Majallah-i ̒Ilmī-i Shīlāt-i Īrān (Jan 2008)
REPRODUCTION AND MATURITY OF FALSE TREVALLY (LACTARIUS LACTARIUS) IN COASTAL WATERS OF THE OMAN SEA
Abstract
In order to determine the reproduction period, the peak time of spawning, length of maturity and mesh standard size for False Trevally (Lactarius lactarius), we conducted a study from November 2007 to October 2008 in coastal waters of the Oman Sea. A total of 702 False Trevally specimens were collected randomly from the catch composition of gillnets and Ferdows-3 stem trawler. Mean total length and total weight were estimated at 22.7±2.13cm and 142.2±41.64g for females and 20.4±1.89 and 103±29.7 for males respectively. Male to female sex ratio was 0.37:1 and females were more abundant than males in all months except June and August. Males had smaller sizes than females and the females outnumbered the mails up to the total length 25.5cm. The maximum of GSI was estimated at 3.69 for females in June and 0.89 for males in July. The trend of GSI and the frequency of maturity stages showed that reproduction period was from February to September with a spawning peak in August. Absolute fecundity was calculated at 102032 ova and relative fecundity was estimated at 4491.9 ova and 780.7 ova to total length and total weight respectively. Lm50%(length of maturity) and standard mesh size was calculated at 24.4cm and 3.9cm, respectively.
