Paredes-Molina F J, Chaparro O R, Navarro J M, Cubillos V M, Montory J A, Pechenik J A
Instituto de Ciencias Marinas y Limnologicas, Universidad Austral de Chile, Valdivia, Chile.
Instituto de Ciencias Marinas y Limnologicas, Universidad Austral de Chile, Valdivia, Chile.
Mar Environ Res. 2023 May;187:105971. doi: 10.1016/j.marenvres.2023.105971. Epub 2023 Mar 30.
Egg capsules of the gastropod Acanthina monodon were maintained during the entire period of encapsulated development at three temperatures (10, 15, 20 °C) and two pCO levels (400, 1200 μatm). Embryos per capsule, size at hatching, time to hatching, embryonic metabolic rates, and the resistance of juveniles to shell breakage were quantified. No embryos maintained at 20 °C developed to hatching. The combination of temperature and pCO levels had synergistic effects on hatching time and developmental success, antagonistic effects on number of hatchlings per capsule, resistance to juvenile shell cracking and metabolism, and additive effect on hatching size. Juveniles hatched significantly sooner at 15 °C, independent of the pCO level that they had been exposed to, while individuals hatched at significantly smaller sizes if they had been held under 15 °C/1200 μatm rather than at 10 °C/low pCO. Embryos held at the higher pCO had a significantly greater percentage of abnormalities. For capsules maintained at low pCO and 15 °C, emerging juveniles had less resistance to shell breakage. Embryonic metabolism was significantly higher at 15 °C than at 10 °C, independent of pCO level. The lower metabolism occurred in embryos maintained at the higher pCO level. Thus, in this study, temperature was the factor that had the greatest effect on the encapsulated development of A. monodon, increasing the metabolism of the embryos and consequently accelerating development, which was expressed in a shorter intracapsular development time, but with smaller individuals at hatching and a lower resistance of their shells to breakage. On the other hand, the high pCO level suppressed metabolism, prolonged intracapsular development, and promoted more incomplete development of the embryos. However, the combination of the two factors can mitigate--to some extent--the adverse effects of both incomplete development and lower resistance to shell breakage.
腹足纲动物单齿刺棘螺的卵囊在包囊发育的整个时期内，分别在三种温度（10、15、20℃）和两种pCO水平（400、1200μatm）下进行培养。对每个卵囊中的胚胎数量、孵化时的大小、孵化时间、胚胎代谢率以及幼体对壳破裂的抵抗力进行了量化。在20℃下培养的胚胎没有发育到孵化阶段。温度和pCO水平的组合对孵化时间和发育成功率具有协同作用，对每个卵囊的孵化幼体数量、对幼体壳破裂的抵抗力和代谢具有拮抗作用，对孵化大小具有累加作用。在15℃下孵化的幼体明显更快，与它们所接触的pCO水平无关，而如果幼体是在15℃/1200μatm而不是10℃/低pCO条件下培养，则孵化时个体明显更小。处于较高pCO水平下的胚胎出现异常的百分比明显更高。对于在低pCO和15℃下培养的卵囊，刚孵化的幼体对壳破裂的抵抗力较小。胚胎代谢率在15℃时明显高于10℃，与pCO水平无关。较低的代谢率出现在处于较高pCO水平下培养的胚胎中。因此，在本研究中，温度是对单齿刺棘螺包囊发育影响最大的因素，它增加了胚胎的代谢，从而加速了发育，这表现为较短的囊内发育时间，但孵化时个体较小且其壳对破裂的抵抗力较低。另一方面，高pCO水平抑制了代谢，延长了囊内发育时间，并促进了胚胎更不完全的发育。然而，这两个因素的组合可以在一定程度上减轻发育不完全和对壳破裂抵抗力较低的不利影响。
