Research Report

Otolith Mass Asymmetry in Lutjanus ehrenbergii (Peters, 1869) Collected from the Sea of Oman  

Abdullah H. Al Balushi1 , Laith A. Jawad2 , Haitham K. Al Busaidi1
1 Oman Animal & Plant Genetic Resources Centre (OAPGRC), Scientific Research Council, Muscat, Sultanate of Oman
2 Flat Bush, Manukau, Auckland 2016, New Zealand
Author    Correspondence author
International Journal of Marine Science, 2017, Vol. 7, No. 37   doi: 10.5376/ijms.2017.07.0037
Received: 18 Aug., 2017    Accepted: 11 Sep., 2017    Published: 15 Sep., 2017
© 2017 BioPublisher Publishing Platform
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:

Al Balushi A.H., Jawad L.A., and Al Busaidi H.K., 2017, Otolith mass asymmetry in Lutjanus ehrenbergii (Peters, 1869) collected from the Sea of Oman, International Journal of Marine Science, 7(37): 366-370 (doi: 10.5376/ijms.2017.07.0037)


Otolith weight difference on both sides of the fish head, x, was estimated. Sagittae otolith mass asymmetry was investigated in the littoral lutjanid species Lutjanus ehrenbergii. The absolute value of |x| in Lutjanus ehrenbergii does correlate with the fish length and otolith development. Such case is similar to that in the symmetrical fish species, the absolute. An increase in the absolute value of otolith asymmetry in relation to the fish size was observed. The range of x magnitude was between -0.2 and +0.2.

Otolith; Weight asymmetry; Lutjanidae; Sea of Oman; Acoustic and vestibular functions


One of the major factors that causing modification in the behaviour of the fish is the case of lightness due to the weight difference of the otolith between the two sides of the head of the fish (Egorov and Samarin, 1970; Hoffman, 1977; Von Baungarten et al., 1982; De Jong et al., 1996; Hilbig et al., 2002; Rehman and Ankan, 2002). Variation in the weight of the fish may be due to the otolith weight differences, which might cause acoustic inadequacies (Lychakov et al., 2006), consequently, the fish cannot avoid the impairment in the function of the sense of hearing.


In fishes, the otolith weight asymmetry is usually 0.2< X < +0.2 or <20% (Lychakov et al., 1987; Lychakov, 1992; Takabayashi, 2003), and the otolith mass asymmetry and length or weight of the fish were not related to each other (Lychakov and Rebane, 2004). Results of several investigators have revealed the function of hearing in the fish will be affected if otolith weight asymmetry becomes lower than the standards stated above for the symmetric fish species (Lychakov et al., 2006). Samarin (1992), Scherer (2001) and Lychakov (2002) have recommended that the mass non-symmetry of otolith might change the quality of reception, which could affect in return the navigation of the fish.


Numerous studies on the weight difference of the otolith of fishes from the Omani waters were published in the recent years (i.e., Jawad et al., 2010; Jawad et al., 2011; Ambuali et al., 2011; Jawad et al., 2012; Jawad, 2013), but there is no such study on L. ehrenbergii. Therefore, the present work is a significant addition to the knowledge of otolith mass asymmetry in the area of Sea of Oman. The objective of the work at hand is to determine and to evaluate the discrepancy of this asymmetry of L. ehrenbergii. Habits of the fish might show deviation from that of the normal pattern once the weight in the otolith is started (Gagliano et al., 2007; Gagliano and McCormick, 2009). The endurance of the juveniles will be endangered with the increasing inability to locate an appropriate place to inhabit and hence noteworthy alterations to the population of the species will yield.


1 Materials and Methods

Otolith mass and fish length were obtained from 50 samples of L. ehrenbergii fished from the Sea of Oman, the City of Muscat, Sultanate of Oman between May and June of 2017 from the commercial artisanal catch. Fish were measured for their standard length was recorded preceding to otolith removal. The otoliths were extracted, washed in 70% ethanol and left to dry in the room temperature for few hours. Analytical balance to an accuracy 0.0001 g was used to record the weight of the otolith. The otolith non-asymmetry (x) was measured using following the formula:



Where MR and ML are the otolith weights of the right and left otoliths and M is the mean mass of the right and left otoliths. Theoretically, x value can take any value between -2 and 2, and x = 0 indicates the absence of mass asymmetry (MR – ML), while x = -2 or x = 2 denote the maximal asymmetry (absence of one otolith). The x positive value indicates that the weight of the otolith on the right is larger than that on the left, while the negative sign denotes the opposite. The association of the species absolute value of |x| and the increase in the growth of the otolith was investigated. The absolute value of the species otolith weight non-asymmetry is estimated as the average individual value. To assess otolith growth rate, the relationship between otolith mass and fish length, m = a x l + b, was determined, where “l” is the length of the fish, “a” is the coefficient illustrating the growth rate of the otolith, and “b” is a constant.


