Comparison of feeding and defecation patterns between fifth-instar nymphs of Triatoma patagonica (Del Ponte, 1929) and Triatoma infestans (Klug, 1934) under laboratory conditions

Among the vectors of Chagas disease, Triatoma patagonica is a species in the process of adaptation to the human environment. However, its vector competence is not well known. This study had the aim of evaluating and comparing feeding and defecation patterns among fifth-instar nymphs of Triatoma patagonica and Triatoma infestans that were fed ad libitum. The results showed that nymphs of Triatoma patagonica had a feeding pattern similar to that of Triatoma infestans. Sixty nine percent and 58% of nymphs of Triatoma patagonica and Triatoma infestans, respectively, produced their first defecation within five minutes after being fed. Triatoma patagonica defecated during feeding, with an average time until first defecation that was shorter than that of Triatoma infestans (3.4 and 6.2 min, respectively). The nymphs of Triatoma patagonica were capable of defecating during or immediately after feeding.

Blood feeding patterns of Nyssomyia intermedia and Nyssomyia neivai (Diptera, Psychodidae) in a cutaneous leishmaniasis endemic area of the Ribeira Valley, State of São Paulo, Brazil

Introduction The aim of this study was to identify the blood feeding sources of Nyssomyia intermedia (Ny. intermedia) and Nyssomyia neivai (Ny. neivai), which are Leishmania vectors and the predominant sandfly species in the Ribeira Valley, State of São Paulo, Brazil, an endemic area for cutaneous leishmaniasis. Methods Specimens were captured monthly between February 2001 and December 2003 on a smallholding and a small farm situated in the Serra district in the Iporanga municipality. The blood meals of 988 engorged females were tested using the avidin-biotin immunoenzymatic enzyme-linked immunosorbent assay (ELISA). Seven blood meal sources were investigated: human, dog, chicken, bovine, pig, horse and rat. Results The results showed that among the females that fed on one or more blood sources, the respective percentages for Ny. intermedia and Ny. neivai, respectively, were as follows: human (23% and 36.8%), pig (47.4% and 26.4%), chicken (25.7% and 36.8%) and dog (3.9% and 0%), and the differences in the blood sources between the two species were statistically significant (p = 0.043). Conclusions Both species had predominant reactivity for one or two blood sources, and few showed reactivity indicating three or four sources. Many different combinations were observed among the females that showed reactivity for more than one source, which indicated their opportunistic habits and eclecticism regarding anthropic environmental conditions.

Eclectic feeding behavior of Lutzomyia (Nyssomyia) intermedia (Diptera, Psychodidae, Phlebotominae) in the transmission area of American cutaneous leishmaniasis, state of Paraná, Brazil

Introduction The blood meal source of sandflies provides valuable information about the vector/host interaction and allows for an understanding of American cutaneous leishmaniasis (ACL) transmission mechanisms. The aim of this study was to identify the blood meal sources of Lutzomyia (Nyssomyia) intermedia in an endemic area of leishmaniasis in Brazil's State of Paraná using a precipitin test. Methods Sandflies were collected in the rural locality of Epitácio Pessoa within the City of Adrianópolis, State of Paraná, in southern Brazil. A total of 864 female sandflies were captured, and 862 (99.8%) were identified as L. intermedia species. However, two unidentified specimens were considered to be part of the genus Lutzomyia. Results Among the females examined, 396 specimens presented reactions to a certain type of tested antiserum, and most (67.9%) reacted to the simple type. These sandflies fed mainly on the blood of birds, opossums, and rodents, but specimens that fed on the blood of humans, dogs, horses, cattle, and cats were also found. Among the cross-reactions found (32.1%), bird/rodent, bird/opossum, bird/dog, bird/human, and horse/dog cross-reactions were the most common. Conclusions These results demonstrate a tendency in the eclectic feeding behavior of L. intermedia and support its potential role as a vector for ACL in the study area.

