Index Of Alimentary Importance Research Articles

Ecología trófica de Brycon henni (Pisces: Bryconidae) en afluentes de los Ríos Nare y Guatapé, cuenca del río Magdalena, Colombia

Understanding the trophic ecology of fish and how they use resources in space and time is important to support conservation and management actions. The trophic ecology of Brycon henni in the Nare and Guatapé rivers, Magdalena river basin, Colombia was determined. Five field samplings were carried out between October 2007 and January 2010, in rainy, dry, and dry-to-rainy transition periods. Stomachs of 262 specimens were collected. A Kruskall-Wallis analysis and a Mann-Whitney pairwise comparison test was performed to detect differences in the alimentary importance index of each food category between sex, size class, hydrological period and basins (Nare vs Guatapé). The Levin’s Measure of Niche Breadth and the Morisita’s Diet Overlapping Index were calculated to establish differences between size class in the different hydrological periods. Vegetable material was the most important food item, followed by Insecta, and fish. Individuals from Guatapé basin consumed more plant material and fish and fewer insects. We observed increased consumption of plant material and fish in ontogeny. Levin's niche breadth was lower and diet overlapping between individuals of length classes was higher during rainy period because the diet was mainly based on plant material. The diet of B. henni was composed mainly of plant material and Insects, and to a lesser extent from other groups such as fish, crustaceans and arachnids.

Feeding Habits of the Non-Native Mayan Cichlid, Mayaheros urophthalmus, in Estuarine Tributaries of Southwest Florida

Foraging habits of the non—native Mayan Cichlid (Mayaheros urophthalmus) were investigated in the tidal tributaries to the Estero Bay and Wiggins Pass estuaries in southwest Florida (USA) during 2011—2013. Dietary analysis was conducted by identifying contents in the digestive tracts of 747 fish and volumetrically measuring the food items. Detritus was the predominant food item by frequency (97–100%), volume (34–48%), and alimentary importance index (47–64%). Bivalves, gastropods, decapod and cirriped crustaceans, coleopterans, serpulid polychaetes, and fish scales frequently (>50%) occurred in samples but volume and importance differed among tributaries. Results indicate that the Mayan Cichlid in southwest Florida tidal tributaries is an opportunistic predator of hard—shelled invertebrates. Although there was considerable overlap in dietary composition, percent volume of food items was significantly different among tributaries during dry seasons. In each tributary, detritus was consumed in greater percentage during the dry season and benthic invertebrates were consumed in greater percentages during the wet season. Consumption of detritus, algae, and plant material may be incidental to predation on benthic invertebrates but more information is needed on digestion and assimilation of food items. Variability in diet among the tributaries in the current study and among other studies was presumably a function of habitat characteristics and the corresponding availability of prey types.

Feeding activity of the cayenne pompano Trachinotus cayennensis (Cuvier 1832) (Perciformes, Carangidae) in estuaries on the western coast of the state of Maranhão, Brazil.

The present paper addresses the feeding activity of Trachinotus cayennensis, collected in Lençóis Bay (1°18'S - 1°19'S; 44°51'W - 44°53'W) on the western coast of the state of Maranhão, Brazil. Sampling was conducted between June 2012 and June 2013 using driftnets with stretch mesh sizes from 95 to 100 mm. A total of 205 individuals (114 females and 91 males) were analyzed. Statistically significant differences in the sex ratio were found in June, September and December 2012. Food items were analyzed based on frequency of occurrence and volumetric method, with the subsequent calculation of the alimentary importance index. Three size groups were defined to determine possible ontogenetic changes in eating habits based on the size range of the individuals collected: I (˂ 29 cm), II (29.1 to 37.0) and III (≥ 37.1). Eleven food item categories were identified: mollusks, polychaetes, crustaceans, nematodes, insects, algae, bryozoans, ophiuroids, fishes, vegetal matter and sediments. The variety of items in the diet of T. cayennensis indicates considerable feeding plasticity and opportunistic behavior. Seasonal variations influenced the feeding pattern of the species, with greater feeding activity in the dry season. The considerable availability of resources in estuarine habitats of the western coast of Maranhão constitutes another factor that influences the feeding behavior of this species.

