UV-absorbing pigments in eye tissues of fish from the Great Barrier Reef

Ocular tissues from 52 species (19 families) of tropical marine fish were examined for levels of UV-absorbing pigments in the spectral region 300-380 nm.Specimens of mackerels, tuna and marlin were caught by surface trolling in Bowling Green and Upstart Bays; all other fish were caught by hand-line or spearfishing at Grub, Hunt and Marion Reefs. The eyes were removed and frozen immediately at -20°C. Lens ocular tissues were excised from defrosted samples, crushed and extracts formed by steeping in 5ml methanol. Visible-u.v. absorption spectra from these extracts were recorded. Solid protein biomass was determined from the solid tissue residues. Mycosporine-like amino acids (Asterina-330, palythene, palythine and palythinol) were separated and quantified (nmol/mg protein) using reverse-phase isocratic high-performance liquid chromatography (HPLC).The efficiency of methanol extraction This research was undertaken to:1. identify and describe the distribution of mycosporine-like amino acid compounds in the lens tissues of marine fish2. develop techniques for quantitative studies of UV absorbing compounds in fish eyes using high performance liquid chromotography3. evaluate the efficiency with which these compounds can be extracted from lens tissues

本研究针对52种（隶属于19个科）热带海水鱼类的眼部组织，检测其在300~380 nm光谱区间内的紫外吸收色素含量。鲭类、金枪鱼及马林鱼的样本采集自鲍灵格林湾与阿普斯塔特湾，采用水面拖钓方式获取；其余所有鱼类样本均在格拉布礁、亨特礁及马里恩礁通过手钓或鱼叉捕鱼方式采集。采集后立即摘除眼球，并置于-20℃环境下速冻保存。将解冻后的样本取出眼部晶状体组织，经研磨后以5毫升甲醇浸泡制备提取液。对上述提取液的可见-紫外吸收光谱进行记录。通过残留固体组织样本测定总蛋白生物量。采用反相等度高效液相色谱法（high-performance liquid chromatography, HPLC）分离并定量类菌孢素氨基酸（mycosporine-like amino acids，包括Asterina-330、palythene、palythine及palythinol），定量单位为nmol/mg蛋白。本研究同时评估了甲醇提取效率，并旨在达成以下三大目标：1. 明确并描述海洋鱼类晶状体组织中类菌孢素氨基酸类化合物的分布特征；2. 建立基于高效液相色谱法的鱼类眼部紫外吸收化合物定量研究技术；3. 评估从晶状体组织中提取上述化合物的实际效率。