Celleporaria cf. repens (Canu and Bassler, 1929)

Celleporaria cf. repens (Canu and Bassler, 1929) View in CoL

Figure 55 View FIGURE 55

cf. 1929 Holoporella repens Canu and Bassler , p. 427, pl. 62, figs. 2–6.

Figured material. PMC EDM-Collection J.H.B.145a, sample 19127; Core 19, Daidokutsu cave, Okinawa, Japan, Holocene.

Description. Colony encrusting, multiserial, multilaminar. Autozooids distinct or indistinct; when distinct, separated by shallow furrows, irregularly polygonal, longer than wide (mean ZL/ZW 1.21), chaotically arranged. Frontal shield convex, coarsely, densely, and evenly tuberculate with rounded tubercles measuring 15–25 µm in diameter, imperforate except for a few (4–5), sparse, circular, marginal areolar pores, each 10–50 µm in diameter. Orifice transversely D-shaped with a straight to slightly concave proximal margin, wider than long (mean OL/OW 0.78), with robust rounded triangular to trapezoidal condyles, 10–16 µm long, placed at proximal corners obliquely and projecting inwards; a short peristome surrounding the orifice; oral spines absent. Avicularium adventitious, suboral, oval, with a raised rostrum partially aligned on the proximal margin of the orifice and partially on the side of a variably developed subconical mucro, 95–125 µm long, directed obliquely and outwardly; avicularian openings semicircular; crossbar complete. Ovicells hyperstomial, globular; ooecium nearly encircling and completely obscuring the orifice, coarsely and densely granular like the frontal shield, sometimes developing a short mucro centrally or proximomedially.

Measurements (µm). ZL 413±32, 375–457 (1, 7); ZW 342±30, 290–384 (1, 7); OL 110±5, 105–116 (1, 4); OW 141±10, 129–152 (1, 4); AvL 74±8, 62– 88 (1, 11); AvW 54±7, 42–64 (1, 11); OvL 171±17, 156–202 (1, 6); OvW 236±13, 213–249 (1, 6).

Remarks. Among Celleporaria species, the Daidokutsu specimen appears most similar to C. repens from an unknown locality in the Philippines, sharing with it several characters: a granular frontal shield with marginal pores, slightly erect zooids, a semielliptical transverse orifice without spines, suboral avicularia with salient rostrum, and an ovicell that nearly encircles the entire aperture. It also lacks interzooidal avicularia. Our uncertainty stems from the limited details in the original species description and illustration, making it impossible to confirm certain features, such as the presence of robust condyles at the corners of the orifice proximal margin. Additionally, our specimen shows sparse marginal areolae, whereas the original images depict a continuous series. However, it is well known that the images in the publications of F. Canu and R.S. Bassler were commonly retouched and might not accurately represent reality. Furthermore, we lack a precise description of the suboral avicularium shape.

Celleporaria species previously described from Japan are distinct: C. bicirrhata (Ortmann, 1890) has a denticulate orifice, two spines, and interzooidal avicularia; C. kataokai Hayami, 1975 has 6–8 spines and lacks suboral avicularia; C. transversa (Ortmann, 1890) has a denticulate proximal margin of the orifice; C. triacantha (Ortmann, 1890) has consistently three oral spines; C. trituberculata (Ortmann, 1890) has non-ovicellate zooids with three prominences surrounding the orifice, each with an avicularium atop.

Other Northwest Pacific species also differ: C. convexa (Canu and Bassler, 1929) has a smooth frontal and frequent interzooidal avicularia; C. discoidea (Busk, 1884) has spatulate avicularia; C. erectorostris (Canu and Bassler, 1929) has numerous interzooidal spatulate avicularia, condyles on the lower third of the orifice, and 3–4 oral spines.; C. inflata (Canu and Bassler, 1929) has very large zooids, frequent spatulate interzooidal avicularia, and frontal pores; C. melanodermorpha Liu in Liu, Yin, and Ma, 2001 has a tall columnar suboral columnar process and lacks orificial condyles (Harmelin, 2014); C. pygmaea (Canu and Bassler, 1929) has a smooth frontal, a very elevated cylindrical process bearing a suboral avicularium, with those of the deeper layer reaching the same height as the avicularium of the second layer; C. subflava (Canu and Bassler, 1929) has very finely granular frontal and frequent interzooidal avicularia.