Unomia stolonifera ( Gohar, 1938 )

Benayahu, Yehuda, Van Ofwegen, Leen P., Ruiz Allais, J. P. & Mcfadden, Catherine S., 2021, Revisiting the type of Cespitularia stolonifera Gohar, 1938 leads to the description of a new genus and a species of the family Xeniidae (Octocorallia, Alcyonacea), Zootaxa 4964 (2), pp. 330-344 : 333

publication ID	https://doi.org/ 10.11646/zootaxa.4964.2.5
publication LSID	lsid:zoobank.org:pub:D3E4491B-E445-42BD-9B94-2B6786ACAA94
DOI	https://doi.org/10.5281/zenodo.4740960
persistent identifier	https://treatment.plazi.org/id/03917065-4161-FFCD-5A82-FF61F670F866
treatment provided by	Plazi
scientific name	Unomia stolonifera ( Gohar, 1938 )
status

Treatment

Unomia stolonifera ( Gohar, 1938) View in CoL

Figs. 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5

Cespitularia stolonifera Gohar, 1938: 483–485 View in CoL , plate I, fig. 1; Utinomi 1950: 16; Utinomi 1959: 305.

Material. Type. Indonesia: BMNH 1889.5.27, Amboina, st. 233, shallow water, coll. H.M.S. Challenger , 1889. Additional material. Indonesia: RMNH. COEL. 42436, SW Sulawesi, Spermonde Archipelago, west of Lumu-Lumu Isl. (= 28 km NW of Ujungpandang), 4 o 58’S 119 o 12’E, coral reef, scuba diving, 27 May 1994, Bug. Prog. UNHAS-NNM. coll. B.W. Hoeksema & L.P. van Ofwegen GoogleMaps ; RMNH. COEL. 42437 details as above; Venezuela : ZMTAU Co. 38081, Valle Seco, Bahia Conoma , Estado Sucre, 4–6 m, 28 November 2012, coll. Juan P. Ruiz Allais , four specimens; ZMTAU Co. 38082 details as above, two specimens .

Description. The type, BMNH 1889.5.27, consists of four soft colonies attached by a spreading membrane to a skeleton fragment of branched Acropora stony coral and an additional colony similarly attached to a smaller fragment ( Fig. 1A View FIGURE 1 ), each measuring approximately 3 X 4 cm. The spreading membrane overgrowing the calcareous substrate is clearly presented in Fig. 1B View FIGURE 1 , in which the type colonies are viewed from the opposite side. The colonies ramify into a number of short branches up to 12–25 mm long, each with a polyp-bearing region on their upper part. Individual polyps are also found on the branches or on the stalk thus indicating the diffuse nature of the polypiferous part of the colony. Some of the polyps are damaged, mostly having lost their tentacles. The polyp body is up to 10–14 mm long and the tentacles up to 5–7 mm long. The pinnules are arranged in 3 rows and occasionally 2 rows, with 18–25 in the outermost row. The pinnules are almost completely contracted, 0.5 mm wide, with an approximately one pinnule-wide space between adjacent ones.

The sclerites are ellipsoid platelets, highly abundant in all parts of the colony, measuring 0.012 –0.015 X 0.018 – 0.021 mm in diameter ( Fig. 2A View FIGURE 2 ). They are composed of calcite rods, uniform in diameter of about 0.001 –0.002 mm, and the tips of the rods are perpendicular to the surface of the sclerite ( Fig. 2B View FIGURE 2 ). The ethanol-preserved type material is cream-white.

RMNH. COEL. 42436, is a flattened, very soft colony, 9 cm high and 6 cm wide, and attached to calcareous fragments by a spreading membrane ( Fig. 1C View FIGURE 1 ). Its stalk is split into 5–6 short branches, each featuring a cluster of polyps; individual polyps are also found on the branches below these clusters. The polyp body is up to 10 mm long and the tentacles are up to 15 mm long. The pinnules are arranged mostly in 3 rows, or rarely in 2 rows, with 18–24 pinnules in the outermost row, exhibiting a gap of up to a pinnule-width between adjacent ones. Some pinnules are contracted and the fully extended ones are up to 2 mm long. The sclerites resemble those of the type, measuring 0.010–0.015 X 0.015–0.021 mm in diameter ( Fig. 3 View FIGURE 3 ) GoogleMaps . RMNH.COEL.42437 differs from RMNH.COEL.42436 only in size ( Fig. 1D View FIGURE 1 ). Both ethanol-preserved colonies are light beige-white in color.

ZMTAU CO 38081 consists of four Venezuelan colonies ( Fig. 1E View FIGURE 1 ). Their morphology resembles the type material, featuring a diffused polypiferous part of the colonies. The polyp body is up to 25 mm long and the tentacles up to 10 mm long, bearing pinnules arranged in 3 rows with 20–25 pinnules in the outermost row and a gap of up to a pinnule-width between adjacent ones. The sclerites also resembles those of the type, measuring 0.014 –0.017 X 0.018 –0.025 mm in diameter ( Fig. 4 View FIGURE 4 ). ZMTAU CO 38082 (not depicted) resembles ZMTAU CO 38081 .

Underwater photographs of live colonies taken at Valle Seco, Bahia Conoma, Estado Sucre, Venezuela , reveal the diffuse nature of the polypiferous part of the colonies ( Fig. 5A View FIGURE 5 ). The live polyps feature elongate dark brown tentacles due to the symbiotic zooxanthellae as well numerous sclerites as presented in Fig. 5B View FIGURE 5 . Individual polyps are found on the stalk, below the level of the polypary ( Fig. 5C, D View FIGURE 5 ).

Remarks. The material from Sulawesi (RMNH.COEL. 42436, 42437) resembles the type of Unomia gen. n. (BMNH 1889.5.27). Notably, the invasive xeniid from Venezuela , which was originally identified as a “xeniid with close genetic affinities to Xenia membranacea Schenk, 1896 ’’ (Ruiz Allais et al. 2014), matches well the above material. The freshly collected and ethanol-preserved specimens from that site enabled the molecular analysis and placement of the species in the phylogenetic tree. Consequently, the taxonomic status of this peculiar invasive soft coral is now confirmed to be U. stolonifera ( Gohar, 1938) .

Distribution. Indonesia ( Ambon, Sulawesi), Venezuela .