Acoustic intensity discrimination by the cichlid fish Astronotus ocellatus (Cuvier)

1993 ◽  
Vol 173 (3) ◽  
pp. 347-351 ◽  
Author(s):  
H.Y. Yan ◽  
A.N. Popper
Keyword(s):  
Cichlid Fish ◽  
Intensity Discrimination ◽  
Acoustic Intensity ◽  
Astronotus Ocellatus

Genomic organization of repetitive DNAs in the cichlid fish Astronotus ocellatus

Genetica ◽  
2008 ◽  
Vol 136 (3) ◽  
pp. 461-469 ◽  
Author(s):  
Juliana Mazzuchelli ◽  
Cesar Martins
Keyword(s):  
Genomic Organization ◽  
Cichlid Fish ◽  
Repetitive Dnas ◽  
Astronotus 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.

scholarly journals Selectivity in regeneration of the oculomotor nerve in the cichlid fish, Astronotus ocellatus

Development ◽  
1965 ◽  
Vol 14 (3) ◽  
pp. 307-317
Author(s):  
R. W. Sperry ◽  
H. L. Arora
Keyword(s):  
Skeletal Muscle ◽  
Cichlid Fish ◽  
General Rule ◽  
Nerve Fibers ◽  
Oculomotor Nerve ◽  
General Validity ◽  
Peripheral Innervation ◽  
Wide Range ◽  
Astronotus Ocellatus ◽  
Regenerating Nerve

It has long been considered a general rule for nerve regeneration that the reinnervation of skeletal muscle is nonselective. Regenerating nerve fibers are supposed to reconnect with one skeletal muscle as readily as another according to studies covering a wide range of vertebrates (Weiss, 1937; Weiss & Taylor, 1944; Weiss & Hoag, 1946; Bernstein & Guth, 1961; Guth, 1961, 1962, 1963). Similarly, in embryogenesis proper functional connexions between nerve centers and particular muscles are supposedly attained, not by selective nerve outgrowth but rather through a process of ‘myotypic modulation’ (Weiss, 1955) that presupposes nonselective peripheral innervation. Doubt about the general validity of this rule and the concepts behind it has come from a series of studies on regeneration of the oculomotor nerve in teleosts, urodeles, and anurans and of spinal fin nerves in teleosts (Sperry, 1946, 1947, 1950, 1965; Sperry & Deupree, 1956; Arora & Sperry, 1957a, 1964).

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