Reteporella mediterranea Hass, 1948

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 : 81-83

Reteporella mediterranea Hass, 1948

( Fig. 15 )

Reteporella mediterranea Hass, 1948: 131 , figs 19–21, 24–25, 29, 39–40, pl. V, figs 19, 24, pl. VI, figs 27, 28; Gautier 1962: 234; Zabala 1986: 543; Ramalho et al. 2018: 92 , fig. 2.

Material examined. MNCN 25.03/4315 : BV-12, 112– 120 m; coll. UMA; seven living and four dead fragments; MNCN 25.03/4316 : BV-12, 112– 120 m; coll. UMA; one living fragment; MNCN 25.03/4317 : BV-14, 96–100 m; coll. UMA; three dead fragments; MNCN 25.03/4318 : BV-15, 96 m; coll. UMA; one dead fragment.

Description. Colony erect, rigid, fenestrate, cup-shaped. Branches formed by three to five series of zooids alternately arranged; fenestrae small and elliptical [L 1364–1424–1459 (N 3, SD 53), W 620–705–767 μm (N 3, SD 77)] ( Fig. 15A ). Frontal shield imperforate, smooth, with a few small, rounded areolar pores. Primary orifice circular with a beaded distal edge ( Fig. 15C ) concealed by the peristome; secondary orifice bearing two delicate proximal spines, a small, rounded pseudospiramen and a small avicularium ( Fig. 15B, C ). Suboral avicularium rounded [L 48–53–60 μm (N 9, SD 5)] with serrated rostrum, directed proximo-laterally ( Fig. 15C ). Some additional avicularia [L 77–92–114 μm (N 15, SD 11)] scattered on the frontal shield, rounded or triangular in shape, randomly directed ( Fig. 15B, C ). Ovicell longer than wide [L 229–237–243 (N 4, SD 6), W 189–212–244 μm (N 4, SD 23)], becoming immersed with ontogeny; frontally an elongate fissure is visible reaching the labellum ( Fig. 15B ). Dorsal side with some triangular [L 77–85–93 μm (N 4, SD 7)], and circular [L 54–61–65 μm (N 4, SD 5)] avicularia located near the sutures and fenestrae ( Fig. 15D–F ).

Remarks. Reteporella mediterranea is known from the Mediterranean Sea and recently recorded for the first time from the Atlantic Ocean-Gulf of Cadiz ( Ramalho et al. 2018), but never mentioned in the Alboran Sea. The material collected in the study area was made of small and large fragments, well-preserved and with fertile zooids. The identification was based on the type description, but unfortunately the type-material has never been figured using scanning electron microscopy, an essential step in order to confirm the identification of this and many other Reteporella species as well as their accurate geographic distribution.

Figures

FIGURE 15. Reteporella mediterranea Hass, 1948 (MNCN 25.03/4316).A. Frontal view of the colony showing three fenestrae. B. Detail view of the branch showing zooids with frontal avicularia and ovicells (arrows). C. Close-up of zooids showing orifices with circular, suboral avicularia, a pair of oral spines and triangular, frontal avicularia. D. Dorsal view of the colony fragment. E. Triangular avicularium on the dorsal side. F. Circular avicularium on the dorsal side. Scale bars: A, 1 mm; B, 300 µm; C, 100 µm; D, 500 µm; E, 30 µm; F, 60 µm.