Sea Cucumber “Holothuria (Thymiosycia) arenicola” induced-autotomy for sustainable development in Egypt: Histological, Ultrastructure, and Chemical studies.

The importance of Echinoderms in Egypt grows day after day, as well as, the usage of the available untapped resources, in particular our interest in mariculture. Sea cucumber fishing was prohibited in Egypt and listed as endangered species, due to overfishing. Although the above decision was right at its time, it is not acceptable to us, due to the economic, nutritional, and pharmaceutical importance of the sea cucumber. So; this work was designed to study the animal well microscopically, apply the artificial induction of autotomy on the animal for the numerical increase and reproduction asexually, and chemically investigate the medical importance of the coelomic fluid of the sea cucumber “Holothuria arenicola”. Materials and methods: the body wall and the coelomic epithelium were studied microscopically. For the animal numerical increase, the autotomy was induced in 3 groups by manual ligation of the body from ¼, ⅓, and ½ of the whole body length of the adults; respectively, in addition to the control group. Side by side with the abovementioned studies, the acellular chemical content of the coelomic fluid was analyzed using GC/MS, and the resulting constituents were furtherly-analyzed by protein docking to investigate the ability of the coelomic fluid to accelerate wound healing. Conclusion: Histologically; the body wall of the sea cucumber’s “Holothuria arenicola” is composed of five layers. Ultrastructurally; the coelomic epithelium small (progenitor) cells (coelomocytes) seem to be hypothetically differentiated into two main types: the neighboring/surrounding cells (that might supply the neighboring dividing cells with the membranes or any cytoplasmic organelles, hypothetically via exocytosis or endocytic recycling trafficking events or by plasma membrane remodeling), and defense cells that resemble the human neutrophils. Experimentally, the artificially-induced autotomy of the half-body-length ligated group is the only successful group that divides completely. Chemically, we found the presence of bioactive GSK3-β protein in the sea cucumber-extracted coelomic fluid which makes them a valuable resource for wound healing treatment especially in diabetics. Finally, the sea cucumber “Holothuria arenicola” is considered a gift for Egypt, due to its proven significant potential for economic and medical applications, both criteria of significance are concomitant with the sustainable developmental goals and Vision of Egypt 2030.