A novel evaluation model for distribution of littoral zoanthids using coverage range index

Zoanthids are abundant benthic cnidarians in the Persian Gulf; but despite their abundance, even basic ecological information is still lacking. According to this, two sites in littoral reefs of Hormuz Island were studied monthly from June 2015 to June 2016. This study aimed to evaluate abundance changes in distribution of zoanthids using coverage range index (CRI), which is also introduced as a new index to assess the influence of the substrate composition on distribution of zoanthids. Line intercept transect method was performed to assess the zoanthid coverage along 6 transects. CRI was selected to tentatively assign the investigated coverage range of zoanthids into 3 coverage range categories: wide, middle, narrow. CRI boundary for each category was also estimated. The results indicated significant relationship between substrate composition and coverage range of zoanthids. Hence, CRI proved to be a reliable index because of its strong fluctuations resulting mainly from total abundance of zoanthids. Our results recommended that the use of CRI could be employed as a cost-effective tool for biomonitoring and controlling of zoanthid habitat in littoral reefs of the Persian Gulf.

کلیدواژه ها:

CRI ، Abundance ، Substrate composition ، Littoral reef ، Persian Gulf