Effect of feeding frequency on the reproductive efficiency of two species of Triatoma with different epidemiological importance

Introduction In Triatominae, reproductive efficiency is an important factor influencing population dynamics, and a useful parameter in measuring a species' epidemiological significance as a vector of Trypanosoma cruzi (Chagas, 1909). The reproductive efficiency of triatomines is affected by food availability; hence, we measured and compared the effects of feeding frequency on the reproductive parameters of Triatoma patagonica (Del Ponte, 1929) and Triatoma infestans (Klug, 1934), and the effects of starvation on T. patagonica. Methods Couples from both species were fed weekly, or every 3 weeks; in addition, females in couples of T. patagonica were not fed. Each couple was observed weekly and reproductive efficiency was assessed on the following parameters: fecundity (eggs/female), fertility (eggs hatched/eggs laid), initiation and end of oviposition, initiation of mating, number of matings/week, and number of reproductive weeks. Relative meal size index (RMS), blood consumption index (CI), and E values (eggs/mg blood) were also calculated. Results Changes in feeding frequency affected the reproductive parameters of T. patagonica only, with a decrease in fecundity and number of reproductive weeks for those fed every 3 weeks, or not fed. The reproductive period, RMS index, and CI were lower for T. patagonica than T. infestans. However, despite the lower fecundity of T. patagonica, this species required less blood to produce eggs, with an E values of 2 compared to 2.94 for T. infestans. Conclusions Our results suggest that the differences in fecundity observed between species reflect the availability of food in their natural ecotopes.

The effects of glutamine-supplemented diet on the intestinal mucosa of the malnourished growing rat

Glutamine is the most abundant amino acid in the blood and plays a key role in the response of the small intestine to systemic injuries. Mucosal atrophy is an important phenomenon that occurs in some types of clinical injury, such as states of severe undernutrition. Glutamine has been shown to exert powerful trophic effects on the gastrointestinal mucosa after small bowel resection or transplant, radiation injury, surgical trauma, ischemic injury and administration of cytotoxic drugs. Since no study has been performed on the malnourished animal, we examined whether glutamine exerts a trophic effect on the intestinal mucosa of the malnourished growing rat. Thirty-five growing female rats (aged 21 days) were divided into 4 groups: control - chow diet; malnutrition diet; malnutrition+chow diet; and malnutrition+glutamine-enriched chow diet (2%). For the first 15 days of the experiment, animals in the test groups received a malnutrition diet, which was a lactose-enriched diet designed to induce diarrhea and malnutrition. For the next 15 days, these animals received either the lactose-enriched diet, a regular chow diet or a glutamine-enriched chow diet. After 30 days, the animals were weighed, sacrificed, and a section of the jejunum was taken and prepared for histological examination. All the animals had similar weights on day 1 of experiment, and feeding with the lactose-enriched diet promoted a significant decrease in body weight in comparison to the control group. Feeding with both experimental chow-based diets promoted significant body weight gains, although the glutamine-enriched diet was more effective. RESULTS: The morphological and morphometric analyses demonstrated that small intestinal villous height was significantly decreased in the malnourished group, and this change was partially corrected by the two types of chow-based diet. Crypt depth was significantly increased by malnutrition, and this parameter was partially corrected by the two types of chow-based diet. The glutamine-enriched diet resulted in the greatest reduction of crypt depth, and this reduction was also statistically significant when compared with control animals. CONCLUSIONS: Enteral glutamine has some positive effects on body weight gain and trophism of the jejunal mucosa in the malnourished growing rat.

