balance blue build buildings cabin concrete construct counterweight crane cranes frame framework heavy lift metal sceleton skies sky steel tower bar bars building construction wire wires adult alien alpine alps aquaticus Austria biology environment europe Gordiacea gordian Gordius hairworm horsehair host hydrostatic long Nematoida nematomorph Nematomorpha parasite parasitic pressure primitive Saitenwurm science slim strange string thin under violin Vitulus aquaticus Wasserkalb water worm