Detailed description and seasonal variation in the diet of the Silvery-Cheeked Antshrike Sakesphorus cristatus (Wied, 1831) (Aves: Thamnophilidae) in a Brazilian semi-arid forest

Despite being an important area for endemic species of birds, the Caatinga biome is highly fragmented due to anthropogenic influences and there is a lack of study on many aspects of its birds’ biology. In this semiarid environment, rainfall is highly seasonal, with two different and well-defined periods: a long dry season, and a short rainy season. This study aimed to qualify and quantify the diet of Sakesphorus cristatus , an endemic thamnophilid bird of the Caatinga, as well as to determine whether there was temporal variation between two different seasons and between dry seasons of two consecutive years. Surprisingly, this was the first study to have focused on describing and quantifying items found of any bird species’ diet in the Caatinga. We analyzed the stomach contents of 72 specimens collected in the municipality of Sao Felix do Coribe, Bahia, Brazil. Data analysis included relative abundance and occurrence, average consumption/sample and alimentary importance index of each food category. Sampling adequacy was assessed using cumulative curves constructed with diversity index and coefficient of variation. In general there is a high predominance of ants and termites, with seasonal shifts in the proportion of each item, and a high contribution of caterpillars during the breeding season. During the dry season, the most predominant prey categories in the diet were Formicidae, Isoptera and Coleoptera (adult, A), while during the rainy season, there was an increase in the proportion of Isoptera, Coleoptera (A) and Lepidoptera (larvae) consumption and a decrease in Formicidae. There was no significant difference between consumption of prey items between the two dry seasons. The overall analysis suggests that S. cristatus feeds mainly on the aforementioned insects and is an opportunistic species, adjusting its diet according to their prey availability.

Feeding resource partitioning between two understorey insectivorous birds in a fragment of Neotropical cloud forest.

The food habits and niche overlap based on diet composition and prey size of two species of understorey insectivorous birds were investigated in an area of montane rain forest in the state of Minas Gerais, southeastern Brazil. A total of 43 birds were captured: 33 individuals of Conopophaga lineata (Conopophagidae) with 13 recaptures, and 10 individuals of Myiothlypis leucoblephara (Parulidae) with 12 recaptures, from which were obtained respectively 33 and 10 fecal samples. Fragments of 16 groups of arthropods, plus insect eggs, were identified in these samples. Conopophaga lineata predominantly consumed Formicidae (32%) and Isoptera (23.6%). However, the index of alimentary importance (AI) of Isoptera (3.53) was lower than other groups such as Formicidae (AI = 61.88), Coleoptera (AI = 16.17), insect larvae (AI = 6.95) and Araneae (AI = 6.6). Myiothlypis leucoblephara predominantly consumed Formicidae (28.2%) and Coleoptera (24.4%), although Coleoptera and Hymenoptera non-Formicidae had the highest values of AI (38.71 and 22.98 respectively). Differences in the proportions of the types of arthropods consumed by birds were not enough to reveal their separation into feeding niches (overlap = 0.618, p observed ≤ expected = 0.934), whereas differences in the use of resources was mainly due to the size of the prey (p<0.001), where C lineata, the species with the highest body mass (p<0.001) consumed larger prey. It is plausible that prey size is an axis of niche dimension that allows the coexistence of these species.

FEEDING ECOLOGY OF &lt;i&gt;Cichlasoma amazonarum &lt;/i&gt; (Teleostei, Cichlidae) IN THE CENTRAL AMAZON LAKES, BRAZIL.

The diet of the cichlid Cichlasoma amazonarum was investigated through an analysis of 270 gastric contents obtained from monthly samples collected from five lakes located in the Central Brazilian Amazon, throughout the year of 2012. The composition of the diet was assessed using the methods of frequency of occurrence and relative dominance (frequency of biomass), which were combined in the Alimentary Importance Index (AIi) in accordance with the hydrological cycle’s extreme periods of drought and high waters. The intestinal coefficient was investigated to demonstrate the feeding tendencies of the species. The breadth and diversity of the trophic niche were also compared for these periods. The intestinal coefficient for the species (0.95), combined with the results of the analysis of food content, showed a species that demonstrates carnivorous/insectivorous habits. During the high water season, the diet is composed of unidentified animal matter, unidentified larvae and insects; and in the drought season, plant matter, unidentified animal matter and insects. Although there was no significant difference in dietary diversity between seasonal extremes, the analysis of the breadth of the trophic niche characterises the species as feeding specialists.

