Induced reproduction and early development histology of Oscar Astronotus ocellatus (Agassiz, 1831)

Zygote ◽  
2013 ◽  
Vol 23 (2) ◽  
pp. 237-246 ◽  
Author(s):  
Maria do Carmo Faria Paes ◽  
Lilian Cristina Makino ◽  
Leonardo Avendaño Vasquez ◽  
João Batista Kochenborger Fernandes ◽  
Fernanda Nogueira Valentin ◽  
...  
Keyword(s):  
Larval Development ◽  
Amazon Basin ◽  
Fish Farming ◽  
Otic Vesicle ◽  
Human Consumption ◽  
Average Temperature ◽  
Astronotus Ocellatus ◽  
Hormonal Action ◽  
Newly Hatched Larvae ◽  
Egg Diameter

SummaryOscar (Astronotus ocellatus) is an important fish from the Amazon Basin that has great potential for fish farming, human consumption, sport fishing and fish keeping. This study aimed to evaluate the effect of two hormonal treatments on the induction of artificial reproduction in broodstock and to describe the histological development of embryos and larvae. Broodstocks were selected and induced using two different hormones: (i) extract of carp pituitary (ECP); and (ii) synthetic human chorionic gonadotropin (hCG). Spawnings were transferred to hatcheries, collected at pre-established times, processed and analysed by histology. Astronotus ocellatus did not respond well to induced reproduction. From 16 couples of breeding fish, only five out of the eight females released oocytes after the hormonal action time, three with hCG and two with ECP; just one male responded positively to hCG. Oscar eggs were oval, and semi-adhesive, the yolk contained granules, and egg diameter was approximately 1.65 ± 0.057 to 1.98 ± 0.038 mm. Development from the initial collection (IC) point until the total absorption of the yolk lasted 315 h, at an average temperature of 27.45 ± 2.13°C. Several events marked embryonic and larval development, including the formation of the optic cup, forebrain, otic vesicle and cephalic divisions. The newly hatched larvae had non-pigmented eyes, and a closed mouth and anus, as well as the presence of adhesive glands on the head. Larval development was characterized by formation of the heart, liver, gaseous bladder, gills, pronephros, brain, fins and also the digestive tract. These results provide important information for the rearing and reproduction of A. ocellatus.

scholarly journals Early development of Astronotus ocellatus under stereomicroscopy and scanning electron microscopy

Zygote ◽  
2011 ◽  
Vol 20 (3) ◽  
pp. 269-276 ◽  
Author(s):  
Maria do Carmo Faria Paes ◽  
Lilian Cristina Makino ◽  
Leonardo Avendaño Vasquez ◽  
João Batista Kochenborger Fernandes ◽  
Laura Satiko Okada Nakaghi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Amazon Basin ◽  
Cichlid Fish ◽  
Fish Farming ◽  
Average Temperature ◽  
Astronotus Ocellatus ◽  
Yolk Absorption ◽  
Otic Vesicles ◽  
Scanning Electron

SummaryAstronotus ocellatus, popularly known as Oscar, is a cichlid fish from the Amazon basin (Brazil) with a great potential for fish farming. The aim of this research is to describe the morphology of eggs and larvae of A. ocellatus under stereomicroscopy and scanning electron microscopy. Eggs from natural spawnings were taken to hatcheries, collected at previously established time periods and then analysed. Oscar's eggs are demersal, adhesive and fragile to touch, with a slightly oval shape. The fertile eggs are yellowish in colour and when unfertilized are a white opaque colour. In the initial collection (IC), the majority of eggs were found to be at the gastrula phase with 30% epiboly. At 12 h after the IC, the formation of the embrionary axis and somites was observed, followed by differentiation of the tail and of the head. Fifteen hours after the IC, the emergence of the optic and otic vesicles, and of adhesive glands and the yolk pigmentation was observed. Larval hatching took place between 46 and 58 h after the first collection, at an average temperature of 27.45 ± 2.13°C. The larval stage was characterized by the development of the heart, fins, branchial apparatus, neuromasts, taste buds and adhesive glands on the head. Larval development to yolk absorption took a period of 257 h. These results provide important information for reproduction, rearing and preservation of A. ocellatus.

