132 
ie) 
Oo 
Landings (t) 
1996 
C 
2000 2004 
fe) 
Oo 
Effort (000s d) 
BS 
(2) 
pe) 
Oo 
2008 
Effort (000s trips) 
Fishery Bulletin 120(2) 
— 
Oo 
a 
oO 
1996 2000 2004 
1996 2000 2004 2008 1996 2000 2004 
Figure 4 
(A) Landings in metric tons (t), (B) fishing effort measured as the number of trips, (C) fishing 
effort measured as the number of days at sea, and (D) catch per unit of effort (CPUE) in kilograms 
per day from 1995 through 2008 for the fishery that targets flathead lobsters (Thenus orientalis) 
in the waters of Saudi Arabia in the Arabian Gulf. The fishery includes large boats called dhow 
(solid lines) and small boats called tarad (dashed lines). 
distribution of the stock and the sexual maturity and 
somatic growth of the samples, and we conducted a stock 
assessment with a validated method that has been used for 
other lobster stocks (Meissa et al., 2021). The stock is dis- 
tributed over the whole region at low densities, on average 
one order of magnitude less than those observed for 
T. parindicus and T. australiensis in Australia (Jones, 1988). 
Females and males have slightly different maturity sched- 
ules, with both sexes of flathead lobster reaching 50% 
maturity at about 60 mm carapace length. The growth of 
this species is fast, and its population structure is composed 
of just 2 cohorts. Recruitment dominates abundance, and 
the life history of this species is characterized by a short 
life, rapid maturation and growth, and high M. 
Our findings regarding sexual maturity and somatic 
growth in general are fairly consistent with results from 
studies of other Thenus lobsters in regions of the Indian 
Ocean. Female flathead lobsters in the Arabian Gulf 
attain sexual maturity at a slightly higher size than 
the sizes reported for T: parindicus and T. australiensis 
(Jones, 2007). The major pulse of spawning occurred in 
November—December with a minor peak in May—June. 
Other Thenus species across various regions also have 
2 spawning peaks (Jones, 1988; Courtney; Jones, 2007; 
Radhakrishnan et al., 2013). The maximum fecundity of 
flathead lobsters in this study (76,144 eggs) was higher 
than the maximum fecundity that has been reported for 
T. parindicus, T. australiensis, and T: unimaculatus (Jones, 
1988; Radhakrishnan et al., 2013). 
The growth rate of flathead lobsters was quite similar 
to the rates reported for other Thenus species from other 
regions (Table 2). The von Bertalanffy growth coefficient, 
