Trimuricea persica n. sp.

(Figs. 21 a, 22–23)

T. aff. reticulata; Samimi-Namin & van Ofwegen 2009a: 43.

NOT Echinomuricea reticulata Thomson & Simpson, 1909: 206 . (= Trimuricea reticulata).

Material: Holotype, RMNH Coel. 38785, Iran, Farur Island, Persian Gulf, coll. S.A. Mohtarami.

Description. The holotype is 16 cm high and 22 cm wide, branched in one plane, with many anastomoses forming a network (Fig. 21 a). The stem is 1 cm long and 0.5 cm thick, and the branches are 3–4 mm thick. The end branches in some parts of the colony have lost their coenenchymal tissue and the axis is visible. The calyces are dome shaped, closely set to each other, and situated all around the branches. They are up to 0.5 mm high and 0.75 mm in diameter.

The points have triradiates (Fig. 22 a), along with curved, hockeystick or boot-shaped sclerites, or spindles (Fig. 22 b), 0.15–0.25 mm long. The upper ray of the triradiates and upper part of the spindles is slightly echinulate or tuberculate for up to 0.18 mm. The collaret spindles are 0.15–0.35 mm long (Fig. 22 c); the middle part of the convex side is more tuberculate than the concave side and both the ends. The concave side is relatively smooth in the center, with some tuberculation at both ends. A few tentacle scales are present, up to 0.10 mm long (Fig. 22 d).

The calyces have thornscales, 0.20–0.40 mm long, with one or more echinulate thorns up to 0.20 mm long (Fig. 23 a). The smaller ones do not have lateral arms.

The coenenchyme has spindles, 0.20–0.60 mm long. The long ones have large, densely placed complex tubercles and short ones have simple tubercles (Fig. 23 b).

Colour. The live colony was reddish-purple in colour, preserved it is brown. All sclerites are colourless. There is no information about the colour of polyps.

Etymology. The specific epithet is derived from the Latin persicus (Persian). It refers to the Persian Gulf where the species was found.

Remarks. This species resembles Trimuricea tuberculosa n. sp. in the tuberculation of the spindles, but differs in having less strongly tuberculated polyp sclerites. It also resembles T. spinosa, but differs in lacking many thornscales with more than one thorn

This species was described by Samimi-Namin & van Ofwegen (2009a: 43) as Trimuricea aff. reticulata . After examination of a fragment of the material described by Thomson & Simpson (1909) as Echinomuricea reticulata (BMNH 1933.3.13.18: = Trimuricea reticulata) it became obvious that our 2009 identification was incorrect. Trimuricea reticulata differs in having far less tuberculate coenenchymal spindles, which are narrower. It also has calicular thornscales with long narrow thorns and less tuberculate roots.