Journal of Biology, Agriculture and Healthcare www.iiste.org ISSN 2224-3208 (Paper) ISSN 2225-093X (Online) Vol 1, No.4, 2011 19 Studies on the Age, Growth and Mortality Rates of Indian Oil Sardine, Sardinella longiceps Valenciennes, 1847 off Oman Sea, Muscat, Sultanate of Oman I. S. Al-Anbouri 1 * M. A. Ambak 1 N. Jayabalan 2 1. Department of Agrotechnology, Faculty of Agrotechnology and Food Science, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu, Malaysia 2. Marine Science and Fisheries Center, Ministry of Agriculture and Fisheries wealth, Muscat, Sultanate of Oman, P.O 427, P.C 100 Muscat * E-mail of the corresponding author: camry2005@yahoo.com The research is financed by the Agriculture and Fisheries Developmental Fund in The Sultanate of Oman (Sponsoring information). Abstract Investigations have been carried out on the age, growth and mortality of sardine Sardinella longiceps based on the length frequency data. The hypothetical asymptotic length (L∞) and growth coefficient (K) were estimated as 220.3 mm and 1.209 yr-1 respectively. The species grows from 155 and 200 mm at the end of 1 and 2 years of life. The life span appeared to be around 2 years of species life. The total (Z), natural (M) and fishing (F) mortalities were represented as 4.11 yr-1, 2.21 yr-1 and 1.91 yr-1 respectively. The exploitation rate (E) was 0.46. The exploitation rate suggested that the stock was below the optimum level of exploitation. As a management plan, there is a need to increase the fishing scale and protecting spawning season to maintain sustainability over time. Keywords: The Hypothetical Asymptotic Length; Growth Coefficient; Mortalities; Exploitation Rate; Sustainability. 1. Introduction The Indian oil sardine Sardinella longiceps is a commercially important small pelagic resource in the Indo- Pacific region. It is widely distributed along the coast of Omani waters. Though, this species forms a considerable proportion in the fish catches of Oman, no detailed studies on the biological characteristics of this fish have been attempted. Hence, a study was carried out to investigate the age and growth based on Length frequency distribution. Studies of age and growth based on length frequency data analysis (LFD) have been investigated by different scientists. The technique provided the evidence and an indication of age, growth and mortality based on length modes progression included for long and short lived species. Age and growth study on S. longiceps was initiated in Oman by Al- Barwani et al. (1989). He showed 2-3 age classes found in along the coast of Oman. Siddeek et al. (1994) investigated the age and growth of S. longiceps in Al-Azaiba, Oman. It was suggested that species had a maximum life span about 3.75 years. Oman has a long coastline of 3,165 km bordered by Arabian Gulf, Oman Sea and Arabian Sea and is rich in biodiversity of species. Fisheries resources in the Sultanate of Oman are one of the significant renewable resources and support the country's economy to a greater extent. Fisheries sector of Oman supports the second national economy after oil and gas. The total fish production of the Sultanate for the year 2009 stood at 158.000 tons of which the artisanal fisheries sector contributed to about 84% of the total fish production and the rest by industrial fleet (MOFW, 2000-2009). The total value of fishery production increased in 2009 to RO 104 million, up by 9% from the previous year 2008 and about 51% of the total fish produced had been exported to other countries. The small pelagic fishes contributed to about 34% of the