Researchers have documented a protozoan species capable of transitioning from a bacterial filter-feeder to a larger, cannibalistic predator.

研究人員記錄了一種原核生物，能夠從細菌濾食者轉變為體型較大的同類相食捕食者。

The organism, identified as Euplotes gigatrox within a seawater filtration apparatus in Curaçao, exhibits a spontaneous morphological transition. In this 'supergiant' state, the cell exceeds twice its standard longitudinal dimension, characterized by an expanded body morphology and an enlarged oral aperture. This physiological shift facilitates a transition in trophic niche; whereas the standard form engages in bacterial filtration, the supergiant form functions as a raptorial predator, consuming clonal relatives at an approximate frequency of one prey every ten minutes.

該生物在庫拉索（Curaçao）的海水過濾裝置中被鑑定為 Euplotes gigatrox，展現出自發性的形態轉變。在這種「超級巨人」狀態下，細胞的縱向尺寸超過標準值的兩倍，其特徵為身體形態擴大且口裂增大。這種生理轉變促進了營養生態位的切換；標準形態進行細菌濾食，而超級巨人形態則充當掠食者，大約每十分鐘消耗一個克隆親緣個體。

Concurrent with morphological alteration, the organism undergoes a behavioral reconfiguration. The standard phenotype utilizes helical trajectories for fluid locomotion and surface ambulation. Conversely, the supergiant phenotype adopts circular trajectories optimized for surface-based predation, though it exhibits diminished swimming proficiency. Genomic and proteomic analyses indicate that this transformation constitutes a distinct developmental stage, evidenced by systemic variances in gene expression, protein synthesis, and membrane architecture. Furthermore, cells reverting from the supergiant state possess specific molecular markers that temporarily inhibit re-transformation. Notably, the supergiant phenotype remains a minority within the population, not exceeding five percent.

與形態改變同步地，該生物經歷了行為重新配置。標準表型利用螺旋軌跡進行流體移動和表面爬行。相反，超級巨人表型採取優化用於表面捕食的圓形軌跡，儘管其游泳能力有所下降。基因組和蛋白質組分析表明，這種轉變構成了一個獨特的發育階段，表現為基因表達、蛋白質合成和膜結構的系統性差異。此外，從超級巨人狀態恢復的細胞具有特定的分子標記，可暫時抑制重新轉變。值得注意的是，超級巨人表型在群體中仍屬少數，不超過百分之五。

This discovery necessitates a reappraisal of developmental biology, which has historically prioritized multicellular organisms. The existence of such complex developmental trajectories in a single-celled entity provides a novel framework for investigating the mechanisms by which cellular form and function are regulated across divergent evolutionary lineages.

這一發現使得重新評估發育生物學變得必要，因為該學科歷史上一直優先考慮多細胞生物。在單細胞實體中存在如此複雜的發育軌跡，為研究跨越不同演化譜系的細胞形態與功能調節機制提供了一個全新的框架。

The discovery of Euplotes gigatrox demonstrates that single-celled organisms can undergo complex developmental shifts to alter their ecological roles.

Euplotes gigatrox 的發現證明了單細胞生物可以經歷複雜的發育轉變，以改變其生態角色。