ORG.one project - Betta hipposideros: Pioneering Genome Assembly of Malaysia's Endangered Peat Swamp Fighter Fish (Betta hipposideros): A Conservation Genomics Approach

Rapid sequencing of the critically endangered Betta hipposideros as part of the ORG.one project https://org.one/oo. Betta hipposideros is a small endangered freshwater fish endemic to Malaysia's North Selangor Peat Swamp Forest (NSPSF) and Riau province's Indragiri River drainage in Sumatra, Indonesia. As an obligate peat swamp inhabitant, this species possesses unique adaptations for survival in highly acidic and hypoxic waters. At approximately 4-5 cm in length, B. hipposideros has developed specialised physiological mechanisms to thrive in oxygen-depleted, tannin-rich peat swamp environments. This project presents the first genome sequencing of B. hipposideros using Oxford Nanopore Technologies' PromethION 2 Solo platform for long-read sequencing. The genome was sequenced from DNA extracted from ocular tissue of a wild-caught specimen. This genomic resource will provide crucial insights into the species' evolutionary adaptations to acidic, hypoxic peat swamp environments and support conservation efforts for this threatened species. The genome data will enable comparative genomic analyses with other Betta species (non-obligate peat swamp inhabitants) and facilitate the development of conservation strategies. This work marks a significant advance in understanding the genetic basis of adaptation in acidic-water fish species and will contribute to the preservation of Malaysia's unique aquatic biodiversity.

本研究作为ORG.one项目（https://org.one/oo）的一部分，对极危物种蹄形搏鱼（Betta hipposideros）开展了快速全基因组测序。蹄形搏鱼是一种小型濒危淡水鱼类，仅为马来西亚北雪兰莪泥炭沼泽森林（North Selangor Peat Swamp Forest，简称NSPSF）以及印度尼西亚苏门答腊廖内省印德里吉里河流域的特有物种。作为专性泥炭沼泽栖息物种，该鱼演化出了独特的适应机制以在强酸性、低氧水域中存活。其体长约4至5厘米，已发育出特化的生理机能，可在缺氧且富含单宁的泥炭沼泽环境中顺利存活繁衍。本项目首次采用牛津纳米孔科技（Oxford Nanopore Technologies）的PromethION 2 Solo平台进行长读长测序，完成了蹄形搏鱼的全基因组测序。本次测序所用的DNA提取自一只野生捕获个体的眼部组织。该基因组资源将为解析该物种对酸性低氧泥炭沼泽环境的演化适应机制提供关键研究视角，并为该受威胁物种的保护工作提供支撑。该基因组数据可用于与其他搏鱼属物种（非专性泥炭沼泽栖息者）开展比较基因组学分析，助力针对性保护策略的制定。本研究在解析酸性水域鱼类适应机制的遗传基础方面取得了重要进展，同时将为保护马来西亚独特的水生生物多样性作出积极贡献。