Sex Ratio as a Function of Size in Hippa pacifica Dana (Crustacea, Anomura, Hippidae): A Test of the Sex Reversal and Differential Growth Rate Hypotheses

1979 ◽  
Vol 113 (3) ◽  
pp. 391-397 ◽  
Author(s):  
Samuel R. Haley
Keyword(s):  
Growth Rate ◽  
Sex Ratio ◽  
Sex Reversal ◽  
Differential Growth ◽  
Differential Growth Rate

scholarly journals APLIKASI TEPUNG TESTIS SAPI YANG MENGANDUNG rGH DALAM PAKAN BUATAN TERHADAP RASIO JENIS KELAMIN, PERTUMBUHAN DAN KELULUSHIDUPAN IKAN NILA (Oreochromis niloticus)

2018 ◽  
Vol 17 (2) ◽  
Author(s):  
Rachmat Nurul Huda ◽  
Titik Sulistiowati ◽  
Tristiana Yuniarti
Keyword(s):  
Growth Rate ◽  
Survival Rate ◽  
Sex Ratio ◽  
Specific Growth Rate ◽  
Oreochromis Niloticus ◽  
Specific Growth ◽  
Sex Reversal ◽  
Average Weight ◽  
Fish Feed ◽  
Male Sex

<p align="center"><strong>ABSTRAK</strong></p><p>Budidaya ikan nila <em>(Oreochromis niloticus) </em>terus dikembangkan hingga saat ini. Berbagai teknologi dalam bidang perikanan telah diterapkan, salah satunya yaitu <em>sex reversal </em>dalam hal ini jantanisasi. Ikan nila jantan lebih cepat pertumbuhannya dari pada ikan nila betina sehingga dapat meningkatkan hasil produksi. Tujuan penelitian ini yaitu untuk mengetahui pengaruh pemberian tepung testis sapi dan dosis terbaik tepung testis sapi dalam pakan yang mengandung  rGH terhadap rasio jenis kelamin, pertumbuhan dan kelulushidupan ikan nila. Bahan uji yang digunakan adalah larva ikan nila dengan stadia larva yang berumur 7 hari setelah lepas kuning telur dan memiliki bobot rata-rata 0,07 gram/ekor. Penelitian ini menggunakan metode eksperimental dengan Rancangan Acak Lengkap 4 perlakuan dan 3 kali ulangan. Perlakuan dalam penelitian ini yaitu dengan menambahkan tepung testis sapi dengan dosis pada perlakuan A (0%/kg pakan), perlakuan B (3%/kg pakan), perlakuan C (6%/kg pakan) dan, perlakuan D (9%/kg pakan). Pakan pada setiap perlakuan dalam penelitian ini telah ditambahkan rGH dengan dosis 2 mg/kg pakan. Data yang diamati meliputi rasio jenis kelamin, laju pertumbuhan spesifik (SGR), dan tingkat kelulushidupan (SR) ikan nila<em>.</em> Hasil penelitian menunjukan bahwa perlakuan C (6% tepung testis sapi/kg pakan) memberikan hasil terbaik dimana nilai rasio jenis kelamin jantan sebesar 74,44±5,09% dan laju pertumbuhan spesifik sebesar 9,48±0,10% bobot/hari. Kesimpulan yang diperoleh dalam penelitian ini yaitu adanya pengaruh nyata terhadap rasio jenis kelamin dan tingkat pertumbuhan spesifik, namun tidak berpengaruh nyata terhadap tingkat kelulushidupan ikan nila dengan pemberian dosis tepung testis sapi terbaik adalah 6% tepung testis sapi/kg pakan.</p><p><strong>Kata kunci: </strong>Sex reversal; Tepung testis sapi;  Pertumbuhan, rGH; Nila<strong></strong></p><p align="center"><strong>ABSTRACT</strong></p><p><em>Tilapia fish (Oreochromis niloticus)cultivation still continue to be developed until nowdays. Many fisheries technology had been applied, and one of them is sex reversal which is masculinization. Male tilapia fish grows faster than the female one, so this can boost the produce of the fish. This research aims to know the effect of cow testicle flour addition and determine the best dosage on the fish feed which contains rGH towards the male-sex ratio, growth, and survival rate of tilapia fish. The material which used in this research was tilapia fish (O. niloticus) which under the larvae phase 7 days post the separated egg yolk which have average weight of 0,07 grams/each. This research used experimental methods with Completely Randomized Design of 4 treatments and 3 times of repetitions. The treatments in this research was addition of  different dosage of bull testicle which treatment A (0%/kg fish feed),treatment B (3%/kg fish feed), treatment C (6%/kg fish feed) and, treatment D (9%/kg fish feed). The fish feed in every treatment had been added with 2mg rGH/kg fish feed. Data observation  during this research were male-sex ratio, specific growth rate (SGR), and survival rate (SR) of tilapia fish. Results of the research showed that treatment C (6%/kg fish feed) gave the best result as male-sex ratio by 74,44±5,09% and specific growth rate by 9,48±0,10% weight/day. Conclusion obtained from this research was: there was different result  towards the male-sex ratio and specific growth rate, but there was no difference between the treatments towards the survival rate, the best bull testicle flour dosage was 6%/kg fish feed. </em></p><p><strong><em>Keywords:</em></strong><em> Sex reversal, Bull testicle flour, Growth, rGH, Tilapia<strong></strong></em></p>

