ABSTRACT
The effects of thermal shock on hematological, biochemical and antioxidant responses were evaluated in liver tissue of juvenile tambaqui (Colossoma macropomum) and tambatinga (â C. macropomum × â Piaractus brachypomus). Forty juveniles of tambaqui and 40 juveniles of tambatinga, of the same age and with an initial weight of 23.3 ± 6.7 g, were randomly distributed in eight 28L circular tanks. A tank (n = 10 fish) of tambaqui and a tank (n = 10 fish) of tambatinga were then used to obtain basal data. The other animals were subjected to thermal shock with sudden temperature reduction from 28 to 18 ºC. Blood and tissue were then collected after 1, 6 and 24 h from the onset of thermal shock. No mortality was observed during the experimental period. Thermal shock increased triglyceride levels after 24 h of stress for tambaqui and reduced values for tambatinga. There was an effect on plasma glucose only for fish group (P < 0.0001) and collection time (P < 0.0001) with a peak observed for the hybrid after 6 h. The interaction of factors for SOD indicated greater activity for tambatinga at the 6 h collection and lower at basal and 1 h collections. There was an interaction for CAT (P = 0.0020) with less activity for tambatinga at 1 h. However, thermal shock and hybridization did not influence GST and TBARS levels in liver tissue. Therefore, the results suggest that the hybrid, tambatinga, is more efficient at promoting adjustments of biochemical responses and antioxidant enzymes during thermal shock.
Subject(s)
Liver , Oxidative Stress , Animals , Liver/metabolism , Characiformes/blood , Heat-Shock Response , Blood Glucose , Triglycerides/blood , Triglycerides/metabolism , Hybridization, Genetic , Antioxidants/metabolism , Superoxide Dismutase/metabolismABSTRACT
Ganoderma species are well recognised by their significant role in the recycling of nutrients in ecosystems and by their production of secondary metabolites of medical and biotechnological importance. Ganoderma spp. are characterised by laccate and non-laccate, woody basidiocarps, polypore hymenophores and double-walled basidiospores generally with truncate apex. Despite the importance of this genus, its taxonomy is unclear and it includes several species' complexes with few circumscribed species and incorrect geographic distributions. The aim of this work was to provide detailed morphological descriptions together with phylogenetic analyses using ITS sequences to confirm the presence of seven species of Ganoderma in Costa Rica: G.amazonense, G.applanatum s.l., G.australe, G.curtisii, G.ecuadorense, G.oerstedii and G.parvulum. This is the first study that integrates morphological and phylogenetic data of Ganoderma from Central America and a key of the neotropical species. Besides, the distribution range of G.curtisii, previously reported from North America and G.ecuadorense from South America, is expanded to Central America.
ABSTRACT
The interest of biofuel producers in Neotropical species that have high growth rates, slight wood density variability, and elemental composition that does not compromise the environment has increased in recent decades. We investigated the density and chemical characteristics of wood of Schizolobium parahyba var. amazonicum (Huber × Ducke) Barneby as a source for the generation of bioenergy. Apparent radial wood density profiles (X-ray densitometry (XRD)) and the elemental distribution (X-ray fluorescence (XRF)) of Cl, S, K, and Ca in the wood of nine S. parahyba var. amazonicum trees, divided into three diameter classes (I = 15.5, II = 19.5, and III = 23.5 cm) were analyzed. The high heating value (HHV) of the wood samples was determined, and the energy density was estimated by the product of the HHV and the apparent density. Trees that grew better (classes II and III) produced wood with higher density. These trees showed higher concentrations of K and S, and lower concentrations of Ca and Cl. The highest Cl concentrations were observed in classes with smaller diameters. The chlorine levels met the standards for use of this wood as fuel, but the sulfur levels were higher than the threshold recommended by the ISO 17225-3:2021 guidelines, which can limit the use of the species for certain energy uses. The wood of S. parahyba var. amazonicum had interesting characteristics for the production of bioenergy due to its low density, so it can be used in the production of solid biofuels such as pellets and briquettes. Monitoring chlorine and sulfur is important, since during the combustion of biomass they are released into the atmosphere and can negatively contribute to the effects of climate change.
