to have the ability to fly.

A vast majority of insects can fly, but some cannot. Flight generally increases how far an individual can travel to access mates, enables the exploitation of additional food resources, and aids in predator avoidance. Despite its functional significance, much remains unknown about the factors that influence the evolution of flight. Here, I use phylogenetic comparative methods to investigate whether average annual temperature or wind speed, two components of the flying environment, is correlated with the evolution of flight using data from 107 species of stick and leaf insects (Insecta: Phasmatodea). I find no association between wind speed and flying ability in this clade. However, I find that colder temperatures are associated with the lack of flying ability. This pattern may be explained by the additional metabolic costs required for insects to fly when it is cold. This finding contradicts previous patterns observed in other insect groups and supports the hypothesis that cold temperatures can influence the evolution of flight.

Sustainability indexes in water–food–energy nexus to develop strategies with respect to virtual water

Abstract The management of water resources requires a correct understanding of the simultaneous management of food and energy resources. The framework of water–food–energy correlation with the approach of sustainability of resources and uses analyzes the combined management and exploitation of water, food, and energy resources with the help of scenario planning. In addition to sustainability concepts, environmental costs such as the emission of carbon dioxide from fossil fuels and its impact on the environment are also discussed. In this research, according to the five defined indicators and based on the potential of using solar energy and the possibility of exploiting renewable energy sources such as solar energy, various management scenarios have been developed. After examining the virtual water management model developed in the Hunan basin as a case study, the development of the water–food–energy nexus model and its calibration, and four scenarios including improving water use efficiency, energy saving, increasing food productivity, and nexus sustainability were developed. The results showed that the nexus strategy can provide sustainability goals according to the weight of each component. After the combined scenario, improving the efficiency of water consumption can be the component with the highest priority in the decision-making model in dry areas.

Not all dung beetles feed on dung: Scarabaeinae (Coleoptera: Scarabaeidae) attracted to different carrion types in contrasting habitats at Brazilian Amazon

AbstractBy understanding how assemblages segregate according to food types, it is possible to depict and understand species distribution and exploitation of similar food resources. Although it is well known that dung beetles may feed on carrion, but the attractiveness of different carrion types for these beetles is still poorly understood. In this study, we compared the dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae) diversity attracted to two carrion types in different habitats in an Amazonian landscape. Dung beetles were captured by using pitfall traps baited with decaying cattle beef and cattle liver in native forest, peach palm plantation, teak plantation and exotic pasture. Overall, we captured 582 dung beetles of 43 species, where Canthidium aff. lentum was classified as a specialist of cattle beef, Deltochilum sp. One was considered specialist of liver carrion, 11 were considered generalists and for the 30 remaining species, it was not possible to determine their carrion preference due to the low number. Abundance, but not species richness, was affected by carrion type, and a higher number of beetles was recorded in beef‐baited traps compared to liver‐baited traps. According to functional groups, endocoprid beetles were more abundant in traps baited with decaying beef, while paracoprid and telecoprid beetles did not show preference for any carrion type. This study suggests a novel scenario of intra‐resource segregation, where species vary their preferences depending to the part of the dead corpse being exploited. The amount of food resource, the maintenance of stable populations and trophic preference mediated by chemical cues are some mechanisms that may explain the segregation of dung beetles among carrion types.

Why the delay in recognizing terrestrial obligate cave species in the tropics?

“Nothing could possibly live there!” They believed. Indeed, until recently, few specialized cave- adapted animals were known from volcanic, tropical, or oceanic island caves, and plausible theories had been put forward to explain their absence. But assume nothing in science! One must illuminate, explore, and survey habitats before declaring them barren. Our understanding of cave biology changed dramatically about 50 years ago following the serendipitous discovery of cave-adapted terrestrial arthropods in Brazil and on the young oceanic islands of the Galápagos and Hawai‘i. These discoveries and subsequent studies on the evolutionary ecology of cave animals have revealed a remarkable hidden fauna and created new sub- disciplines within biospeleology. Biological surveys of caves in other regions have continued to expand our understanding of the evolution, adaptation, and ecology of the subterranean biome. We now predict that, rather than being relicts trapped in caves by changing climate, many animals actively colonized caves and adapted to exploit food resources wherever there were suitable subterranean voids. The physical environment in caves can be determined with great precision because the habitat is buffered by rock. Furthermore, the bizarre adaptations displayed by obligatory cave animals are similar across many taxonomic groups. These two characteristics make caves nearly ideal natural laboratories for studying evolution and ecology. However, to the untrained researcher, caves can appear hostile and dangerous, and in fact, fieldwork in caves requires a unique marriage of athletic ability and science. In other words, cave research is exciting! In this contribution, I describe the exploration, discovery, and research in tropical caves and describe the factors that delayed the recognition of a significant tropical cave fauna.

