Musa Keshavarz; Maryam Soyuf Jahromi
Volume 6, Issue 1 , May 2017, , Pages 121-132
Abstract
Sea urchin as a bioerosion, is an effective factors on coral reef ecosystems which the observable biometry of urchin and its relationship with the jaw is important. Therefore, within this survey, sea urchin Echinometra mathaei were examined for summertime (July–September, 2014) between the intertidal ...
Read More
Sea urchin as a bioerosion, is an effective factors on coral reef ecosystems which the observable biometry of urchin and its relationship with the jaw is important. Therefore, within this survey, sea urchin Echinometra mathaei were examined for summertime (July–September, 2014) between the intertidal areas of Dayyer Port (51˚53’49.39ʼ’E, 27˚50ʼ3.57’’N), Iran. A total of 91 individuals lively transferred to a lab. Total wet weight was weighted by a digital scale and the test height and diameters and the jaw length was measured by caliper (0.01 precision). The relationships between heights and diameters with weights were calculated according to indices and the relationships between the jaw lengths and test height and diameter were achieved. The results illustrated that the relationship between test height to its diameter (HDR index) is independent of test diameter (the slop near to zero) and therefore, there is a direct relationship between test height and diameter (a=0.47). Although the highest values of test height and spin length refer to males, but females achieved bigger values of test diameter, height and thickness (mean test height, diameter and thickness of females were 24.13±3.52 mm, 44.93±5.71 mm, 0.83±0.16 mm; and males: 21.22±6.82 mm, 37.67±12.27 mm, and 0.73±0.20 mm, respectively). The test diameter and weight of immature samples were less than 20 mm and 6.66 gr, respectively where can be as a primary criterion of Echinometra mathaei sexual maturity. Two indices HWR and DWR of both females and males had obvious differences with total samples, which also can be related to immature samples. Moreover, the jaw length was half of height (a=0.49, r=0.87) and a quarter of diameter (a=0.25, r=0.89). Results also illustrated well that larger samples had longer jaws that it could help identifying higher erosive samples.
