Aljahdali MO and Molla MHR (2022), Population dynamics and fecundity estimates of ...

ECB-ART-50973

Saudi J Biol Sci 2022 Sep 01;299:103395. doi: 10.1016/j.sjbs.2022.103395.

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Population dynamics and fecundity estimates of Long-spined Black Sea Urchin Diadema savignyi (Audouin, 1890) from the Red Sea, Saudi Arabia.

Aljahdali MO , Molla MHR .

Abstract
Sea Urchin is not only the crucial keystone species for the coral reef restoration but also it has antimicrobial and anti-cancer activities. This study undertaken to focus on length weight relationship, size fecundity distribution and the estimation of fecundity from the long-spined Sea Urchin, Diadema savignyi at the coastal water of the middle Red Sea, Saudi Arabia. A total of 633 specimen of D. savignyi has been collected from the coastal water of Obhur Creak during the sampling time. In each species, total length (TL) measured as a TW = 11.908 × 0.9995 (R2 = 0.8975) through the linear regression graph and digital slide callipers and, individual body weight estimated by the digital balance. The natural and fishing mortality 2.02/yr and 0.19/yr respectively has documented from study area. The Asymptotic length value (L∞) (cm) were estimated 7.35 where the growth coefficient (K) was 0.67 from the monthly length-frequency numeric data by using FAO FISAT II software for generating and estimating the population parameters and age. However, the recruitment pattern was observed to be increased gradually with the maximum recruitment peak between the months of September and October 2021. Therefore, the estimation of fecundity varied from 49,226 ova (total length 3.1 cm) to 466,133 ova (total length 6.8). As a result, analysis of the relationship between the absolute fecundity (F) and total length (TL), and between the fecundity and drained body weight (DW), revealed a linear regression model with a positive and significant relationship at p < 0.05. This is the first approach to study the detailed population dynamic of the ecologically and economically important tropical long spine sea urchin (D. savignyi) endemic to the region. However, the result so far obtained from this research would greatly be useful towards the understanding of the detailed population structure and growth patterns that will undoubtedly help us to develop captive breeding, seed production, culture protocols, conservation strategies and isolation bioactive compounds of this high-valued species incommensurate with national and international perspectives.

PubMed ID: 35935102
PMC ID: PMC9352549
Article link: Saudi J Biol Sci

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References [+] :

Atta, Conspicuous and cryptic reef fishes from a unique and economically important region in the northern Red Sea. 2019, Pubmed

	Fig. 1. Location of sampling area at Obhur region of north Jeddah seashore, Red Sea.
	Fig. 2. Length weight relationship of D. savignyi from in the coastal water of northern (middle) area, Red sea, Saudi Arabia.
	Fig. 3. The growth performance index (Ï'- phi prime) of sea urchin (D. savignyi).
	Fig. 4. Growth curve of D. savignyi by ELEFAN 1 superimposed on the restructured length-frequency diagram (Lâ = 12.38Â cm and KÂ =Â 1.7/yr.).
	Fig. 5. Length-converted catch curve of D. savignyi in the coastal water of middle area, Red sea, Saudi Arabia.
	Fig. 6. Recruitment pattern of D. savignyi in the coastal water of northern (middle) area, Red sea, Saudi Arabia from January to December 2021.
	Fig. 7. Length structured virtual population analysis (VPA) of D. savignyi in the coastal water of northern (middle) area, Red Sea, Saudi Arabia.
	Fig. 8. Relative yield per recruit and biomass per recruit curves for D. savignyi in the Obhur Creak, Kingdom of Saudi Arabia.
	Fig. 9. Cumulative probability of D. savignyi. The predicted maximum length value and the 95% confidence interval are obtained from the intersection of the overall maximum length with the.
	Fig. 10. Relationship between the absulate fecundity (F) and total length (TL) also revealed linear regression model with a positive and significant relationship at pÂ <Â 0.05.