954 resultados para fish species
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Tese de Doutoramento, Ciências do Mar (Biologia Marinha)
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Studies on the feeding habits of aquatic organisms are a requirement for the management and sustainable use of marine ecosystems. The aim of the present research was to analyze the habits and trophic similarities of decapods, starfish and fish in order to propose trophic relationships between taxa, using Hennigian methods of phylogenetic systematics. This new grouping hypothesis, based on shared and exclusive food items and food types, corresponds to the broad taxonomic groups used in the analysis. Our results indicate that algae, Mollusca, Polychaeta, Crustacea, Echinodermata and Actinopterygii are the most exploited common resources among the species studied. Starfish were differentiated from other organisms for being stenophagic, and were grouped for feeding on bivalve mollusks. A larger group of fish and crustaceans shares algae and mainly crustaceans as food items. A third group united all eight species of Actinopterygii. This largest subgroup of fish is typically carnivorous, feeding on Anthozoa and a great quantity of Crustacea. Synodus foetens has a special position among fishes, due to its unique feeding on nematodes. A Euclidean distance dendrogram obtained in a previous publication grouped S. foetens with starfish. That result was based on a few non-exclusive shared similarities in feeding modes, as well as on shared absences of items, which are not an adequate grouping factor. Starfish are stenophagic, eating bivalves almost exclusively. Synodus foetens and Isopisthus parvipinnis have restricted food items, and are thus intermediary in relation to starfish, decapods, and other fish, which are euryphagous. The trophic cladogram displays details of food items, whether or not shared by all species. The resulting trophic analysis is consistent with known historical relationships.
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Maciel & Costa (2010) reported the presence of 17 species of costal sea urchins (Echinoidea) in the Azores, while Porteiro et al. (2010) reported six species of pipefishes (Syngnathidae) for the area. During SCUBA diving at Santa Maria Island, the first author detected a sea urchin and a pipe fish which are new to the marine fauna of the Azores.
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Comportamento alimentar oportunista do marimbá Diplodus argenteus (Perciformes, Sparidae): interação humana-peixe em dois sistemas de costões rochosos do SE e SU do Brasil. Esse artigo aborda dois tipos de comportamentos alimentares do marimbá Diplodus argenteus em dois sistemas de costões rochosos do Atlântico sul no Brasil. Essa espécie alimentou-se sobre o fundo e exibiu comportamentos ocasionais e oportunísticos.
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Ciguatera fish poisoning (CFP) is a syndrome caused by the ingestion of fish contaminated with Ciguatoxins (CTXs). These phycotoxins are produced mainly by dinoflagellates that belong to the genus Gambierdiscus that are transformed in more toxic forms in predatory fish guts, and are more present in the Indo-Pacific and Caribbean areas. It is estimated that CFP causes per year more than 10,000 intoxications worldwide. With the rise of water temperature and anthropogenic intervention, it is important to study the prevalence of CFP in more temperate waters. Through inter- and subtidal sampling, 22 species of organisms were collected, in Madeira and Azores archipelagos and in the northwestern Moroccan coast, during September of 2012 and June and July of 2013. A total of 94 samples of 22 different species of bivalves, gastropods, echinoderms and crustaceans where analyzed by Ultra Performance Liquid Chromatography-Mass Spectometry-Ion Trap-Time of Flight (UPLC-MS-IT-TOF) and Ultra Performance Chromatography- Mass Spectrometry (UPLC-MS). Our main aim was to detect new vectors and ascertain if there were some geographical differences. We detected for the first time putative CTXs in echinoderms, in two starfish species—M. glacialis and O. ophidianus. We detected differences regarding uptake values by organisms and geographical location. Toxin amounts were significant, showing the importance and the need for continuity of these studies to gain more knowledge about the prevalence of these toxins, in order to better access human health risk. In addition, we suggest monitoring of these toxins should be extended to other vectors, starfish being a good alternative for protecting and accessing human health risk.
