| wallinia chavarriae n. sp. (trematoda: macroderoididae) in astyanax aeneus (gunther, 1860) and bryconamericus scleroparius (regan, 1908) (osteichthyes: characidae) from the area de conservación guanacaste, costa rica. | wallinia chavarriae n. sp. is described from the small-bodied characids astyanax aeneus and bryconamericus scleroparius in the area de conservación guanacaste, northwestern costa rica. the species differs from w. valenciae in possessing an acetabulum that is smaller than the oral sucker and vitelline follicles that are ovoid or rounded rather than elongate and tubular. detailed comparison between these 2 species is handicapped by the less than satisfactory condition of the type and only museum s ... | 2002 | 12053949 |
| [species richness and diversity of a fish community in a temporal water body at caño negro national wildlife refuge, costa rica]. | we evaluated fish community, species richness and diversity in a temporal water body of rio frio, caño negro national wildlife refuge. these evaluations were done for three categories of water levels: low (below 1.5 m), intermediate (between 1.5 and 3.0 m) and high (deeper than 3 m). a total of 10,264 individuals were collected (nine families, 18 genera and 21 species). the most abundant species were poecilia gillii (37%) and astyanax aeneus (19%) and the least abundant were ophisternon aenigmat ... | 2006 | 18494329 |
| dactylogyrids (monogenoidea) parasitizing the gills of astyanax spp. (characidae) from panama and southeast mexico, a new species of diaphorocleidus and a proposal for characithecium n. gen. | diaphorocleidus orthodusus n. sp. and diaphorocleidus kabatai (molnar, hanek and fernando, 1974) jogunoori, kritsky, and venkatanarasaiah, 2004 are detailed from astyanax orthodus and astyanax aeneus, respectively. palombitrema heteroancistrium (price and bussing, 1968) is described from specimens collected from a. aeneus, and urocleidoides strombicirrus (price and bussing, 1967) is reported for the first time from a. aeneus and astyanax fasciatus in panama. characithecium costaricensis (price a ... | 2009 | 19245277 |
| [rapid ecological assessment of tropical fish communities in a gold mine area of costa rica]. | gold mining impacts have generated a great concern regarding aquatic systems and habitat fragmentation. anthropogenic disturbances on the structure and heterogeneity of a system can have an important effect on aquatic community stability. ecological rapid assessments (1996, 2002, and 2007) were employed to determine the structure, composition and distribution of tropical fish communities in several rivers and smaller creeks from a gold mining area in cerro crucitas, costa rica. in addition, spec ... | 2008 | 19419095 |
| helminths and lipid peroxidation in astyanax aeneus (pisces: characidae) from a river in the humid subtropics of southeastern mexico. | xenobiotic mixtures in aquatic ecosystems may compromise fish health by inducing oxidative stress, decreasing resistance, and fostering susceptibility to pathogens such as helminths. lipid peroxidation (lpo) is one of the most commonly used methods to evaluate oxidative stress. the present study examines the potential correlations between lpo in liver, muscle, and gill and the presence of helminths in astyanax aeneus from a subtropical river in mexico. five helminth species were identified: the ... | 2010 | 20377011 |
| an index of biotic integrity for shallow streams of the hondo river basin, yucatan peninsula. | an index of biotic integrity (ibi) is proposed, based on the fish communities and populations in streams of the hondo river basin, mexico-belize. freshwater environments in this area are threatened by exotic fishes, eutrophication, and pesticide pollution, among other problems. this ibi should allow to identify the most vulnerable sites and eventually guide rehabilitation efforts. data on composition, structure, and function of fish communities were evaluated. twenty-three sites in the mexican p ... | 2010 | 21146199 |
| use of cholinesterase activity as a biomarker of pesticide exposure used on costa rican banana plantations in the native tropical fish astyanax aeneus (günther, 1860). | in costa rica, thousands of tones of agricultural pesticides have been used for decades and their use is continuously increasing due to intensive and expanding production of coffee, pineapple, rice, ornamental plants and bananas. the objective of this study was to evaluate whether choline esterase (che) activity could be used as a biomarker of exposure to pesticides in the costa rican native fish astyanax aeneus (characidae). three methods used in order to evaluate the che biomarker were as foll ... | 2014 | 24579519 |