Subject(s)
Fabaceae , Wood , Wood/chemistry , Chlorine/analysis , Trees , Biofuels/analysis , Biomass , Halogens/analysisABSTRACT
Behavior is a useful trait for comparative studies that provide the comprehension of phylogenetic relationships among species. Here, we present a description of two spiny-rats species' behavioral repertoire, Clyomys laticeps and Trinomys setosus (Rodentia: Echimyidae). The affiliative and agonistic behavioral patterns were sampled during a three-year study of captive populations of wild animals. Observational data were collected in two phases under different arrangements of individuals in groups. We also compare the behavioral traits of T. setosus and C. laticeps with the known behavioral patterns of Trinomys yonenagae. We add categories to the previous descriptions of T. setosus and a standard ethogram for C. laticeps. Trinomys setosus showed a visual and vocal display we called foot-trembling, which was not described in this form and function for other species studied until now. We discuss the differences in their sociality levels and similarities and differences among behavior patterns and repertoires.(AU)
O comportamento é uma característica útil para estudos comparativos que fornecem a compreensão das relações filogenéticas entre as espécies. Apresentamos aqui uma descrição do repertório comportamental de duas espécies de ratos-de-espinho Clyomys laticeps and Trinomys setosus (Rodentia: Echimyidae). Os padrões comportamentais afiliativos e agonísticos foram amostrados durante um estudo de três anos em populações de animais silvestres em cativeiro. Os dados foram coletados em duas fases sob diferentes arranjos de indivíduos em grupos sociais. Comparamos as características comportamentais de T. setosus e C. laticeps com as da espécie mais conhecida, T. yonenagae. Adicionamos categorias às descrições anteriores de T. setosus, e um etograma padrão para C. laticeps. Trinomys setosus mostrou uma exibição visual e vocal que chamamos de saltitar, que não foi descrito nesta forma e função para outras espécies do gênero estudado até agora. Discutimos diferenças nos níveis de socialidade e similaridades e diferenças entre os padrões comportamentais e repertórios.(AU)
Subject(s)
Animals , Rats , Rodentia , Behavior, AnimalABSTRACT
Abstract Behavior is a useful trait for comparative studies that provide the comprehension of phylogenetic relationships among species. Here, we present a description of two spiny-rats species' behavioral repertoire, Clyomys laticeps and Trinomys setosus (Rodentia: Echimyidae). The affiliative and agonistic behavioral patterns were sampled during a three-year study of captive populations of wild animals. Observational data were collected in two phases under different arrangements of individuals in groups. We also compare the behavioral traits of T. setosus and C. laticeps with the known behavioral patterns of Trinomys yonenagae. We add categories to the previous descriptions of T. setosus and a standard ethogram for C. laticeps. Trinomys setosus showed a visual and vocal display we called foot-trembling, which was not described in this form and function for other species studied until now. We discuss the differences in their sociality levels and similarities and differences among behavior patterns and repertoires.
Resumo O comportamento é uma característica útil para estudos comparativos que fornecem a compreensão das relações filogenéticas entre as espécies. Apresentamos aqui uma descrição do repertório comportamental de duas espécies de ratos-de-espinho Clyomys laticeps and Trinomys setosus (Rodentia: Echimyidae). Os padrões comportamentais afiliativos e agonísticos foram amostrados durante um estudo de três anos em populações de animais silvestres em cativeiro. Os dados foram coletados em duas fases sob diferentes arranjos de indivíduos em grupos sociais. Comparamos as características comportamentais de T. setosus e C. laticeps com as da espécie mais conhecida, T. yonenagae. Adicionamos categorias às descrições anteriores de T. setosus, e um etograma padrão para C. laticeps. Trinomys setosus mostrou uma exibição visual e vocal que chamamos de saltitar, que não foi descrito nesta forma e função para outras espécies do gênero estudado até agora. Discutimos diferenças nos níveis de socialidade e similaridades e diferenças entre os padrões comportamentais e repertórios.
Subject(s)
Animals , Rats , Rodentia , Social Behavior , Phylogeny , Brazil , Animals, WildABSTRACT
Behavior is a useful trait for comparative studies that provide the comprehension of phylogenetic relationships among species. Here, we present a description of two spiny-rats species' behavioral repertoire, Clyomys laticeps and Trinomys setosus (Rodentia: Echimyidae). The affiliative and agonistic behavioral patterns were sampled during a three-year study of captive populations of wild animals. Observational data were collected in two phases under different arrangements of individuals in groups. We also compare the behavioral traits of T. setosus and C. laticeps with the known behavioral patterns of Trinomys yonenagae. We add categories to the previous descriptions of T. setosus and a standard ethogram for C. laticeps. Trinomys setosus showed a visual and vocal display we called foot-trembling, which was not described in this form and function for other species studied until now. We discuss the differences in their sociality levels and similarities and differences among behavior patterns and repertoires.