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Out of the twenty-four samples of shrimp and fish muscle used for this study, twelve were collected near a large marine sewer for waste disposal, 3 km off the coast of Fortaleza (Brazil) and used for the isolation of E. coli. Other twelve were collected at the Mucuripe fresh fish market (Fortaleza, Brazil) and used for the isolation of Staphylococcus aureus. Ethanol, water and acetone-diluted extracts of guava and papaya leaf sprouts were tested on the bacteria in order to verify their microbicidal potential. The E. coli strains used in the trials were rated LT positive. The papaya leaf extracts (Carica papaya Linn) showed no microbicidal activity while the guava sprout extracts (Psidium guajava Linn) displayed halos exceeding 13 mm for both species, an effect considered to be inhibitory by the method employed. Guava sprout extracts by 50% diluted ethanol most effectively inhibited E. coli (EPEC), while those in 50% acetone were less effective. It may be concluded that guava sprout extracts constitute a feasible treatment option for diarrhea caused by E. coli or by S. aureus-produced toxins, due to their quick curative action, easy availability in tropical countries and low cost to the consumer.
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Bacciger pellonae n. ep. (Trematoda, Fellodistomidae) is described from the intestinal tract of a freshwater fish, Pellona castelnaeana Valenciennes, from the Brazilian state of Rondônia. The new species is similar to the type species of the genus, B. bacciger (Rudolphi, 1819) Nicoli, 1914, but differs from it in having a post-testicular, lobate ovary, intertesticular ceca and an acetabulum that is smaller than the genus to be reported from South America and the first from freshwater.
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Two new genera and species of Paramphistomidae (Tremadota, Digenea) are described from freshwater fish of the Brazilian Amazon. Anavilhanatrema robustagen. et sp. nov. is characterized as having a cylindrical body with an anterior expansion, small suckers, a small cirrus sac, large lobate testes, a lobate ovary, long ceca and extensive vitellaria. Pacudistoma turgidagen. et sp. nov., on the other hand, is distinguished by having a stout, cylindrical body, a large oral sucker with internal diverticula, a large genital sucker, smaller lobate testes, a spherical ovary, long ceca and relatively extensive vitellaria. Both species appear to be host specific with A. robustafound in Pristobrycon striolatus(STEINDACHNER) while P. turgidaoccurus in Hyleus pacu(SCHOMBURCK).
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The surface morphology of specimens from ten different genera of amphistomes (Trematoda, Cladorchiidae) from Amazonian fishes is described and illustrated. The importance of body shape as a generic character is considered. Morphological changes as a result of growth are shown and explained in relation to the species Dadaytrema oxycephala. Additionally, Doradamphistoma bacuensis gen. et sp. n. is described from the catfish, Megalodoras irwini Eigenmann, 1925.The new genus and species is elongate and flattened, with external pharyngeal pouches, an esophageal bulb, a spherical cirrus sac, a post-bifurcal genital pore and pre-equatorial testes.
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The present work aims to update a series of information about the regional fishing production, by presenting and characterizing the contribution of the different sub-systems of the Amazon basin to the catch landed at the main fishing market of Manaus, Brazil, from 1994 to 1996. Collectors specifically hired for this function registered key information on the fisheries. Thirty nine types or groups of fish were found in the fishing production landed. Jaraqui (Semaprochilodus spp.), curimatã (Prochilodus nigricans), pacu (Myleinae), matrinchã (Brycon cephalus), sardine (Triportheus spp.), aracu (Anostomidae) and tambaqui (Colossoma macropomum) were the most important items during three consecutive years. In 1994 these items summed up 91.6% of the total production; in 1995 and 1996 these values were, respectively, 85.3% and 86.4% of the total production. Tambaqui landed decreased remarkably during the period 1976-1996. There was a strong seasonal component in the production of the main species; jaraqui and matrinchã were mostly landed between April and June, while curimatã, pacu, and sardine were mostly landed during the dry season. Other important items showed a strong inter-annual variation in their production. The fishing production landed came mostly from the sub-system of the Purus River (around 30% of the total production). The subsystem of the Medium-Solimões contributed with an average of 15% and the sub-systems of the Madeira, Lower-Solimões, Upper-Amazon and Juruá, together contributed with 11.5% of the total production landed. Finally, the remaining sub-systems contributed with only 7.6% of the production.
