Sex Control in Fish with Particular Reference to Salmonids

Edward M. Donaldson; George A. Hunter

doi:10.1139/f82-012

Sex Control in Fish with Particular Reference to Salmonids

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f82-012 ◽

1982 ◽

Vol 39 (1) ◽

pp. 99-110 ◽

Cited By ~ 126

Author(s):

Edward M. Donaldson ◽

George A. Hunter

Keyword(s):

Surgical Procedures ◽

Inbred Lines ◽

Sex Reversal ◽

The Other ◽

Experimental Production ◽

Steroid Administration ◽

Sex Control ◽

Androgen Treatment ◽

Other Hand

Techniques for sex control in trout, char, and salmon are reviewed in the context of their application to salmonid culture. Procedures for the production of all female, male, or sterile salmonids using estrogen or androgen treatment, respectively, are described and compared for Salmo, Salvelinus, and Oncorhynchus species. The production of homozygous monosex salmonids by radiation gynogenesis and techniques for the production of potentially sterile triploid and polyploid salmonids arc discussed. Finally, alternative sterilization techniques which do not depend on steroid administration or zygote manipulation are reviewed including irradiation, and autoimmune and surgical procedures. Direct and indirect hormonal techniques for production of all female salmonid groups are now sufficiently developed to permit pilot application as is the direct androgen sterilization technique. The procedure of radiation gynogenesis is available for the rapid experimental production of inbred lines. On the other hand, further work is required to determine the effectiveness of induced triploidy and polyploidy as sterilization procedures.Key words: sex reversal, estrogen, androgen, sterilization, gynogenesis, androgenesis, polyploidy, Salmo, Oncorhynchus, Salvelinus

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Sex Reversal on Congo Tetra Fish (Micraleptus intterruptus ) Larvae

Jurnal Akuakultur Indonesia ◽

10.19027/jai.1.69-74 ◽

2007 ◽

Vol 1 (2) ◽

pp. 69 ◽

Cited By ~ 1

Author(s):

Harton Arfah ◽

, Alimuddin ◽

K. Sumantadinata ◽

Julie Ekasari

Keyword(s):

Survival Rate ◽

Fish Larvae ◽

Sex Reversal ◽

The Other ◽

Fish Length ◽

Font Size ◽

Male Fish ◽

Other Hand ◽

Key Word ◽

Different Doses

ABSTRACT Experiment was performed to assess the effect of 17a-methyltestosterone (MT) treatment on Congo tetra fish larvae. To evaluate the optimal pattern of MT treatment, three different treatments were administrated. Three months old larvae were submerged in three different doses of MT; 1, 2 and 4 mg/l. These studies showed that the highest percentage of male fish was obtained by 4 mg/l MT treatment, 87,17%. The 2 mg/l and 1 mg/l MT treatments obtained 77,53% and 69,86% male respectively, two times higher than control, 38,96%. On the other hand, the 4 mg/l MT treatment also resulted the highest percentage of hermaphrodite fishes, 17,58%. The highest survival rate was shown by 1 mg/l MT treatment, 62,77% and the lowest was shown by the 4 mg/l MT treatment, 47,20%. The highest rate of fish length and weight was shown by the 4 mg/l MT treatment, 4,4 cm and 1,65 gram respectively. These findings suggest that MT treatment offers an advantage in growth of tetra Congo larvae. Key word : Sex reversal, methyltestosterone, Congo tetra fish, Micraleptus intterruptus. ABSTRAKPenelitian ini bertujuan untuk mengetahui pengaruh perendaman larva di dalam larutan hormon 17a-metiltestosteron pada dosis 1, 2 dan 4 mg/l larutan. Persentase tertinggi ikan jantan dihasilkan oleh perlakuan 4 mg/l, yaitu 87,17%. Perlakuan 2 mg/l dan 1 mg/l masing-masing menghasilkan 77,53% dan 69,86% sedangkan kontrol menghasilkan 38,96% jantan. Efek lain dari perlakuan MT ini adalah hermafroditisme. Perlakuan 4 mg/l menghasilkan persentase hermafrodit tertinggi yaitu 17,58%, sedangkan pada kontrol kelangsungan hidup tertinggi diperoleh pada perlakuan 1 mg/l (62,77%) dan terendah pada perlakuan 4 mg/l (47,20%). Hasil tersebut menunjukkan adanya pengaruh dosis hormon terhadap kelangsungan hidup ikan. Pengukuran bobot dan panjang ikan pada setiap perlakuan menunjukkan nilai tertinggi dihasilkan oleh perlakuan 4 mg/l yaitu 1,65 gram dan 4,40 cm. Hal ini diduga bahwa hormon MT merangsang pula pertumbuhan ikan.Kata kunci : Pergantian kelamin, metiltestosteron, ikan tetra Kongo, Micraleptus intterruptus.

