reported that two syntopic frog species in the Amazon differed in their feedinghabits due to their body size, microenvironment exploration, and activity time. We observed L. natalensis foraging during the day and in the evening, a behaviour that may have contributed to its widely diversified diet, with most food items classified as accidental or secondary, compared to other species. Also, for some community assemblages, seasonal division is a plausible mechanism to avoid competition because the majority of prey populations have short life cycles (L IMA & M AGNUSSON , 1998).
ABSTRACT: The aim of this study was to verify the activity of some digestive enzymes in four fish species with different feedinghabits. Knowledge of these enzymatic activities can help us to understand the species’ digestive processes. The species chosen for this study were Ctenopharyngodon idella (herbivore), Rhamdia quelen (omnivore), Leporinus obtusidens (omnivore) and Hoplias malabaricus (carnivore). The digestive tract of these species was divided into four portions to estimate enzymatic activity: stomach, anterior, mid and posterior intestine. Ctenopharyngodon idella had the highest amylase and maltase activities in all portions of the gut, followed by L. obtusidens. The highest trypsin activity was observed in all gut portions of H. malabaricus, followed by the mid intestine of L. obtusidens and the anterior intestine of C. idella. The highest chymotrypsin activity was found in all portions of C. idella followed by the anterior intestines of R. quelen, L. obtusidens and H. malabaricus. In the stomach, acid protease activity was sig- nificantly lower in R. quelen and L. obtusidens compared to H. malabaricus. Ctenopharyngodon idella showed high activity of enzymes that hydroly- ze carbohydrates, represented in this study by amylase and maltase and H. malabaricus showed higher protease activity and low amylase activity. Key words: freshwater fishes, feedinghabits, enzymatic activity, amylase, alkaline protease, maltase, trypsin.
The present study compared some morphometric parameters of the digestive tract of four teleosts with different feedinghabits: traira (Hoplias malabaricus, carnivore), silver catfish (Rhamdia quelen, omnivore), hassar (Hoplosternum littorale, omnivore), and grass carp (Ctenopharyngodon idella, herbivore). The digestive tract was removed from fish collected from nature and fixed for some morphometric analyses, such as: intestinal quotient, intestinal area quotient, vilosity height, digestive somatic index, and hepatosomatic index. Grass carp showed the highest values of intestinal quotient and height vilosity. On the other hand, the intestinal area quotient was higher in traira than in the other species. The intestinal quotient can be used to estimate the feeding habit, and the intestinal area quotient, vilosity height and the relationships between digestive tract length and fish weight or digestive tract weight can provide important additional information to analyze the feedinghabits.
Iheringichthys labrosus (Lütken, 1874; Siluriformes, Pimelodidae) is a South American non migratory freshwater fish that is abundant in numerous reservoirs (Burges, 1989) and rivers (Abes et al., 2001; Teixeira-de Mello et al., 2008). The maximum total length reported for this species is 33.4 cm (Fagundes et al., 2008). Iheringichthys labrosus shows no parental care behaviour and reproduces along the year, with multiple spawning reproductive peaks synchronized with rainy season (Santos et al., 2006). This species exhibits a sub-terminal mouth, with dentigerous plates (Fugi et al., 2001), thick lips and free superior margin (Abes et al., 2001). It has a wide space between gill rakers, a sacciform stomach and a short intestine (Fugi et al., 2001). Particularly, this species is one of the most abundant in Paraná River basin which counts with several local studies of its feedinghabits (e.g. Fugi et al., 2001; Abes et al., 2001; Peretti & Andrian, 2004).
ABSTRACT. Knowing the feeding biology of a population and its ontogenetic aspects can help in understanding the functioning of fi sh assemblages, essential to the conservation of the habitat biodiversity in which these species are found. Annual fi shes complete their life cycle in temporary aquatic environments, existing in adult stage only for brief annual periods. Changes in the feedinghabits between diff erent size classes could indicate that a species belongs to diff erent feeding groups in diff erent growth phases. The aim of this work was to characterize the diet of Cynopoecilus fulgens Costa, 2002 in a temporary fl ooded area in the coastal plain of southern Brazil, taking into consideration possible alterations in feedinghabits in diff erent body size classes caused by ontogenetic changes, to explain the coexistence of these individuals in a short space of time. The diet analysis indicated that C. fulgens is a generalist, consuming small crustaceans and autochthonous insects. Intraspecifi c diff erences in diet were determined when compared between nine classes of standard length. Adults fed mainly on autochthonous insects, and juveniles ingested mostly crustaceans, with the population being separated into two trophic groups: invertivores and invertivores with a tendency towards zooplanktivory. It is possible to conclude that the ontogenetic changes in the diet of C. fulgens are related to morphological restrictions due to the size of the individuals, since feeding competitive relations are probably not so evident.