Biología de poblaciones y dieta de &lt;i&gt;Pomadasys corvinaeformis&lt;/i&gt; (Perciformes: Pomadasyidae) en Bahía Caraguatatuba, sureste de Brasil

Pomadasys corvinaeformis inhabits sandy and rocky bottoms in coastal waters, and is common in trawl samples taken from beaches. The species is very abundant on the Brazilian coast, and is of high economic and ecological importance. This study examined the spatio-temporal distribution, population biology and diet of P. corvinaeformis in Southeastern Brazil. Samples were taken by trawling monthly from August 2003 to October 2004, in two previously selected areas. The Northern area is more exposed to wave activity and is influenced by a river, functioning as a small estuary. In contrast, the Southern area is relatively sheltered from wave energy and influenced to a lesser degree by smaller rivers. The length of the specimens was measured, and the sex and gonadal stage were macroscopically identified. The abundance of this species was compared between areas and among months. The diet was analyzed seasonally by the frequency of occurrence, the percent volume, and the index of alimentary importance. P. corvinaeformis occurred in unequal proportions in the two study areas (86% in the Northern area and 14% in the Southern area) and was found most abundant in May 2004, followed by June 2004. The proportion of mature and in-maturation individuals increased gradually from autumn to summer. Nine major groups of food items were recorded in the diet of P. corvinaeformis, and crustaceans comprised five of the categories: unidentified crustacean fragments, zoea larvae, amphipods, copepods and shrimps. In both, fish stomach and intestine, crustacean fragments were the most frequent item. The second most frequent items were shrimp in the stomach, and amphipods in the intestine (mainly represented by their tubes). These results demonstrate that P. corvinaeformis can be considered a carnivore, with a preference on benthic organisms.

Variaciones estacionales en el tamaño corporal y dieta de la estrella de mar Astropecten marginatus (Paxillosida, Astropectinidae) frente a la costa de Paraná, sur de Brasil

The sea star Astropecten marginatus has a neotropical distribution and is a highly abundant and frequent species in shrimp trawling by-catchin many places along the Brazilian coast. This has caused its threat to extinction and in addition, its bio-ecological aspects are poorly known. Thus, the main objective of this study was to analyze the seasonal variations of population length structure and feeding habits of the sea stars A. marginatus inhabiting off state of Paraná, Southern Brazil. The analyzed specimens were collected in February (summer), April (fall), June (winter) and October (spring) of 2008 from shrimp by-catch trawling. In the laboratory, each individual had its length measured and then weighed on an analytical scale. Afterwards, the stomach contents of 10 individuals of each of two most frequent length classes were seasonally analyzed. The relative frequency and abundance for each prey category was determined and, then combined into an index of alimentary importance. A total of 994 individuals of A. marginatus were collected with length ranging from 7.0 to 56.2mm, but most individuals were in the 20.1-25mm length classes. Individuals larger than 40mm were only collected in the spring while a few recruits (<10mm) were found in fall and winter. The total weight of individuals ranged from 0.1 to 15.3g and the weight-length relationships showed a negative allometric growth (b<2.54). Regarding its food consumption, this sea star explored eleven food items, with cumaceans and mollusks as the most frequent items. High frequency of empty stomach was recorded at fall. Seasonal differences in the amount explored preys and ingested items as well as in the prey composition were also observed. Higher amount of explored prey categories and ingested items were recorded at winter-spring than summer-fall periods. Predominance in prey category changed from gastropods (summer and fall) to cumaceans (winter and spring). The importance of gastropods as main prey category at summer and fall should be carefully considered since it was coincidently observed with high frequency of empty stomach and low amount of ingested items. The observed seasonal differences in feeding behavior pattern were mainly associated to low prey availability and to changes in the sea star feeding rates, and probably reflected in some biological traits such as small body size of the population inhabiting waters off the Paraná coast, Southern Brazil.

Mutilating predation in the Cheirodontinae Odontostilbe pequira (Characiformes: Characidae)

We observed individuals of Odontostilbe pequira, a small characid, approaching and biting individuals of larger-bodied fishes of other species. This observation was made in two clear water headwater streams of the Cuiabá basin, Paraguay River system, located in Nobres, Mato Grosso State, Brazil, which led us to investigate the behavioral interactions of these fish. We characterized behavioral interactions between species by direct underwater observations using snorkelling and video recordings. Additionally, we proceeded diet analyses of O. pequira, obtaining intestinal coefficient and the index of alimentary importance. During underwater observations we checked the relative frequency of attacks by O. pequira on larger fish species. Odontostilbe pequira attacked individually or in large groups, and the anostomid Leporinus friderici was the preferred target prey species, while Prochilodus lineatus was apparently avoided. Our study sustains that O. pequira is omnivorous, with a diet that varies seasonally. It feeds mainly on plants, but also on animal prey, including the scales of small fishes, and, possibly, the mucus and epidermis of larger fish species. We suggest the term "mutilating predation" to describe the latter relationship.

