Cyphastrea kausti Bouwmeester & Benzoni

Bouwmeester, Jessica, Benzoni, Francesca, Baird, Andrew H. & Berumen, Michael L., 2015, Cyphastreakausti sp. n. (Cnidaria, Anthozoa, Scleractinia), a new species of reef coral from the Red Sea, ZooKeys 496, pp. 1-13 : 4-8

Taxon classification Animalia Scleractinia Merulinidae

Cyphastrea kausti Bouwmeester & Benzoni sp. n. Figures 2, 3a, c, e, 4

Material examined.

Type material.Holotype: MNHN-IK-2012-14236 (KAUST SA1307). Type locality: Fsar (Thuwal), N 22°13.78', E 39°01.73', depth 13.6 m, coll. J. Bouwmeester 20/10/2013.

Paratype: MNHN-IK-2012-14237 (KAUST SA522). Sodfa (Thuwal), N 22°12.07', E 38°57.52', depth 2.0 m, coll. D. Huang, 24/04/2013.

Other material (Red Sea, Saudi Arabia).

SA443 Qita al Kirsh (Thuwal), N 22°25.60', E 38°59.77', coll. F. Benzoni, 18/03/2013; SA446 Qita al Kirsh (Thuwal), N 22°25.60', E 38°59.77', coll. F. Benzoni, 18/03/2013; SA498 Sodfa (Thuwal), N 22°12.07', E 38°57.52', depth 10.4 m, coll. D. Huang, 24/04/2013; SA607 Abu Madafi (Thuwal), N 22° 3.73', E 38°45.82', depth 6.1 m, coll. J. Bouwmeester, 28/04/2013; SA643 Tahla (Thuwal), N 22°17.04', E 39° 3.10', depth 6-12 m, coll. J. Bouwmeester, 08/07/2013; SA644 Tahla (Thuwal), N 22°17.04', E 39° 3.10', depth 6-12 m, coll. J. Bouwmeester, 08/07/2013; SA973 Magna (Gulf of Aqaba), N 28°24.23', E 34°44.44', coll. F. Benzoni, 29/09/2013; SA1103 Shaybarah (Al Wajh), N 25°21.69', E 36°54.75', coll. F. Benzoni, 03/10/2013; SA1121 Marker 9 (Yanbu), N 24°26.56', E 37°14.86', coll. F. Benzoni, 04/10/2013; SA1165 Marker 9 (Yanbu), N 24°26.56', E 37°14.86', depth 12.5 m, coll. J. Bouwmeester, 04/10/2013; SAE015 Fsar (Thuwal), N 22°13.78', E 39°01.73', depth 12m, coll. J. Bouwmeester, 21/09/2014.

Description of holotype.

The holotype is part of a 12 cm high and 17 cm wide encrusting colony living on an inclined surface (Figure 4 a–b), and is constituted of two fragments sampled from a single colony (Figure 2a). The first fragment is the bigger of the two, bell-shaped, 4.5 cm high and 3.8 cm wide (Figure 2a, left). The second fragment is smaller, triangular-shaped, 2.5 cm high with a 2.5 cm base (Figure 2a, right). The number of septa is eight but in a small number of corallites (4/40), the number of septa is seven or nine. The septa are exsert and carry densely ornamented spines. The costae are composed of a line of ornamented spines, which continue on the coenosteum, adding to its already dense and elaborate arrangement of ornamented spines. The columella is trabecular and surrounded by a crown of paliform lobes (Figure 2c). Extra-calicular budding can be observed on both fragments (Figure 2a). The calice diameter of the corallite is 1.11 ± 0.06 mm and the corallite diameter is 1.77 ± 0.14 mm. The corallite density varies from 13 to 22 corallites per cm2 (Figure 2c).

Diagnosis.

The number of primary septa in Cyphastrea kausti sp. n. is typically eight (Figures 2e, h, 3e) but in some cases, seven, nine, or even ten septa can be observed in some corallites of the same colony. However, the majority of corallites have eight primary septa and the average number of septa throughout examined samples is 8.0 ± 0.4 (61 corallites examined from four specimens). This character distinguishes it from Cyphastrea microphthalma , which on average has 9.8 ± 0.5 primary septa per corallite, although in one case a corallite with eight septa was observed (Table 1).

In Cyphastrea kausti sp. n. the calice diameter of the corallite is 1.01 ± 0.13 mm and the corallite diameter is 1.62 ± 0.19 mm. This is smaller than in Cyphastrea microphthalma , which has a calice diameter of 1.27 ± 0.11 mm and a corallite diameter of 2.01 ± 0.18 mm (Table 1).

The corallite density is highly variable between colonies of Cyphastrea kausti sp. n. but also within a colony, and varies from 11 to 31 corallites per cm2 (e.g. Figures 2c, e, 3c). The corallite density is generally lower on convex surfaces, and higher on concave surfaces, but remains highly variable between colonies, and is not dependant on depth. Indeed, SA607, which had the lowest number of corallites per cm2, was sampled at 6 m depth, shallower than the other colonies examined here. In a similar way, corallite density is also highly variable in Cyphastrea microphthalma and varies from 11 to 33 corallites per cm2.

The first order septa are clearly exsert, the second order septa are weak and never reach the columella, and the third cycle of septa is absent (Figures 2, 3a, c, e). A distinct crown of eight ornamented paliform lobes, corresponding to the number of first order septa, surrounds the columella (Figure 2c). Columella is trabecular and compact (Figures 2 h–i, 3c, e). Septal teeth are prominent and ornamented, and granules are scattered on the septal face (Figure 2 e–f). Costae are composed of a continuous or dotted line of ornamented spines, which become more and more spaced out while extending on the coenosteum, blending in with the already dense arrangement of ornamented spines, which covers the remaining of the coenosteum (Figure 2 c–i). The height of each corallite is also variable, leading to colonies with corallites appearing more exsert than in others (e.g. Figure 4e-f).

Field characteristics and identification.

Colonies of Cyphastrea kausti sp. n. are encrusting (Figures 4 a–c) to submassive (Figure 4d), often growing on inclined substrate, and are found mostly at 6-12 m depth although they have been observed at 2.0-13.6 m depth. They appear similar to Cyphastrea microphthalma but close observation of the corallites will reveal the typical eight-arm snowflake septal arrangement (Fig. 2, 3a, c, e). The size of the colonies is variable but generally is 10-60 cm. Colour in the field is cream, yellow, or brown.

Etymology.

This species is named after the King Abdullah University of Science and Technology (KAUST), which has facilitated a considerable increase in marine biodiversity research in the Red Sea since its opening in 2009. Moreover, Cyphastrea kausti sp. n. was first observed by the authors on Al Fahal, a reef in front of KAUST, in Thuwal, Saudi Arabia.

Distribution.

Cyphastrea kausti sp. n. has been recorded in the northern and central Red Sea, from Magna in the Gulf of Aqaba, to Thuwal (Figure 1). It was not found in the southern Red Sea, where a similar sampling effort was made.