Taxonomical Characteristics and Biochemical Properties of Namalycastis abiuma: A Promising Nutritional Resource for Aquaculture

Namalycastis abiuma polychaete species is generally found in mangrove mud flats, whereas ten specimens were observed, with six being complete, ranging from 128 to 135 chaetigers. The species exhibits an elongated body with a convex dorsum and flat ventral surface. The prostomium is trapezoidal with a distinct anterior cleft, and the antennae are short and subconical. Moreover, the species has two pairs of eyes, tentacular cirri with smooth cirrostyles, and a button-shaped pygidium with two smooth anal cirri. The determination of proximate composition widely accepted standard methods were followed, whereas it revealed rich protein content with 54.24 ± 2.4%, and moderate lipid at 32.3 ± 1.2%, a lesser amount of carbohydrate with 17.2 ± 0.7%, and an ash percentage of 7.2 ± 0.5%. The fatty acid profile revealed that 30 numbers of fatty acids belong to SFA, MUFA, and PUFA; at the same time, omega-3 fatty acids, including EPA and DHA, are notable fatty acids that comprise 12.64 ± 1% of the total fatty acids. Unlike other polychaetes, the species of Namalycastis abiuma, generally found in mangrove environments, plays a significant role in nutrient cycling, giving crucial support to the coastal ecosystem's health, and the species has also shown great potential of biochemical profile, including protein, lipid, and carbohydrates, and specifically the presence of higher amounts of protein and omega-3 fatty acids, which collectively gives great attention to this species as a promising nutrient source that would support the aquaculture-adapted species like shrimp and fish in their immune system enhancement, reproduction, and growth. This study highlighted that this species is an alternative source for formulating feed, in contrast to reliance on traditional fishmeal, which may create more sustainable and affordable aquaculture practices.