Hemichromis bimaculatus es una especie de peces de la familia Cichlidae en el orden de los Perciformes. El cuerpo es alargado y comprimido en los lados, presentando igual curvatura en los partes superior e inferior. Las aletas dorsal y anal son alargadas y prolongadas en punta. El borde de la aleta dorsal y borde superior de la aleta caudal son de color rojo brillante.
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Directory of Open Access Journals Sweden. The paleoenvironment of the Lumbrera Formation is interpreted as a perennial lake deposited under temperate climatic conditions during the early to middle Eocene. Its fossil content is made up of palynomorphs, insects, crocodiles, turtles, lizards, and mammals, besides an ichthyofauna formed by cichlids, poeciliids and dipnoans. This species was recovered most closely related to Australoheros and to the deep-bodied South American heroins.
The occurrence of an Eocene Heroini , as well as of other cichlid lineages in the same stratigraphical level, is evidence of an ancient diversification in this family. This ancient age supports the hypothesis that the Cichlidae originated on Gondwana. Aim: We present a molecular phylogenetic and biogeographical analysis of the Mesoamerican cichlid fishes Cichlidae : Cichlasomatinae: Heroini , a dominant part of the freshwater biodiversity of the region.
Based on these analyses we investigate the spatial and temporal origins and diversification of the group. Location: Mesoamerica. Methods: Model-based phylogenetic methods MrBayes using seven molecular markers with a virtually complete species-level taxon sampling, together with the Bayesi Organogenesis of the digestive system of the fish Pterophylum scalare Perciformes : Cichlidae. There is little knowledge on the development of the angelfish Pterophyllum scalare Liechtenstein , a species of economical and biological value for inland water ecosystems.
We recorded net development time of each organogenetic stage, cumulative time and characteristic structure differentiation for each stage. We found eight organogenetic stages for the digestive system, between the gastrula and the total re-adsorption of the vitelin sack. The total time for the organogenetic development of the digestive system was hours and 44 minutes. Epub December Estructura y la ultraestructura del ovario de Cichlasoma urophthalmus Perciformes : Cichlidae.
Se realizaron cortes finos y semifinos contrastados con citrato de plomo y acetato de uranilo. Los ovarios de C. Structure and ultrastructure of the ovary of Cichlasoma urophthalmus Osteichthyes: Cichlidae. The study of the normal development, differentiation, structure and function of various components of developing follicles in the ovaries of numerous fish species have been a consistent focus of comparative reproduction.
The structural and ultrastructural features of gonads from Cichlasoma urophthalmus have received scarce attention. In this work, we realized a descriptive study of female gonads of Cichlasoma urophthalmus. A total of 40 samples were collected in the Veracruz Alvarado Lagoon, Mexico in period including the. Se reporta, por primera vez, la presencia de dos especies de moluscos en Costa Rica.
Se identificaron siete morfotipos de cercarias parasitando las cinco especies de moluscos encontradas. En el presente trabajo se reporta por primera vez Centrocestus formosanus en Costa Rica.
Centrocestus formosanus Opisthorchiida: Heterophyidae as a cause of death in gray tilapia fry Oreochromis niloticus Perciforme : Cichlidae in the dry Pacific of Costa Rica. Centrocestus formosanus is a zoonotic trematode from Asia and has been mainly associated as cause of death of cultured fish. To identify pathogen trematode species in tilapia fry Oreochromis niloticus and to determine mollusks hosting these parasites, freshwater mollusks were collected from tilapia cultured ponds and experimental infections were carried out with tilapia fries and.
It belongs to the subtropical moist forest warm life zone, and has very important flora and fauna diversities. Among the fish species, the white fish Petenia splendida is of high commercial value. Les relations de C. The interaction between the fish Oreochromis mossambicus Percifomes: Cichlidae and aquatic insects after application of chicken, cow, and pig manure was studied in 7,liter plastic aquadams.
Principal component analysis showed that most of the variation in water quality after application of manure was accounted for by potassium, nitrogen, dissolved oxygen, phosphate, and alkalinity.
Canonical correspondence analysis showed that Gyrinidae, Elminidae, Hydrophilidae, Hydraenidae, and Athericidae were associated with high nutrient levels nitrogen, phosphorus, and potassium characteristic of the chicken manure. However, the most abundant aquatic insects Gerridae, Notonectidae, and Culicidae were close to the centre of the ordination and not defined by any nutrient gradient.
The Shannon-Wiener diversity was highest in the aquadams treated with chicken manure. The most frequently occurring aquatic insects in the diet of O. However, in the laboratory, Chironomidae were the most preferred because they lacked refuge. Notonectidae and Gerridae were not recorded in the diet of O. This may be because of their anti-predation strategies. Laboratory experiments showed that Notonectidae, Gyrinidae, and Gerridae fed on Chironomidae and Culicidae.
This implies that aquatic predatory insects competed for food with O. All rights reserved. For Permissions, please email: journals. Full Text Available La edad y crecimiento de la tilapia Oreochromis niloticus x Oreochromis aureus fueron determinados por medio de la lectura de escamas.