Public health implications of waste water reuse for fish production

1995 ◽  
Vol 32 (11) ◽  
pp. 145-152 ◽  
Author(s):  
M. El-S. Easa ◽  
M. M. Shereif ◽  
A. I. Shaaban ◽  
K. H. Mancy
Keyword(s):  
Public Health ◽  
Waste Water ◽  
Water Reuse ◽  
Monitoring Program ◽  
Health And Safety ◽  
Fish Farming ◽  
Human Consumption ◽  
Fresh Water Fish ◽  
Adverse Health Effects ◽  
Treated Effluent

Public health and safety concerns have traditionally been the main reasons for resisting waste water reuse for fish farming. Potential adverse health effects in such applications could be avoided if the waste is sufficiently treated before reuse. In a full scale demonstration study in Suez, Egypt, about 400 m3/d of raw sewage were treated using a multi-compartment stabilization pond system, for a total residence time from 21-26 days. The treated effluent conformed to WHO guidelines and was used for rearing two types of local fish (tilapia and gray mullet). The produced fish were subjected to an extensive monitoring program. Bacteriological examination revealed that in all samples the fish muscles were free of bacterial contaminants. Nevertheless, low levels of Escherichia coli andAeromonas hydrophila, were isolated from the surface of the fish. Salmonellae, shigellae and staphylococcus aureus were absent from the surface of all the fish sampled. In addition, toxic metals (Pb, Cu, Zn, and Cd) were found to be at much lower levels than the international advisory limits for human consumption. It is concluded that fish reared in the treated effluent at Suez Experimental Station is (a) suitable for marketing for human consumption, and (b) it's quality is equal or better than fresh water fish in Egypt.

scholarly journals Reproductive performance of female Nile tilapia Oreochromis niloticus L. in South Kivu (DR Congo): comparison of two strains differing in origin and history of domestication

2019 ◽  
Vol 7 (08) ◽  
Author(s):  
Nihoreye, F.J. ◽  
Nyongombe, U.N. ◽  
Alunga, L.G. ◽  
Akonkwa, B.D. ◽  
Isumbisho, M.P. ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Oreochromis Niloticus ◽  
Sexual Maturity ◽  
Democratic Republic Of Congo ◽  
Local Strain ◽  
Fish Farming ◽  
Nile Tilapia Oreochromis Niloticus ◽  
History Of ◽  
South Kivu ◽  
Egg Diameter

This study was conducted to evaluate the reproductive performance of females of Oreochromis niloticus originating from a strain of distant origin and extensively exploited in fish farming (Nyakabera strain) and a local strain recently removed from the natural environment (Lac Kivu strain). The experiment was carried out in triplicate with fry of 4.9 to 6.3 g placed in earthen ponds for a period of 6 months, at the Nyakabera fish station in South Kivu, Democratic Republic of Congo. The comparison of the two strains focused on the size of the first sexual maturity, gonado-somatic ratio, fecundity, egg diameter and condition factor. The results showed that under similar managed rearing conditions, the Nyakabera strain reaches sexual maturity earlier and is characterized by a higher gonado-somatic ratio and higher relative fertility, but a worse condition compared to the Lac Kivu strain. These differences, which indicate a better reproductive success of the Nyakabera strain, are related to the origin and the history of domestication, which are just as different from these two strains.

scholarly journals Identifying Problems in Watering Ponds with Different Purposes

Environments ◽  
2020 ◽  
Vol 7 (9) ◽  
pp. 63
Author(s):  
Manuel Pulido ◽  
Alberto Alfonso-Torreño ◽  
Jesús Barrena-González ◽  
Rafael Robina-Ramírez ◽  
Mohamed Amine Abdennour
Keyword(s):  
Fish Farming ◽  
High Water ◽  
Water Shortage ◽  
Quality Parameters ◽  
Mitigation Strategies ◽  
Fecal Coliforms ◽  
Human Consumption ◽  
Subtropical Climate ◽  
Livestock Farming ◽  
Azolla Filiculoides

