蚂蚁

大自然充满太多神奇。儿子昨天晚上听了关于蝉的睡前故事，讲到蝉出生后唱歌，然后很快死亡的故事。今天早上儿子问我一个问题，“有没有只活一天的动物？”，于是上网查了一下，真有这种动物，就是蜉蝣，没有嘴没有消化系统，生出来只为交配，不吃不喝24小时内死亡。另外我早就了解大肠杆菌可以20分钟分裂一次，那么有一个问题是大肠杆菌会不会变老，细菌会不会自然死亡？似乎没有人研究过这个问题。现在看《自然》杂志报道了蚂蚁蛹会产奶的报道。 研究人员第一次观察到蚂蚁会分泌一种乳汁状的液体，用来滋养蚁群中的其他蚂蚁。这项发表在11月30日《自然》杂志上的研究揭示，蚂蚁蛹这是一个不活跃的发育阶段，但蚂蚁蛹能产生一种营养丰富的液体，供成虫和幼虫食用。刚孵出的幼虫依赖这种液体生长和生存，就像哺乳动物的新生儿依赖牛奶一样。如果成年蚂蚁和幼虫不消耗液体，液体就会积聚起来，被真菌污染，从而杀死蛹。也就是说这种奶如果变质，也能把蚂蚁蛹自己毒死。 “我们发现了一种将蚁群联合起来的机制，将不同发育阶段的蚂蚁——成虫、幼虫和蛹——结合成一个连贯的实体，即超级有机体，”纽约洛克菲勒大学的生物学家、合著者Orli Snir说。 a, Developmental timeline and protocol for rearing pupae in social isolation (Methods). b, Pupa with secretion droplet accumulated over 24 h in isolation. c,d, Secretion dynamics of isolated pupae over nine days before eclosion. c, Patterns of melanization and secretion during pupal development. n = 211 pupae. d, The daily social fluid volume per secreting pupa increases over time (Methods). Pearson correlation coefficient (r) = 0.93, two-sided t-test, t(34) = 14.63, P = 3.11 × 10−16. Data are mean ± s.e.m. from n = 6 biological replicates with 149–166 pupae each. e, Dynamics of pupal secretion and eclosion under social isolation (left; n = 942 pupae) and in colonies with adults (right; n = 907 pupae). Data are pooled from six biological replicates. f, Food dye injected into the pupal exuvial space is taken up by adult ants. The inset shows the dye-filled crop of an adult ant. g, When given the choice, adults spend more time attending to secreting pupae (blue) compared with pupae prevented from secreting (orange) by occluding the tip of the gaster with a paint dot (orange square) (Methods). Secreting pupae received a control dot of paint on the head. One-sided t-test, t(5) = −3.04, *P = 0.014. n = 6, with 3 adults, 5 secreting and 5 occluded pupae each. h, The survival of pupae to eclosion with (blue) and without (orange) removal of the secretion. One-way ANCOVA with White adjustment. Secretion removal: F(1,16) = 616.67, ***P = 3.32 × 10−14. n = 9 biological replicates for ‘isolated in tube’ with ‘pupal fluid removed’, and n = 3 for all other conditions (30–166 pupae per replicate). See Supplementary Data 1 for pairwise comparisons. Inset shows a representative pupa isolated in an empty nest, with fungal growth at the time of expected eclosion. Box plots show median (centre line), interquartile range (IQR) (box limits) and 1.5× IQR (whiskers). ...