Tubastrea diaphana ( Dana, 1846 )

Lam, Katherine, Morton, Brian & Hodgson, Paul, 2008, Ahermatypic corals (Scleractinia: Dendrophylliidae, Oculinidae and Rhizangiidae) recorded from submarine caves in Hong Kong, Journal of Natural History 42 (9 - 12), pp. 729-747 : 738

Tubastrea diaphana ( Dana, 1846)

( Figure 2E–J )

Dendrophyllia diaphana Dana, 1846

Tubastrea diaphana Ogawa & Takahashi, 1993:99 , Plate 2, Figs 9–10, Plate 5, Fig. 7

Description

Dendroid (bushy), colonial corallum. Main branch is not obvious. Extra-tentacular budding occurs near the base of old corallites. Colony size ranges from 15 mm to 20 mm in length and width and 15–20 mm in height. Corallite circular with diameters ranging from 7.1–9.8 mm. Septal order is hexameral and in four cycles. Septal size, in a descending order, is S 15 S 2.S 45 S 3. Both S 4 and S 3 are weakly developed. Columella is deep and spongy. In older polyps, columella is thicker. Living colonies are dark brown or black.

Distribution

Japan ( Ogawa and Takahashi 1993) and Conic Island and Steep Island Caves, Hong Kong (this study).

Remarks

In this study, this species was observed to be being grazed by a nudibranch, Aeolidiella sp. ( Figure 3 ).

Figures

Figure 2. Tubastrea sp. A–B, calicular (longer diameter58.2 mm) and top view of a colony of T. coccinea (length×width598.7 mm×34.6 mm); C–D, calicular (longer diameter56.37 mm) and top view of a colony of T. faulkneri (length×width568.9 mm×21.56 mm); E–J, calicular and side views of colonies of T. diaphana (height of F533 mm, height of G and H518.5 mm, longer calicular diameter and height of I and J59.9 and 21.5 mm, respectively); K–L, calicular (longer diameter59.5 mm) and top view of a colony of T. sibogae (height531.3 mm); M–O, calicular (longer diameter58.3 mm), top and side view of a colony of T. turbinata (height522.7 mm).

Figure 3. Tubastrea diaphana collected from Conic Island cave being grazed by three individuals of Aeolidiella sp. The white area of the skeleton is the grazed area. One Aeolidiella is on the top of the colony, the second is on the bottom and the third one was dislodged during collection.