Coronellina fagei ( Gautier, 1962 )

Souto, Javier, Reverter-Gil, Oscar & Fernández-Pulpeiro, Eugenio, 2010, Bryozoa from detritic bottoms in the Menorca Channel (Balearic Islands, western Mediterranean), with notes on the genus Cribellopora, Zootaxa 2536, pp. 36-52 : 41-43

Coronellina fagei ( Gautier, 1962)

( Figs 10–12 ; Table 3)

Material examined. MNCN-25.03/3822, 3824: Stn P2, 39.77571º N, 3.49746º E, 01/03/2009, 57.4 m. Other reference material: Lectotype of Coronellina fagei (designated here): MNHN-8777: Stn 699, Gautier Collection.

Description. Colony encrusting, unilaminar, pale yellow when dry. Zooids generally arranged in alternating series, sometimes irregularly disposed; disjunct, each zooid being linked to its neighbours by 9–14 (average 12) short tubules, each produced from a basal pore-chamber (dietella), thus each zooid is linked to a neighbour by two (sometimes 1 or 3) tubules; zooids can also be contiguous, in which case they are separated by deep grooves. Autozooids oval, the distal wall regularly rounded, generally truncate proximally; frontal surface membranous, surrounded by a granular wall, raised in the distal portion, less elevated proximally. Cryptocyst granular, occupying more than 75% of frontal-wall length; depressed, especially in its distal third, where the opesiules are placed; distally raised towards opesia, forming a lip flanked by a pair of distinct notches. Opesia transversely elliptical, small, widest proximally. Operculum semicircular, yellowish, occupying most of the opesia; opercular muscles inserted level with the lateral notches. A pair of rounded opesiulae in the distal third of the zooid, in the most concave portion of the cryptocyst, placed near each other. Ovicell independent, hyperstomial, with recessed frontal surface flat, granular, sloping towards the distal zooid; frequently, an asymmetrical pore inside the smooth distal rim of the ectooecium; proximal edge of ovicell arched, its aperture hidden in frontal view. Small abortive kenozooids sometimes present, filling small spaces in the colony where autozooids cannot develop; these irregularly shaped, with smooth gymnocyst and a membranous frontal area; cryptocyst granular, with a small rounded pore placed near the centre.

Mean SD Minimum Maximum N Autozooid length 0.411 0.0338 0.337 0.458 21 Autozooid width 0.300 0.0333 0.229 0.349 21 Opesia length 0.060 0.0097 0.042 0.084 21 Opesia width 0.117 0.0173 0.084 0.157 21 Ovicell length 0.176 0.0193 0.163 0.204 4 Ovicell width 0.242 0.0255 0.214 0.276 4

SD, Standard deviation; N, number of measurements.

Remarks. In the original description of the species, Gautier (1962) reported that neighbouring zooids are united by six tubules. Prenant & Bobin (1966) re-examined Gautier’s material but did not mention the number of tubules, however their figure 112 shows 2–3 tubules between autozooids, just as we observed in our material and in the lectotype of the species, the only original colony apparently preserved (MNHN-8777). Although the separation between zooids is quite variable they are frequently very close, which hinders observation of tubules.

The material examined by us has a smaller zooid size than that originally indicated by Gautier (1962) whereas Arístegui Ruiz (1984) gave measurements far exceeding the original data based on material from the Canary Islands, so perhaps the size of C. fagei is widely variable.

Coronellina fagei has been found at depths of 60–90 m in Sicily and in the area of Marseille, where it is abundant in underwater caves at shallow depths (Harmelin, pers. comm. February 2010). It has also been reported in the Eastern Mediterranean, in Santorini ( Harmelin 1968, 1969) and Chios ( Hayward 1974), as well as in the circumlittoral area of all the islands forming the Canary Archipelago ( Arístegui Ruiz 1984). In Iberian waters this species has been reported, with some uncertainty, in the Medes Islands (Cataluña) ( Zabala 1986); the present record thus confirms the presence of this species in Iberian waters.

Figures

FIGURES 10, 11. Coronellina fagei (MNCN – 25.03 / 3822). 10, view of the colony; 11, autozooids.

FIGURE 12. Ovicellate zooids of Coronellina fagei (MNCN – 25.03 / 3822).