Kebira uteoides Row, 1909

Figs 85a–g, 86a–e

Kebira uteoides Row, 1909: 210, pl. 20 figs 8–9, text-figs 7–8; Burton 1952: 164; Ilan & Vacelet 1993: 110, figs 2–4.

Material examined. RMNH Por. 9563, Saudi Arabia, Jeddah, near Thuwal, Al Fahal N, 22.300194°N 38.959583°E, depth 12 m, coll. N.J. de Voogd, scuba, field nr. THU04/JED052, 8 November 2014 ; RMNH Por. 9664, Saudi Arabia, Jeddah, near Thuwal, Um Albalam, 22.193556°N 38.9475°E, depth 15 m, scuba, coll. N.J. de Voogd, field nr. THU10/JED168, 12 November 2014 .

Description. Squat, laterally flattened, irregularly tubular individuals (Figs 85a–d), attached to vertical walls and hanging down from the ceiling of cavities, with large apical or lateral oscules. In life (Figs 85a,c), colors are shades of grey and pinkish white, on deck (Figs 85b,d) and in preservation they become yellow. Size up to 4 cm high, and 5 x 3 cm in lateral expansion. Oscules 4–6 mm in diameter. Surface smooth. Consistency firm to hard.

Aquiferous system. Leuconoid.

Skeleton. (Figs 85e–g) In cross section (Fig. 85e), there is a cortical skeleton of sagittal triactines, mostly with long unpaired actines (Fig. 85f), carried by tangentially arranged giant diactines. Underneath, the choanosomal skeleton is formed by perpendicular giant diactines, tracts of nail-shaped triactines (arrows in Fig. 85e) and large sagittal triactines with long unpaired actines. The atrial skeleton (Fig. 85g) is predominantly formed by sagittal triactines with short unpaired actines.

Spicules. (Figs 86a–e) Giant diactines, nail-shaped triactines, sagittal triactines, microdiactines.

Giant and smaller diactines (Fig. 86a), fusiform, symmetrical, sharply pointed, in a wide size range, 540– 1489 –2022 x 25– 79 –108 µm.

Nail-shaped triactines (Figs 86b,b 1), thinly fusiform, pointed at one end, at the opposite end provided with two conical actines arranged at a slight angle, in a large size range, unpaired actines 105– 317 –477 x 5.5– 8.5 –10 µm, paired actines 3–7 x 3 µm.

Large sagittal triactines (Fig. 86c), with long unpaired actines, and flaring paired actines; unpaired actines 306– 371 –462 x 7 – 7.9 –8.5 µm, paired actines 204– 227 –248 x 9 – 10.4 –12 µm.

Atrial sagittal triactines (Figs 86d) with short unpaired actines and straight paired actines; unpaired actines 57– 86 –121 x 8.5– 10.1 –12 µm, paired actines 179– 228 –282 x 11.5– 13.9 –17 µm.

Small thin diactines with tiny spines at both ends (Figs 86e,e 1), rare, not certainly proper to the sponge, but sufficiently characteristic to be a possible, previously unobserved, spicule type, 51–102 x 2–7 µm.

Distribution and ecology. Northern Red Sea: Gulf of Suez, Egypt (Sharm-al-Sheik), Saudi Arabia (Jeddah), hanging down in caves on shallow water reefs.

Remarks. The only noteworthy difference with Row’s description of the type specimen is that he confused the position of the cortical and the atrial sagittal triactines. It can be clearly seen in our Fig. 85g, showing the atrial surface, that the predominant spicule type is the sagittal triactine with short unpaired actine. In Figs 85e (upper part) and f, the dominant spicule type is the long-shafted sagittal triactine clearly visible. Our spicule sizes are more or less the same as in Row’s specimen, although we did not observe giant diactines of 4 mm length.

The small spined diactines may or may not be proper to the sponge.

Burton (1952) did not give a description other than mentioning that his specimen from Sharm al Sheik (Egypt) was 2 cm high.

Ilan & Vacelet (1993) found giant diactines up to 4 mm, but omitted further spicule measurements, concentrating on a description of the soft parts.

We obtained partial 28SrRNA sequences for the two specimens. In our Phylogeny of Fig. 3, these grouped along with the new Kebira species described below in a larger clade together with Ute ampullacea, Paragrantia waguensis Hôzawa, 1940, and Grantiopsis heroni Wörheide & Hooper, 2003 . These species were added to our analysis to confirm the affiliation of Kebira . The position of Ute ampullacea (cf. also above) in the group is surprising, but Kebira, Grantiopsis and also Paragrantia (see Van Soest et al. 2015) are likely members of the gamily Lelapiidae .