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Relations of yolk, albumen and egg weight in inbred lines of brown leghorns

The Journal of Agricultural Science ◽

10.1017/s0021859600045755 ◽

1954 ◽

Vol 45 (1) ◽

pp. 32-35 ◽

Cited By ~ 11

Author(s):

J. E. Erasmus

Keyword(s):

Egg Size ◽

Marked Decrease ◽

Inbred Lines ◽

Negative Association ◽

The Other ◽

Egg Weight ◽

Reciprocal Crosses ◽

Other Hand ◽

Independent Variation ◽

Pure Lines

1. The relations of yolk, albumen and egg weight were studied in seven inbred lines of Brown Leghorns and reciprocal crosses of two of these lines.2. In all the lines the eggs produced by hens had a bigger proportion of yolk than those produced by pullets.3. Besides changes in both components accompanying differences in egg size the line means for albumen weight still differ significantly after adjustment is made for its covariance with yolk weight. This independent variation leads to differences in the yolk-albumen ratio of the hens.4. Within the lines there is a significant negative association between egg size and the yolk/albumen ratio.5. The wide differences in egg size, dividing the pure lines into two groups characterized by large and small eggs respectively, resulted from a marked decrease in the amount of albumen in the eggs of the latter group. Yolk weights, on the other hand, could be ranked in a fairly regular series with adjacent lines differing by 2 g. or less.6. There is some source of variation in the yolk/ albumen ratio for line means which is not accounted for by differences in egg size.

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A study of cometary eruptions through OH radio-lines

International Astronomical Union Colloquium ◽

10.1017/s025292110003150x ◽

1999 ◽

Vol 173 ◽

pp. 249-254

Author(s):

A.M. Silva ◽

R.D. Miró

Keyword(s):

Short Duration ◽

Growth Curves ◽

The Other ◽

Initial Mass ◽

Radio Lines ◽

Other Hand ◽

Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

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Closing the GAP—A 5Å Scanning Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100061938 ◽

1969 ◽

Vol 27 ◽

pp. 6-7

Author(s):

A. V. Crewe

Keyword(s):

Normal Form ◽

The Other ◽

Resolving Power ◽

Scanning Microscope ◽

Conventional Microscope ◽

Other Hand ◽

Closing The Gap ◽

Thermal Sources ◽

Better Than ◽

Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

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Life Beyond 1MeV

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000118 ◽

1980 ◽

Vol 38 ◽

pp. 30-33

Author(s):

K.H. Westmacott

Keyword(s):

Electron Microscopy ◽

Past Experience ◽

The Other ◽

Good Case ◽

Other Hand ◽

The U.S

Life beyond 1MeV – like life after 40 – is not too different unless one takes advantage of past experience and is receptive to new opportunities. At first glance, the returns on performing electron microscopy at voltages greater than 1MeV diminish rather rapidly as the curves which describe the well-known advantages of HVEM often tend towards saturation. However, in a country with a significant HVEM capability, a good case can be made for investing in instruments with a range of maximum accelerating voltages. In this regard, the 1.5MeV KRATOS HVEM being installed in Berkeley will complement the other 650KeV, 1MeV, and 1.2MeV instruments currently operating in the U.S. One other consideration suggests that 1.5MeV is an optimum voltage machine – Its additional advantages may be purchased for not much more than a 1MeV instrument. On the other hand, the 3MeV HVEM's which seem to be operated at 2MeV maximum, are much more expensive.

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Can the Academic Self-Concept be Positive and Realistic?

Zeitschrift für Pädagogische Psychologie ◽

10.1024/1010-0652.19.3.132 ◽

2005 ◽

Vol 19 (3) ◽

pp. 129-132 ◽

Cited By ~ 6

Author(s):

Reimer Kornmann

Keyword(s):

Academic Performance ◽

Opposite Effect ◽

Self Esteem ◽

Point Of View ◽

The Other ◽

Self Concept ◽

High Ability ◽

Self Image ◽

Other Hand

Summary: My comment is basically restricted to the situation in which less-able students find themselves and refers only to literature in German. From this point of view I am basically able to confirm Marsh's results. It must, however, be said that with less-able pupils the opposite effect can be found: Levels of self-esteem in these pupils are raised, at least temporarily, by separate instruction, academic performance however drops; combined instruction, on the other hand, leads to improved academic performance, while levels of self-esteem drop. Apparently, the positive self-image of less-able pupils who receive separate instruction does not bring about the potential enhancement of academic performance one might expect from high-ability pupils receiving separate instruction. To resolve the dilemma, it is proposed that individual progress in learning be accentuated, and that comparisons with others be dispensed with. This fosters a self-image that can in equal measure be realistic and optimistic.

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Stories and the Self

Journal of Media Psychology Theories Methods and Applications ◽

10.1027/1864-1105/a000255 ◽

2020 ◽

Vol 32 (2) ◽

pp. 47-58 ◽

Cited By ~ 1

Author(s):

Stefan Krause ◽

Markus Appel

Keyword(s):

Meta Analysis ◽

The Self ◽

The Other ◽

Lower Degree ◽

Contrast Effects ◽

Self Perception ◽

Self Perceptions ◽

Other Hand ◽

The One ◽

Implicit And Explicit

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.

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Don’t Put Me in This Group

Social Psychology ◽

10.1027/1864-9335/a000363 ◽

2019 ◽

Vol 50 (2) ◽

pp. 80-93

Author(s):

Jort de Vreeze ◽

Christina Matschke

Keyword(s):

Positive Emotions ◽

Negative Emotions ◽

Negative Information ◽

The Self ◽

The Other ◽

Other Hand ◽

Group Memberships

Abstract. Not all group memberships are self-chosen. The current research examines whether assignments to non-preferred groups influence our relationship with the group and our preference for information about the ingroup. It was expected and found that, when people are assigned to non-preferred groups, they perceive the group as different to the self, experience negative emotions about the assignment and in turn disidentify with the group. On the other hand, when people are assigned to preferred groups, they perceive the group as similar to the self, experience positive emotions about the assignment and in turn identify with the group. Finally, disidentification increases a preference for negative information about the ingroup.

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