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The zoanthid genus Neozoanthus was originally described in 1972 from a single species in Madagascar. This monotypic genus was placed within its own family, Neozoanthidae, given its unusual characters of only partial sand encrustation, and an endodermal sphincter muscle combined with a brachycnemic mesenterial arrangement. Recently, undescribed specimens of Neozoanthus were discovered thousands of kilometers away in both Australia and Japan. While the phylogenetic and evolutionary aspects of Neozoanthus spp. are now somewhat well understood, the new specimens remained undescribed. Here we describe the specimens as two new species, Neozoanthus uchina sp. n. from the Middle Ryukyu Islands of southern Japan, and Neozoanthus caleyi sp. n. from the waters around Heron Island, on the Great Barrier Reef in Australia. Both species can be distinguished from each other and the type species, Neozoanthus tulearensis, by their distributions, oral disk colors, and average numbers of tentacles. Additionally, each species appears to have subtle differences in their cnidae. The division of Japanese and Australian specimens into two species is strongly supported by recently reported phylogenetic data. The discovery and description of these two species highlights how little is known of zoanthid species diversity in the Indo-Pacific.
Zoanthid, Great Barrier Reef, Okinawa, Neozoanthus, new species
Zoanthids are a hexacorallian order (Zoantharia =Zoanthidea) of benthic anthozoans with gross morphological characteristics partially reminiscent of both hard corals and sea anemones. Similar to many Scleractinia, most zoanthid species are colonial, with individual polyps connected by common tissue (=coenenchyme). However, like actiniarians, most zoanthids do not secrete hard skeletons. Instead most zoanthids incorporate sand and/or detritus into their body walls to help strengthen their structure. There are, however, exceptions to these general characters within Zoantharia, with some solitary (e.g. the genus Sphenopus), non-encrusting (Zoanthidae; Zoanthus, Acrozoanthus, Isaurus), and skeleton-secreting (Savalia) taxa.
While zoanthids can be found in a wide variety of marine environments from shallow waters to the deep sea, much of their diversity is found in subtropical and tropical coral reef ecosystems, particularly within the suborder Brachycnemina (
There is one additional family of brachycnemic zoanthids, the monotypic Neozoanthidae. Neozoanthidae was erected by
Neozoanthus represents a unique evolutionary step in the zoanthid phylogeny as the only partially encrusted group of zoanthids (
In this study, utilizing both morphological and molecular techniques, we formally describe two new Neozoanthus species from subtropical regions of the Great Barrier Reef, Australia and the Ryukyu Archipelago, Japan by examining specimens recently reported in
Summary of morphological characters of major brachycnemic zoanthid genera compared with specimens examined in this study (adapted from
Genus | Encrustation? | Sphincter complexity | Sphincter position | Lacunae? | Mesogleal canals? | Endodermal invagination? |
---|---|---|---|---|---|---|
Palythoa | Yes | Simple | Mesogleal | No | Yes | No |
Zoanthus | No | Double | Mesogleal | Yes | Yes | No |
Isaurus | No | Simple | Mesogleal | No | No | Yes |
Neozoanthus | Partial | Simple | Endodermal | No | No | No |
Specimens in this study | Partial | Simple | Endodermal | No | No | No |
Internal structure of Neozoanthus uchina sp. n. showing encrustation in outer mesoglea and ectoderm, characteristic of Neozoanthus spp., with irregularly-sized encrustation A light microscope histological cross-section, and B scanning electron microscope image. Both images of specimen RMNH Coel 40098 (Table 2). Abbreviations: cm=complete mesenteries, e= sand/detritus encrustation (in B) or where encrustation existed before decalcification (in A), im=incomplete mesenteries, ec=ectoderm, en=endoderm, m=mesoglea, ss=encrusted sponge spicules. Scales: A=100 µm, B=200 µm.