The main goal of this study was to identify the problems that are putting the viability of watering ponds at risk. For doing that, we have analyzed five different study cases: (I) livestock consumption, Mediterranean climate (rangelands of SW Spain), (II) multifunctional ponds (Arroyo de la Luz, Spain), (III) ecotourism (Valdepajares de Tajo, Spain), (IV) crop irrigation and fish farming, semi-arid climate (the wilaya of Ouargla, Algeria), and (V) livestock consumption, humid subtropical climate (Prudentópolis, Brazil). The identification of problems was made through surveys, personal interviews, local knowledge and literature review as well as through the analysis of water quality parameters such as the concentration of phosphates and fecal coliforms in some ponds. We have identified problems of water shortage (ca. 50% of rangeland farmers), pollution induced by agriculture (maximum values of phosphates = 1.33 mg L−1) and livestock farming (maximum value of fecal coliforms ≈ 7000 cfu mL−1), low potability for human consumption (score: 2.8/7.0), invasive species such as Azolla filiculoides (10 out of 17 watering ponds), high water temperature for aquaculture in summer (Algeria) and the increase of turbidity in nearby water courses due to the actions of free-fattening pigs (Brazil), among many other problems. We conclude an extra effort by stakeholders is still needed in order to agree mitigation strategies.

An individual-based analysis of the variability of eggs and their newly hatched larvae of Atlantic cod (Gadus morhua) on the Scotian Shelf

1995 ◽  
Vol 52 (5) ◽  
pp. 1083-1093 ◽  
Author(s):  
Thomas J. Miller ◽  
Tomasz Herra ◽  
William C. Leggett
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Seasonal Pattern ◽  
Size Variation ◽  
Seasonal Temperature ◽  
Scotian Shelf ◽  
Larval Size ◽  
Newly Hatched Larvae ◽  
Shelf Region ◽  
Egg Diameter

We assessed the seasonal pattern of size variation in cod eggs on the Scotian Shelf region of the Northwest Atlantic during the period March 1991–May 1993. Cod eggs were present from October to May during the surveys. Spawning was not strongly bimodal. There was a dominant autumn peak, in contrast to the historically dominant spring spawning. Egg diameter varied seasonally. Seasonal temperature patterns explained 52% of the variation in egg diameter. By incubating the eggs on-board ship, we also assessed the seasonality of the standard length (SL) of larvae that hatched from these eggs. Larval SL also varied seasonally. Egg diameter and SL were significantly correlated, but the correlation was weak (r2 = 0.3). However, the strength of correlation was consistent with laboratory estimates based on individual data. The results suggest that previous estimates of the egg size – larval size correlations are inflated. Temperature exerted a significant effect on both egg diameter and larval size, and is hypothesized to be the agent responsible for the observed seasonal variation.

scholarly journals Phenylalanine Hydroxylase RNAi Knockdown Negatively Affects Larval Development, Molting and Swimming Performance of Salmon Lice

2020 ◽  
Vol 7 ◽  
Author(s):  
Prashanna Guragain ◽  
Bjørnar Sporsheim ◽  
Astrid Skjesol ◽  
Anna Solvang Båtnes ◽  
Yngvar Olsen ◽  
...  
Keyword(s):  
Larval Development ◽  
Developmental Stages ◽  
Phenylalanine Hydroxylase ◽  
Swimming Performance ◽  
Expression Patterns ◽  
Fish Farming ◽  
Economic Losses ◽  
Larval Stages ◽  
Salmon Lice ◽  
Morphological Defects

