Tetralophophora mesoamericana, Rützler, Klaus, Piantoni, Carla, Van, Rob W. M. & Díaz, Cristina, 2014

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 : 17

Tetralophophora mesoamericana new species

( Figures 3 a, 7, 8)

Material. Holotype: USNM 1228906, Curlew Bank forereef cave, 18 m; C. Piantoni and M. Parrish, col. 25 Aug 2012.

Diagnosis. Encrusting to cushion-shaped, yellow-ochre plakinid with small but numerous aquiferous openings evenly distributed over the surface, and with tetralophose calthrops (51 µm mean diameter) scattered across the ectosome and choanosome.

External morphology. The holotype is encrusting another sponge ( Agelas schmidti ), 1–6 mm thick, and covering about 15 cm 2 of surface area. The surface is smooth but sprinkled by circular oscular and ostial openings, 0.2–0.5 µm in diameter. Consistency is firm but compressible, color yellowish ochre.

Skeleton structure and histology. Spicules are densely and about evenly distributed throughout the ectosome and choanosome. Embryos are common and in various stages of development, averaging 250 µm in diameter. Diplodal choanocyte chambers are abundant and measure 25–38 µm in cross sections.

Spicules. All are tetralophose calthrops with diameters of 33–61 (51) µm. Typical rays (including distal spines) measure 18– 33 x 4–8 (28 x 6) µm. Most rays have 2–5 apical spines, which may have points adorned by two or three spines, some have one or two spines halfway along their length, a few are furcated half way, then ending in spined points.

Ecology. Discovered in a forereef cave in 18 m; overgrowing coral rock and a specimen of another sponge, Agelas schmidti .

Distribution. Belize.

Etymology. Named for the location of its discovery, the Mesoamerican Barrier Reef.

Comments. We introduce a new genus with hesitation but the latest review of the family ( Muricy and Díaz, 2002) does not provide for a suitable allocation among established taxa. According to this review, the genus Placinolopha Topsent is closely related to our Tetralophophora by sharing the tetralophose calthrops, but it also includes diactinolophose and triactinolophose and, in some species, non-lophose spicules. Presence of diplodal choanocyte chambers and absence of candelabras make it impossible to include our species in the current definitions of Plakina or Corticium .

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).