Specimens were collected as detailed in
Neozoanthus specimens examined in this study with cytochrome oxidase subunit I (COI) and mitochondrial 16S ribosomal DNA (mt 16S rDNA) GenBank Accession Numbers. Data based on similar table in
Specimen number | Species | Collection location | Latitude and longitude | Depth (m) | Collection date | Collector(s) | COI | mt 16S rDNA |
---|---|---|---|---|---|---|---|---|
NSMT Co1554 | Neozoanthus caleyi | North West Reef, GBR, Australia | 23.3180°S, 151.7170°E | 10 | Nov. 17, 2009 | JD Reimer | NA | NA |
HI141 | Neozoanthus caleyi | Sykes Reef, GBR, Australia | 23.4322°S, 152.034°E | 21 | Nov. 18, 2009 | JD Reimer | HM991247" | HM991230" |
HI142 | Neozoanthus caleyi | Sykes Reef, GBR, Australia | 23.4322°S, 152.0338°E | 21 | Nov. 18, 2009 | JD Reimer | HM991248" | HM991231" |
HI143 | Neozoanthus caleyi | Sykes Reef, GBR, Australia | 23.4322°S, 152.0338°E | 21 | Nov. 18, 2009 | JD Reimer | NA | HM991232" |
HI144 | Neozoanthus caleyi | Sykes Reef, GBR, Australia | 23.4322°S, 152.0338°E | 20 | Nov. 18, 2009 | JD Reimer | NA | HM991233" |
HI145 | Neozoanthus caleyi | Sykes Reef, GBR, Australia | 23.4322°S, 152.0338°E | 18 | Nov. 18, 2009 | JD Reimer | HM991249" | HM991234" |
HI199 | Neozoanthus caleyi | Heron Channel, GBR, Australia | 23.4448°S, 151.9504°E | 22 | Nov. 22, 2009 | JD Reimer | NA | NA |
HI200 | Neozoanthus caleyi | Heron Channel, GBR, Australia | 23.4448°S, 151.9504°E | 23 | Nov. 22, 2009 | JD Reimer | HM991250" | HM991235" |
HI209 | Neozoanthus caleyi | Sykes Reef, GBR, Australia | 23.4322°S, 152.0338°E | 28 | Nov. 23, 2009 | JD Reimer | HM991251" | HM991236" |
HI214 | Neozoanthus caleyi | Sykes Reef, GBR, Australia | 23.4322°S, 152.0338°E | 9 | Nov. 23, 2009 | JD Reimer | HM991252" | HM991237" |
MTQ G65793 | Neozoanthus caleyi | Sykes Reef, GBR, Australia | 23.4322°S, 152.0338°E | 4 | Nov. 23, 2009 | JD Reimer | HM991253" | HM991238" |
HI224 | Neozoanthus caleyi | Heron Channel, GBR, Australia | 23.4532°S, 151.9005°E | 26 | Nov. 24, 2009 | JD Reimer | HM991254" | HM991239" |
HI225 | Neozoanthus caleyi | Heron Channel, GBR, Australia | 23.4532°S, 151.9005°E | 25 | Nov. 24, 2009 | JD Reimer | HM991255" | HM991240" |
HI227 | Neozoanthus caleyi | Heron Channel, GBR, Australia | 23.4532°S, 151.9005°E | 25 | Nov. 24, 2009 | JD Reimer | HM991256" | HM991241" |
HI231 | Neozoanthus caleyi | Heron Channel, GBR, Australia | 23.4530°S, 151.9171°E | 23 | Nov. 24, 2009 | JD Reimer | HM991257" | HM991242" |
HI101114-13 | Neozoanthus caleyi | Sykes Reef, GBR, Australia | 23.4316°S, 152.0493°E | 29 | Nov. 14, 2010 | JD Reimer | NA | NA |
RMNH Coel 40098 | Neozoanthus uchina | Manza, Okinawa, Japan | 26.5047°N, 127.8450°E | 25 | Sept. 1, 2008 | JD Reimer et al. | NA | NA |
MISE 545 | Neozoanthus uchina | Teniya, Okinawa, Japan | 26.5638°N, 128.1408°E | 1 to 2 | Sept. 5, 2008 | JD Reimer et al. | NA | NA |