2 Results

The x mean value is 0.0049 + 0.0237 SE, n = 45 (Figure 1) and the value of |X| is 0.0156 + 0.0134 SE, n = 45 (Figure 2). Absence of association between fish length and both |X| was revealed (y = 0. 0006 x + 0.0222) (P > 0.05, R2 = 0.1107) and x (y= -0.0001 x +0.0328) (P > 0.05, R2 = 0.0219).



Figure 1 Saccular otolith mass asymmetry x in Lutjanus ehrenbergii as a function of fish length



Figure 2 Absolute otolith mass asymmetry as function of fish length


The correlation between otolith mass difference (MR – ML), and fish length was more intricate than the relation between x and fish length (n = 45, standard length = 210-230 mm, P > 0.05, y = -2E- 05x + 0.0051, R2 = 0.0177) (Figure 3).The saccular otolith mass difference increases with fish length.



Figure 3 Saccular otolith mass difference in Lutjanus ehrenbergii as a function of fish length


3 Discussion

The results have shown that the value of x falls in the range -0.2 and +0.2, which is comparable to what is normally given for other marine fish species (Lychakov, 2013) and it is found that the mass asymmetry in the otolith is less than 0.05. An agreement with the value of weight asymmetry observed in marine fishes (Lychakov et al., 2006) and did not depend on otolith growth rate. Moreover, the absolute value of the otolith non-asymmetry with the fish length and this is a characteristic of the littoral fishes (Lychakov, 2013).


The function of the ear of the fish can be disturbed because of the difference in the weight of the otolith (Lychakov and Rebane, 2004; 2005). As in the previous cases on several fish species, including the lutjanid fish observed, otolith weight non-asymmetry is low (|x| < 0.5), irrespective of fish size. This low level of otolith asymmetry is one of the features of both the hearing organs. Lychakov and Rebane (2005) have indicated that fishes with large otoliths and |x| > 0.2 may, in theory, develop difficulties with sound processing due to inconsistency and peculiarity of the movement of the two otoliths in the head of the fish. Consequently, large number of fish species can avoid the loss in hearing ability of their otolith mass non-asymmetry is ranging below the value (0.2< X < +0.2).


This study showed results support those acquired for a number of fish species, where otolith mass non-asymmetry dissociate with the fish length (Jawad et al., 2017). Nevertheless, the relationship of the otolith mass difference and fish size is complicated. This study showed that this correlation is very ineffectual and near non-absence. Lychakov and Rebane (2004) have revealed comparable results on a number of fish species and suggested that the minimal correlation or non-appearance of such association may because to the small number of samples studied, with specimens are very close in their sizes.


The results obtained for Beryx splendens and Lutjanus bengalensis (Jawad et al., 2012) and Rhynchorhamphus georgi (Jawad et al., 2011) appeared to be species specific due to their high inconsistency in weight of the left and right otolith. In the analysis where a large number of specimens is used with clear differences in the fish size, such discrepancies in the otolith weight between the two sides of fish head become minimal (Lychakov et al., 2006).


Authors’ contributions

All authors have contributed equally toward the publication of this paper.



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.



Ambuali A., Jawad L.A., and Al-Mamry J.U.M.A., 2011, Otolith mass asymmetry in the adult Indian Mackerel Rastrelliger kanagurta (Cuvier, 1816), collected from the Sea of Oman, Asian Fisheries Science, 24: 426-431


De Jong H.A.A., Sondag E.N.P.M., Kuipers A., and Oosterveld W.J., 1996, Swimming behaviour of fish during short periods of weightlessness, Aviation Space Environ Medicine, 67: 463-466


Egorov A.D., and Samarin G.I., 1970, Possible change in the paired operation of the vestibular apparatus during weightlessness, Kosmicheskaya Biologiva i Aviakosmicheskaya Medicine, 4: 85-86 (in Russian)


Gagliano M., Depczynski M., Simpson S.D., and Moore J.A.Y., 2008, Dispersal without errors: symmetrical ears tune into the right: frequency for survival, Proceedings of the Royal Society B, 275: 527-534

PMid:18077258 PMCid:PMC2596807


Gagliano M., and Mc Cormick M., 2004, Feeding history influences otolith shape in tropical fish, Marine Ecology Progress Series, 278: 291-296


Hilbig R., Anken R.H., Bäuerle A., and Rahmann H., 2002, Susceptibility to motion sickness in fish: a parabolic aircraft flight study, Journal of Gravity Physiology, 9: 29-30


Hoffman R.B., Salinas G.A., and Baky A.A., 1977, Behavioural analyses of killifish exposed to weightlessness in the Apollo-Soyus Test Project, Aviation Space Environmental Medicine, 48: 712-717