O comportamento é uma característica útil para estudos comparativos que fornecem a compreensão das relações filogenéticas entre as espécies. Apresentamos aqui uma descrição do repertório comportamental de duas espécies de ratos-de-espinho Clyomys laticeps and Trinomys setosus (Rodentia: Echimyidae). Os padrões comportamentais afiliativos e agonísticos foram amostrados durante um estudo de três anos em populações de animais silvestres em cativeiro. Os dados foram coletados em duas fases sob diferentes arranjos de indivíduos em grupos sociais. Comparamos as características comportamentais de T. setosus e C. laticeps com as da espécie mais conhecida, T. yonenagae. Adicionamos categorias às descrições anteriores de T. setosus, e um etograma padrão para C. laticeps. Trinomys setosus mostrou uma exibição visual e vocal que chamamos de saltitar, que não foi descrito nesta forma e função para outras espécies do gênero estudado até agora. Discutimos diferenças nos níveis de socialidade e similaridades e diferenças entre os padrões comportamentais e repertórios.
Subject(s)
Animals , Rats , Behavior, Animal , RodentiaABSTRACT
Abstract Behavior is a useful trait for comparative studies that provide the comprehension of phylogenetic relationships among species. Here, we present a description of two spiny-rats species behavioral repertoire, Clyomys laticeps and Trinomys setosus (Rodentia: Echimyidae). The affiliative and agonistic behavioral patterns were sampled during a three-year study of captive populations of wild animals. Observational data were collected in two phases under different arrangements of individuals in groups. We also compare the behavioral traits of T. setosus and C. laticeps with the known behavioral patterns of Trinomys yonenagae. We add categories to the previous descriptions of T. setosus and a standard ethogram for C. laticeps. Trinomys setosus showed a visual and vocal display we called foot-trembling, which was not described in this form and function for other species studied until now. We discuss the differences in their sociality levels and similarities and differences among behavior patterns and repertoires.
Resumo O comportamento é uma característica útil para estudos comparativos que fornecem a compreensão das relações filogenéticas entre as espécies. Apresentamos aqui uma descrição do repertório comportamental de duas espécies de ratos-de-espinho Clyomys laticeps and Trinomys setosus (Rodentia: Echimyidae). Os padrões comportamentais afiliativos e agonísticos foram amostrados durante um estudo de três anos em populações de animais silvestres em cativeiro. Os dados foram coletados em duas fases sob diferentes arranjos de indivíduos em grupos sociais. Comparamos as características comportamentais de T. setosus e C. laticeps com as da espécie mais conhecida, T. yonenagae. Adicionamos categorias às descrições anteriores de T. setosus, e um etograma padrão para C. laticeps. Trinomys setosus mostrou uma exibição visual e vocal que chamamos de saltitar, que não foi descrito nesta forma e função para outras espécies do gênero estudado até agora. Discutimos diferenças nos níveis de socialidade e similaridades e diferenças entre os padrões comportamentais e repertórios.
ABSTRACT
The new genus Borgesminthurinus gen. nov. from Bolivia shares with Sminthurinus the presence of antennal segment IV undivided, antennal segment III with one papilla; sacs of ventral tube smooth; each tenacular rami with 3 teeth and a basal appendix. They also have dens with ventral chaetotaxy reduced and lack mucronal seta; but new genus clearly differs in having thick and barbulate setae on head and body, lacking neosminthuroid setae on abdomen and the presence of seta a0 on Abd. VI acuminate. The new genus differs from Katianna which has divided antennal segment IV, vertex of head with spine-like setae and setae of the body long and smooth.