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The present work evaluated several aspects of the generalized stress response [endocrine (cortisol), metabolic (glucose), hematologic (hematocrit and hemoglobin) and cellular (HSP70)] in the Amazonian warm-water fish matrinxã (Brycon amazonicus ) subjected to an acute cold shock. This species farming has been done in South America, and growth and feed conversion rates have been interesting. However, in subtropical areas of Brazil, where the water temperature can rapidly change, high rates of matrinxã mortality have been associated with abrupt decrease in the water temperature. Thus, we subjected matrinxã to a sudden cold shock by transferring the fish directly to tanks in which the water temperature was 10ºC below the initial conditions (cold shock from 28ºC to 18ºC). After 1h the fish were returned to the original tanks (28ºC). The handling associated with tank transfer was also imposed on control groups (not exposed to cold shock). While exposure to cold shock did not alter the measured physiological conditions within 1h, fish returned to the ambient condition (water at 28º C) significantly increased plasma cortisol and glucose levels. Exposure to cold shock and return to the warm water did not affect HSP70 levels. The increased plasma cortisol and glucose levels after returning the fish to warm water suggest that matrinxã requires cortisol and glucose for adaptation to increased temperature.
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The aim of this study was not only to determine the red blood cells parameters, thrombocyte and leukocyte counts in farmed Brycon amazonicus (matrinxã), to compare these parameters among Bryconinae species from literature, and also to investigate the presence of special granulocytic cells in these fish. The results of the blood cells parameters here established for farmed B. amazonicus, a species of great economic importance in Brazilian aquaculture, could help a better understanding of the blood features in natural populations of this Amazon species. Blood parameters varied between Bryconinae species investigated, mainly the red blood cell counts, hemoglobin, hematocrit and mean corpuscular volume (MCV). The presence of the blood granulocytes, neutrophils and heterophils in matrinxã suggest that both leukocytes can be a characteristic for Bryconinae family. Furthermore, it indicates that the existence of special granulocytic cells in the blood of Bryconinae species from literature is an artifact, and this was herein discussed.
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The Giant of Amazon basin, pirarucu, Arapaima gigas, is the largest scaled freshwater fish in the world. pirarucu cultivation has recently started, driven by the decline in natural populations and high market value. Currently, there are no reliable methods for sexual differentiation in this species other than direct examination of gonads, which requires dissection of specimens. A non-lethal and less invasive method for sexual identification is highly desirable in order to properly group broodstock for mating and offspring production. We utilized laparoscopic examination in anesthetized pirarucu to differentiate between male and female individuals. This method allowed for the observation and differentiation of the reproductive organs within an individual. Our results suggest that laparoscopy is an efficient method for sex differentiation in pirarucu causing minimal stress to the fish.
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In this study we investigated the relationship between tambaqui fish (Colossoma macropomumi Cuvier 1818) and parasites in two fish farms (L204S and L180N) in the state of Rondônia, Brazil, during a 1-year period. The objective of the study was to describe the relationships between parasites, hosts and the environment. From the 80 fish specimens collected, 100% were parasitized by at least one parasite species. Seven ectoparasites species were recorded, six of the class Monogenea: Anacanthorus spathulatusi, Mymarothecium spp. (Mymarothecium sp. 1, Mymarothecium sp. 2 and M. viatorum), Notozothecium sp. and Linguadactyloides brinkimanni, classified as dominants, and the copepod Perulernaea gamitanae, classified as subordinate. Despite their high prevalence, the parasites were not abundant. A. spathulatus presented positive and significant correlations between the abundance of parasitism and the standard length of the hosts in the two fish farms; Mymarothecium spp. showed significant correlations, negative in L180N, and positive in L204S; significant positive correlations were observed for Notozothecium sp. in L204S, and for L.brinkimanni in L180N. Young monogeneans were found; these parasites presented a negative correlation in L180N and a significant negative correlation in L204S. The results of the correlation between the relative condition factor (Kn) and the abundance of parasites were not significant for the recorded parasite species. Regarding the hepatosomatic relation (HSR) of fish and the abundance of parasites, Anacanthorus spathulatusi showed a significant negative correlation with the HSR in L180N, and a positive correlation in L204S. Mymarothecium spp. and Notozothecium sp. presented significant positive correlations in L204S. Considering the correlation of the fish splenosomatic relation (SSR) and the abundance of parasites, L. brinkimanni presented significant correlations, positive in L180N and negative in L204S. Despite 100% prevalence, the high water quality contributes to infracommunities with low parasite abundance and good levels of Kn, HSR and SSR, allowing good tambaqui development.
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Dissertação mestrado em Biologia Molecular, Biotecnologia e Bioempreendedorismo em Plantas