Monanchora arbuscula ( Duchassaing & Michelotti, 1864 )

Rützler, Klaus, Piantoni, Carla, Van, Rob W. M. & Díaz, Cristina, 2014, Diversity of sponges (Porifera) from cryptic habitats on the Belize barrier reef near Carrie Bow Cay, Zootaxa 3805 (1), pp. 1-129 : 64-65

Monanchora arbuscula ( Duchassaing & Michelotti, 1864)

( Figure 3 d)

Synonymy and References. Echinostylinos unguiferus de Laubenfels, 1953b: 528, fig. 6. Monanchora barbadensis Hechtel, 1969: 21 , fig. 3; van Soest (1984a): 40, fig. 12.

Material. USNM 1229045, Carrie Bow Cay forereef, low spur and groove zone, underside of Agaricia coral rubble, 8–9 m; K. Ruetzler col. 7 May 1973. USNM 1229046, 1229047, Carrie Bow Cay forereef slope, lower surface of coral rock, 25 m; K. Ruetzler col. 26 Apr 1974. USNM 1229048, Carrie Bow Cay forereef, low spur and groove zone, underside of Agaricia coral rubble, 8–9 m; K. Ruetzler col. 11 May 1975. USNM 1229049, Carrie Bow Cay forereef, high spur and groove zone, mini-cave, 4 m; K. Ruetzler col. 11 May 1979. USNM 1229050, Carrie Bow Cay forereef spur, at the base of the sponge Svenzea zeai (Alvarez, van Soest & Ruetzler), 6 m; K. Ruetzler col. 1 Feb 1997. USNM 1229051, 1229052, Curlew Bank, forereef cave, 20 m; C. Piantoni col. 28 Jun 2007. USNM 1229053, Curlew Bank forereef, lower surface of dead Agaricia coral plate, 21 m; C. Piantoni, col. 28 Jun 2007. USNM 1229054, Carrie Bow Cay forereef, cryptic in cavity, 28 m; M. C. Diaz col. 8 Sep 2009. USNM 1229055, Curlew Bank forereef slope, small cave, 20 m; C. Piantoni and M. Parrish col. 23 Aug 2012. Field observation (12-30, no material preserved): Curlew Bank forereef slope, small cave, 20 m; C. Piantoni and M. Parrish col. 23 Aug 2012.

External morphology. All specimens encountered were thin (1–3 mm) encrustations covering 2–50 cm 2 substratum. Small oscula (1–2 mm), slightly elevated. Most specimens, when undisturbed, show dark red subectosomal canals leading toward the oscula, contrasted against a whitish hue in the surrounding ectosome. Color is deep red throughout.

Skeleton structure. Megascleres (subtylostyles, tylostyles) may be erect at the base but are mostly forming tracts that brush out toward the ectosome. Microscleres are dispersed between the tracts.

Spicules. Thick subtylostyles I, usually straight, ranging from pure styles to tylostyles with poorly pronounced tyle: 160–360 x 4–15 (237 x 9) Μm; thin subtylostyles II (more common than I), straight or slightly curved: 120–280 x 3–8 (237 x 4) Μm; anchorate isocheles (unguiferate, with 3–5 teeth): 20–30 (23) Μm; reduced chelae (appearing like sigmas): 6–12 (8) Μm.

Ecology. In forereef caves or cryptic under rocks and platy coral rubble, 4– 28 m.

Distribution. Gulf of Mexico, Caribbean, off Brazil.

Figures

FIGURE 3. In-situ photographs of new sponge species reported in this contribution (measurements in parentheses are picture widths): a, Tetralophophora mesoamericana (3 cm); b, Geodia cribrata (12 cm); c, Placospongia caribica on “ pseudostalactite ” made up by calcareous serpulid tubes (5 cm); d, Prosuberites carriebowensis (adjacent to Monanchora arbuscula to the lower right) (4 cm); e, Timea diplasterina (8 cm); f, Timea oxyasterina (4 cm); g, Rhaphidhistia belizensis (14 cm).