Hincksina longispinosa Harmelin & d’Hondt, 1992

Ramalho, Laís V., Rodríguez-Aporta, Raquel & Gofas, Serge, 2022, Preliminary account on the bryozoans of the Alboran platform (Western Mediterranean), with description of two new species, Zootaxa 5094 (1), pp. 53-91 : 69

Hincksina longispinosa Harmelin & d’Hondt, 1992

( Fig. 6 )

Hincksina longispinosa Harmelin & d’Hondt, 1992a: 32 , pl. I, fig. d–f.

Material examined. MNCN 25.03/4290 ; MNCN 25.03/4291 : BV12, 112– 120 m; coll. UMA; five and two living fragments, respectively; all specimens encrusting shell fragments.

Description. Colonies encrusting, unilaminar ( Fig. 6A, B ). Zooids hexagonal, longer than wide [L 430–495– 571 (N 14, SD 37), W 265–309–340 μm (N 17, SD 31)] ( Fig. 6B ). Gymnocyst reduced, bearing thin, delicate spines numbering four on the oral region, directed frontally, and 10–12 encircling and overarching the opesia ( Fig. 6A ); cryptocyst negligible. Avicularia interzooidal, longer than wide [L 96–108–124 μm (N 7, SD 15)], placed on a developed cystid and directed longitudinally but usually transversely when associated with an ovicell ( Fig. 6B, C ); mandible semi-circular, hinged on a small pair of denticles ( Fig. 6C, D ). Ovicell large [L 93–200–223 (N 9, SD 17), W 207–235–254 μm (N9, SD 18)], immersed in the avicularium cystid ( Fig. 6C, D ).

Remarks. Hincksina longispinosa was described and uniquely recorded from the Gulf of Cadiz in two different depth zones, 137–150 m and 460–524 m ( Harmelin & d’Hondt 1992a). This record expands its geographic distribution to the Alboran Sea at slightly shallower depths (112–120 m). In comparison with the Gulf of Cadiz, the material collected on the Alboran platform has shorter avicularia (L 96–124 vs 141–148 µm).

Figures

FIGURE 6. Hincksina longispinosa Harmelin & d’Hondt, 1992a (MNCN 25.03/4291).A. General view of the colony showing zooids with spines around the opesia, ovicells and avicularia. B. General view of the colony showing zooids with spine bases around the opesia, interzooidal avicularia associated with ovicells and isolated avicularia (arrow). C. Detail of a fertile zooid showing avicularium directed transversely (associated to the ovicell) and longitudinally (arrow). D. Detail of a colony showing a fertile zooid and some spines. Scale bars: A, 500 µm; B, 400 µm; C, 200 µm; D, 100 µm.