Life cycle and population dynamics ofAnnina mesopotamica(Ahmed), (Isopoda, Flabellifera) in the Shatt Al-Arab Region, Basrah, Iraq
✍ Scribed by Salman D. Salman; Virginia K. Oshana; Malik H. Ali
- Book ID
- 104615611
- Publisher
- Springer
- Year
- 1996
- Tongue
- English
- Weight
- 729 KB
- Volume
- 330
- Category
- Article
- ISSN
- 1573-5141
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✦ Synopsis
A population of the intertidal, ovoviviparous, cirolanid isopod Annina mesopotamica was studied at the Al-Chibassy tributary of the Shatt Al-Arab river from 14 May 1973 to 29 April 1974, and at the Garmat-Ali river of the Shatt Al-Arab, Basrah, Iraq from 5 November 1984 to 30 June 1986 . Population density varied between 128 to 5760 individuals m-2 with a mean of 1218 m -2 . Highest numbers occurred between June and September . Breeding extended for most of the year except November/January to February/March, although ovigerous females were present throughout the year . The incubation period varied with season, and was ca . 2 weeks during the warmest period, and about a month at lower temperatures . Egg numbers varied between 4 to 66 with mean 24 . Brood size was linearly proportional to female size . The size frequency distribution of the population was polymodal with a predominance of females over males . Four different types of growth curves were found : exponential, concave, convex, and intermediate between concave and convex . Growth rate varied between 0 .63 and 2 .19 mm month -1 . Mortality was higher among summer cohorts . Life span varied between 5 and 11 months .