Differential Growth Rate in the Tail of the Pacific Big Skate, Raja binoculata

1971 ◽  
Vol 28 (1) ◽  
pp. 95-98 ◽  
Author(s):  
Peter Ford
Keyword(s):  
Growth Rate ◽  
Gill Filament ◽  
Tail Length ◽  
Analysis Of Covariance ◽  
Differential Growth ◽  
Relative Growth ◽  
The Pacific ◽  
Chronological Sequence ◽  
Total Body ◽  
Differential Growth Rate

Over a period of years the egg cases of Raja binoculata Girard were collected from waters in the Strait of Georgia, British Columbia, and measurements of the total body lengths and tail lengths were recorded. From these data an hypothesis was formulated suggesting that the relative growth rate of the tail to the growth of embryos is related to the mode of respiration utilized at a given time during development.The method of respiration employed by embryos of elasmobranchs follows a chronological sequence of integumentary, external gill filament, and spiracular–branchial respiration. To determine whether this hypothesis was tenable the data were subjected to a statistical analysis. A linear regression on the logarithms of the data was performed for caudal lengths below and above 8.5 cm. In each instance the probability that the resulting slope was not zero was Jess than 0.0001. Further, an analysis of covariance was performed that indicated that the two slopes were significantly different with a probability of less than 0.005.It would seem reasonable on the basis of the above analysis to assume that the tail length-respiration relation is a tenable hypothesis.

scholarly journals SuperSAGE digital expression analysis of differential growth rate in a European sea bass population

2019 ◽  
Vol 4 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Bruno Louro ◽  
Rute S.T. Martins ◽  
Patricia I.S. Pinto ◽  
Richard Reinhardt ◽  
Dirk-Jan de Koning ◽  
...  
Keyword(s):  
Growth Rate ◽  
Expression Analysis ◽  
Sea Bass ◽  
Differential Growth ◽  
European Sea Bass ◽  
Digital Expression ◽  
Digital Expression Analysis ◽  
Differential Growth Rate

scholarly journals The growth-rings on herring scales

1916 ◽  
Vol 89 (615) ◽  
pp. 258-260
Keyword(s):  
Growth Rate ◽  
Individual Growth ◽  
Teleostean Fish ◽  
Differential Growth ◽  
Growth Rings ◽  
Differential Growth Rate

This note summarises the results of certain investigations on this subject carried out in the Laboratory of the Board of Agriculture and Fisheries. The researches of each author were carried out independently, and their full reports will be published in the Fisheries Investigation Series of Reports of the Board. The number of scales on Teleostean fish being roughly the same throughout life, it is reasonable to suppose that they follow in their individual growth the growth of the fish as a whole: that when the fish is growing fast the scales grow at a corresponding rate. This differential growth-rate is clearly shown on those scales which are marked with concentric striations, for in these cases the striæ appear closer together when growth is slack than they do when growth is vigorous.

scholarly journals Sex Ratios in a Warming World: Thermal Effects on Sex-Biased Survival, Sex Determination, and Sex Reversal

2021 ◽  
Vol 112 (2) ◽  
pp. 155-164
Author(s):  
Suzanne Edmands
Keyword(s):  
High Temperature ◽  
Sex Ratio ◽  
Sex Determination ◽  
Heat Tolerance ◽  
Sex Ratios ◽  
Sex Reversal ◽  
Survival Sex ◽  
Ratio Distortion ◽  
Warming World ◽  
Sex Ratio Distortion

Abstract Rising global temperatures threaten to disrupt population sex ratios, which can in turn cause mate shortages, reduce population growth and adaptive potential, and increase extinction risk, particularly when ratios are male biased. Sex ratio distortion can then have cascading effects across other species and even ecosystems. Our understanding of the problem is limited by how often studies measure temperature effects in both sexes. To address this, the current review surveyed 194 published studies of heat tolerance, finding that the majority did not even mention the sex of the individuals used, with &lt;10% reporting results for males and females separately. Although the data are incomplete, this review assessed phylogenetic patterns of thermally induced sex ratio bias for 3 different mechanisms: sex-biased heat tolerance, temperature-dependent sex determination (TSD), and temperature-induced sex reversal. For sex-biased heat tolerance, documented examples span a large taxonomic range including arthropods, chordates, protists, and plants. Here, superior heat tolerance is more common in females than males, but the direction of tolerance appears to be phylogenetically fluid, perhaps due to the large number of contributing factors. For TSD, well-documented examples are limited to reptiles, where high temperature usually favors females, and fishes, where high temperature consistently favors males. For temperature-induced sex reversal, unambiguous cases are again limited to vertebrates, and high temperature usually favors males in fishes and amphibians, with mixed effects in reptiles. There is urgent need for further work on the full taxonomic extent of temperature-induced sex ratio distortion, including joint effects of the multiple contributing mechanisms.

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