Spicules: The megascleres typically are slightly curved (sub)tylostyles, thicker towards the pointed end, with a more or less pronounced head; length 220-(275)-320µm, varying between individuals. The microscleres includes palmate isochelae in 3 size groups. The largest are ca. 31-47µm and, when present in any numbers, are grouped into rosettes in the surface. The middle size (ca. 12-25µm) are solitary and variable in number (and may even be absent). The smallest isochelae are solitary, often abundant, with one tooth characteristically standing out from the shaft giving the spicule a noticeably angular profile, ca. 13-15µm. Sigmata (of two sizes) are present. The larger are numerous, robust and somewhat twisted, sizes generally in the range 40-65µm. The smaller are thinly scattered and very slender and consequently sometimes hard to find, ca. 16-22µm. Toxa are either single and scattered or, nearly always, in small bundles forming toxodragmata. They are small (ca. 20-70µm) and fine, with a widely extended central flexion. They are always present but sometimes rare and difficult to detect.
Sponges of British Isles – A Colour Guide and Working Document, 2007
Mycale contarenii tylostyles Mycale contarenii sigmata Mycale contarenii toxa Spicules – (sub)tylostyles Spicules – sigmata, toxa Spicules – toxa, isochelae Spicules – toxa, isochelae Spicules – sigmata Spicules – (sub)tylostyles Spicules – sigmata Spicules – sigmata Spicules – (sub)tylostyles, sigmata Spicules – (sub)tylostyles, sigmata Spicules – (sub)tylostyles
