Harmelinius Rosso, 2018

Rosso, A., Beuck, L., Vertino, A., Sanfilippo, R. & Freiwald, A., 2018, Cribrilinids (Bryozoa, Cheilostomata) associated with deep-water coral habitats at the Great Bahama Bank slope (NW Atlantic), with description of new taxa, Zootaxa 4524 (4), pp. 401-439 : 430

Genus Harmelinius Rosso n. gen.

Type species. Cribrilina uniserialis Harmelin, 1978 .

Diagnosis. Colony uniserial, consisting of caudate zooids with an extensive gymnocyst and a frontal shield with costae lacking pelmatidia and intercostal bridges, with only thin, elongated intercostal spaces; oral spines absent; hyperstomial, cleithral ovicells with smooth non-pseudoporous ooecia with a longitudinal suture, formed by a distal kenozooid/avicularium; rare paired, small and round adventitious avicularia, at level with the suboral bar; kenozooids of similar size and outline as autozooids, with small central opesia.

Etymology. Named in honour of Jean-Georges Harmelin for his outstanding contribution to the ecology and taxonomy of bryozoans. Masculine

Remarks. This genus is erected to allocate Cribrilina uniserialis Harmelin, 1878 ( Figs 85, 86 ), for which the new combination Harmelinius uniserialis n. comb. is suggested. This species was examined owing to similarities with Teresaspis lineata n. comb.

It is, indeed, the only known present-day cribrimorph exhibiting a uniserial growth habit. It was described based on only two colonies collected between 810–825 m depth in the central Atlantic archipelago of the Azores, at about 37° N and 25° W. Following Harmelin (1978, 177, fig. 2 and pl. 1, fig. 2), H. uniserialis n. comb. is characterised by: a frontal shield consisting of 13–16 wide and flat costae lacking pelmatidia; absence of oral spines; smooth ooecia without pseudopores and with an evident longitudinal “fissure”, associated with a distal kenozooid bearing a small avicularium; paired, small and round avicularia probably only occuring in ovicellate zooids; kenozooids of similar size and outline of autozooids, with a simple roundish opesia. SEM images of the type material, kindly provided by B. Berning ( Figs 85, 86 ) show extremely thin intercostal spaces not detected by Harmelin (1978). This author himself argumented about the difficulty of accommodating this species in Cribrilina Gray, 1848 . The type species of Cribrilina, Lepralia punctata Hassall, 1841, has a pseudoporous ooecium, and zooidal shields consisting of costae with pelmatidia, connected by intercostal bridges leaving large intercostal pores (see Bishop 1994: 226). In contrast, H. uniserialis n. comb. lacks pseudopores in the ectooecium as well as pelmatidia and intercostal bridges. Because of all these differences, Harmelin’s species cannot be maintained within Cribrilina . Additional characters of H. uniserialis n. comb., such as the absence of oral spines, the presence of kenozooids and the uniserial arrangement of zooids, have been so far never reported for species assigned to Cribrilina . Several features of H. uniserialis n. comb., such as the presence of smooth, non-pseudoporous ooecia and paired oral avicularia, are reminescent of Cretaceous cribrimorph genera with runner-like colonies, e.g. Otopora Lang, 1916 and Andriopora Lang, 1916 . Andriopora , however, possesses oral spines, and ooecia are formed by the distal autozooid. The possible accommodation of ‘C.’ uniserialis in Andriopora was discussed and discarded by Harmelin (1978).

Figures

FIGURES 85–86. Harmelinius uniserialis (Harmelin, 1978) n. comb., holotype MNHN IB-2008-7908, Biacores Station 197, 5.11.1971, 37°49.5’N 25°01.5’W, 815 m. 85. Uniserial chain of autozooids with a laterally budded kenozooid with smooth surface and a central opesia (bottom right). 86. Close-up of a regenerated autozooid lacking oral spines, with a shield of flat costae separated by thin fissures without intercostal bridges and pelmatidia. Scale bars: 85 = 500 µm; 86 = 200 µm.