microscleren.
/ˈmʌɪkrə(ʊ)sklɪə/, U.S. /ˈmaɪkroʊˌsklɪ(ə)r/, /ˈmaɪkrəˌsklɪ(ə)r/ Zoology.
A small, isolated spicule of a sponge. Cf. megasclere n.
ΘΚΠ
the world > animals > invertebrates > subkingdom Parazoa > phylum Porifera > [noun] > member of > parts of > sponge spicule > flesh spicule
tension-spicule1886
microsclere1887
1887 W. J. Sollas in Encycl. Brit. XXII. 417/2 It is doubtful whether a distinction between megascleres and microscleres can be maintained in the calcareous sponges.
1899 Amer. Naturalist 33 335 Microscleres, when present, always asters or microrhabdi.
1946 H. Woods Palæontol. Invertebr. (ed. 8) 37 In most siliceous sponges, two kinds of spicules may be distinguished, the skeletal-spicules or megascleres which build the main part of the skeleton, and the flesh-spicules or microscleres which are smaller and isolated.
1957 G. E. Hutchinson Treat. Limnol. I. xiv. 799 The formation of megascleres was much less inhibited than that of microscleres.
1987 M. S. Laverack & J. Dando Lect. Notes Invertebr. Zool. (ed. 3) iii. 26/1 Sponges are classified according to the chemical composition of the skeletal elements, the size of the spicules (megascleres or microscleres), [etc.].
1993 E. N. K. Clarkson Invertebr. Palaeontol. & Evol. (ed. 3) iv. 89/2 Six-rayed megascleres are found in the central trabecular and choanocytic layers, together with the much smaller stellate or dumb-bell-shaped microscleres, not often found fossil.
Derivatives
ΚΠ
1890 Cent. Dict. Microsclerous.
This entry has been updated (OED Third Edition, December 2001; most recently modified version published online March 2022).
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n.1887