Subject(s)
Arthropods , Animals , Bolivia , HeadABSTRACT
Six new Hepialidae species are described from high elevation habitats in the Andes of Peru and Ecuador. One species is assigned to the genus Kozloviella gen. n., K. viazmenskyi sp. n., from Peru, and five to the genus Pfitzneriella Viette, 1951: P. antonkozlovi sp. n., P. olafi sp. n., P. titarenkoi, sp. n., P. yuliyakovalevae sp. n. from Peru and P. rawlinsi sp. n., from Ecuador. Dugdaleiella gen. n., is proposed to accommodate the Ecuadorian species Dugdaleiella monticola (Maassen, 1890) comb. n., formerly placed in Pfitzneriella. The taxonomic (but not the phylogenetic) status of P. lucicola (Maassen, 1890) is unaltered pending future opportunity to examine the type series. Preliminary phylogenetic analysis of the morphological characters supports Kozloviella gen. n., and Pfitzneriella as sister taxa, and separates P. titarenkoi sp. n., from the other species of Pfitzneriella. We suggest that the ancestor of these high elevation genera already occupied a pre-Andean upland habitat across Peru and Ecuador and this ancestor further diverged into the modern genera and species during the Andean orogeny. We consider it likely that there is a considerable diversity of endemic high elevation Hepialidae that remains to be discovered in the eastern Andes between Venezuela and Bolivia.
Subject(s)
Lepidoptera , Phylogeny , Animals , Bolivia , Ecuador , Peru , VenezuelaABSTRACT
The subgenus Melanoconion of the mosquito genus Culex is taxonomically diverse and is widely distributed in the Neotropical Region, with 10 species occurring in the Nearctic Region. Species of this subgenus pose a taxonomical challenge because morphological identification is based largely on anatomical characters of the male genitalia. We addressed the monophyly of the Spissipes and Melanoconion Sections of the subgenus Melanoconion and some of the informal groups in each section. Our sample taxa included 97 specimens representing 43 species, from which we analysed fragments of two single-copy nuclear genes (CAD, HB) and one mitochondrial gene (COI). Phylogenetic relationships within the subgenus are presented based on results of maximum-likelihood and Bayesian analyses using a multi-locus matrix of DNA sequences. We show a molecular phylogeny of Melanoconion in which both sections were recovered as monophyletic groups. The monophyly of the Atratus and Pilosus groups was confirmed. Within each section, other monophyletic groups were recovered highlighting the potential need for future nomenclature rearrangement. The phylogenetic signal contained in nuclear genes, when analysed together, was more informative than each gene analysed separately, corroborating monophyly of Melanoconion relative to Culex (Culex) species included in the analyses, the Melanoconion and Spissipes Sections and some species groups. Our results provide new information for the classification of the subgenus and additional data that can be used to improve species identification when a more representative taxon sampling is available.
ABSTRACT
Banded Knifefishes (Gymnotus, Gymnotidae) comprise the most species-rich genus of Neotropical electric fishes, with 41 species currently described from throughout the humid Neotropics, from Mexico to Argentina. Despite substantial alpha-taxonomic work in recent years, the diversity of Gymnotus in some regions remains poorly understood. Here we describe the Gymnotus fauna of the Upper Madeira basin of Bolivia and Peru from examination of more than 240 adult specimens. Species are delimited and described using body proportions (traditional morphometrics), fin-ray, squamation and laterosensory-pore counts (meristics), quantitative shape differences (geometric morphometrics), osteological traits, and color patterns. Comparisons of standardized linear measures as well as multivariate statistical methods validate the presence in the Upper Madeira basin of three previously described species, two with wide-spread geographic distributions throughout Greater Amazonia (G. carapo and G. coropinae), and one (G. chaviro) endemic to southwestern Amazonia. We also diagnose and describe two new species that are endemic to the Upper Madeira basin: G. eyra n. sp., morphologically most similar to G. mamiraua from lowland Amazonia, and G. riberalta n. sp., morphologically most similar to G. pantanal from the Paraguay-Paraná basin. The five Gymnotus species from the Upper Madeira basin are not monophyletic, each species being more closely related to a different species from another region; i.e. the Gymnotus species from the Upper Madeira represents a polyphyletic assemblage. These descriptions to 43 the number of valid Gymnotus species.
