Effect of size on the relationship between habitat suitability index and niche overlap in Namak chub (Squalius namak Khaefi et al., 2016) in Jajrood River, Namak Lake basin

Document Type : Research Article

Authors

1 Ph.D Student, Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran

2 Associate Professor, Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran

Abstract

The habitat suitability index can be applied to predict the distribution of living organisms in the aquatic ecosystem i.e. it can reveal their correlation with environmental factors. By examining the relationship between the habitat suitability index and the ecological niche of a species, important findings can be obtained from the functional aspects of ecological niche theory and intra-species competition. In this study, using traditional morphometric data and k-mean clustering, 103 samples of Squalius namak were grouped based on two groups of small and large fish. Then, to calculate the habitat suitability index, a non-parametric smoothing method was used to draw the relationship between each environmental variable and the number of fish in each station. A polynomial equation was then fitted to the data predicted by the smoothes. The ratio of the common area below the plots to the total area was used as the niche overlap. Finally, using linear regression, the relationship between the habitat suitability of each parameter and the amount of niche overlap obtained from the same parameter was investigated for both size groups. The height and slope of the two linear regressions were analyzed using the analysis of covariance. The results showed that there was no significant difference in the height and slope of the two fitted regression lines, indicating the same changes in the habitat suitability index on the niche overlap of small and large river fish. The average of niche overlap of small and large samples was 52%. Therefore, other parameters are likely to be effective in the competition of two different size of S. namak species.

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  • Abrams P. Some Comments on Measuring Niche Overlap. Ecol. 1980;61(1): 44-49.
  • Zamani Faradonbe M., Eagderi S., Zarei N. Determination of habitat suitability index of Capoeta gracilis, Keyserling 1861 from Taleghan River. J Fish 2015;68(3): 409-419. [In Persian]
  • Hirzel AH, Le Lay G. Habitat suitability modelling and niche theory. J Appl Ecol. 2008;45(5): 1372-1381.
  • McNyset K. Use of ecological niche modelling to predict distributions of freshwater fish species in Kansas. Ecol of Fresh Fish. 2005;14(3): 243-255.
  • Ahmdzadeh M, Poorbagher H, Eagderi S. Calculating the habitat suitability index of Siahmahi (Capoeta buhsei, Kessler 1877) using the kernel smoothing in the Jajrood River, Namak basin of Iran. Aqua Sci. 2019;6(2), 99-108. [In Persian]
  • Khaefi R, Esmaeili HR, Sayyadzadeh G, Geiger MF, Freyhof J. Squalius namak, a new chub from Lake Namak basin in Iran (Teleostei: Cyprinidae). Zootaxa 2016;4169(1): 145-159.
  • Mouludi-Saleh A, Keivany Y, Jalali SAH. Geometric morphometric comparison of Namak Chub (Squalius namak, Khaefi et al., 2016) in rivers of lake Namak basin of Iran. Research in Zoology 2017;7(1): 1-6.
  • Mouludi-Saleh A, Keivany Y. Morphometric analysis of Squalius namak Khaefi et al. 2016 in Khaznagh and Ghare-Chai rivers. Sri Lanka Jouranl of Aquatic Science 2018;23(2): 173-178.‏
  • Mouludi-Saleh A, Keivany Y, Jalali SAH. Biometry of Chub (Squalius namak Khaefi et al., 2016) in rivers of Namak Basin. Experimental animal Biology 2018;7(1): 107-118.‏ [In Persian]

 

  • Shabanloo H, Poorbagher H, Eagderi S. Effects of environmental parameters on morphological traits of Squalius namak in the Jajrood River. Aquaculture Sciences 2021;9(1): 172-181. [In Persian]
  • Eagderi S, Poobagher H, Zamani Faradonbe M. Habitat suitability index of Capoeta buhsei, Kessler 1877 in Jajroud River (Namak Lake basin). The Forth Iranian Conference of Ichthyology, Ferdowsi University of Mashhad, 20-21 July 2016. [In Persian]
  • Esmaeili HR, Sayyadzadeh G, Eagderi S, Abbasi K. Checklist of freshwater fishes of Iran. FishTaxa 2018;3(3): 1-95.‏
  • Armbruster JW. Standardized measurements, landmarks, and meristic counts for cypriniform fishes. Zootaxa 2012;3586(1): 8-16.
  • Shabanloo H, Poorbagher H, Eagderi S. The effect of ecological nich overlap of different fish
    size groups on changes in habitat suitability, morphological characteristics and genetic diversity of Squalius namak, Khaefi et al., 2016. M.Sc. thesis of Aquatic Ecology, University of Tehran. 2018. [In Persian]
  • Taghinezhad I, Ahmadi M, Kamali A, Haghbayan S. Ecological response of macrobenthos in Jadjrud River by human sewages. J Renew Nat Reso Res. 2015;6(1): 11-24. [In Persian]
  • Zaret TM, Rand AS. Competition in Tropical Stream Fishes: Support for the Competitive Exclusion Principle. Ecol 1971;52(2): 336-342.
  • Evangelista C, Boiche A, Lecerf A, Cucherousset J. Ecological opportunities and intraspecific competition alter trophic niche specialization in an opportunistic stream predator. J Anim Ecol. 2014; 83(5), 1025-1034.
Volume 9, Issue 4
January 2023
Pages 751-759
  • Receive Date: 18 May 2022
  • Revise Date: 19 August 2022
  • Accept Date: 19 December 2022
  • First Publish Date: 19 December 2022
  • Publish Date: 22 December 2022