Salinity tolerance, burrowing behaviour and pedicle regeneration in the brachiopod, Lingula anatina from north Queensland

Lingula anatina were collected from the intertidal sand flat at Shelly Beach, near Townsville and transported to the laboratory at the Australian Institute of Marine Science in 1972.After acclimation for 7 days in normal seawater, 20 Lingula anatina were placed in each of 8 aquaria, which contained seawater at salinities of 50.0, 36.5, 25.5, 20.6, 16.0, 11.5, 5.0 and 0 ppt respectively. The aquaria were maintained at a temperature 23±1°C. The viability (rapid "snap" reflex of valves) of the animals was monitored for 35 days and the time of loss of viability and time of death were recorded. Animals surviving after 35 days were returned to normal seawater and observed for a further 7 days.Burrowing experiments were conducted using 10 intact animals and 10 without pedicles. Animals were placed in aquaria with circulating seawater and buried at depths of 5, 10 and 20 cm in sand from Shelly Beach. The number of animals reaching the surface was recorded at 12 hour intervals or less for 5 days. Groups of animals with and without pedicles were also placed on the surface of sand from Shelly Beach in either stationary or slowly oscillating trays and burrowing monitored for 5 days.Ten animals, which had cast off their pedicles during transport to the laboratory were placed in each of 4 aquaria containing seawater at salinities of 36.5, 30, 20, and 10 ppt respectively and maintained at a temperature 25±1°C. Pedicle regeneration was observed for 14 days and then observed for a further 14 days after transferring the animals to normal seawater. To simulate more natural conditions, a further 10 animals without pedicles were buried under 10 cm of sand in an aquarium with circulating seawater. After 14 days the animals were removed form the sediment and the pedicles measured. This research was undertaken to investigate salinity tolerance, burrowing behaviour and pedicle regeneration in the infaunal brachiopod, Lingula anatina. The results were used to determine the possible effects that movement of substratum and reduced salinity, resulting from severe storms and cyclones may have on the survival of Lingula anatina populations.

1972年，研究人员于汤斯维尔附近的贝壳滩潮间带砂滩采集舌形贝（Lingula anatina），并将其转运至澳大利亚海洋科学研究所（Australian Institute of Marine Science）实验室。在正常海水中驯化7日后，将20只舌形贝分别放入8个水族箱（aquaria）中，各水族箱的海水盐度依次为50.0、36.5、25.5、20.6、16.0、11.5、5.0及0 ppt，且所有水族箱均维持在23±1℃的恒温条件下。研究人员连续35天监测受试个体的存活状态——即壳瓣快速“弹合”反射，记录其丧失存活能力的时间与死亡时间。35天后仍存活的个体被放回正常海水中，继续观察7天。掘穴行为实验共使用10只完整个体与10只去除腹柄（pedicle）的舌形贝：将受试动物置于配有循环海水的水族箱中，分别埋入取自贝壳滩的砂质底床5、10及20 cm深度处，在5天内以不超过12小时的间隔统计到达砂面的个体数量。此外，将带腹柄与无腹柄的受试动物分别放置在静止或缓慢振荡的砂盘表面，连续5天监测其掘穴行为。另有10只在转运至实验室过程中脱落腹柄的舌形贝，被分别放入4个盐度分别为36.5、30、20及10 ppt的水族箱中，维持温度为25±1℃。研究人员连续14天观察其腹柄再生情况，随后将受试动物转移至正常海水中，再持续观察14天。为模拟更贴近自然的环境条件，研究人员还将10只无腹柄个体埋入10 cm深的贝壳滩砂质底床中，水族箱配备循环海水。14天后将受试动物从沉积物中取出，测量其新生腹柄的长度。本研究旨在探究底栖腕足类（brachiopod）舌形贝的盐度耐受能力、掘穴行为及腹柄再生机制，研究结果用于解析强风暴与气旋引发的底床移动及盐度降低可能对舌形贝种群存活产生的潜在影响。