Subject(s)
Gymnotiformes , Animals , Argentina , Bolivia , Mexico , Paraguay , PeruABSTRACT
The biological invasion process is widely debated topic, as the population depletion of some species and the extinction of others are related to this process. To accelerate the identification of species and to detect non-native forms, new tools are being developed, such as those based on genetic markers. This study aimed to use Barcode DNA methodology to identify fish species that had translocated between the Parana and Paraguay River Basins. Based on a database of two studies that were conducted in these regions, 289 sequences of Cytochrome Oxidase C subunit 1 (COI) were used for General Mixed Youle Coalecent (GMYC) analysis, including 29 morphospecies that were sampled in both river basins. As a result, we observed that while some morphospecies have low variation, demonstrating a recent occupation of the basins, other morphospecies probably represent species complexes. A third of the morphospecies had well-defined lineages but not enough to be treated as different Molecular Operational Taxonomic Units (MOTUs). These results demonstrate that human interventions possibly participated in the distribution of some lineages. However, biogeographical historical processes are also important for the morphospecies distribution. The data suggest that the number of species that are present in these two basins is underestimated and that human actions can irreversibly affect the natural history of the species in these regions.
Subject(s)
DNA Barcoding, Taxonomic/methods , Fishes/genetics , Animals , Electron Transport Complex IV/genetics , Fish Proteins/genetics , Introduced Species , ParaguayABSTRACT
Brazilian fish cytogenetics started as early as the seventies in three pioneering research groups, located at the Universidade Estadual Paulista (UNESP, Botucatu, SP), Universidade Federal de São Carlos (UFSCar, São Carlos, SP) and Universidade de São Paulo (USP, São Paulo, SP). Investigations that have been conducted in these groups led to the discovery of a huge chromosomal and genomic biodiversity among Neotropical fishes. Besides, they also provided the expansion of this research area, with the genesis of several other South American research groups, in view of a number of dissertations and doctoral theses developed over years. The current authors were encouraged to make their thesis catalog accessible from a public source, in order to share informations on the taxa and subject matter analyzed. Some of the key contributions to evolutionary fish cytogenetics are also being highligthed.
ABSTRACT
Seasonality is an important aspect associated with population dynamic and structure of tropical insect assemblages. This study evaluated the effects of seasonality on abundance, richness, diversity and composition of an insect group, drosophilids, including species native to the Neotropical region and exotic ones. Three preserved fragments of the northern Atlantic Forest were surveyed, where temperatures are above 20 °C throughout the year and rainfall regimes define two seasons (dry and rainy). As opposed to other studies about arthropods in tropical regions, we observed that abundance of drosophilids was significantly higher in the dry season, possibly due to biological aspects and the colonization strategy adopted by the exotic species in these environments. Contrarily to abundance, we did not observe a seasonal pattern for richness. As for other parts of the Atlantic Forest, the most representative Neotropical species (Drosophila willistoni, D. sturtevanti, D. paulistorum and D. prosaltans) were significantly more abundant in the rainy season. Among the most abundant exotic species, D. malerkotliana, Zaprionus indianus and Scaptodrosophila latifasciaeformis were more importantly represented the dry season, while D. simulans was more abundant in the rainy period. The seasonality patterns exhibited by the most abundant species were compared to findings published in other studies. Our results indicate that exotic species were significantly more abundant in the dry season, while native ones exhibited an opposite pattern.
Subject(s)
Biodiversity , Drosophilidae , Seasons , Animals , Brazil , Female , Forests , MaleABSTRACT
The Pseudoplatystoma sp. is species of carnivorous fish that require special attention in the diet offered. This work had the objective to determine the digestible protein requirement of juvenile the Pseudoplatystoma sp. reared in net cages. The test consisted of four isoenergetic diets (2606.69 ± 39.16 kcal kg-1 of digestible energy) containing increasing levels of digestible protein (23, 24, 26 and 28%PD) provided to juveniles of surubim (157.35±11.23g) for five months. The parameters of growth, fillet composition, metabolic liver enzymes and morphometry of the intestine and liver were analyzed in completely randomized design with four treatments and four replicates. An increase of protein in the diet provided better weight gain. The metabolic liver enzymes increased in fish fed 24PD. The histopathological changes were not observed in the liver of the fish. The bowel histology showed adaptation to increased protein in the diet until the 26 level PD. juveniles of Pseudoplatystoma sp. Were demanding in digestible protein, showing the best results of production performance and nutrient use efficiency with the diet containing 28%PD.(AU)