Phenylalanine hydroxylase (PAH) is a crucial enzyme involved in tyrosine biosynthesis, having roles in neurological and physiological processes. The purpose of PAH has received little attention in crustaceans despite extensive investigations in other arthropods. Here, we characterize the PAH gene for the first time in the parasite Lepeophtheirus salmonis, a copepod that is responsible for huge economic losses in salmonid fish farming. Phylogenetic and sequence analyses confirmed that LsPAH is closely related to the metazoan PAH with conserved ACT regulatory and catalytic domains. Temporal expression patterns revealed that LsPAH is expressed throughout all developmental stages peaking during the copepodite stages, suggesting an essential role in developmental physiology. We used RNAi to knockdown LsPAH expression in the nauplius I stage to study developmental function during the larval stages. PAH knockdown impaired larval development, molting and swimming ability with severe morphological defects. This study provides insight into the role of PAH in copepods and demonstrates the importance of this metabolic gene in salmon louse growth and development.

scholarly journals Structural and ultrastructural description of larval development in Zungaro jahu

Zygote ◽  
2017 ◽  
Vol 25 (2) ◽  
pp. 149-159 ◽  
Author(s):  
Camila Marques ◽  
Francine Faustino ◽  
Bruno Bertolucci ◽  
Maria do Carmo Faria Paes ◽  
Fernanda Nogueira Valentin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Larval Development ◽  
Sensory System ◽  
Mouth Opening ◽  
Habitat Destruction ◽  
Swim Bladder ◽  
Energy Reserves ◽  
Yolk Absorption ◽  
Newly Hatched Larvae ◽  
Scanning Electron

SummaryThe Zungaro jahu is an important large catfish of the order Siluriformes that is in danger of extinction due to habitat destruction. Studies on its biology are scarce and the majority relates only to nutrition or parasitology. In order to provide greater information on its morphology and aid husbandry and larviculture studies, the aim of this study was to characterize larval development in Z. jahu from hatching to total yolk absorption. Samples were collected at pre-established times, processed, stained, and analyzed under stereomicroscopy, light microscopy, and scanning electron microscopy. Total yolk absorption was observed by 60 hours post-hatching (hph) at 28.75 ± 0.59°C. The newly hatched larvae showed slightly pigmented body, the outline of the digestive tract, evident eyes, and the first swimming movements. Mouth opening took place at 12 hph and the connection between the oral cavity and the rudimentary intestine was observed at 24 hph. Were analyzed the main larval organs and systems: digestive organs, heart, gill arches, sensory system, thyroid, kidney, and swim bladder. As the larvae grew, these organs became more mature and functional. The development of the sensory and feeding structures was observed at the start of larval development, and thus before depletion of endogenous energy reserves, the strategy for this species is to increase its chances of survival in the environment.

embryonic and larval development of the malabar grouper, epinephelus malabaricus (pisces: serranidae)

2005 ◽  
Vol 85 (5) ◽  
pp. 1249-1254 ◽  
Author(s):  
ming-yih leu ◽  
chyng-hwa liou ◽  
lee-shing fang
Keyword(s):  
Larval Development ◽  
Larval Habitat ◽  
The Body ◽  
Tank Bottom ◽  
Newly Hatched Larvae ◽  
First Time ◽  
Embryonic And Larval Development ◽  
H 30 ◽  
Epinephelus Malabaricus ◽  
Pelvic Fin

the embryonic and larval development of epinephelus malabaricus are described and illustrated for the first time. fertilized eggs, with a mean diameter of 0.90±0.02 mm and a range from 0.87 to 0.93 mm, were spherical, transparent, buoyant and unpigmented. embryonic development lasted 26 h 30 min at 25.5°c. newly hatched larvae were 1.93±0.04 mm in total length (tl) with 26 (11+15) myomeres and had an oil globule in the ventroposterior area of the yolk sac. three days after hatching (2.76 mm tl), the mouth opened. early larvae had two clusters of well-developed melanophores appearing on the alimentary canal and at the caudal region of the body, and the appearance of xanthophores on the dorsal finfold. nine days after hatching (4.04 mm tl), the buds of the second dorsal and pelvic fin spines had appeared. at 5.41 mm tl, the notochord was slightly flexed, and the hypural bones and caudal fin rays had begun to develop. at 7.39 mm tl, the ratios of the second dorsal and pelvic-fin spine lengths to tl attained their maximums, 52.68% and 48.62%, respectively. at 20.19 mm tl, all fins had the adult complement of rays and spines. by 30.18 mm tl, the body had become red, with five irregular, oblique, dark brown bars visible on the body. the larval habitat shifted from the surface and middle layers to the tank bottom.

