Research Report

Fluctuating Asymmetry in the Otolith of two Parrotfish Species, Chlorurus sordidus (Forsskal, 1775) and Hipposcarus harid (Forsskal, 1775) from Hurghada, Red Sea coast of Egypt  

Mohamed Abu El-Regal1 , Laith A. Jawad2 , Sahar Mehanna3 , Yassin Ahmad4
1. Department of Marine Science, Faculty of Science, Port Said University, Port Said, Egypt
2. Flat Bush, Manukau, Auckland, New Zealand
3. Laboratory of Population Dynamics, Fisheries Division, National Institute of Oceanography and Fisheries, Suez Branch, Suez, Egypt
4. Laboratory of Population Dynamics, Fisheries Division, National Institute of Oceanography and Fisheries, Red Sea Branch, Hurghada, Egypt
Author    Correspondence author
International Journal of Marine Science, 2016, Vol. 6, No. 37   doi: 10.5376/ijms.2016.06.0037
Received: 24 Aug., 2016    Accepted: 10 Oct., 2016    Published: 11 Oct., 2016
© 2016 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:

El-Regal M.A., Jawad L., Mehanna S., Ahmad Y., 2016, Fluctuating Asymmetry in the Otolith of two Parrotfish Species, Chlorurus sordidus (Forsskål, 1775) and Hipposcarus harid (Forsskål, 1775) from Hurghada, Red Sea coast of Egypt, International Journal of Marine Science, 6(37): 1-5 (doi: 10.5376/ijms.2016.06.0037)

Abstract

Fluctuating asymmetry was calculated for the otolith length and width of the adult fishes Chlorurus sordidus and Hipposcarus harid. The results showed that the level of asymmetry of the otolith length was the higher than that of the otolith width in both species. For C. sordidus, the lowest level of asymmetry in the otolith length was at the fish total length ranging between 150-260 mm, and the highest at the fish total length 160-260 mm. For the otolith width, the highest level of asymmetry is at the fish length ranging between 24-26 mm and it has zero value in the other length groups. For H. harid, the lowest level of asymmetry in the otolith length was at the fish length ranging between 160-170 mm, and the highest at the fish length 240-260 mm. For the otolith width, the highest level of asymmetry is at the fish length ranging between 240-260 mm and it has zero value in the other length groups. The possible cause of the asymmetry in these species has been discussed in relation to the general presence of pollutants in the area. An increasing asymmetry with the fish length (age) was noticed.

Keywords
Otolith; Dimensions; Bilateral asymmetry; Scaridae; Ecological indicator

Introduction

Fluctuating asymmetry is a differential development of a bilateral character between the sides of an organism (Van Vallen, 1962; Leary and Allendroff, 1989). Developmental instability can be reflected by fluctuating asymmetry which is a random deviation from perfect bilateral system. In another words, it is the inability of an organism to compensate for disturbances during development (Zakharov, 1992), and such incapability can be affected by stress related to environmental or genetic conditions. As a result, high fluctuating asymmetry could indicate the worst condition of fish that experience unfavourable environments. Therefore, the bilateral asymmetry measure could show an environmental influence on the fitness of the organism.

 

Several adult fish species were used to study the relationship between fish condition and fluctuating asymmetry. In such a studies, numbers of measurements have been proposed, including the number of gill arks, pectoral fin rays, fish body proportions, eye spot area, or otolith size and shape (Escós et al., 1995; Somarakis et al., 1997; Jawad, 2001, 2003, 2004; Gonçalves et al., 2002; Jawad et al., 2012).

 

In having an asymmetrical otolith, fish will face some consequences that might change its habit or behaviour (Gagliano et al., 2007; Gagliano and McCormick, 2004). The survival of young individuals will be threatened as it will be difficult for them to find a proper place for settlement. On the other hand, fluctuating asymmetry in the otolith would be of interest to fisheries managers as it can supply a sort of measurement of past individual and population fitness due to the possibility to study otolith of specimens from old populations. Such information will assist in the collapse of a present time stock and throws light on the future management strategies (Díaz-Gil et al., 2015).

 

As fluctuating asymmetry studies were never performed on the otolith dimensions of the species in question or on that of the same species from other localities in Egyptian waters the present study represents the first study on fish otolith asymmetry of the Egyptian waters.

