Fig. 1: Examples of the diversity of meiofauna using different imaging techniques.

A Dalyella sp. (Platyhelminthes) from a cave in Toscana (Italy), 250 µm. B Ototyphlonemertea aff. elenae (Nemertea), Santa Marta (Colombia), 1 mm. C Schizorhynchia (Platyhelminthes), São Sebastião (Brasil), 500 µm. D Flagellophora apelti (Nemertodermatida), Helgoland (Germany), 700 µm. E Paraproporus sp. (Acoela), Fort Pierce (USA), 1.2 mm. F Lindrilus flavocapitatus (Annelida), Odessa (Ukraine), 2 mm. G Pontohedyle sp. (Gastropoda), Santa Marta (Colombia), 800 µm. H Pholidoskepia sp. (Solenogastres), Friday Harbor (USA), 700 µm. I Nematoplana sp. (Proseriata), Porto Sant’Elpidio (Italy), 2 mm. J Kata sp. (Proseriata), Itaipuaçu, Rio de Janeiro, 750 µm. K Notholca sp. (Rotifera), Katwijk (The Netherlands), 250 µm. L Tubiluchus lemburgi (Priapulida), Tenerife (Canary Islands, Spain), 1 mm. M Leiocanthus satanicus (Kinorhyncha), Gulf of Mexico, 500 µm. N Paradraconema sp. (Nematoda), São Sebastião (Brasil), 200 µm. O Hemicyclophora sp. (Nematoda), Nordwijk (The Netherlands). P Enoplolaimus sp. (Nematoda), Nordwijk (The Netherlands). Q Neochromadora sp. (Nematoda), Scheveningen (The Netherlands). R Stilbonematinae (Nematoda), Sardegna (Italy), 750 µm. S Draciculiteria sp. (Gastrotricha), Helgoland (Germany), 200 µm. T Turbanella cornuta (Gastrotricha), Katwijk (The Netherlands), 400 µm. U Halammohydra vermiformis (Cnidaria), Helgoland (Germany), 400 µm. V Callistocypris sp. (Ostracoda) from phytothelmata Sian Ka'an (Mexico), 500 µm. W Palpophria aestheta (Copepoda) from the water column, Túnel de la Atlántida (Canary Islands, Spain), 400 µm. X Eucyclops sp. (Copepoda) from wells in Haría (Canary Islands, Spain), 750 µm. Y Scaphognathus sp. (Acarii), Arousa (Galicia, Spain), 400 µm. Measurements refer to body length. A–E; G, I–K, N—U, light micrographs; F, drawing; H, L, M, Y, scanning electron micrographs; V–X, maximal projections of confocal laser scanning stacks. Credits: A, D, E, Ulf Jondelius. B, G Alejandro Martínez (AM), Ana Milena Lagos and María Victoria León. C, J, N Maikon Di Domenico. H Kevin M. Kocot. I. Marco Curini-Galletti (MCC). K Diego Fontaneto. L, S Andreas Schmidt-Rhaesa (ASR). M Nuria Sánchez. O–Q, T Marta García-Cobo, Jan Macher and Alejandro Martínez. R MCC, AM. U ASR and Lenke Tödler. V, Y Nancy Mercado-Salas (NMC). W AM, NMC, Terue Kihara. X Guillermo García-Gómez.