Chartella elongata Cook, 1968

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 : 67

Chartella elongata Cook, 1968

( Fig. 5E, F )

Chartella elongata Cook, 1968: 136 , fig. 7.

Hincksinoflustra elongata: d’Hondt 1978: 450 ; Álvarez 1992b: 284, fig. 8.

Material examined. MNCN 25.03/4288 ; MNCN 25.03/4289 : BV-13, 95–99 m; coll. UMA; one living colony, attached on bioclast and one fragment without substrate, respectively .

Description. Colony delicate, erect, slightly calcified, with branched, bilaminar fronds composed of up to 9–10 linear zooidal series. Zooids rectangular, longer than wide [L 870–975–1065 (N 11, SD 73), W 180–194–215 μm (N 11, SD 11)], placed in quincunx; operculum D-shaped; a pair of small latero-distal spines. Avicularium located distal to the zooids, at the bifurcation of the zooidal rows, directed distally; mandible semicircular; cystid rectangular [L 100–133–169 (N 5, SD 30), W 102–117–136 μm (N 5, SD 14)]. Ovicell not observed.

Remarks. Six species of Chartella are known worldwide. Three species occur in the Mediterranean Sea: C. papyracea ( Ellis & Solander, 1786) , C. papyrea ( Pallas, 1766) and C. tenella ( Hincks, 1887) . Chartella papyracea has no avicularium; C. tenella has a pair of spines but the avicularium has a triangular, acute mandible and is directed obliquely ( Gautier 1962); C. papyrea is characterized by the absence of avicularia and spines, and by small, endooecial ovicells ( Gautier 1962). Cook (1968), in the original description, mentioned that C. elongata lacks oral spines, but Redier & d’Hondt (1976) examined the holotype and observed zooids with a pair of oral spines. This observation has been reaffirmed in two subsequent works (d’Hondt 1978, 1979). The size of zooids and avicularia in the Alboran platform material is similar to that of previous records (e.g. Gulf of Cadiz: zooids: L 790–1112, W 177–322 µm; avicularia: L 95–160, W 94–145 µm; Álvarez 1992b). Chartella elongata was described from the eastern Atlantic off the Mauritania – Western Sahara border, and later reported from Morocco and the Gulf of Cadiz at depths of 12–80 m ( Cook 1968; d’Hondt 1978; Álvarez 1992b). In the Alboran platform, the colonies were found at 95–99 m, slightly increasing its bathymetric range and expanding its geographic distribution to the Alboran Sea.

Figures

FIGURE 5. A–D. Crassimarginatella solidula Hincks, 1880 (MNCN 25.03/4287). A. General view of a colony with the ancestrula. B. Part of the colony showing zooids with prominent knobs. C. Close-up showing periancestrular zooids and ancestrula. D. Detail of the ancestrula (*). E, F. Chartella elongata Cook, 1968 (MNCN 25.03/4289). E. Part of the branch showing zooid delimitation and a bifurcation. F. Detail showing zooidal operculum and the distal avicularium. Scale bars: A, C, 200 µm; B, 300 µm; D, F, 100 µm; E, 1 mm.