O surubim (Pseudoplatystoma sp.) é uma das espécie de peixe carnívora que exige atenção especial na dieta ofertada. Este trabalho teve o objetivo determinar a exigência de proteína digestível de juvenis de surubim (Pseudoplatystoma sp.) criados em tanque-rede. O ensaio foi constituído por quatro dietas isoenergéticas (2606,69±39,16 kcal. kg-1 de energia digestível) contendo níveis crescentes de proteína digestível (23, 24, 26 e 28 % PD) fornecidas aos juvenis de surubim (157,35± 11,23g) durante cinco meses. Os parâmetros de crescimentos, composição do filé, enzimas metabólicas hepáticas e morfometria do intestino e fígado foram analisados em delineamento inteiramente casualizado com quatro tratamentos e quatro repetições. O aumento de proteína na dieta proporcionou melhor ganho em peso. As enzimas do metabolismo hepático aumentaram nos peixes alimentados com 24%PD. Não foram observadas alterações histopatológicas no fígado dos peixes. A histologia do intestino revelou adaptação ao aumento de proteína na dieta até o nível de 26% PD. Os juvenis de surubim mostraram-se exigentes em proteína digestível, apresentando os melhores resultados de desempenho de produção e de eficiência de utilização dos nutrientes com a dieta contendo 28% de PD.(AU)
Subject(s)
Animals , Catfishes/metabolism , Dietary Proteins , Animal Feed , AquacultureABSTRACT
The Pseudoplatystoma sp. is species of carnivorous fish that require special attention in the diet offered. This work had the objective to determine the digestible protein requirement of juvenile the Pseudoplatystoma sp. reared in net cages. The test consisted of four isoenergetic diets (2606.69 ± 39.16 kcal kg-1 of digestible energy) containing increasing levels of digestible protein (23, 24, 26 and 28%PD) provided to juveniles of surubim (157.35±11.23g) for five months. The parameters of growth, fillet composition, metabolic liver enzymes and morphometry of the intestine and liver were analyzed in completely randomized design with four treatments and four replicates. An increase of protein in the diet provided better weight gain. The metabolic liver enzymes increased in fish fed 24PD. The histopathological changes were not observed in the liver of the fish. The bowel histology showed adaptation to increased protein in the diet until the 26 level PD. juveniles of Pseudoplatystoma sp. Were demanding in digestible protein, showing the best results of production performance and nutrient use efficiency with the diet containing 28%PD.
O surubim (Pseudoplatystoma sp.) é uma das espécie de peixe carnívora que exige atenção especial na dieta ofertada. Este trabalho teve o objetivo determinar a exigência de proteína digestível de juvenis de surubim (Pseudoplatystoma sp.) criados em tanque-rede. O ensaio foi constituído por quatro dietas isoenergéticas (2606,69±39,16 kcal. kg-1 de energia digestível) contendo níveis crescentes de proteína digestível (23, 24, 26 e 28 % PD) fornecidas aos juvenis de surubim (157,35± 11,23g) durante cinco meses. Os parâmetros de crescimentos, composição do filé, enzimas metabólicas hepáticas e morfometria do intestino e fígado foram analisados em delineamento inteiramente casualizado com quatro tratamentos e quatro repetições. O aumento de proteína na dieta proporcionou melhor ganho em peso. As enzimas do metabolismo hepático aumentaram nos peixes alimentados com 24%PD. Não foram observadas alterações histopatológicas no fígado dos peixes. A histologia do intestino revelou adaptação ao aumento de proteína na dieta até o nível de 26% PD. Os juvenis de surubim mostraram-se exigentes em proteína digestível, apresentando os melhores resultados de desempenho de produção e de eficiência de utilização dos nutrientes com a dieta contendo 28% de PD.
Subject(s)
Animals , Catfishes/metabolism , Dietary Proteins , Animal Feed , AquacultureABSTRACT
The appropriate feeding regime for larvae and post-larvae of crustacean decapods is essential for successful larval culture. Reports on the development and morphology of the mouthparts and foregut of these crustaceans have aided in the selection of appropriate larval foodstuffs and consequently increased larval survival and growth rate during development. In the present study, the functional morphology of foregut and mouthparts was investigated in larvae and post-larvae of the freshwater prawn M. amazonicum (Heller, 1862). From observations gathered on both the outer and inner feeding apparati the first stage larvae have obligatory lecithotrophy and feeding behaviour is initiated after molting to the second stage. The foregut of the larvae undergoes diverse morphological changes during larval development and the larval foregut of this species is primarily a mixing organ due to the absence of gastric mills and similar structures. After metamorphosis into post-larvae, drastic morphological changes occur in the foregut and mouthparts to adapt the animals to feed on the greater diversity of foods that are available in their new benthic habitat.
