Factors Influencing the Prospect of Asexual Reproduction in Holothuria Arenicola (Semper, 1868)

Abstract

Asexual reproduction by transverse fission was studied in populations of Holothuria arenicola through investigation of different factors affecting the fission and survival rates. Size, fission position, and temperature impacts were experimentally assessed. It was observed that higher fission rate was recorded in small specimens as compared to large ones. The fission position at 30% yielded higher fission rate (90%) as compared to that obtained in 45% fission (70%). Temperature showed a considerable effect on either fission or survival rate with a direct proportional relationship between temperature and both rates. At 20°C, fission started in the 2 nd day to be at rate of 20% which was gradually increased until reaching 100% by the 8 th day; sharp decline of survival rate was occurred reaching 35% by the 9 th day. At 25°C, fission reached 70% by the 8 th day; the survival rate became constant at 50% from the 17 th day onward. At 30°C, the highest fission rate was attained in the 4 th day but the survival rate was zero in the 5 th day. It was noted that the woundhealing period took longer time at 30°C than at 20°C and 25°C. Additionally, changes of anterior parts (A) and posterior parts (P) internal organs were followed weekly over two months after fission induction to detect both of the dissolved structure and regenerated one.

Ecological study of two sea cucumbers (Holothuria parva and Holothuria arenicola) in the Hormozgan and Bushehr provinces of Persian Gulf

“…The value of b from the power function equation was tested and used to determine growth patterns of the sea cucumber (i.e. isometric growth (b=3) or allometric growth (b≠3) by using the Students t-test (Pauly, 1984). The coefficient of determination (R 2 ), that is, the degree of relation between the length and weight, was computed by linear regression analysis.…”

“…Holothuria parva is brownish in colour and lighter colour in ventral side and ventral mouth and its habitat is rocky shores in the intertidal zone, as the individuals was usually hidden under stones (Pauly, 1984). Mouth of this species is located in abdominal position, and anus is terminal type (Salari-Aliabadi & Monjezi-Veysi, 2020).…”