Microporella ciliata (Pallas, 1766)

Martino, Emanuela Di & Rosso, Antonietta, 2021, Seek and ye shall find: new species and new records of Microporella (Bryozoa, Cheilostomatida) in the Mediterranean, ZooKeys 1053, pp. 1-42 : 1

Microporella ciliata (Pallas, 1766)

Fig. 4

Eschara ciliata Pallas, 1766: 38.

Microporella ciliata (Pallas): Kukliński and Taylor 2008: 1895, fig. 1a-i.

Microporella ciliata Non Microporella ciliata (Pallas): Hayward and McKinney 2002: 83, fig. 37e-j.

Examined material.

Italy • 1 dead colony; Ionian Sea, SE Sicily, Gulf of Noto ; sample WP120; 36°44'26"N, 15°10'3"E; 50 m; 1996; E. Mollica leg.; dredging; PMC Rosso-Collection I. H. B. 85a .

Remarks.

The neotype chosen by Kukliński and Taylor (2008) was selected from material collected in 1984 and 2005 at Penta Palummo Bank, a submerged volcanic edifice in the Bay of Naples rising up to about 40 m depth from the surrounding 80 m shelf. Kukliński and Taylor (2008) already suggested that the Mediterranean material overall assigned to M. ciliata , might actually correspond to more than one closely related species. This was observed, for instance, in SEM images of north Adriatic specimens in Hayward and McKinney (2002), which differ from the neotype. Following Kukliński and Taylor (2008), Rosso et al. (2010), Chimenz Gusso et al. (2014), and Rosso and Di Martino (2016) remarked on the need for a revision of the material assigned to this species, whose accorded great variability (e.g., Gautier 1962; Hayward and Ryland 1999) is very likely to correspond to a species complex. The effort to disentangle the Microporella ciliata complex began with the recent description of Microporella modesta Di Martino, Taylor & Gordon, 2020, and is pursued in the present paper with the description of two new species sharing with M. ciliata the general appearance and the presence of a single, lateral avicularium as well as non-personate ovicells. Examination of all material available to us, as well as images available in the literature, suggest that M. ciliata , as defined by the neotype, is possibly a rare species in the Mediterranean Sea, or at least a species with a very restricted geographical and/or ecological distribution. A similar conclusion was reached by Chimenz Gusso et al. (2014) after revising their material identified as M. cf. ciliata , found associated to Posidonia and algae between 5 and 88 m depth in several localities of the Tyrrhenian Sea (i.e., off Latium; Spargiotto Island, NE Sardinia; Ustica and Volcano Islands) and the Sicily Strait (Lampedusa Island). The revision of all specimens originally assigned to M. ciliata or M. gr. ciliata in the collections of one of us (AR), originating from several regions and habitats of the Mediterranean Sea, led to the detection of only one colony corresponding with the neotype (Fig. 4 ). Although the type locality is unknown, it is likely that the original material described by Pallas (1766) was collected in shallow waters from easily accessible substrates, which is not the case for the selected neotype. Colonies of M. ciliata recorded from different western Mediterranean localities ( Gautier 1962; Zabala 1986, and references therein), Greece ( Harmelin 1969) and Turkey ( Ünsal 1975), all show great variability and need to be revised to ascertain their identity.

Distribution.

Awaiting a general revision of specimens reported from all over the world, focusing on the Mediterranean Sea, the occurrence of Microporella ciliata to date is only confirmed in the Gulf of Naples (SE Tyrrhenian Sea) and the Gulf of Noto (W Ionian Sea).

Figures

Figure 4. Microporella ciliata (Pallas, 1766) from the Ionian Sea, Gulf of Noto, PMC Rosso-Collection I. H. B. 85 a A general view of the colony B autozooids at the colony margin showing distal and distolateral pore chamber windows C ovicellate autozooids D autozooid with the characteristic four, thin, oral spine bases. Note how commonly avicularia regenerate E close-up of the orifice showing a series of median denticles and two lateral condyles. Scale bars: 500 µm (A); 250 µm (B); 200 µm (C); 100 µm (D); 50 µm (E).