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الدورة التكاثرية للروبيان النهري الشرقي Macrobrachium nipponenseو (De Haan, 1849 [In De Haan, 1833 - 1850]) ارتباطها ببعض العوامل البيئية في نهر المسحب جنوب شرق هور الحمار، البصرة، العراق == Reproductive cycle of Oriental River Prawn Macrobrachium nipponense (De Haan, 1849 [ In De Haan, 1833 - 1850]) and its correlation with environmental factors in Al - Masshab River, Southern East of Al - Hammar Marsh, Basrah, Iraq
Author name:
اشواق طالب عباس
Supervisor name:
عبد الحسین حاتم غازي | عبد الحسین حاتم غازي
General topic:
Agricultural sciences
Specific topic:
Zoology - Fish And Marine Wealth
Degree:
Master
University:
University Of Basrah - Faculty Of Agriculture - Department Of Fish And Marine Wealth
Language:
Arabic
University location:
Basrah
First pages:
31T1893 - p.pdf
Abstract:
The present study, investigated the reproductive cycle of freshwater prawn, Macrobrachium nipponense during period from December 2015 to November 2016 at Al - Masshab River, Southern of East Al - Hammar Marsh/ Basrah. The water temperature, salinity, pH, dissolve oxygen and turbidity were recorded, the maximum average for water temperature was 28 ºC recorded in July, while the minimum was 12 ºC in January. Water salinity was fluctuation between 0.8 - 2 ppt. in April and November respectively. pH values ware recorded between 7 - 7.6 during all study months. The minimum of oxygen concentration was 5.5 mg/ L in July and the maximum 8.29 mg/ L in the December. Also there are some changes in turbidity of water, the lower was 15.3 NTU in February and the highest was 40.1 NTU in the April. The results of length groups showed, occurrence of group between 44 - 35 mm for females and between 54 - 36 mm for males. The minimum length for females was 48.3 mm in November, and for males was 52.1 mm in November. While themaximum length for females and males were 69.1 mm and 74.7 mm in September and August respectively. The minimum average of weight was recorded in the November for females and males ( 1.6 and 2.0 ) gm respectively, while the maximum average was 4.3 gm for females in September and 4.5 gm for males in August. The total carapace length for females between ( 19.3 - 32.5 ) mm in November and September respectively , and for males was between 21.0 - 31.6 mm for the same period. Length - weight parameters (a and b) of the equation : W = aLb were estimated for M. nipponense , positive correlation ( r= 0.67) for females and ( r= 0.90 ) for males, while the relationship between carapace length and total length were (r = 74) for females and (r = 0.85) for males. Additional to relationship between carapace length and body weight were (r= 62) for females and (r = 0.75) for males. The highest Gonadosomatic Index (GSI) was 10.6 recorded in September, and the lower was 2.7 recorded in July. In this study we observed two peaks for reproductive, the first in Jun. and second in the August. The best percentage for ovigorous was recorded in August 98.7 % whereas, percentage of the non ovigorous in this month was 1.3 % .The condition factor for females was changed between 1.1 during November and 2.10 during September. While for males was between 1.3 to 2.9 during November and August respectively. The seasonal variations in the sex ratio of prawn was different according reproductive cycle, and there was more females than males during reproductive period. The minimum was 1 : 0.17 ( male / female) in February and the maximum percentage was 1 : 9.00 ( male / female) in the Jun. The overall fecundity of 307 ovigorous female of M. nipponense was calculated, the Absolute fecundity ranged from (799 - 2047) egg/ individual, while the relative fecundity between (208 - 578) egg/ gm. The correlations of fecundity with total length and fecundity with body weight were positive for both, it were r= 94 and r= 0.90 respectively. Additional, the eggs had been classified into four stages, based on the external morphological characters such as colour ,size and histological. Egg dimensions varied between 675 + 28 to 763 + 31 μm.
