GROWTH RATE OF Penaeus semisulcatus IN THE WATER ARO{iND QATAR.

GROWTH RATE OF Penaeus semisulcatus

IN THE WATER ARO{iND QATAR.

A. A. ALSA YES AND J. A. AL-KHA YAT

‘~rine S~ience uepartment, Faculty of Science, University of Qatar.

ABSTRACT
Penaeus se111sulcatus is the most important shrimp species
in the Gulf area. The life cycle and growth rate of this
species have been dealt by various authors in the Gulf
countries.
It is attempted in the present investigation to use the
probability paper for the analysis of length frequency
distribution of Penaeus 5elrisulcatus. The aim of this analysis
is to distinguish the size classes of this shrimp s~cies
population around the Qatari waters.
Two size classes have been distinguished to the length
frequency’ measurements of randon samples taken from the
commercial catch landed at Doha in October 1983.
It has been proposed that these two separate size classes

were recruited from’ two reproduction periods. This proposal

,may confirm the suggestions of previous authors that Penaeus

5elrisulcatus has two reproduction peaks in the Gulf area.
It can also be concluded that this shrimp species grows

to 8.6 CUI total body length within the first six months

of its life. On the other hand it attains 14.3 cm in length

when it is one year old.

The above conclusion means that the largest individuals

recorded in the catch would be less than two years old.