Neozoanthus caleyi, Reimer, James Davis, Irei, Yuka & Fujii, Takuma, 2012

Reimer, James Davis, Irei, Yuka & Fujii, Takuma, 2012, Two new species of Neozoanthus (Cnidaria, Hexacorallia, Zoantharia) from the Pacific, ZooKeys 246, pp. 69-87 : 71-72

Neozoanthus caleyi sp. n. Figures 235ATables 23S1

Neozoanthus caleyi Synonymy: "GBR clade" of Neozoanthus Reimer et al. 2011a: fig. 2.

Neozoanthus caleyi "Neozoanthus sp. Australia" - Reimer et al. 2011a: 986, 989, fig. 4.

Material examined.

Type specimens. Holotype, specimen number MTQ G65793. Colony in two pieces, 5 polyps on a 2.5 × 2.0 cm stone and 4 polyps on a 2.0 × 1.0 cm stone (originally one colony). Polyps approximately 2.3-5.0 mm in diameter, and approximately 2.5-3.0 mm in height from stoloniferous coenenchyme. Polyps and coenenchyme encrusted with irregularly sized and colored sand grains. There was no noticeable variation between holotype and other specimens. Preserved in 99.5% ethanol.

Paratype (fromAustralia): Paratype 1. Specimen number NSMT Co1554. North West Reef, Queensland, at 10 m by JDR, November 17, 2009.

Type locality.Australia, Queensland: Great Barrier Reef, Sykes Reef, 23.4322°S, 152.0338°E, reef with coral rubble, at 4 m, 23 November 2009, JDR leg.

Other material (all from Great Barrier Reef, Queensland, Australia; coll. JDR): Sykes Reef MISE HI-141 to 145 (n=5), 18-21 m, 18 November 2009; MISE HI-209, 28 m, 23 November 2009; MISE HI-214, 9 m, 23 November 2009; MISE HI101114-13, 29 m, 14 November 2010. Heron Island Channel, MISE HI-199 to 200 (n=2), 22-23 m, 22 November 2009; MISE HI-224 to 225, 227 (n=3), 25-26 m, 24 November 24 2009; MISE HI-231, 23 m, 24 November 2009 (see also Table 2).

Description.

Size: Polyps in situ approximately 2-5 mm in diameter when open, and approximately 2-3 mm in height.

Morphology: Neozoanthus caleyi sp. n.has 28 to 40 (average 33 ± 3.9, n=18 polyps on 8 colonies) conical tentacles. Tentacles are usually shorter than the expanded oral disk diameter (e.g. 50-80% of oral disk width). Tentacles may be grayish-blue, yellow, or transparent, often with black, white, or fluorescent blue bands or patterning (Figure 3). Well-developed, simple endodermal sphincter. No bractae are visible. All specimens are zooxanthellate. Polyps are externally heavily encrusted with sand and other particles of irregular sizes, excepting the oral end, which is free of encrustation and appears a bluish-gray similar to as seen in some Zoanthus species. When fully contracted, the sand-free oral end is often not visible, and polyps resemble small balls of sand. Polyps extend well clear of reduced or stoloniferous coenenchyme (Figure 3). Oral disks ma y be a variety of colors, including light gray-blue, white, or deep wine red. Occasionally, white, yellow, or light blue dots may be seen on the oral disk in regular circular patterns, and the oral opening (mouth) is often white in color. A “skirt” of different coloration (usually white or lighter coloration than remainder of oral disk) covering up to approximately 90 degrees of the oral disk is often seen in the area of the dorsal directive. Colonies consist of tens to <100 polyps, connected by stolons with no well-developed coenenchyme.

Cnidae: Basitrichs and microbases (often difficult to distinguish), holotrichs (large and small), spirocysts (see Table S1, Figure 5).

Differential diagnosis.

Differs from Neozoanthus tulearensis Herberts, 1972 and Neozoanthus uchina sp. n. with regards to distribution (southern Great Barrier Reef as opposed to Madagascar and Ryukyu Archipelago, respectively), coloration (no yellow observed in any Neozoanthus uchina sp. n.), and tentacle count ( Neozoanthus tulearensis = 38 to 44 tentacles (n= 8 colonies; 18 polyps), Neozoanthus uchina sp. n. = average 38 ± 3.0 tentacles, n= 9 colonies; 24 polyps). The two new Neozoanthus species’ tentacle counts are statistically significant (t-test, p<0.001). The two new Neozoanthus species mt 16S rDNA sequences differ by three base pairs ( Reimer et al. 2011a).

Etymology.

Named for Dr. Julian Caley, the leader of the Australian Census of Coral Reef Ecosystems (CReefs) project. Dr. Caley’s acceptance of the first author’s participation in CReefs led to the discovery of this species. Noun in genitive.

Habitat, ecology and distribution.

Specimens from the Great Barrier Reef were found at depths from 4 to 29 m. Despite repeated surveys, no Neozoanthus caleyi sp. n. have been found further north around Lizard Island despite zoanthid-focused surveys ( Burnett et al. 1997; J.D. Reimer & T. Fujii, unpublished data), and it may be that this species is limited to a subtropical distribution in the Great Barrier Reef.

Neozoanthus caleyi sp. n., although not found at many locations surveyed, was locally common, particularly at locations that were characterized by strong currents and some sedimentation, with large coarse sand particles scattered over the bottom or rocks, for example on the bottom of Heron Channel. Preference for such environments may be related to its encrustation patterns. Colonies were never found in locations completely exposed to light, yet all colonies were zooxanthellate. Most colonies were relatively small, consisting of tens (not hundreds) of polyps, with polyps spread out and connected by thin stolons (Figure 3).

Notes.

This species can close its polyps much more rapidly than those of other zooxanthellate zoanthid genera (Reimer pers. obs).

DNA Sequences.

Originally listed in Table S1 in Reimer et al. (2011a).

Cytochrome oxidase subunit I: HM991247-HM991257

Mitochondrial 16S ribosomal DNA: HM991230-HM991242