Description of new diplonemids (Diplonemea, Euglenozoa) and their endosymbionts: Charting the morphological diversity of these poorly known heterotrophic flagellates.

Summary: Imagine a microscopic world in the ocean teeming with life we barely understand. Scientists have just discovered four new species of "diplonemids"—tiny, single-celled swimmers that are incredibly diverse but rarely seen. One of these new species, Lacrimia, surprised researchers by having a hidden talent: it conceals its "tails" (flagella) to glide along surfaces, a trick previously thought to belong to a completely different group. This discovery forced scientists to rewrite the family tree for these creatures. Even more intriguing, these tiny swimmers were found carrying hitchhikers—bacteria living inside them. One of these bacterial guests is related to Chlamydia, suggesting that these plankton might act as "Trojan horses," potentially spreading disease to marine fish.