International Journal of Marine Science 2017, Vol.7, No.40, 386-393
391
The strong correlation between the otolith size and fish body measurements suggests that somatic growth have
noteworthy effect on the otolith growth (Munk, 2012). Both otolith length and width were found to be an
appropriate for inferring fish length for
L. ehrenbergii
. There is no substantial difference between the right and left
otolith indicated that these are mirror images of each other (Hunt, 1979). Previous studies by Harvey et al. (2000)
and Waessle et al. (2003) confirmed the similarity of right and left otolith in
Lutjanus benghalensis
. Similarly,
Jawad et al. (2011c) showed the same results on
Lutjanus benghalensis
from Omani waters. The relationship
between otolith length width and fish body proportions is related to the growth rate of the fish (Mugiya and
Tanaka, 1992) and these relationship became curvilinear in some larval or juvenile fishes (West and Larkin, 1987),
such curvilinearity was observed in the present study, but not in the previous similar studies on fishes from Oman
(Al-Mamry et al., 2010; Jawad et al., 2011a; 2011b; Jawad and Al-Mamry, 2012). Harvey et al. (2000), Waessle et
al. (2003) and Battaglia et al. (2010) have suggested that there is a possibility of getting error in the final results of
the relationship between otolith dimensions and fish size due to changes in this relationship during the life history
of the fish and as the fish length changes (Frost and Lowry, 1981; Hare and Cowen, 1995).
Since
L
.
ehrenbergii
being a dominant species in reef areas and prey of many carnivorous fishes, the assessment
of specific relationships would be very much useful to estimate the size of preys during the food and feeding
studies. This study anticipated to give an enhanced understanding in the trophic relationship in the Sea of Oman
food web by the reconstruction of the prey size using the otolith dimensions. It also will be useful in the
paleontological studies. Such numerical relations to predict fish size from the otolith size need to be determined
for more species, to supplement the studies and understand the trophic relationship between the fishes from the
Omani waters, quite renowned for its rich fish diversity.
Otolith may have been exposed to chemical and mechanical abrasion while they are in the stomach of the predator.
Such unfavourable exposure might lead to under valuation of otolith size (Granadeiro and Silva, 2000). The
strongly correlated relationship of head length and total length of the fish and otolith width was inspected and the
study resolved that these equations can be used to calculate the prey size for trophic dynamics studies. Battaglia et
al. (2010) have suggested that these equations are suitable within the size ranges used in this study for precise
estimations. On the other hand, Campana and Casselman (1993), Reichenbacher et al. (2009), Hare and Cowen
(1995) have gave a set of limitations in predicting the prey size of even the same species using the regression
equations. These limitations are the geographical areas, stocks, populations, sexes, ontogenic changes in the life
history.
4 Conclusion
In conclusion, the relationships between otolith length and width were shown to be good indicators for the total
and head length of fish and to a less extent to the standard length of the fish. Linear function offered the best fit
for relations between otolith and fish body proportions.
Authors’ contributions
All authors have contributed equally toward the publication of this paper.
Acknowledgments
Our sincere thanks are due to Oman Animal & Plant Genetic Resources Centre (OAPGRC), Scientific Research Council, Muscat,
Sultanate of Oman, for giving us the opportunity to work on the fish specimens. Also, to N. Jayabalan, India for the assessment in the
statistical analyses.
References
Al-Mamry J., Jawad L.A., Al-Busaidi H., Saoud Al-Habsi A., and Al-Rasbi S., 2010, Relationships between fish size and otolith size and weight in the
bathypelagic species,
Beryx splendens
Lowe 1834 collected from the Arabian Sea coasts of Oman,
Quaderni del Museo di Storia Natturale di Livorno,
23:
79-84