Heart hypoplasia in an animal model of congenital diaphragmatic hernia

PURPOSE: In previous papers, we described a new experimental model of congenital diaphragmatic hernia in rabbits, and we also reported noninvasive therapeutic strategies for prevention of the functional and structural immaturity of the lungs associated with this defect. In addition to lung hypoplasia, pulmonary hypertension, biochemical, and structural immaturity of the lungs, the hemodynamics of infants and animals with congenital diaphragmatic hernia are markedly altered. Hence, cardiac hypoplasia has been implicated as a possible cause of death in patients with congenital diaphragmatic hernia, and it is hypothesized to be a probable consequence of fetal mediastinal compression by the herniated viscera. Cardiac hypoplasia has also been reported in lamb and rat models of congenital diaphragmatic hernia. The purpose of the present experiment was to verify the occurrence of heart hypoplasia in our new model of surgically produced congenital diaphragmatic hernia in fetal rabbits. METHODS: Twelve pregnant New Zealand rabbits underwent surgery on gestational day 24 or 25 (normal full gestational time - 31 to 32 days) to create left-sided diaphragmatic hernias in 1 or 2 fetuses per each doe. On gestational day 30, all does again underwent surgery, and the delivered fetuses were weighed and divided into 2 groups: control (non-surgically treated fetuses) (n = 12) and congenital diaphragmatic hernia (n = 9). The hearts were collected, weighed, and submitted for histologic and histomorphometric studies. RESULTS: During necropsy, it was noted that in all congenital diaphragmatic hernia fetuses, the left lobe of the liver herniated throughout the surgically created defect and occupied the left side of the thorax, with the deviation of the heart to the right side, compressing the left lung; consequently, this lung was smaller than the right one. The body weights of the animals were not altered by congenital diaphragmatic hernia, but heart weights were decreased in comparison to control fetuses. The histomorphometric analysis demonstrated that congenital diaphragmatic hernia promoted a significant decrease in the ventricular wall thickness and an increase in the interventricular septum thickness. CONCLUSION: Heart hypoplasia occurs in a rabbit experimental model of congenital diaphragmatic hernia. This model may be utilized for investigations in therapeutic strategies that aim towards the prevention or the treatment of heart hypoplasia caused by congenital diaphragmatic hernia.

Necrotizing enterocolitis, pathogenesis and the protector effect of prenatal corticosteroids

Necrotizing enterocolitis is the most frequently occurring gastrointestinal disorder in premature neonates. Animal models of necrotizing enterocolitis and prenatal administration of cortisone have demonstrated that cortisone may accelerate maturation of the mucosal barrier, therefore reducing the incidence of this gastrointestinal disorder. The authors present a review of the literature of the most important risk factors associated with necrotizing enterocolitis, such as inflammatory gastrointestinal mediators, enteral feeding and bacterial colonization, and immaturity of the gastrointestinal barrier, and we emphasize the necessity for additional studies to explore the prenatal administration of cortisone as a preventive strategy for necrotizing enterocolitis.

Habitat preferences, diet, feeding strategy and social organization of the black spider monkey [Ateles paniscus paniscus Linnaeus 1758] in Surinam

A Socioecological Field Study.This monograph reports on a 26 month socioecological study of black spider monkeys (Ateles paniscus paniscus)in the Raleigh-vallen — Voltzberg Nature Reserve, Surinam. It recognizes the fundamental importance of food to the behavior and the regulation of population density fox this primate. It clarifies the complex temporal and spatial effects of tropical rain forest food sources on the behavior of a group of spider monkeys, concentrating on food category, food plant identity and phenology, and quantity, density and dispersion of the most important food sources. In addition, the present study describes habitat choice, optimal feeding strategy and sexual behavior of the spider monkey, and discusses implications of diet for social behavior. This study is also fundamental to conservation. Specialized in eating mature fruits, the spider monkey is a very important dispersal agent for many trees and lianes, particularly canopy species. However, the spider monkey is probably the most vulnerable monkey species in Surinam and it is disappearing rapidly throughout the remainder of its range. Unfortunately, it is large and noisy and can be easily tracked and hunted. It is largely restricted to undisturbed high forest, and consequently habitat destruction has more effect on it than on most other species. Together with its slow reproductive rate (a female gives birth only once every four or five years), this means that the species is poorly adapted to recover from exploitation. In order to implement proper measures for conservation, data on forest type preferences, diet and social behavior of the species, or on closely related species, in undisturbed areas, such as the one described in this monograph, are essential tools for assessing the potential of proposed protected areas.

