Studies on day-night distribution, composition and abundance of copepod groups in Manora waters along Karachi coast of North Arabian sea, Pakistan
Muhammad Jawed Abbasi, Zarina Abbasi, Farah Naz Khokhar, Pirzada Jamal Ahmed Siddiqui
The present study was conducted to determine the distribution, composition and abundance of copepods during night and day time from Manora waters during April 2008 to March 2009 and recorded three groups, Cyclopoid, Calanoid and Herpacticoid. Copepods are major parts of all zooplankton groups. During the study period air temperature ranged from 19ºc -27ºc, water temperature ranged from 18ºc to 28ºc, Ph ranged from 7-7.5 and DO ranged from 4.5mg ̸ L¯¹ to 9.3mg ̸L¯¹ during night time and in day time it was recorded as air temperature ranged from 20ºc -27ºc, water temperature ranged from 19ºc to 28ºc, Ph ranged from 7-7.5 and DO ranged from 4.9mg ̸ L¯¹ to 9.4mg ̸L¯¹. During this study the cyclopoid comprising 25.09%, calanoid comprising 64.05% and herpacticoid comprising 10.84% in night time and 21.32%, 69.70% and 8.97% in day time, respectively. Copepods indicated monthly richness (S) and evenness (E), ranging between 1.098 and 0.642-0.830 respectively, in day time and 1.098 and 0.706-0.946 respectively, in night time. Density of copepods was positively correlated with air temperature, water temperature, salinity, Ph, Transparency and DO. The diversity indices such as Shannon’s diversity index (1.039- 0.776) in night time and (0.912-0.706) in day time were calculated. The calanoid among the copepod groups shows high abundance in night and day collection during the whole year 2008-9. This study reveal that copepod groups in manora waters are most abundant during day time and their abundance enhance the fishing activities during day time.