 

The present work studied fluctuating asymmetry in the otolith length, width of the two parrotfish Chlorurus sordidus and Hipposcarus harid collected from Hurghada, Red Sea coast of Egypt. It aims to provide information related to the detection of suitable settlement habitats by the larvae of those two species.

 

1 Materials and Methods

Description of sampling area

Hurghada lies at the northern part of the Red Sea between latitude 270 10’ N- 270 33' N and longitudes 330 70' E – 330 85' E (Figure 1). It is located on the western coast of the Red Sea, 500km south-east of Cairo, and stretches for about 36 kilometres along the seashore, and it does not reach far into the surrounding desert. The vicinity of Hurghada was chosen as it represents one of the main fishing grounds for the two species in question and asymmetry study for Chlorurus sordidus and Hipposcarus harid is important to show the effect of this phenomenon on the settlement of the larvae in this important fishing ground.

 

  

Figure 1 Sampling area

 

Sample collection

Specimens of parrotfish were obtained during the fishing season 2012-2013 through monthly sampling from the commercial landings. The fishes were caught using gill nets of 60 to 100 m long with mesh size of 2 – ¼ mm. Standard length (SL) was measured to the nearest 1.0 mm using digital caliper. Both left and right sagittae were removed through a cut in the cranium to expose them and then cleaned and stored dry in glass vials. Sagittae specimens were collected from 30 specimens (150-260 mm SL) of Chlorurus sordidus and 30 specimens (160-260 mm SL) of Hipposcarus harid of different fish length groups. Specimens with obvious evidence of calcite crystallization or other aberrant formations were not considered for this study. Each sagittae were systematically placed with the sulcus acusticus oriented towards the observer and the length was determined using ordinary light microscope. The maximum length (OL) and the maximum height (OW) were measured to an accuracy of 0⋅01 mm, recording the greatest distance from the anterior tip to the posterior edge (OL) and the greatest distance between the otolith dorsal and ventral margins (OW), according to Harvey et al. (2000) and Battaglia et al. (2010).

 

Statistical analysis

The statistical analysis was based on the squared coefficient of asymmetry variation (CV2 a) for the three otolith dimensions according to Valentine et al. (1973):

CV2 a = (S r-l X 100/X r + l)2

Where S r-l is the standard deviation of signed differences and X r + l is the mean of the character, which is calculated by adding the absolute scores for both sides and dividing by the sample size.

 

  

Table 1 Squared coefficient of asymmetry (CV2 a) value and character means (Xr+1) of Chlorurus sordidus and Hipposcarus harid

 

2 Results

The results of asymmetry data analysis of the otolith length, width of C. sordidus and H. harid collected from Hurghada, Red Sea coast of Egypt are shown in Table 1. The results showed that the level of asymmetry of the otolith length was higher than that of the otolith width. For C. sordidus and for both otolith variables, the lowest and highest values are found in the fish total length groups 150-170 mm and 240-260 mm. The asymmetry coefficient has zero value for other length groups. In both species, the results showed that asymmetry was correlated with fish length (Table 2).

 

  

Table 2 Squared coefficient of asymmetry and character means by size of Chlorurus sordidus and Hipposcarus harid

 

The percentage of the individuals showing asymmetry in the otolith length character was the highest among the percentages obtained for the two otolith characters in both species (Table 1).

 

3 Discussion

Abnormal swimming and behaviour in some fish individuals resulted in interference with the sound localization and lead for these individuals to decrease their ability to integrate with the environment that they living in (Lychakov and Rebane, 2005). Such consequences are results of the bilateral asymmetry in otolith mass.

 

The variations in the dimensions of the otolith of C. sordidus and H. harid, can affect the capability of the young individuals to locate and settle down in their suitable habitats (Gagliano and McCormick, 2004; Gagliano et al., 2007). Due to the asymmetry observed, settlement of larvae might be affected. Since the species in question are among the commercial species in Egypt, such studies are considered relevant to the ecology of these species in order to assess their stock in the area.