ABSTRACT
The appropriate feeding regime for larvae and post-larvae of crustacean decapods is essential for successful larval culture. Reports on the development and morphology of the mouthparts and foregut of these crustaceans have aided in the selection of appropriate larval foodstuffs and consequently increased larval survival and growth rate during development. In the present study, the functional morphology of foregut and mouthparts was investigated in larvae and post-larvae of the freshwater prawn M. amazonicum (Heller, 1862). From observations gathered on both the outer and inner feeding apparati the first stage larvae have obligatory lecithotrophy and feeding behaviour is initiated after molting to the second stage. The foregut of the larvae undergoes diverse morphological changes during larval development and the larval foregut of this species is primarily a mixing organ due to the absence of gastric mills and similar structures. After metamorphosis into post-larvae, drastic morphological changes occur in the foregut and mouthparts to adapt the animals to feed on the greater diversity of foods that are available in their new benthic habitat.
ABSTRACT
The appropriate feeding regime for larvae and post-larvae of crustacean decapods is essential for successful larval culture. Reports on the development and morphology of the mouthparts and foregut of these crustaceans have aided in the selection of appropriate larval foodstuffs and consequently increased larval survival and growth rate during development. In the present study, the functional morphology of foregut and mouthparts was investigated in larvae and post-larvae of the freshwater prawn M. amazonicum (Heller, 1862). From observations gathered on both the outer and inner feeding apparati the first stage larvae have obligatory lecithotrophy and feeding behaviour is initiated after molting to the second stage. The foregut of the larvae undergoes diverse morphological changes during larval development and the larval foregut of this species is primarily a mixing organ due to the absence of gastric mills and similar structures. After metamorphosis into post-larvae, drastic morphological changes occur in the foregut and mouthparts to adapt the animals to feed on the greater diversity of foods that are available in their new benthic habitat.
ABSTRACT
Some species of drosophilids have been intensely studied, especially in the areas of genetics and molecular biology. However, little is known about their ecology and biogeography. Here, we revise the records of Drosophilidae species in the Cerrado domain, in order to organize the available information and to recognize patterns of geographic distribution and endemism. The 43 sampled sites in this domain reveal 100 species of drosophilids (10 of them exotic to the Neotropical region), distributed in eight genera. The collections were concentrated mainly in the States of Goiás (including the Federal District) and Minas Gerais. Serra do Cipó is the site with the highest richness of these insects. Of the 90 neotropical species found in the Cerrado, 77 also occur outside this domain, most of which are in the Atlantic Forest. Since extensive areas of this domain were poorly sampled for drosophilids and most studies used only baited traps to collect the flies, this absence of endemism should be carefully considered. It is recommended new inventories in poorly sampled regions, especially in the northeastern part of the domain. Also diversification of collection methods and improvement in the taxonomy of these flies are proposed. These directions should provide a significant increase in the list of species of drosophilids of the Cerrado; and thus, increase our knowledge about its biodiversity.
Algumas espécies de drosofilídeos têm sido intensamente estudadas, principalmente nas áreas de genética e biologia molecular. Entretanto, a ecologia e biogeografia do grupo ainda são pouco conhecidas. Aqui revisamos os registros das espécies de Drosophilidae no domínio do Cerrado, visando organizar a informação disponível e reconhecer eventuais padrões de distribuição geográfica e endemismos. As 43 localidades amostradas no domínio apresentaram 100 espécies de drosofilídeos (10 delas exóticas à região Neotropical), distribuídas em oito gêneros. As coletas estão concentradas principalmente nos Estados de Goiás (incluindo Distrito Federal) e Minas Gerais. A Serra do Cipó é o local com maior riqueza desses insetos. Das 90 espécies neotropicais encontradas no Cerrado, 77 também ocorrem fora do domínio, a maioria na Mata Atlântica. Como áreas extensas do domínio foram pouco amostradas para drosofilídeos e a maior parte dos estudos utilizaram apenas iscas de banana para coletar as moscas, a ausência de endemismos deve ser analisada com precaução. São recomendados novos inventários em regiões pobremente amostradas, especialmente na parte noroeste do domínio. Também são propostas a diversificação dos métodos de coleta e o aumento do esforço de identificação taxonômico dessas moscas. Essas diretrizes devem permitir um aumento significativo na lista de espécies de drosofilídeos do Cerrado e, consequentemente, no conhecimento da biodiversidade do domínio.