Diet and food consumption of the pearl cichlid Geophagus brasiliensis (Teleostei: Cichlidae): relationships with gender and sexual maturity

Despite the importance of the pearl cichlid Geophagus brasiliensis for the aquarium fish trade worldwide and its wide distribution, many aspects of its biology, such as the relationships between its feeding ecology and reproductive behavior, are not fully understood in natural conditions on its native habitat. In this paper, we investigated its diet focusing on how differences in diet and food consumption are related to differences in gender and sexual maturity. The digestive tract of each individual was dissected and had its content analyzed, whereas each gonad was microscopically analyzed to determine gender (male/female) and sexual maturity (immature/mature). A total of 28 females and 31 males were analyzed. Mature individuals were more common than immature specimens both for males (64.50%) and females (64.30%). The analysis of 52 individuals with non-empty digestive tracts revealed a diet comprised of 27 items. According to the Index of Alimentary importance (%IAi), the most important food items in the diet were Gastropoda (37.30%), fragments of vascular plants (15.16%), detritus (10.14%), Amphipoda (9.24%), and fish scales (6.29%). Mature males had more empty stomachs (65.00%) when compared to immature males (27.27%) and immature (55.56%) and mature females (40.00%). Also, mature females seemed to have more food consumption (greater mean values of total volume) in their digestive tracts than mature males. Some hypotheses are proposed in order to distinguish if this gender-based difference in food consumption in mature individuals of the pearl cichlid could be associated with the development of primary and secondary sexual characteristics or with asymmetrical time invested in parental care activities.

Comparative dietary analysis of Eurycheilichthys pantherinus and Pareiorhaphis hystrix: two Loricariidae species (Ostariophysi, Siluriformes) from Campos Sulinos biome, southern Brazil

This work was carried out in Marco river, São José dos Ausentes municipality, state of Rio Grande do Sul, southern Brazil. This region is located within the Campos Sulinos biome, an area of great biological importance due to its high diversity and endemism of fish. The feeding habits and food overlap between Eurycheilichthys pantherinus (Reis &amp; Schaefer, 1992) (n=108) and Pareiorhaphis hystrix Pereira &amp; Reis, 2002 (n=60) are described. Monthly samples were obtained between September 2000 and July 2001 with dipnets using the kick sampling technique. Stomach contents were analyzed based on frequency of occurrence, volumetric frequency and index of alimentary importance. The level of dietary specialization and food overlap were determined by the Levins measure and the Morisita index, respectively. Eurycheilichthys pantherinus fed mainly on immature aquatic insects, such as Dipterans and Ephemeropterans, and was classified as insectivore. Pareiorhaphis hystrix fed mainly on detritus associated with small amounts of aquatic insects, and was classified as detritivore. Species are clearly segregated by the use of food resources in Marco River. Their diets did not overlap and the differences observed in their feeding habits probably contribute for their coexistence.

Variações ontogênicas e sazonais na dieta de Etropus crossotus Jordan e Gilbert, 1882 (Paralichthydae) na baía de Ubatuba-Enseada, Estado de Santa Catarina, Brasil

Ontogenetic and seasons changes in the diet of Etropus crossotus Jordan and Gilbert, 1882 (Paralichthydae) at Ubatuba-Enseada Bay, Santa Catarina State, Brazil. Ontogenetic and seasonal changes in the diet of Etropus crossotus sampled at Ubatuba-Enseada Bay in Santa Catarina State, Brazil were investigated. A trawl net was used for the surveys, and 60 fish were collected monthly during October (2003) and September (2004). The highest similarity of the Alimentary Importance Index (AII) was observed between spring and autumn. Crustacea Decapoda represented 50% of the feeding items during spring and fall, and Crustacea Amphipoda were the most representative item in winter. The highest AII similarity was observed among length classes 1, 2 and 4, which was related to Decapoda representation, and among length classes 5, 6 and 7, because of Decapoda and Amphipoda importance. Results were similar to other studies in the southern coast of Brazil.