Aspects of the Biology of Pseudocarcinonemertes homari and Its Association with the American Lobster, Homarus americanus

1985 ◽  
Vol 42 (2) ◽  
pp. 351-356 ◽  
Author(s):  
D. E. Aiken ◽  
S. L. Waddy ◽  
L S. Uhazy
Keyword(s):  
Larval Development ◽  
Homarus Americanus ◽  
Egg Mass ◽  
American Lobster ◽  
Free Swimming ◽  
European Lobster ◽  
Newly Hatched Larvae

Pseudocarcinonemertes homari can reproduce on and destroy the egg mass of both the American (Homarus americanus) and the European lobster (H. gammarus) but does not appear to be a problem for brachyuran species. The eggs of P. homari are subspherical, average 251 × 260 μm, and are contained in individual compartments in a membranous brood sac that is attached to the lobster abdomen or egg mass. An average of 39 eggs occur in a brood sac. Newly hatched larvae are ciliated, lack anterior and posterior tufts, cirri or flagella, and are retained in the brood sac. Larval development is direct, and there is no free-swimming stage. After the larvae break out of the brood sac they join the adults and juveniles on the lobster egg mass. Many lobsters gradually remove infested eggs, but on those that do not, the nemertean population can increase to more than 14 000 individuals. After the lobster eggs are destroyed, the nemerteans disperse. Some form mucoid aggregations at protected sites on the exoskeleton; others move to the branchial chamber and gills or transfer to other lobsters. Reproduction occurs almost exclusively on the lobster egg mass, but P. homari appears capable of reproducing on lobster gills if denied access to lobster eggs for extended periods.

scholarly journals Forest Diversity and Structure in the Amazonian Mountain Ranges of Southeastern Ecuador

Diversity ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 196 ◽  
Author(s):  
Wilson Quizhpe ◽  
Ángel Benítez ◽  
Klever Cuenca ◽  
Hernán Uvidia ◽  
Isau Huamantupa ◽  
...  
Keyword(s):  
Amazon Basin ◽  
Annual Rainfall ◽  
Permanent Plots ◽  
Scaling Analysis ◽  
Terra Firme ◽  
Forest Diversity ◽  
Mountain Ranges ◽  
Average Temperature ◽  
Diameter Structure ◽  
Amazonian Forests

We analyze the structure of diameter, richness, and diversity of the forests in the upper limit of the great Amazon basin located in the Ecuadorian territory of the Cordilleras del Cóndor and Cutucú. Our hypothesis was that the forests of the eastern mountain ranges are not homogeneous, but rather present differences in their structure, richness, and floristic diversity. Our main objective was to classify the types of forests based on the characteristics of the diameter structure and the species composition of the Amazonian forests of the eastern mountain ranges in southern Ecuador, and we determined the influence of critical edaphic, environmental, and geomorphological factors, For this we installed eight permanent plots of one hectare in homogeneous and well preserved forest stands, four plots in the province of Zamora Chinchipe and four in the province of Morona Santiago. We identified and measured all trees >10 cm at chest height and for each plot, soil samples, as well as environmental and slope data were taken. We performed an non-metric multidimensional scaling analysis (NMDS) analysis to evaluate changes in climatic and geomorphological gradients, and used the CCA analysis to assess the relationship between the composition of the species at the plot level and the edapho-climatic variables. Finally, we modeled the change in diversity ad species (Fisher’s alpha) in relation to climatic, altitudinal, and geomorphological gradients using a GLM. We determined the existence of two different types of forest, the first called Terra Firme, characterized by the presence of a greater number of species and individuals per plot as compared to the second type of forest called Tepuy or Sandstone forest. Species richness was negatively correlated with the phosphorus content of the soil and the pH, annual average temperature, annual rainfall, and altitude. Terra Firme forests, settled in more stable and nutrient-rich climatic areas, were more diverse and Sandstone forests are poor in nutrients and develop in areas with greater seasonality.

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