ABSTRACT. Feedinghabits of the Molina’s hog-nosed skunk, Conepatus chinga (Molina, 1782) in the extreme south of Brazil. We analyzed 60 stomachs of road-kills of C. chinga in the extreme south of Brazil. The contents revealed 808 prey parts, including invertebrates (frequency of occurrence – FO = 96.7% and relative abundance – RA = 94.7%), verte- brates (FO = 18.3% and RA = 2.8%) and plants (FO = 31.7% and RA = 2.3%). We identified 18 kinds of food, including the invertebrate order Coleoptera which showed the highest FO (86.7%) and RA (75.2%). Other important orders were Orthoptera (FO = 35% and RA = 10.4%) and Araneae (FO = 41.7% and RA = 4%). The combination of occurrence and abundance of the preys consumed allowed classifying C. chinga as an omnivorous with a predominance of insects, especially Coleoptera, consuming other invertebrates, vertebrates and plants in smaller numbers. Behavioral and mor- phological adaptations of C. chinga favor the predation of insects, which are preys that offer low physical resistance and are available in all terrestrial environments.
Feedinghabits of Stellifer rastrifer (Perciformes, Sciaenidae) at Guaratuba mangrove, Parana, Brazil, were studied from February 1996 to February 1997. It was observed that its diet was based on invertebrates, mainly Decapoda non-Brachyura and Polychaeta. In a smaller proportion there were plants, Copepoda, Gammaridea and Mollusca. The level of contribution of each food item changed according to the season and the individual size. Such plasticity in feeding behaviour was similar to that described to some fish populations from other estuaries, and could be an indicator of the high level of instability presented by this kind of ecosystem.
Headwater habitats are small and fragile and canopy exerts an im- portant role in their maintenance (Barrella & Petrere Jr. 2003). There are indicators that tropical fishes depend on the food resources from the riparian forest, suggesting that alterations in the composition and struc- ture of these forests may cause serious impacts on the fish community (Angermeier & Karr 1983). Headwaters are characterized by altitudinal gradient and water discharge is highly variable. Due to the turbulence these waters are well oxygenated, but the low volume is responsible to the relationship between air and water temperatures. These rivulets are formed by rapids and backwaters and the water velocity determines the transport of sediments. Fishes in this habitat are adapted to the water flow variation and the subsequent diary and seasonal fluctuations in temperature. These adaptations are observed in body shapes, presence of modified paired fins, spines that could serve as anchors, and buccal apparatus specialization. Such morphological adaptations enable the species to occupy distinct microhabitats regarding depth and current velocity, which may be important to minimize interspecific competition among species with similar feedinghabits (Wootton 1992).
ish, followed by vegetable remains and detritus, respectively. In high and falling waters, third and fourth quarters of the year, vegetable remains and ish were the most consumed trophic groups (Figure 3). Flexible feedinghabits are an adaptive feature of animal behavior when the natural environment varies spatially or temporarily, and ish respond to low food availability by altering their behavior (16). Most ish species seem to experience increased competition in shallow waters, which may be a consequence of reduced volumes of water or because lood areas, which provide food and cover in high waters, are not accessible (17), which leads many species to change their feeding preferences during the water cycle (18), as observed in this study.
The article describes the feedinghabits of the catfish Sciades herzbergii caught in the Crabs Island (Ilha dos Caranguejos), an important coastal area of the Maranhão state, Brazil. A total of 167 individuals were collected: 110 females and 57 males. All the stomach contents were identified to the closest taxonomic level. The frequency of occurrence, biomass, numerical frequency and index of relative importance (IRI) of food items were determined for both genders. Stomach repletion was predominant, demonstrating good feeding conditions for S. herzbergii. The main alimentary items in the diet of this catfish were crustaceans, fish, oligochaets and polychaets, and the decapods crustaceans were the most representative.