Feeding ecology of Hypostomus punctatus Valenciennes, 1840 (Osteichthyes, Loricariidae) in a costal stream from Southeast Brazil

In the present study we aimed to compare the feeding ecology of Hypostomus punctatus from a coastal stream from Southeast Brazil with data previously published for the same study site before environmental changes. Feeding preferences were assessed through a sample of 138 specimens (67 from the dry and 71 from the rainy season) using the Index of Alimentary Importance (IAi). We registered five different food items (detritus, plant fragments, Diatoms, Chloroficeae and Cianobacteries) composing the species diet. Detritus was the most abundant one both during the rainy and dry seasons (IAirainny = 90.34 and IAidry = 96.30). No significant differences were registered for the volume of food items consumed during the rainy and dry seasons. The Frequency of Occurrence analysis showed that four (detritus, plant fragments, Diatoms and Chloroficeae) among the five all other consumed ones, were always frequent. Comparing our own results with those available for the study site, we suggest that the feeding habit of H. punctatus has changed according to environmental changes and that the species diet is strongly dependent upon environmental conditions.

Biologia alimentar de quatro espécies simpátricas de Cheirodontinae (Characiformes, Characidae) do rio Ceará Mirim, Rio Grande do Norte

Este estudo foi realizado no rio Ceará Mirim, Estado do Rio Grande do Norte. No local de coleta, este rio apresenta águas transparentes e predominância de macrófitas aquáticas nas margens. Este estudo teve como objetivos descrever os hábitos alimentares e verificar a existência de sobreposição alimentar na dieta de quatro espécies simpátricas de Cheirodontinae: Compsura heterura Eigenmann, 1915 (n= 452), Serrapinnus heterodon (Eigenmann, 1915) (n= 473), S. piaba (Lütken, 1875) (n= 509) e Serrapinnus sp. A (n= 313). Os espécimes foram coletados mensalmente, entre abril de 2001 e abril de 2002, com redes de arrasto. Os conteúdos estomacais foram analisados através dos métodos de frequência de ocorrência, composição percentual e índice de importância alimentar. A sobreposição alimentar foi calculada entre os pares de espécies através do índice de Morisita. As espécies não mostraram variação sazonal na dieta. Algas, matéria vegetal, microcrustáceos e insetos autóctones foram predominantes na dieta das espécies. Serrapinnus heterodon e Serrapinnus sp. A apresentaram hábito alimentar onívoro, enquanto C. heterura e S. piaba apresentaram o hábito alimentar onívoro com tendência à herbivoria. Além disso, altos valores de sobreposição alimentar entre as espécies foram observados em decorrência do consumo de itens similares. Estes resultados sugerem que os recursos alimentares são abundantes e suficientes para serem partilhados por estas quatro espécies onívoras em simpatria.

Feeding of two Cichlidae species (Perciformes) in an hypertrophic urban lake

Diet of two cichlid species, Cichlasoma facetum (Jenyns, 1842), and Gymnogeophagus rhabdotus Hensel, 1870, was studied in Rodo Lake, an urban hypertrophic lake in Uruguay. The stomach contents from 192 individuals of C. facetum and 202 of G. rhabdotus, obtained through seasonal sampling in the year 2000, were analyzed. The occurrence frequency and the alimentary importance index of each food item were calculated for each season and size class in both species. Cichlasoma facetum fed upon insects (mainly chironomid larvae and pupae), fish (Cnesterodon decemmaculatus Jenyns, 1842), and vegetals (algae, periphyton and macrophytes debris); large individuals also fed upon the freshwater shrimp Palaemonetes argentinus Nobili, 1901. Gymnogeophagus rhabdotus consumed zooplankton (mainly copepods), vegetals (algae and detritus) and Chironomidae larvae in a lesser extent.

Diet of Astyanax species (Teleostei, Characidae) in an Atlantic Forest River in Southern Brazil

Feeding habits of six species of Astyanax from river Maquiné are described. Fishes were sampled bi-monthly from November/95 to September/96 in two zones of the river. Items were identified, counted and had their abundance estimated according to a semi-quantitative scale. Frequency of occurrence, alimentary importance index (IFI) values and a similarity analysis of diets for each species-river zone sample were examined. All the species were considered typically omnivorous, with insects and vegetal matter being the most important items in their diet. These species could act as seed dispersers, particularly for macrophytes. Intra-specific spatial differences were not observed in comparisons of samples from two diferent regions of the river, except for A. fasciatus. The presence of Podostemaceae macrophytes in the mid-course of the river seemed to be important both as an autochthonous food resource and as habitat for several organisms preyed by the Astyanax species.