Body armour and lateral-plate reduction in freshwater three-spined stickleback Gasterosteus aculeatus: adaptations to a different buoyancy regime?
Body armour and lateral-plate reduction in freshwater three-spined stickleback Gasterosteus aculeatus: adaptations to a different buoyancy regime?
复制标题
淡水三刺刺鱼 Gasterosteus aculeatus 的防弹衣和侧板减少：适应不同的浮力状态？
作者：
F. Myhre;T. Klepaker
比较了三棘鱼Gasterosteus aculeatus一个海水种群和两个淡水种群的浮力相关因子。所有三个种群的鱼浮力接近中性的环境水。这表明，无论是海水还是淡水G. aculeatus使用游泳和水力提升来防止下沉。比较鱼鳔的体积表明，淡水完全镀G。aculeatus有一个显着更大的鱼鳔体积比完全镀海洋和低镀淡水G。刺肌此外，低板组的体组织密度较低。棘皮鱼的数量比完全镀覆的海水和淡水鱼的数量多。结果表明，G.棘突藻要么减少组织密度，要么增加鳔体积，以适应较低的水密度。侧板和骨盆的质量测量表明，低板G。aculeatus可以解释低平板和全平板G.刺肌这表明淡水中普遍发生的板甲减少现象。aculeatus种群可能是对较低水分密度的一种适应。
Several factors related to buoyancy were compared between one marine and two freshwater populations of three-spined stickleback Gasterosteus aculeatus. Fish from all three populations had buoyancy near to neutral to the ambient water. This showed that neither marine nor freshwater G. aculeatus used swimming and hydrodynamic lift to prevent sinking. Comparing the swimbladder volumes showed that freshwater completely plated G. aculeatus had a significantly larger swimbladder volume than both completely plated marine and low-plated freshwater G. aculeatus. Furthermore, body tissue density was lower in low-plated G. aculeatus than in the completely plated marine and freshwater fish. The results show that G. aculeatus either reduce tissue density or increase swimbladder volume to adapt to lower water density. Mass measurements of lateral plates and pelvis showed that loss of body armour in low-plated G. aculeatus could explain the tissue density difference between low-plated and completely plated G. aculeatus. This suggests that the common occurrence of plate and armour reduction in freshwater G. aculeatus populations can be an adaptation to a lower water density.