Assessment of tunicate distribution and Polycarpa sp. tunic color variation in the Ambon Island waters

Abstract

Updated information regarding tunicates distribution and diversity in the waters around Ambon Island is scarce if any. We carried out an assessment using the underwater census approach in June 2018 to obtain the said information. Tunicates' composition and distribution were described based on six sampling station observations. Their average density in five of six stations was less than one individual per meter square. Predominant genera observed were Didemnum and Polycarpa. Tunicates belonging to Polycarpa sp. had 12 color variations on its tunic. Those sampled in Hitu had the most variations (8 variants) compared to all the other four stations. Didemnum sp. was highly abundant in three stations (Morella, Hitu, and Larike). Those identified as Polycarpa sp. were predominant only in two stations (Mamala and Wakal). Further studies are needed to investigate the anthropogenic pressure effect on these tunicates, as they were known as biomarkers in ecotoxicological studies.