Un total de individuos fueron capturados mediante el uso de redes agalleras y atarrayas. Le, el peso total en g Pt y se obtuvieron muestras de escamas para registrar el largo de la escama en mm.
Las tallas y pesos de recolecta variaron entre 38 a mm Le y de 8. Studies on age and growth in fishes are essential to establish models on population dynamics. The previos issues were determined in this study by scale growth analyses. Between September and May , organisms were captured using gill and atarraya nets.
Eight samples were developed every. Early development in the mouth-brooding cichlid fish Satanoperca pappaterra Perciformes : Cichlidae. Full Text Available The Neotropical region exhibits the largest diversity of fish worldwide; however, little is known about the early development of fish species from this region.
Therefore, to contribute to this knowledge, this study aimed to morphologically describe the early stages of development eggs, larvae and juveniles of S. After the adults were identified, the offspring were classified according to its stage embryonic, larval or juvenile period, and various morphometric and meristic variables were individually measured when possible.
The eggs of this species are yellow in color, oval shaped, show dendritic pigmentation within their yolk, have small to moderately sized perivitelline spaces and lack a mucous membrane and oil droplets. The horizontal and vertical diameters of the sample yolks ranged from 1. The standard length of the larval period varied from 4. Larvae exhibit yolk sacs with internal dendritic pigmentation and dark punctate pigmentation in the dorsal and ventral body regions, whereas irregular transverse spots along the flanks are observed during the juvenile period.
Adhesive organs are only present during the yolk-sac stage and at the beginning of the flexion stage. The mouth is terminal during all stages of development. Growth analyses identified periods of important change in larval morphology i. Therefore, the morphological development of S. Epub March Ecology and life history of an Amazon floodplain cichlid: the discus fish Symphysodon Perciformes : Cichlidae.
Full Text Available The discus fishes of the genus Symphysodon are popular ornamental cichlids that occur in floodplain lakes and flooded forests of the lowland Amazon Basin.
These habitats are characterized by extreme seasonal fluctuations in the availability of food, shelter and dissolved oxygen, and also the densities of predators and parasites. Most aspects of discus biology are influenced by these fluctuating conditions.
This paper reports an autoecological study of the western Amazonian discus S. This species feeds predominantly on algal periphyton, fine organic detritus, plant matter, and small aquatic invertebrates.
At high water it forages alone or in small groups in flooded forests. At low water it forms large aggregations in fallen tree crowns along lake margins. Breeding occurs at the beginning of the flood season, ensuring that the progeny are well grown before the next low water period. Symphysodon haraldi is an iteroparous partial spawner, reaches reproductive maturity within a year, and undertakes parental care of its eggs and larvae. Threatened fishes of the world: Coptodon walteri Thys van den Audenaerde Perciformes : Cichlidae.
Full Text Available Coptodon walteri Thys van den Audenaerde , an endemic cichlid of Ivory Coast and Liberia, is assessed as Near Threatened due to fishing pressure and loss of habitats, and aquatic pollution as a result of extensive clandestine gold mining in the bed of the Cavally River.
There is an immediate need for developing conservation and management plans for this species. Full Text Available There are emissions of mercury to the atmosphere, soil and rivers of the Brazilian Amazon stem from many sources.
Once in the atmosphere, the metal is oxidized and immediately deposited. In the water, the transformation to methylmercury takes place mostly by the action of microorganisms. The formation of methylmercury increases the dispersion and bioavailability of the element in the aquatic environment.
Methylmercury can be assimilated by plankton and enters the food chain. The concentration of mercury increases further up in the trophic levels of the chain and reaches the highest values in carnivorous fishes like tucunare. Therefore, mercury emissions cause the contamination of natural resources and increase risks to the health of regular fish consumers.
The objective of this work was to study the bioaccumulation of mercury in tucunares Cichla sp. One location is near a former informal gold mining area. The other is far from the mining area and is considered pristine. Average values of total mercury concentration and accumulation rates for four different collection groups were compared and discussed. Tucunares collected in presented higher mercury contents and accumulated mercury faster than tucunares collected in notwithstanding the decline of mining activities in this period.
The aggravation of the mercury contamination with time not only in an area where informal gold mining was practiced but also far from this area is confirmed. Full Text Available This study aimed to estimate age and growth of the peacock bass Cichla temensis from the rio Negro Brazilian Amazonia by analyzing scale annuli.
Specimens were captured between October and September in the main channel of the river and in adjacent lakes in the municipality of Barcelos, AM, Brazil. Six growth checks were identified on the scales of specimens.
The annual variation in body condition observed suggests that fat is accumulated during the dry season. Results for the GSI gonadosomatic index showed that peak reproduction occurred in the receding-water period, indicating that the fish had energy deficiencies as a result of reproductive activity. RMI relative marginal increment analysis revealed that an annulus is formed once a year during the receding-water period.
Crab And Lobster
Vampire crab. Crab And Lobster. Hermit Crabs. Weird And Wonderful. Naturally Beautiful. Picture of the Geosesarma dennerle vampire crab with purple claws.
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