*4.1. Sponge Collection*

Sponges were collected from Paniki (2◦42 31.4 N, 125◦21 36.8 E), Pehe (2◦44 03.3 N, 125◦21 33.3 E), and Ulu (2◦43 53.4 N, 125◦24 42.8 E) of Siau Islands Regency and from Batulewehe (3◦36 00.7 N, 125◦29 44.5 E), Kolongan (3◦38 11.4 N, 125◦25 28.9 E), and Kuma (3◦34 51.2 N, 125◦34 28.2 E) of Sangihe Islands Regency North Sulawesi Indonesia at a depth between ~4 and ~20 m during May 2019. After morphological description and underwater documentation by photograph (GoPro Hero 4.0, except for specimens from Kolongan which were taken by GroPro Hero 7.0), each specimen was cut and kept individually in a plastic bag. Samples were transferred to the laboratory in Politeknik Negeri Nusa Utara Tahuna Indonesia where the specimens were stored at <sup>−</sup><sup>16</sup> ◦C until used. From each specimen, a small portion (1 cm3) was taken for taxonomic identification using slightly modified bleach digestion method [42,43]. All specimens were individually sliced into small pieces, dried in the oven at 45 ◦C for 3 days and blended to give either powder or mash of sponges. This drying step was performed, since the infrastructure available at the islands is limited and the material prepared in this way was then ready to be sent by normal post. Sponges of 2 to 5 g were packed individually in a small plastic bag separately secured in 76 sample bottles and sent to Justus-Liebig-University Giessen, Germany on October 2019.