Mycophagy of Attini Ants (Hymenoptera, Formicidae, Myrmicinae) with Agaricales Mushrooms (Basidiomycota, Agaricomycetes) at Riparian Zone in Southern Brazil

Attini ants (Hymenoptera, Formicidae, Myrmicinae) have great diversity in exploiting food resources. However, little is known about the mycophagy involving Agaricales fungi (Basidiomycota, Agaricomycetes). Moreover, these associations are of paramount importance in riparian zones, as the interaction among soil, fauna and flora is fundamental to the maintenance of these environments. Thus, the aim of this study was to describe cases of mycophagy between ants and fungi in order to understand how these associations occur in riparian zones. To this, collections were made between 2021-2022 in the valleys of the Rio Vacacaí, Rio dos Sinos and Rio Pardo in the state of Rio Grande do Sul, Brazil. The samples were analyzed for characters macro and microscopic and identified taxonomically. Mycophagy activities of six species of ants worker were cataloged, among them Acromyrmex niger, Acromyrmex versicolor, Tranopelta gilva, Tranopelta subterranea, Pheidole flavens and Mycetosoritis hartmanni, which included in their diet the mushrooms Agaricus rufoaurantiacus, Macrocybe titans, Agrocybe underwoodii, Dactylosporina steffenii, Lepiota micropholis and Neopaxillus echinospermus, respectively. The observed interactions demonstrate the dispersal of fungal spores through ant body structures, such as legs, antennae, thorax and abdomen; basidiomata as aliment source, such as pileus, lamellae and stipe; and generalized and specialized levels of predation on various fungi structures. Our results demonstrate unprecedented mycophagous relationships and show that Agaricales fungi can be considered a food source for Attini in riparian zones in Brazil south.

Addressing the food, nutrition and environmental nexus: The role of socio-economic status in the nutritional and environmental sustainability dimensions of dietary patterns in Chile

The effects of climate change and water scarcity on food security in Latin America and the prevalence of metabolic risk factors that increase the likelihood of non-communicable diseases (NCDs) among Chilean citizens are considered two significant challenges. The 2020 Sustainable Development Goals Report shows that an increasing number of people are suffering from food insecurity, and the growing stress on the environment associated with food production and resource exploitation. Therefore, the evaluation and monitoring of nutritional habits must be addressed because of their central role in meeting healthy and sustainable food goals. The objective of this study was to assess the environmental impacts (carbon and water footprint), nutritional quality and cost of diets of different socio-economic subgroups in Chile, mapping environmental hotspots and food insecurity. It was found that higher income was associated with higher environmental burdens related to food choices and higher dietary costs. Carbon and water footprints ranged from 2.42 to 4.74 kg CO2eq·person−1·day−1 and 1683–3110 L·person−1·day−1 for the first and fifth quintile, respectively. Chilean residents in the highest socio-economic quintile consumed more meat and fewer starch-based products than those in the lowest quintile. Meat was the main contributor to the carbon (56%–59%) and water (40%–43%) footprints and the determining factor in the differences between income quintiles. Although current diets in Chile do not meet nutritional recommendations, diet quality also increased with socioeconomic status. These findings could serve as a reference to implement public policies in Chile, ensuring healthy eating and food security in the context of climate change and water scarcity.

History and significance of tropical cave biology

“Nothing could possibly live there!” They said. Indeed, until recently, few specialized cave-adapted animals were known from volcanic, tropical, or oceanic island caves, and plausible theories had been put forward to explain their absence. But assume nothing in science! One must illuminate, explore, and survey habitats before declaring them barren. Our understanding of cave biology changed dramatically about 50 years ago following the serendipitous discovery of cave-adapted insects and other terrestrial arthropods in lava caves on the young oceanic islands of the Galapagos and Hawai‘i. The discovery and subsequent studies on the evolutionary ecology of cave animals have revealed a remarkable hidden fauna and created new sub-disciplines within biospeleology. Biological surveys of caves in other regions have confirmed the results developed in Hawai‘i. We now predict that, rather than being relicts trapped in caves by changing climate, animals actively colonized caves and adapted to exploit food resources wherever there were suitable subterranean voids. The physical environment in caves can be determined with great precision because the habitat is buffered by rock. Furthermore, the bizarre adaptations displayed by obligate cave animals are similar across many taxonomic groups. These two characteristics make caves nearly ideal natural laboratories for studying evolution and ecology. However, to the untrained researcher, caves can appear hostile and dangerous, and in fact, fieldwork in caves requires a unique marriage of athletic ability and science. In other words, it is exciting! Join me on a virtual tour of exploration, discovery, and research in caves during the past half-century.