 

Due to unavailable data on the correlation between different environmental pollutions and the morphology of the two species dealt with in the present study to evaluate asymmetry along a pollution gradient, or from fish taken from impacted vs control (non-impacted) sites, it is not possible at this stage to have precise indication on the significance of this phenomenon. However, based on previous studies in this field, it is possible to suggest a correlation between environmental stress due to pollution and asymmetry in the morphology of this species. Such environmental factors are present in the waters of Hurghada, Red Sea coast of Egypt (Mansour et al., 2000; Mansour et al, 2005; Madkour et al., 2006; Madkour and Dar, 2007; Madkour et al., 2008, Mansour et al., 2011).

 

The environmental causes might be natural events, and several factors are known to produce nutritional deficiencies such as various pathogens and various population phenomena (Bengtsson and Hindberg, 1985), and it is highly possible that these factors may be in action in Oman Sea as they seem to be common in the aquatic environment.

 

Several authors have shown a relationship between the coefficient of asymmetry and fish length (Al- Hassan et al., 1990; Al- Hassan and Hassan, 1994; Al- Hassan and Shwafi, 1997; Jawad, 2001, 2013) where there was a trend of increase in the asymmetry value with the increase in fish length. The otolith morphological characters studied were identical and gave zero value for the asymmetry coefficient in several length groups studied. The results also show a trend of increase of otolith length and width asymmetry value with fish length.

 

References

Al- Hassan L A. J., Al- Dubaikel A.Y., Wahab N.K. and Al-Daham N.K., 1990. Asymmetry analysis in the catfish, Heteropneustes fossilis collected from Shatt al-Arab River, Basrah, Iraq. Revista de Idrobiologia 29 775-780.

 

Al- Hassan L. A. J. and Hassan S.S., 1994, Asymmetry study in Mystus pelusius collected from Shatt al-Arab River, Basrah, Iraq. Pakistan Journal of Zoology 26, 276-278.

 

Al- Hassan L. A. J. and Shwafi N., 1997, Asymmetry analysis in two marine teleost fishes collected from the Red Sea coast of Yemen. Pakistan Journal of Zoology 29, 23-25.

 

Battaglia P., Malara D., Romeo T. and Andaloro F., 2010, Relationship between otolith size and fish size in some mesopelagic and bathypelagic species from the Mediterranean Sea (strait of Messina), Italy. Scientia Marina 74, 605-612. 

http://dx.doi.org/10.3989/scimar.2010.74n3605

 

Bengtsson B.E. and Hindberg M., 1985, Fish deformities and pollution in some Swedish waters. Ambio 14, 32-35.

 

Díaz-Gil C., Palmer M., Catalán I. A., Alósi J., Fuiman L.A., García, E., Gil M.M., A. Grau A., Kang A., Maneja, R., Mohan J., Morro J., Schaffler J.J., Butty L., Riera-Batl I., Tolosa B. and Morales- Nin B., 2015, Otolith fluctuating asymmetry: a misconception of its biological relevance? ICES Journal of Marine Science 72, 2079-2089

http://dx.doi.org/10.1093/icesjms/fsv067

 

Escós J., Alados C.L., J.M. Emlen J.M. and Alderstein S., 1995, Development instability in the hake parasitized by myxosporean Kudoa spp. Transaction American Fisheries Society 124, 943-945.

http://dx.doi.org/10.1577/1548-8659(1995)124<0943:DIITPH>2.3.CO;2

 

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

http://dx.doi.org/10.1098/rspb.2007.1388 PMid:18077258 PMCid:PMC2596807

 

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

http://dx.doi.org/10.3354/meps278291

 

Gonçalves D.M., Simóes P.C., Chumbinho A.C., M. J. Correira M.J. and Oliviera R.F., 2002, Fluctuating asymmetry and reproduction success in the peacock blenny. Journal of Fish Biology 60, 810-820.

http://dx.doi.org/10.1111/j.1095-8649.2002.tb02411.x

 

Harvey J.T., Loughlin T.R., M. A. Perez M.A. and Oxman D.S., 2000, Relationship between fish size and otolith length for 63 species of fishes from the eastern North Pacific Ocean. NOAA Technical report NMFS, 150, pp. 35.