| spot the difference: two cryptic species of gyrodactylus von nordmann, 1832 (platyhelminthes: monogenea) infecting astyanax aeneus (actinopterygii, characidae) in mexico. | over the course of one year, undescribed specimens of gyrodactylus were recovered from banded tetra, astyanax aeneus collected in the la antigua and nautla river basins in central veracruz, mexico. parasites were processed for morphometric and molecular analyses. morphometrically, gyrodactylus samples collected in the la antigua river had slightly smaller haptoral structures than those collected from the nautla river. during the 12month-collection of samples, however, water temperature varied co ... | 2016 | 27208885 |
| assessing the health condition profile in the freshwater fish astyanax aeneus in champoton river, mexico. | the use of biomarkers for monitoring aquatic environmental quality has gained considerable interest worldwide. the effects of the environmental conditions of río champotón, méxico, in the hotspot of mesoamerica, were assessed in astyanax aeneus, a native fish of the tropics of southwestern méxico. pollution from agrochemical residues is a major problem in río champotón. three study sites along the freshwater portion of the river were monitored in april, july, and november 2007 and february 2008. ... | 2014 | 24579529 |
| morphometric variation between two morphotypes within the astyanax baird and girard, 1854 (actinopterygii: characidae) genus, from a mexican tropical lake. | phenotypic variation is important for evolutionary processes because it can allow local adaptation, promote genetic segregation, and ultimately give rise to speciation. lacustrine systems provide a unique opportunity to study the mechanisms by which sister species can co-occur by means of ecological segregation. the fish genus astyanax is characterized by high levels of phenotypic variability, providing an excellent model for the study of local specialization. here, we analyze the morphological ... | 2014 | 24470053 |
| reproductive traits and population structure of astyanax aeneus (characiformes: characidae) from a subtropical river in mexico. | champotón river is an unknown area within the mesoamerican hotspot in southestern méxico. reproductive traits and population structure of astyanax aeneus were analyzed along an environmental gradient of the upper, middle and lower sections of the river, where diverse environmental factors were recorded. for this, nets were cast for 1 h at each site and a. aeneus were collected from all sections with sweep nets (5 and 10 m long by 5 m deep, 0.03m mesh size) and a casting net (0.05m mesh size). at ... | 2013 | 23885588 |
| new species of cacatuocotyle (monogenoidea, dactylogyridae) parasitizing the anus and the gill lamellae of astyanax aeneus (pisces, ostariophysi: characidae) from the rio lacantún basin in the biosphere reserve of montes azules, chiapas, mexico. | as part of a biological inventory of the rio lacantún basin in the biosphere reserve of montes azules from chiapas state (southeastern, mexico), the following monogenoid ectoparasites infecting the external surface of the anal opening and the gill lamellae of the freshwater fish astyanax aeneus (characidae) in ten streams were found: cacatuocotyle chajuli sp. nov. (anus), cacatuocotyle exiguum sp. nov., and cacatuocotyle sp. (gill lamellae). c. chajuli is differentiated from its single congener, ... | 2013 | 23052760 |
| [ichthyofauna from wetlands of san pedro, balancán, tabasco, méxico]. | san pedro river's wetlands sustain trophic nets in the fluvial system, due to the high habitat availability, and space and temporal variations. in order to describe the relationship between environmental parameters and ichthyofauna, this study evaluated fish assemblages composition, distribution, abundance, density, biomass, richness species, diversity and equitability in the wetlands. sampling considered three different sites and climatic seasons (dry, rainy and cold fronts). the physical and c ... | 2011 | 21721234 |
| role of the fish astyanax aeneus (characidae) as a keystone nutrient recycler in low-nutrient neotropical streams. | nutrient recycling by animals is a potentially important biogeochemical process in both terrestrial and aquatic ecosystems. stoichiometric traits of individual species may result in some taxa playing disproportionately important roles in the recycling of nutrients relative to their biomass, acting as keystone nutrient recyclers. we examined factors controlling the relative contribution of 12 neotropical fish species to nutrient recycling in four streams spanning a range of phosphorus (p) levels. ... | 2011 | 21618918 |
| astyanax cocibolca, a new characid (pisces: ostariophysi) from lake nicaragua, central america. | astyanax cocibolca, a small filter-feeding species is a new characid species endemic to lake nicaragua. it is distinguished from the syntopic astyanax aeneus by its high gill raker count, slender body, upturned snout, long maxillary bones, conical outer premaxillary teeth, lower number of scales above lateral line, more intense black lateral band, smaller size, and trophic niche partitioning. at present the new species utilizes the open-water habitat at least as a nursery where young can feed on ... | 2008 | 19419049 |