Produtividade sazonal da floresta e atividade de forrageamento animal em habitat de terra firme da Amazônia

Durante 13 meses (de janeiro de 1986 a janeiro de 1987), quatro trilhas, de aproximadamente 2,5 km de comprimento cada uma, cortando diferentes ambientes de mata de terra firme, foram seguidas diariamente por um mínimo de dois pesquisadores para observar animais forrageando no chão o em diferentes estratos da floresta. O local de estudo foi em porção de floresta protegida em Tucuruí, estado do Pará. Foram investigadas por observação contínua no campo as tendências sazonais de utilização de ítens de alimentos preferidos demonstrados por quelôneos: os jabutis Geochelone carbonaria, G. denticulata e a aperema Platemys platicephala; por roedores: o quatipuru Sciurus gilvigularis e a cutia Dasyprocta aguti; por cervídeos: o veado-mateiro Mazama americana e o veado fuboca Mazama guazoubira; e por primatas: o macaco-prego Cebus apella, o guariba Alouatta belzebul, o cuxiú Chiropotes satanas , o macaco-mão-de-ouro Saimiri sciureus, e o sagui preto Saguinus midas. Todos esses animais foram estudados através de observação contínua nessas trilhas de transectos, estabelecidas na mata de terra firme. As observações foram feitas pela manhã entre 06:00 e 10:00 horas e à tarde, entre 15:00 e 19 horas. O estudo demonstrou que as dietas dessas espécies animais de habitat de terra firme depende da disponibilidade de alimento na floresta na estação do ano. A importância desses ítens de alimento é demonstrada pela mudança sazonal da atividade de forrageamento, dependendo do ítem alimentar em oferta. Os jabtutis (Geochelone carbonaria e G. denticulata) alimentam-se basicamente de frutos disponíveis entre setembro e janeiro, sendo esses mesmo frutos compatilhados por cutia (Dasyprocta aguti), enquanto o macaco-prego (Cebus apella) expande sua dieta baseada em frutas, em dois picos, um entre janeiro e março, com um máximo de atividade em fevereiro, e outro pico entre julho e dezembro. Essas mesmas frutas são também compartilhadas por Chiropotes satanas. Embora o guariba (Alouatta belzebul) seja observado comendo grande porcentagem de folhas, nas estações de produção de frutos, porém, durante os dois picos anuais, (fevereiro e dezembro) tornam-se oportunisticamente frugívoros.

DISTRIBUTION AND FEEDING ECOLOGY OF THE AFRICAN TILAPIA Oreochromis mossambicus (TELEOSTEI, PERCIFORMES, CICHLIDAE) IN SURINAME (SOUTH AMERICA) WITH COMMENTS ON THE TILAPIA-KWIKWI (Hoplosternum littorale) (TELEOSTEI, SILURIFORMEs, CALLICHTHYIDAE) INTERACTION

The geographical distribution of the African Tilapia Oreochromis mossambicusin Suriname is restricted to a narrow strip of land along the Atlantic coast. Within the coastal plain, O. mossambicusoccurs in brackish lagoons, oligohaline canals, and shell-sand pit lakes. Physico-chemical characteristics and phytoplankton composition of representative Tilapia water bodies are described. Blue-green algae and fine flocculent detritus are dominant food items in the diet of the Tilapia, while Rotifera and microcrustacea are also important in the diet of larvae and juveniles. Intraspecific diet overlap among ontogenetic stages of the Tilapia did not differ significantly from 1, which means that these diets showed complete overlap. Interspecific diet overlap between the Tilapia and the indigenous armoured catfish Hoplosternum littoralewere moderate or low. The results are discussed in relation to recent developments in the Surinamese fisheries and aquaculture sector.

Nutritional preferences of wood-feeding termites inhabiting floodplain forests of the Amazon River, Brazil

The alimentary preferences of five species of wood-feeding termites of the genus Nasutitermes that coexist in the inundated forests of the floodplains of the Amazon river várzea for species of fresh wood and for wood in different stages of decomposition was evaluated in laboratory tests. Wood of low density was generally preferred; the decay stages were preferred over fresh wood. The five termite species differ in the amplitude of their choices, indicating a strong differentiation in food choice among them. Differences in feeding preferences may be a niche-separating factor for these five Nasutitermes species of the floodplains.

