Commercial resource potential of an invasive sea cucumber: nutritional analysis of Synaptula reciprocans

Synaptula reciprocans, originally native to the Indo-Pacific region, is widespread in the Red Sea. The species entered the Mediterranean during the 1970s and 1980s and has been reported along the Turkish coastline since 2003, where it has established invasive populations. European Union Regulation No. 1143/2014 encourages the investigation of alternative uses and the assessment of the economic potential of invasive species as part of management and control strategies. This study aims to evaluate the nutritional value and elemental composition of S. reciprocans, an invasive species in the Mediterranean, in order to assess its suitability for human consumption and potential alternative applications.

S. reciprocans were sampled from two different stations (L1: Gokova Bay and L2: Gulluk Bay) over two seasons, as winter (S1) and summer (S2), and transported to the laboratory under cold chain conditions (+4 °C). Moisture, ash, crude protein, crude fat, fatty acid, amino acid, and elemental content analyses were performed using standardized methods, including gravimetric, Kjeldahl, GC/MS, LC/MS-MS, and ICP-OES techniques.

The findings indicate that both locality and season significantly influence the species' nutritional properties (p < 0.05). Dry matter content exhibited considerable variation across seasons, with the highest concentration observed in L2/S2 and L2/S1. Crude protein levels peaked in winter across both regions (L2S1, L1S1), while fat content was consistently higher in Bodrum samples compared to Gokova (p < 0.05). Ash content was highest in Gokova across both seasonal periods (p < 0.05). The fatty acid profile demonstrated notable seasonal and regional differences (p < 0.05), with linoleic acid (C 18:2) emerging as the predominant polyunsaturated ω-6 fatty acid. Additionally, amino acid analysis revealed significant variation (p < 0.05), identifying alanine, asparagine, glutamine, and proline as the dominant amino acids. Elemental analysis highlighted the absence of copper (Cu) in all sampled tissues, while sodium (Na) was consistently the most abundant mineral.