Espinosa-Magaña Alí, Lozano-Álvarez Enrique, Briones-Fourzán Patricia
Posgrado en Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, México; Unidad Académica de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Puerto Morelos, Quintana Roo, México.
Unidad Académica de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México , Puerto Morelos , Quintana Roo , México.
PeerJ. 2017 Jan 4;5:e2852. doi: 10.7717/peerj.2852. eCollection 2017.
The non-feeding postlarva (puerulus) of spiny lobsters actively swims from the open ocean to the coastal habitats where it settles and molts to the first-stage juvenile (JI). Because pueruli use much of their energy reserves swimming and preparing for the post-settlement molt, the survival of JIs presumably depends on resuming feeding as soon as possible. To test this hypothesis, the resistance to starvation of JIs of the Caribbean spiny lobster, , was evaluated by measuring their point-of-no-return (PNR, minimum time of initial starvation preventing recovery after later feeding) and point-of-reserve-saturation (PRS, minimum time of initial feeding allowing for food-independent development through the rest of the molting cycle) in a warm and a cold season. Each experiment consisted of eight groups: a continuously fed control (FC) group, a continuously starved control (SC) group, and six groups subjected to differential periods of either initial starvation and subsequent feeding (PNR experiments) or initial feeding and subsequent starvation (PSR experiments). No JIs molted under continuous absence of food (SC). In both PNR experiments (temperature in warm season: 29.79 ± 0.07°C, mean ± 95% CI; in cold season: 25.63 ± 0.12°C) mortality increased sharply after 9 d of initial starvation and intermolt periods increased with period of initial starvation, but were longer in the cold season. The PNR was longer in the warm season (12.1 ± 1.2 d, mean ± 95% CI) than in the cold season (9.5 ± 2.1 d). In PRS experiments (temperature in warm season: 29.54 ± 0.07 °C; in cold season: 26.20 ± 0.12 °C), JIs that molted did so near the end of the feeding period; all JIs initially fed for up to 6 d succumbed, and no JIs molted after 13 d of starvation despite having fed previously. The PRS did not differ between the cold (13.1 ± 0.7 d) and warm seasons (12.1 ± 1.1 d). JIs of exhibit a remarkable resistance to starvation considering that the previous non-feeding, energy-demanding puerulus phase lasts for ∼3 weeks. However, JIs appear to have a relatively higher degree of dependence on food to complete development to JII during the cold season than during the warm season. Therefore, JIs of would appear to be more resistant to starvation during the warm season.
多刺龙虾的非摄食后期幼体（叶状幼体）会主动从公海游向沿海栖息地，并在那里定居并蜕变为第一阶段幼体（J1）。由于叶状幼体在游泳以及为定居后蜕皮做准备时消耗了大量能量储备，所以J1幼体的存活大概取决于能否尽快恢复摄食。为了验证这一假设，研究人员通过测量加勒比多刺龙虾J1幼体在温暖季节和寒冷季节的绝食点（PNR，即初始饥饿阻止后期恢复摄食后的恢复的最短时间）和储备饱和点（PRS，即初始摄食允许在剩余蜕皮周期中进行不依赖食物发育的最短时间），来评估其对饥饿的抵抗力。每个实验包括八组：一个持续投喂的对照组（FC）、一个持续饥饿的对照组（SC），以及六组分别经历不同时长的初始饥饿和后续投喂（PNR实验）或初始投喂和后续饥饿（PSR实验）的组。在持续无食物的情况下（SC组），没有J1幼体蜕皮。在两个PNR实验中（温暖季节温度：29.79 ± 0.07°C，平均值 ± 95%置信区间；寒冷季节温度：25.63 ± 0.12°C），初始饥饿9天后死亡率急剧上升，蜕皮间期随初始饥饿时长增加，且在寒冷季节更长。温暖季节的PNR（12.1 ± 1.2天，平均值 ± 95%置信区间）比寒冷季节（9.5 ± 2.1天）更长。在PRS实验中（温暖季节温度：29.54 ± 0.07°C；寒冷季节温度：26.20 ± 0.12°C），蜕皮的J1幼体在投喂期接近结束时蜕皮；所有最初投喂长达6天的J1幼体都死亡了，尽管之前有过投喂，但饥饿13天后没有J1幼体蜕皮。寒冷季节（13.1 ± 0.7天）和温暖季节（12.1 ± 1.1天）的PRS没有差异。考虑到之前不摄食、能量需求高的叶状幼体阶段持续约3周，J1幼体对饥饿表现出了显著的抵抗力。然而，J1幼体在寒冷季节似乎比温暖季节在完成向J2幼体发育过程中对食物的依赖程度相对更高。因此，Jasus edwardsii的J1幼体在温暖季节似乎对饥饿更具抵抗力。