Observations on dynamics of foraging hole construction of two leaf-feeding, soil-inhabiting Syntermes species (insecta: Isoptera) in an Amazonian Rainforest, Brazil

The intensity of construction of foraging access holes by two leaf-litter feeding, soil- inhabiting termite species, Syntermes molestus and Syntermes spinosus, in a Central Amazonian rain forest, was observed on consecutive nights for two weeks. Between 11 and 48 nest entrances per m2 were counted. Interaction between the two species was intense; some entrance holes were overtaken by the larger species during the observations; however, both species coexist in the area. A calculated minimum of 35 entrances/m2 is built every year by both species, emphasizing the importance of soil-burrowing termites for soil structure, aeration and water regime.

Feeding of the Brycon cephalus, Triportheus elongatus and Semaprochilodus insignis (osteichthyes, characiformes) larvae in Solimões/Amazonas River and floodplain areas.

Information on larval fish feeding is essential for understanding their trophic relations, including the management in conditions totally or partially controlled by humans. An experiment was designed to evaluate the larval diets of three commercially important species. Four varzea-lakes and the adjacent river were sampled with bongo and hand nets from January 1993 to November 1995. Larval diets were evaluated by length-classes and capture sites, and were tested by two factor ANOVA. The larvae were feeding in all habitats, except in the flooded forests. The three species had different diets, which varied with their length and lake. The rotifers were the main initial food item of the three species, replaced by fish larvae in Brycon cephalus, cladocerans in Triportheus elongatus and detritus in Semaprochilodus insignis. The increase of the ingestion limit, as the larvae grew, was higher than the increase in the consumed prey size for the three species.

Aproveitamento de alimentos de origem animal pela tartaruga-da-amazônia: Podocnemis expansa criada em cativeiro

Foi realizado um trabalho para determinar o aproveitamento alimentar da farinha de carne e ossos (FCO), farinha de vísceras de aves (FVA) e farinha de peixe (FP) em tartaruga-da-amazônia, por meio dos coeficientes de digestibilidade aparente (CDA) da matéria seca (MS), proteína bruta (PB), extrato etéreo (EE) e energia bruta (EB). Os animais experimentais foram 136 filhotes provenientes do Projeto Quelônios da Amazônia, no estado do Mato Grosso, mantidos em caixas com renovação de água e temperatura média de 29ºC. Os CDA foram determinados com dietas contendo 0,1% do marcador óxido de crômio III (Cr2O3). Os CDA da MS, PB, EE e EB foram, respectivamente, de 79,10; 87,61; 93,83 e 79,61% para FCO; 92,45; 94,89; 96,55 e 92,71% para FV e 93,53; 95,13; 94,05 e 93,18% para FP. Os melhores coeficientes foram obtidos com a farinha de peixe e a farinha de vísceras de aves.

Natural diet and feeding habits of a freshwater prawn (Macrobrachium carcinus: Crustacea, Decapoda) in the estuary of the Amazon River

Macrobrachium carcinus is a Brazilian native prawn with recognized potential for use in aquaculture activities. However, there is little information about the natural diet and feeding habits of this species. The aim of this study was the identification of the diet items of M. carcinus based on the analysis of the stomach contents. Specimens were collected in the Amazon River estuary between January 2009 and January 2010. The stomach analysis was carried out by using the frequency of occurrence (FO), methods of points (MP) and feeding index (FI). It was observed that prawns fed on detritus, animals and plant fragments as the most important food items. Sediment accounted for the main stomach content, accounting for 43.2% by the MP, 44.9% by FI and 100% by the FO. Sexual differences in feeding preferences were not found in this study, and seasonal differences in the frequency of items ingested by M. carcinus were not observed. The results indicated that M. carcinus can be considered omnivorous species, but with an important carnivorous component, similar to that found in other Macrobrachium species.