جاسم عبد العباس عبد الله العبودي

 

           Abstract

 

The phenomenon of Protandrous hermaphrodite has been studies in Acanthopagrus latus that is currently available in Al Razaza lake which fished by gill nest or cast net . A sample of 161 was chosen for the period of begining of August 2008 up to the end of January 2009 . Through this study , the fish gender and its sexual maturation were limited , and a studying monthly varieties of gonads function values GSI and liver function HIS and studying fish length at the first sex adulthood . The study also included the external and structure descriptive of the fish gonads . It was notices , according to the study , that the sex proportion was 38.51 for males and 44.72 for females and 16.77 for the hermaphrodite . This proportion was counted , when some hermaphrodite fish was considered as female when the ovary forms more than 95% of the gonad size and considered males when the testicle form more than 95% of the gonad size . The statistic analysis results showed that there are no moral differences between the observed and expected sex proportion ( p >0.05 ) . For the male proportion to the female in the total gathering is 1:0.86 ; it was noticed that the proportion tends to for the female with the age progress .this refers to the sex diversion from the male to male Protandrous .   The study showed that the Acanthopagrus latus males formed the majority during December and January , while the during August , September , October and November . The hermaphrodite fish was noticed in all months save August , and reached its top in November forming the majority . The monthly changes in gonad function values of males and females showed that the increase in GSI values of both sexes start from September with a continual increase till reach the highest value in January 1.47 for male and 2.30 for female . The monthly change of the liver function showed that the increase in HIS values start from September with a continual increase reaching the top in January to 2.11 for male and 2.26 for female . It was also noticed that the sex maturity was age of two years for male and of three years for female . So the males have the majority at the age of two years forming 62.5 while the females have the majority at the age of six years forming 83.33 . The hermaphrodite fish had the highest proportion 30.35 at the age of two years . It was also noticed that the smallest sex adult male was about 193 mm with an age of two years . The smallest sex adult female was about 200 mm with an age of three years . This study also asserted that the males dominate the small lengths between ( 13-15 ) cm while the female dominate in big lengths between ( 16-30 ) cm. The lengths of the hermaphrodite fish was between 135 to 202 mm . This indicates that the males mature before the females in length and age . The external examination for the Acanthopagrus latus gonads identified three types of gonads : male , female and hermaphroditic . The mature male gonads are white and stripe forming three quarters of abdominal cavity ; the female gonads with a red , rosy , transverse , lobated and veined occupy three quarters of the abdominal cavity . The hermaphrodite gonads appear as one gonad consisted of two parts . The first is external and rosy representing the ovary . The second is abdominal and white representing the testicles . The tissue examination of gonads indicated presence of male and female sex cells with their mature stages . Concerning the hermaphrodite gonads , it was noticed that the gonads contain the male and the female sex cells with various sizes , numbers , and proportion . The study showed that the Acanthopagrus latus is hermaphrodite of Protandrous type , that because the males change in to females through age progress of the different lengths .

 

 

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