Sex Differences Dictate the Movement Patterns of Striped Hyenas, Hyaena hyaena, in a Human-Dominated Landscape

Large-carnivore populations have experienced significant declines in the past centuries in extended parts of the world. Habitat loss, fragmentation, and depletion of natural resources are some of the main causes of this decline. Consequently, behavioral flexibility, enabling the exploitation of anthropogenic food resources in highly disturbed human-dominated landscapes, is becoming critical for the survival of large carnivores. These behavioral changes increase the potential for human-large carnivore conflict and can further intensify carnivore persecution. Here, we examine how land cover types (representing a gradient of anthropogenic disturbance) alter the behavior of striped hyenas (Hyaena hyaena) in a human-dominated landscape in Israel, and whether differences in life history between males and females affect their reaction to such disturbances and consequently their level of exposure to humans. We used a Hidden Markov Model on GPS-tracking data for seven striped hyenas to segment individual-night trajectories into behavioral states (resting, searching, and traveling). We then used multinomial logistic regression to model hyenas’ behavioral state as a function of the interaction between land cover and sex. Females traveled less than males both in terms of average distance traveled per hour, per night, and nightly net displacement. Most steps were classified as “searching” for females and as “traveling” for males. Female hyenas spent a higher proportion of time in human-dominated areas and a lower proportion in natural areas compared to males, and they were also more likely to be found close to settlements than males. Females changed their time allocation between natural and human-dominated areas, spending more time resting than traveling in natural areas but not in human-dominated ones; males spent more time searching than resting in human-dominated areas but were equally likely to rest or search in natural ones. The differences in life history between male and female hyenas may reflect different motivations for space use as a means to optimize fitness, which affects their exposure to humans and therefore their potential involvement in human-hyenas conflict. Understanding the mechanisms that lead to behavioral change in response to human disturbance is important for adaptive management and promoting human large-carnivores co-existence in general.

Observations of interference competition between the introduced black rat and native marsupial gliders in Australia

AbstractIntroduced rodents, particularly the black rat (Rattus rattus), have caused serious ecological impacts due to their ability to interact with native species as both predators, and by eliciting competitive pressure. However, impacts of black rats upon many Australian mammals have yet to be determined, particularly when those mammals are arboreal. Here, we present novel observations in the form of camera trap footage and photographs of interspecific competition between the introduced black rat and two species of arboreal gliding marsupial (sugar gliders (Petaurus breviceps) and squirrel gliders (Petaurus norfolcensis)) in urban bushland reserves in New South Wales, Australia. Gliders were found to flee or were prevented from exploiting food resources due to antagonistic posturing and physical attacks by black rats. While interspecific aggression and interference competition between black rats and native mammal species has been demonstrated previously, this appears to be the first observation of such interactions for Australian gliders. Our findings may have implications for the future management of glider populations in urban bushland where they co‐occur with rats; however, further research needs to be undertaken to determine the extent of this potential threat.

Exploiting Sheep and Goats at the Late Lengyel Settlement in Racot 18

Abstract The excavations of Late Lengyel settlement in Racot 18 near Kościan are the most important archaeological achievements of Lech Czerniak in the first period of his outstanding academic career. This large settlement was made of numerous trapezoidal houses and several internal, external, and loam pits associated with them. The work at Racot 18 led to the discovery of a large assemblage of animal bones in an excellent state of preservation. The article examines the characteristics of the sheep and goat-based economy at the settlement of Racot 18. A comprehensive analysis of the caprine bones involved contextually driven faunal studies comprising taphonomy, separating sheep and goats, and kill-off patterns. The work implies a complex system of sheep and goat exploitation that includes the use of specialised harvesting strategies and the exploitation of different food resources, including meat and marrow and secondary products, most likely milk and wool. The significance of this work for recognizing the characteristics of Late Danubian agriculture in the Polish lowlands is also discussed.

