Growth parameters and Mortality rates of Skinnycheek Lanternfish Benthosema pterotum (Alcock, 1890) in the Iranian waters of Oman Sea

Abstract

Introduction: In this research, the population dynamics of Skinnycheek Lanternfish
Benthosema pterotum (Alcock, 1890), in the Iranian waters of Oman Sea of were
investigated.
Materials & Methods: This research with using monthly longitudinal frequency
analysis from April 2019 to March 2020 was studied. A total of 2893 individuals were
sampled and used for analysis.
Results: Total length ranged from 21-60 mm and the average length was 39 .4 mm. More
than 84% of the samples were between 33-45 mm TL. The length-weight relationship
was obtained TW=0.00008TL2.379 and shown negative allometric growth. The
asymptotic length (Loo) and growth constant (K) were estimated at 63 mm and 1.6 yr-1
respectively. Also, tmax and t0 were calculated 1/73 and -0/15 yr -1 respectively. VBGE
was calculated Lt= 6.3 (1-e -1.6(t+0.15)). The coefficients of total mortality (Z), instantaneous
natural mortality (M), and fishing mortality (F) were estimated as 6/65 yr-1, 2/62 yr-1, and
4/03 yr -1 respectively. Size at first capture (Lc) was estimated at 35.67 mm (TL). The
exploitation rate (E) was estimated as 0/60 yr -1.
Conclusion: According to the obtained exploitation coefficient and the ratio of fishing
to natural mortality, it is suggested to reduce the current exploitation rate.