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vol-16TIlE BIOLOGY OF LETHRINUS ELONGATUS, VAL. 1830
(TELEOSTS: LETHRINIDAE) IN THE RED SEA.
ELHAM A. WASSEF* AND F. BAWAZEER
Girls College, Jeddah, Saudi Arabia.
*. To whom correspondence should be addressed.
ABSTRACT
A thorougll Investigation on the biolosy of longnose enperor
Lethrfnus elenaatu. Val. In the Red Sea off Jeddah weters was
carried out Age and growth was dete,..ined by _ans of scales
interpretation. Back-calculated lengths and weights at ave were
obtained up to the tenth year of life. Both sexes gave virtually
identical results in their growth rate. Fish length (L) and scale
radius (S) were closely correlated (r=O.99), the relationship Can
be written as: L = -3.8357 • 3.8555 S. Conditions factor (K)
values varied from 1.01 to 1.07 (Av.O’ 1.1) and have not shown to
be influenced with the change in fish size. Breeding started in
Hay and ended in July, with peak activity In June when water
t~rature was around 300C. Feeding intensity was relatively
hillher In Febl”uary (11 II ing inde,,’ 3.65) and August (FI = 3.30)
than in other ~ths of the year and lower in May (F.J =2.27),
coincided with fish spawning, and Sept_er (F.J “‘2.35). The von
Bertalanffy’s growth equation wes fitted to the age/ length data
and the following par_ters were ettlMllted: L = 54.69 cm, II =
1641.2 9, K “‘ 0.2163 &to = 0.0995 yr for L.•longatus.