Microalgae: Bioactive Composition, Health Benefits, Safety and Prospects as Potential High-Value Ingredients for the Functional Food Industry

Global population is estimated to reach about 9.22 billion by 2075. The increasing knowledge on the relationship between food biochemistry and positive health gives an indication of the urgency to exploit food resources that are not only sustainable but also impact human health beyond basic nutrition. A typical example of such novel food is microalgae, an aquatic microorganism with a plethora of diverse bioactive compounds including phenolics, carotenoids, vitamin B12 and peptides. Microalgal bioactive compounds have been shown to possess positive health effects such as antihypertensive, anti-obesity, antioxidative, anticancer and cardiovascular protection. Although, the utilization of microalgal biomass by the functional food industry has faced lots of challenges because of species diversity and variations in biomass and cultivation factors. Other documented challenges were ascribed to changes in functional structures during extraction and purification due to inefficient bio-processing techniques, inconclusive literature information on the bioavailability and safety of the microalgal bioactive compounds and the fishy odor and taste when applied in food formulations. In spite of these challenges, great opportunities exist to exploit their utilization for the development of functional foods. Microalgae are a renewable resource and have fast growth rate. Therefore, detailed research is needed to bridge these challenges to pave way for large-scale commercialization of microalgal-based healthy foods. The focus of this review is to discuss the potential of microalgae as natural ingredients for functional food development, factors limiting their acceptance and utilization in the food industry as well as their safety concerns with respect to human consumption.

Moving in and moving out: Explaining final Pleistocene-Early Holocene hunter-gatherer population dynamics on the Korean Peninsula

While adaptive responses to ecological settings have been the focus of traditional approaches to the spatial organization of mobile hunter-gatherers, social factors also affect the positioning of bands. Hunter-gatherers position themselves in locations not just to exploit food resources, but also to maintain a certain distance to neighboring bands. Hunter-gatherer spatial organization was an agglomerated consequence of balancing two behaviors: spacing and proximizing. Thus, any given band’s decision to relocate affects other bands’ positioning, possibly resulting in a domino effect on a regional scale. We explain population fluctuations in Korea from the Last Glacial Maximum (LGM) to the early Holocene. The population history of southern Korea is characterized by an increasing occupational density during the LGM and population decline in periods of climatic amelioration. Contrasting this pattern to the population fluctuations observed in the northern latitudes of continental East Asia, we suggest that population increase in southern Korea during the LGM resulted from the southward movement of a wider hunter-gatherer network. As sea levels rose during the post-LGM, the network moved to the north and bands on the southern Korean peninsula moved north to avoid isolation. This process explains depopulation on the peninsula during the post-LGM and early Holocene.

Guild structure of stored grain insects reflects food resource availability in tropical forest ecosystems

The Guild concept has been of great interest to ecologists, and widely applied in entomology, particularly to study the activity of insects in various ecosystems. However, the guild concept in storage entomology is understudied. We hypothesized that the feeding guild structure of stored grain insect (SGI) community changes with different food resources available. In the present study, we examined the community structure of insects in the tribal grain storage system. Further, we established a classification system for the stored grain insect species based on their food resource exploitation pattern and the role of associated factors involved in the spatial and temporal structure of the SGI community. The species richness showed that cereal feeder was dominated in tribal grain storage system, abundance varied greatly, and high number of pulse feeders reflect the availability of resources. Further, it shows non-significant association among the number of species in each feeder community at different altitudes of the study area and SGI from different feeding guilds were randomly distributed, however, congregated more on their preferred food sources.

Morphometric variation of Middle-American cichlids: Theraps– Paraneetroplus clade (Actinopterygii: Cichliformes: Cichlidae)

This study assesses the patterns of variation in body shape, and relations of morphological similarity among species of theTheraps–Paraneetroplusclade in order to determine whether body shape may be a trait in phylogenetic relations. A total of 208 specimens belonging to 10 species of theTheraps–Paraneetroplusclade were examined. The left side of each specimen was photographed; in each photograph, 27 fixed landmarks were placed to identify patterns in body shape variation. Images were processed by using geometric morphometrics, followed by a phylogenetic principal component analysis. The phylogenetic signal for body shape was then calculated. To determine the relations in morphological similarity, a dendrogram was created using the unweighted pair group method and arithmetic mean values, while a Procrustes ANOVA and post-hoc test were used to evaluate significant differences between species and habitats. We found three morphological groups that differed in body length and depth, head size, and the position of the mouth and eyes. The body shape analysis recovered the morphotypes of seven species, and statistical differences were demonstrated in eight species. Based on traits associated with cranial morphology,Wajpamheros nourissati(Allgayer, 1989) differed the most among the species examined. No phylogenetic signal was found for body shape; this trait shows independence from ancestral relatedness, indicating that there is little congruence between morphological and genetic interspecific patterns. As evidenced by the consistently convergent morphology of the species in theTheraps–Paraneetroplusclade, the diversification of the group is related to an ecological opportunity for habitat use and the exploitation of food resources. Although no phylogenetic signal was detected for body shape, there appears to be an order associated with cranial morphology-based phylogeny. However, it is important to evaluate the intraspecific morphologic plasticity produced by ecological segregation or partitioning of resources. Therefore, future morphological evolutionary studies should consider cranial structures related to the capture and processing of food.