Conlan Jessica A, Humphrey Craig A, Severati Andrea, Francis David S
School of Life and Environmental Sciences, Deakin University, Warrnambool, Victoria, Australia.
The National Sea Simulator, Australian Institute of Marine Science, Townsville, Queensland, Australia.
PeerJ. 2018 Jan 29;6:e4239. doi: 10.7717/peerj.4239. eCollection 2018.
Scleractinian corals are colonial organisms comprising multiple physiologically integrated polyps and branches. Colonialism in corals is highly beneficial, and allows a single colony to undergo several life processes at once through physiological integration and compartmentalised functioning. Elucidating differences in the biochemical composition of intra-colonial branch positions will provide valuable insight into the nutritional reserves underlying different regions in individual coral colonies. This will also ascertain prudent harvesting strategies of wild donor-colonies to generate coral stock with high survival and vigour prospects for reef-rehabilitation efforts and captive husbandry. This study examined the effects of colony branch position on the nutritional profile of two different colony sizes of the common scleractinian, . For smaller colonies, branches were sampled at three locations: the colony centre (S-centre), 50% of the longitudinal radius length (LRL) (S-50), and the colony edge (S-edge). For larger colonies, four locations were sampled: the colony centre (L-centre), 33.3% of the LRL (L-33), 66.6% of the LRL (L-66), and the edge (L-edge). Results demonstrate significant branch position effects, with the edge regions containing higher protein, likely due to increased tissue synthesis and calcification. Meanwhile, storage lipid and total fatty acid concentrations were lower at the edges, possibly reflecting catabolism of high-energy nutrients to support proliferating cells. Results also showed a significant effect of colony size in the two classes examined. While the major protein and structural lipid sink was exhibited at the edge for both sizes, the major sink for high-energy lipids and fatty acids appeared to be the L-66 position of the larger colonies and the S-centre and S-50 positions for the smaller colonies. These results confirm that the scleractinian coral colony is not nutritionally homogeneous, and while different regions of the coral colony are functionally specialised, so too are their nutritional profiles geared toward meeting specific energetic demands.
石珊瑚是由多个生理整合的珊瑚虫和分支组成的群体生物。珊瑚的群体结构非常有益，它能使单个群体通过生理整合和分区功能同时进行多种生命过程。阐明群体内不同分支位置的生化组成差异，将为了解单个珊瑚群体不同区域的营养储备提供有价值的见解。这也将确定野生供体群体的合理采集策略，以培育出具有高生存能力和活力前景的珊瑚种群，用于珊瑚礁修复和圈养养殖。本研究考察了群体分支位置对两种不同大小的常见石珊瑚群体营养特征的影响。对于较小的群体，在三个位置取样：群体中心（S-中心）、纵向半径长度（LRL）的50%处（S-50）和群体边缘（S-边缘）。对于较大的群体，在四个位置取样：群体中心（L-中心）、LRL的33.3%处（L-33）、LRL的66.6%处（L-66）和边缘（L-边缘）。结果表明分支位置有显著影响，边缘区域蛋白质含量较高，可能是由于组织合成和钙化增加。同时，边缘区域的储存脂质和总脂肪酸浓度较低，这可能反映了高能营养物质的分解代谢，以支持增殖细胞。结果还显示在所研究的两类群体中，群体大小有显著影响。虽然两种大小的群体边缘都是主要的蛋白质和结构脂质库，但高能脂质和脂肪酸的主要库对于较大群体是L-66位置，对于较小群体是S-中心和S-50位置。这些结果证实，石珊瑚群体在营养上并非均匀一致，虽然珊瑚群体的不同区域在功能上是专门化的，但它们的营养特征也是为满足特定的能量需求而专门化的。