 

Jawad L. A., 2001, Preliminary asymmetry analysis of some morphological characters of Tilapia zilli (Pisces: Cichlidae) collected from three localities in Libya. Bolletino del Museo Regionale di Scienze Naturali Torino 18, 251-257.

 

Jawad L. A., 2003, Asymmetry in some morphological characters of four sparid fishes from Benghazi, Libya. Oceanological and Hydrobiological Studies 32, 83-88.

 

Jawad L. A., 2004, Asymmetry analysis in the mullet, Liza abu collected from Shatt al-Arab River, Basrah, Iraq. Bolletino del Museo Regionale di Scienze Naturali Torino 21, 145-150.

 

Jawad L. A., Z. Sadighzadeh Z. and Al-Mamry D., 2012, Preliminary study on the asymmetry in some morphological characters Lutjanus ehrenbergii (Peter, 1869) (family: Lutjanidae) collected from Bender Abbas, Persian Gulf. Natura Montenegrina 11, 463-472.

 

Jawad L. A., 2013, On the asymmetry of some morphological characters of the silver-cheeked toadfish Lagocephalus sceleratus (Gmelin, 1789) collected from the Sea of Oman. Water Research Management 3, 25-30.

 

Leary A. and Allendroff F.W., 1989, Fluctuating asymmetry as an indicator of stress: implications for conservation biology. Trend in Evolution 4, 214-217.

http://dx.doi.org/10.1016/0169-5347(89)90077-3

 

Madkour H.A. and Dar M.A., 2007, The anthropogenic effluents of the human activities on the Red Sea coast at Hurghada Harbour (Case study). Egyptian Journal of Aquatic Research 33, 43–58.

 

Madkour H.A., Ahmed A.A., and Mohamed A.W., 2006, Coastal sediments and their polluting metals of El- Hamrawein Harbour, Egyptian Red Sea coast: Clues for monitoring environmental hazards. Sedimentology of Egypt 14, 155–131.

 

Madkour H.A., A. W. Mohamed A.W. and Ahmed N.A., 2008, The impact of anthropogenic activities on the physical and chemical characteristics of surface sediments in some coastal lagoons along the Egyptian red sea coast. Egyptian Journal of Aquatic Research 34, 53 – 68.

 

Mansour A.M., Nawar A.H. and Madkour H.A., 2005, Metals concentration of recent invertebrates along the Red Sea Coast of Egypt: A Tool for monitoring environmental hazards. Sedimentology of Egypt 13, 171–185.

 

Mansour A.M., Nawar A.H. and Mohamed A.W., 2000, Geochemistry of coastal marine sediments and their contaminant metals, Red Sea, Egypt: A legacy for the future and a tracer to modern sediment dynamics. Sedimentology of Egypt 8, 231–242.

 

Mansour A.M., Nawar A.H. and Madkour H.A., 2011, Metal pollution in marine sediments of selected harbours and industrial areas along the Red Sea coast of Egypt. Annalen des Naturhistorischen Museums in Wien Series A 113, 225–244.

 

Somarakis S., Kostikas I. and Tsimenides N., 1997, Fluctuating asymmetry in the otoliths of larval fish as an indicator of condition: conceptual and methodological aspects. Journal of Fish Biology 51, 30-38.

http://dx.doi.org/10.1111/j.1095-8649.1997.tb06091.x

 

Valentine D. W., Soule M.E. and Samollow P., 1973, Asymmetry in fishes: a possible statistical indicator of environmental stress. Fishery Bulletin 71, 357-370.

 

Van Vallen L., 1962, A study of fluctuating asymmetry. Evolution 16, 125-142.

http://dx.doi.org/10.2307/2406192

 

Zakharov V. M.., 1992, Population phenogenetics: analysis of developmental stability in natural populations. Acta Zoologica Fennica 191, 7-30.

International Journal of Marine Science
• Volume 6
View Options
. PDF(519KB)
. FPDF
. HTML
. Online fPDF
Associated material
. Readers' comments
Other articles by authors
pornliz suckporn porndick pornstereo . Mohamed Abu El-Regal
. Laith A. Jawad
. Sahar Mehanna
. Yassin Ahmad
Related articles
. Otolith
. Dimensions
. Bilateral asymmetry
. Scaridae
. Ecological indicator
Tools
. Email to a friend
. Post a comment