Microporella maldiviensis, Harmelin, Jean-Georges, Ostrovsky, Andrew N., Cáceres-Chamizo, Julia P. & Sanner, Joann, 2011

Harmelin, Jean-Georges, Ostrovsky, Andrew N., Cáceres-Chamizo, Julia P. & Sanner, Joann, 2011, Bryodiversity in the tropics: taxonomy of Microporella species (Bryozoa, Cheilostomata) with personate maternal zooids from Indian Ocean, Red Sea and southeast Mediterranean, Zootaxa 2798, pp. 1-30 : 21-22

Microporella maldiviensis n. sp.

( Fig. 12 A–I, Table 6)

Material examined. Holotype: 2010-0002-0001 DPUV, on Pteria penguin . Maldive Islands, North Male Atoll, Helengeli Island, March 1983, coll. F.F. Steininger. Piece of the holotype mounted on SEM stub. Paratypes: 2010- 0002-0002 DPUV, on Pteria penguin , Maldive Islands, North Male Atoll, Helengeli Island, March 1983, coll. F.F. Steininger. Mounted on SEM stubs: 2010-0002-0003 DPUV, 2010-0002-0004 DPUV, on coral overgrowing bivalve shell, Maldive Islands, North Male Atoll, Helengeli Island, March 1983, coll. F.F. Steininger. 2010-0002- 0 0 0 5 DPUV, on bivalve shell. Maldive Islands, North Male Atoll, Kuda Haa, 04°20’914” N, 073°40’778” E, 8–35 m, 26 January 2008.

Etymology. From the Maldive Islands where the species was discovered.

Description. Colony encrusting, unilaminar, small or medium-sized. Autozooids oval, penta- or hexagonal, longer than broad (mean L/ W 1.40). Frontal shield moderately convex, entirely covered with small rounded nodes and 69–86 pseudopores. Marginal areolae well differentiated, elongated or oval, 7–11 in number. Primary orifice slightly wider than long, anter round, with semicircle of 7–15 irregular, wide and low ‘denticles’ with round summit, wave-shaped in frontal view. Proximal border smooth or slightly corrugated, with shoulder-shaped condyles. Spines 3–4 in most cases, sometimes 5, always in distal position. Ascopore at a distance to proximal edge of orifice, equal to orifice length or a little shorter, oval or round, slightly compressed distally, surrounded by thin rim; lumen large, kidney-shaped with relatively small median process, round, bordered by 24–32 short denticles, sometimes with bifurcated tip. Avicularium single, lateral or proximolateral to ascopore, orientated distolaterally or laterally; opesia relatively large; rostrum short, channelled with nearly parallel sides and narrow truncated tip; crossbar complete, robust; mandible shorter than autozooid width, setiform, narrow, with strong, backwardly curving hooked tip, preceded by finely serrated edges and 2 pointed lateral processes curved basally, which lean against the rostrum tip; avicularia can be occasionally paired in zooids showing traces of repair; a few zooids devoid of avicularia. Ovicells personate, with a tall, arched, granular collar, distally adjacent to ascopore; entooecium granular, bearing ‘pseudopores’ that are distinctly smaller than those of frontal shield. Triangular, oval or irregularly shaped kenozooids with nodular frontal shield and a few marginal pores occasionally present. Older zooids often with irregular patches of ‘secondary calcification’ developing over zooidal margins.

AzL: 659.3 ± 62.5, 560–760 (30)

AzW: 469.7 ± 41.4, 390–570 (30)

OrL: 91.2 ± 4.5, 80–100 (30)

OrW: 109.8 ± 7.8, 100–125 (30)

OvL: 263.3 ± 5.8, 260–270 (3)

OvW: 363.3 ± 20.8, 340–370 (3)

MdL: 257.6 ± 17.9, 220–300 (25)

Remarks. Microporella maldiviensis n. sp. recalls M. browni n. sp., M. collaroides n. sp. and M. orientalis in possessing orifices with distal ‘dentition’ (a feature shared with only very few species), personate ovicells and unpaired avicularia. It differs from these species in the shape and size of the distal denticles, which are less developed than in M. orientalis and M. browni n. sp. and like the ‘denticles’ in M. collaroides n. sp. in being rather low and forming a wavy shelf rather than a succession of individualized teeth. The condyles, which are similarly developed in both M. maldiviensis n. sp. and M. collaroides n. sp. but have a different shape, are more prominent in these species than in M. browni n. sp. and, moreover, than in M. orientalis . The particular shape and size of the avicularian mandible, relatively short with a hooked tip and serrated edges, is another diagnostic character of M. maldiviensis n. sp., which clearly distinguishes it from M. browni n. sp., while in M. orientalis the mandible is also hooked but distinctly shorter. On the other hand, these four species share the same type of personate ovicell and most likely constitute a species complex. Interestingly, the validity of the morphological differences observed between M. maldiviensis n. sp. and M. browni n. sp. is reinforced by the finding of both species cohabiting the same locality in the Maldive Islands.

Figures

FIGURE 12. M. maldiviensis n. sp., specimens from Maldive Islands (A, F: paratype 2010 - 0002 - 0005 DPUV; B, G: paratype 2010 - 0002 - 0004 DPUV; C, E, I: fragment of the holotype 2010 - 0002 - 0001 DPUV; D, H: paratype 2010 - 0002 - 0003 DPUV). A: non-ovicellate zooids. B: maternal zooid and ovicell with typical personate structure. C: distal half of non-ovicellate zooid with 4 oral spines in distal position. D: avicularium with hooked and finely denticulate mandible resting in the rostrum. E – G: primary orifice with 3 (E), 4 (G) or 5 spines (F), low rounded denticles on the distal edge, shoulder-shaped condyles and slightly corrugated proximal edge. H: avicularium with mandible in open position showing the pointed processes corresponding to the rostrum tip. I: three non-ovicellate zooids with 1, 0 or 2 avicularia respectively, and patches of ‘ secondary calcification’. Scale bars: A, I = 200 µm; B, C = 100 µm; D, H = 50 µm; E – G = 30 µm.