First results of larval rearing and development of the bluestriped angelfishChaetodontoplus septentrionalis(Temminck & Schlegel) from hatching through juvenile stage with notes on its potential for aquaculture

2013 ◽  
Vol 46 (5) ◽  
pp. 1087-1100 ◽  
Author(s):  
Ming-Yih Leu ◽  
Yu-Hsuan Sune ◽  
Pei-Jie Meng
Author(s):  
Jeremy Tan

The present study aims to expand the market potential of the streaked spinefoot rabbitfish (Siganus javus) in Malaysia and provide consumers more choices of affordable protein source from aquaculture. Spawning hehavior of S.javus was recorded in a week after the new moon in October 2019 and January 2020. Spawning occurred between midnight and early morning, and the eggs hatched about 16 to 18 hours later. Throughout the incubation and larvae rearing period, water temperature was maintained at 30 to 31 °C. Water salinity, pH and DO were 31 to 33 ppt, 7.8 to 8, and 5 to 7 mg/l, respectively. Eggs diameter ranged from 0.550 to 0.603 mm. At 1 day after hatched (d AH), eyes of the larvae were formed but unpigmented and mouth structure was not developed. At 2 d AH, the pigmentation of eyes darkened, digestive tract formed, and anus and mouth opened. At 3 d AH, the lower jaw began to show movement, indicating that the ability of larvae to indulge in feeding. The buds of dorsal and ventral fins started to develop and elongate from 9 d AH and were covered with melanophores. At 25 d AH, the body of the larvae turned brownish and abdominal cavity was deeply pigmented, indicating the onset of metamorphosis. By the age of 30 d AH, the larvae completed development into juvenile stage. At 270 d AH, the juvenile reached maximum size of 21 cm in total length. This study was the first successful attempt at naturally spawning and hatchery rearing of S. javus into juvenile stage in the country. The development of a complete larval rearing protocol for S. javus could provide information of practical importance in hatchery breeding of other rabbitfish species.


2007 ◽  
Vol 16 (1) ◽  
pp. 69-84 ◽  
Author(s):  
Marcelino Herrera ◽  
Ismael Hachero ◽  
Montserrat Rosano ◽  
José Francisco Ferrer ◽  
José Manuel Márquez ◽  
...  

Aquaculture ◽  
2005 ◽  
Vol 250 (1-2) ◽  
pp. 155-161 ◽  
Author(s):  
N. Papandroulakis ◽  
C.C. Mylonas ◽  
E. Maingot ◽  
P. Divanach

2021 ◽  
Vol 2 (1) ◽  
pp. 22-28
Author(s):  
Sevim Hamzaçebi ◽  
◽  
Erkan Can ◽  
Keyword(s):  

2012 ◽  
Vol 45 (4) ◽  
pp. 689-700 ◽  
Author(s):  
J Roo ◽  
H Fernández-Palacios ◽  
C M Hernández-Cruz ◽  
A Mesa-Rodriguez ◽  
D Schuchardt ◽  
...  

1976 ◽  
Vol 32 ◽  
pp. 577-588
Author(s):  
C. Mégessier ◽  
V. Khokhlova ◽  
T. Ryabchikova

My talk will be on the oblique rotator model which was first proposed by Stibbs (1950), and since received success and further developments. I shall present two different attempts at describing a star according to this model and the first results obtained in the framework of a Russian-French collaboration in order to test the precision of the two methods. The aim is to give the best possible representation of the element distributions on the Ap stellar surfaces. The first method is the mathematical formulation proposed by Deutsch (1958-1970) and applied by Deutsch (1958) to HD 125248, by Pyper (1969) to α2CVn and by Mégessier (1975) to 108 Aqr. The other one was proposed by Khokhlova (1974) and used by her group.


1976 ◽  
Vol 32 ◽  
pp. 109-116 ◽  
Author(s):  
S. Vauclair

This paper gives the first results of a work in progress, in collaboration with G. Michaud and G. Vauclair. It is a first attempt to compute the effects of meridional circulation and turbulence on diffusion processes in stellar envelopes. Computations have been made for a 2 Mʘstar, which lies in the Am - δ Scuti region of the HR diagram.Let us recall that in Am stars diffusion cannot occur between the two outer convection zones, contrary to what was assumed by Watson (1970, 1971) and Smith (1971), since they are linked by overshooting (Latour, 1972; Toomre et al., 1975). But diffusion may occur at the bottom of the second convection zone. According to Vauclair et al. (1974), the second convection zone, due to He II ionization, disappears after a time equal to the helium diffusion time, and then diffusion may happen at the bottom of the first convection zone, so that the arguments by Watson and Smith are preserved.


Author(s):  
H. Seiler ◽  
U. Haas ◽  
K.H. Körtje

The physical properties of small metal particles reveal an intermediate position between atomic and bulk material. Especially Ag has shown pronounced size effects. We compared silver layers evaporated in high vacuum with cluster layers of small silver particles, evaporated in N2 at a pressure of about 102 Pa. The investigations were performed by electron optical methods (TEM, SEM, EELS) and by Photoacoustic (PA) Spectroscopy (gas-microphone detection).The observation of cluster layers with TEM and high resolution SEM show small silver particles with diameters of about 50 nm (Fig. 1 and Figure 2, respectively). The electron diffraction patterns of homogeneous Ag layers and of cluster layers are similar, whereas the low loss EELS spectra due to plasmon excitation are quite different. Fig. 3 and Figure 4 show first results of EELS spectra of a cluster layer of small silver particles on carbon foil and of a homogeneous Ag layer, respectively.


Author(s):  
H.S. von Harrach ◽  
D.E. Jesson ◽  
S.J. Pennycook

Phase contrast TEM has been the leading technique for high resolution imaging of materials for many years, whilst STEM has been the principal method for high-resolution microanalysis. However, it was demonstrated many years ago that low angle dark-field STEM imaging is a priori capable of almost 50% higher point resolution than coherent bright-field imaging (i.e. phase contrast TEM or STEM). This advantage was not exploited until Pennycook developed the high-angle annular dark-field (ADF) technique which can provide an incoherent image showing both high image resolution and atomic number contrast.This paper describes the design and first results of a 300kV field-emission STEM (VG Microscopes HB603U) which has improved ADF STEM image resolution towards the 1 angstrom target. The instrument uses a cold field-emission gun, generating a 300 kV beam of up to 1 μA from an 11-stage accelerator. The beam is focussed on to the specimen by two condensers and a condenser-objective lens with a spherical aberration coefficient of 1.0 mm.


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