Jawad L.A., 2013, Otolith mass asymmetry in Carangoides caerulepinnatus (Rüppell, 1830) (Family: Carangidae) collected from the Sea of Oman, Croatian Journal of Fisheries, 71: 37-41


Jawad L.A., Al-Mamry J.M., and Al-Busaidi H.K., 2010, Otolith mass asymmetry in the teleost Beryx splendens Lowe, 1834 (Family: Bercidae) collected from the Arabian Sea coasts of Sultanate of Oman, Thalassas 26(1): 43-47


Jawad L.A., Al-Mamry J., Al-Mamary D., and Al-Hasani L., 2012, Study on the otolith mass asymmetry in Lutjanus bengalensis (Family: Lutjanidae) collected from Musct City on The Sea of Oman, Journal of Fisheries Sciences, 61: 74-79


Jawad L.A., Mehanna S.F., Abu El-Regal M.A., and Ahmed Y.A., 2017, Otolith mass asymmetry in two parrotfish species, Chlorurus sordidus (Forsskål, 1775) and Hipposcarus harid (Forsskål, 1775) from Hurghada, Red Sea Coast of Egypt, International Journal of Marine science, 7: 200-204


Jawad L.A., Al-Mamry J.M., Al-Mamari H.M., Al-Yarubi M.M., Al-Busaidi H.K., and Al-Mamary D.S., 2011, Otolith mass asymmetry in Rhynchorhamphus georgi (Valenciennes, 1846) ( Family: Hemiramphidae) collected from the Sea of Oman, J. Black Sea/Mediterranean Environment, Vol. 17(1): 47- 55


Lychakov D.V., 1992, Morphometric studies of fish otoliths in relation to vestibular function, Zhurnal Evolyutsionnoi Biokhimii i Fiziologii, 28: 531-539 (in Russian)


Lychakov D.V., 2002, Otolithic membrane: structural and functional organization, evolution, ecomorphological plasticity and tolerance to extreme conditions (Doctorskaya Dissertaziya), Vol 1. Sechenov Institute, St.-Petersberg (text, tables), pp.1-266, Vol. 2 (illustrations), pp.1-107 (in Russian)


Lychakov D.V., 2013, Behavioural lateralization and otolith asymmetry, Journal of Evolutionary Biochemistry Physiology, 49: 441-456


Lychakov D.V., and Rebane Y.T., 2004, Otolith mass asymmetry in 18 species of fish and pigeon, Journal of Gravity Physiology, 11: 17-34


Lychakov D.V., and Rebane Y.T., 2005, Fish otolith mass asymmetry: morphometry and influence on acoustic functionality, Hearing Research, 201: 55-69



Lychakov D.V., Boiadzhieva-Mikhaĭlova A., Khristov I., Pashchinin A.N., and Evdokimov I.I., 1987, Changes in the otolithic apparatus of rats and fish after long-term rotation with increased acceleration, Kosmicheskaia biol i aviakosmicheskaia Med, 22: 27-33


Lychakov D.V., Rebane T.Y., Lombarte A., Demestre M., and Fuiman L., 2008, Saccular otolith mass asymmetry in adult flatfishes, Journal of Fish Biology, 72: 2579-2594


Lychakov D.V., Rebane Y.T., Lombarte A, Fuiman L.A., and Takabayashi A., 2006, Fish Otolith asymmetry: morphometry and modelling, Hearing Research, 219: 1-11



Rahman H., and Anken R.H., 2002, Gravitational biology using fish as model systems for understanding motion sickness susceptibility, Journal of Gravity Physiology, 9: 19-20


Samarin G.I., 1992, Study of the labyrinth asymmetry and its possible role in the motion sickness genesis (Tezisy Kandidatskoi Dissertazii), Institute for Biomedical Problems, Moscow, pp.1-33 (in Russian)


Scherer H., Helling K., Clarke A.H., and Hausmann S., 2001, Motion sickness and otolith asymmetry, Biological Sciences in Space, 15: 401-404



Takabayashi A., 2003, Functional asymmetry estimated by measurements of otolith in fish, Biological Sciences in Space, 17: 293-297



Von Baumgarten R.J., Wetzig J., Vogel H., and Kass J.R., 1982, Static and dynamic mechanisms of space vestibular malaise, Physiology, 25: 33-36 

International Journal of Marine Science
• Volume 7
View Options
. PDF(375KB)
. Online fPDF
Associated material
. Readers' comments
Other articles by authors
. Abdullah H. Al Balushi
. Laith A. Jawad
. Haitham K. Al Busaidi
Related articles
. Otolith
. Weight asymmetry
. Lutjanidae
. Sea of Oman
. Acoustic and vestibular functions
. Email to a friend
. Post a comment