Marine predators provide valuable information about prey abundance and composition (Potier et al., 2007; Olson et al., 2014). Stomach content analyses also facilitate the identification of feedinghabits as well as competition or resource partitioning between species that occurs in the same region (Baker, 1966; Vaske et al., 2004; Shimose et al., 2010), ecological aspects that are not commonly considered for billfishes. Traditionally, studies on the feedinghabits of billfishes in the Pacific Ocean have focused on a single species (Abitia-Cárdenas et al., 1999; Rosas-Alayola et al., 2002; Shimose et al., 2006; Watanabe et al., 2009; Abitia-Cárdenas et al., 2011; Tsai et al., 2015) or prey group (Rosas-Luis et al., 2016).
reproductive condition evaluated: males were classified as non-reproductive (with abdominal testis) or reproductive (scrotal testis); and females as non-reproductive (normal abdomen, non- apparent nipples) or pregnant (pregnancy detected by abdominal inspection); lactating (enlarged nipples, with milk secretion verified by light pressure on the nipples), or post-lactating (no milk produced, hair surrounding the nipples recovering). Feedinghabits were inferred from fecal samples. The feces of the animals were placed on glassine papers for later analyses. Most food items were separated into categories [pollen/nectar, pulp (fruits), fruits (with seeds), and arthropods], with no specific identification attempted. However, samples with seeds were separated into morfo- species, and in some cases identified as to genus. Each different item found in a fecal sample was treated as an individual sample. Besides, the presence of pollen in a bat body and fruit carried by captured animals was considered in the sampling. After the analyses, each bat was individually marked with numbered plastic rings on the forearm and released.
The aim of this work was to observe and describe the feedinghabits and available food resources of the swallow-tailed hummingbird, Eupetomena macroura. The study was carried out in a municipal park located in the city of Taubaté, in the state of São Paulo. The observations took place between December 2003 and October 2004, recording the following variables: 1) the plant species visited for feeding and territorial defense; 2) the kinds of food resources; and 3) the kinds of flight to procure and obtain food. E. macroura visited 12 plant species. For territorial defense, Mangifera indica was the most visited, whereas Malvaviscus arboreus was most visited for feeding. The foliage was the plant part that received the most frequent visits. In order to obtain nectar, the only species visited was M. arboreus; to obtain arthro- pods, the species most visited were Mangifera indica and Hymenaea stilbocarpa. In the dry season, the hummingbirds visited flowers, whereas in the rainy season they visited leaves to acquire food. The arthropod groups most frequently found on leafy branches were Homoptera and Psocoptera. Finally, the results of the type of flight analysis showed that flight used to capture food was more often observed than were flights to search for food. In conclusion, these observa- tions suggest that E. macroura shows plasticity in feeding behavior, which can help it to persist in urban areas.
Results: The results showed that 55.4% of them had empty guts and 44.6% contained food in their guts. The emptiness index did not vary significantly according to size classes or sexes of T. a. imperialis. Basic food consisted of teleosts (Mugilidae, Gobidae and Belonidae) (62.6%) followed by crustaceans (37.3%), mostly decapods Sycionia carinata (5.4%). A decrease in the feeding rate at the peak of the spawning season was observed for both sexes. A diet variation among juvenile and adult specimens of T. a. imperialis was found.
The prey importance and feeding strategy diagrams (Figs 3 and 4) show that no food item was dominant in the diet of A. cyclophora. We reached this conclusion because no items occur in area IV of the diagram (Fig. 3). However, two items were the most important, Brachyura and fragments of Teleo- sts. The other items were rare, because they occur in area III (Fig. 3). When whole groups were taken into consideration, Crustacea were dominant (presence in are IV), but Fishes were
Some species of Tydeidae are considered agricultural pests and can eventually cause economic and environmental loss, whereas others are identified as agriculturally beneficial (André, 2011; Hernandes et al., 2006; Tilney et al., 2012). Existing information on the feedinghabits of B. formosa remains controversial, as there are doubts on its phytophagy (Smirnoff, 1957; Badii et al., 2001). On the leaves and fruit of the orange plant, one can observe mild discolouration of the tissue at the site of B. formosa (Aguilar et al., 2001). However, Mendel and Gerson (1982) and Walter and Proctor (2013) have reported that B. formosa is not a phytophagous species because these feed on true fungi, pollen, and sugary secretions produced by hemipterans and on the eggs and