MISE 546 | Neozoanthus uchina | Teniya, Okinawa, Japan | 26.5638°N, 128.1408°E | 1 to 2 | Sept. 5, 2008 | JD Reimer et al. | NA | NA |
USNM 1194728 | Neozoanthus uchina | Teniya, Okinawa, Japan | 26.5638°N, 128.1408°E | 1 to 2 | Sept. 5, 2008 | JD Reimer et al. | HM991246" | HM991227" |
MISE 549 | Neozoanthus uchina | Teniya, Okinawa, Japan | 26.5638°N, 128.1408°E | 1 to 2 | Sept. 5, 2008 | JD Reimer et al. | NA | NA |
NSMT Co1553 | Neozoanthus uchina | Teniya, Okinawa, Japan | 26.5638°N, 128.1408°E | 1 to 2 | Sept. 5, 2008 | JD Reimer et al. | HM991243" | NA |
MISE 560 | Neozoanthus uchina | Yona, Okinawa, Japan | 26.7684°N, 128.1976°E | 13 | Sept. 24, 2008 | JD Reimer, T Fujii | NA | NA |
MISE 1092 | Neozoanthus uchina | Teniya, Okinawa, Japan | 26.5638°N, 128.1408°E | 1 | July 2008 | JD Reimer | NA | NA |
MISE 1093 | Neozoanthus uchina | Teniya, Okinawa, Japan | 26.5638°N, 128.1408°E | Inter-tidal | July 2008 | JD Reimer | NA | NA |
MISE 1115 | Neozoanthus uchina | Tinyuhama, Korijima, Okinawa, Japan | 26.7149°N, 128.0127°E | 24 | Dec. 28, 2008 | JD Reimer | HM991245" | HM991228" |
MISE 1116 | Neozoanthus uchina | Tinyuhama, Korijima, Okinawa, Japan | 26.7149°N, 128.0127°E | 24 | Dec. 28, 2008 | JD Reimer | HM991244" | HM991229" |
MISE 1400 | Neozoanthus uchina | Omonawa, Tokunoshima, Kagoshima, Japan | 27.6669°N, 128.9685°E | 9 | March 9, 2010 | JD Reimer | NA | NA |
MISE 1401 | Neozoanthus uchina | San, Tokunoshima, Kagoshima, Japan | 27.8693°N, 128.9699°E | 10 | March 10, 2010 | JD Reimer | NA | NA |
MISE 1402 | Neozoanthus uchina | San, Tokunoshima, Kagoshima, Japan | 27.8693°N, 128.9699°E | 12 | March 10, 2010 | JD Reimer | NA | NA |
MISE 1403 | Neozoanthus uchina | Zampa, Okinawa, Japan | 26.4414°N, 127.7119°E | NA | August 29, 2008 | JD Reimer | NA | NA |
MISE MO-100 | Neozoanthus uchina | Tebiro, Amami-Oshima, Kagoshima, Japan | 28.4013°N, 129.6178°E | 10 | March 16, 2011 | M Obuchi | NA | NA |
Abbreviations: GBR=Great Barrier Reef; NA=not acquired. Sample number abbreviations as in Methods.
Specimens were examined, decalcified, and sectioned as detailed in
External morphology of specimens was examined using both preserved specimens and in situ images. Polyp dimensions (oral disk diameter, polyp height) for both in situ and preserved specimens were obtained, as were the following data: tentacle number, color of polyp, color(s) of oral disk, relative amount of sand encrustation, associated/substrate species. Additionally, the relative development of the coenenchyme was examined.
For internal examinations, the following data were obtained: mesentery form (brachycnemic or macrocnemic arrangement), mesentery numbers, presence/absence of encrustations, location of encrustations, location and development of the sphincter muscle, presence/absence of gonads. Decalcification, histology and electron microscopy were performed as described in
Undischarged nematocysts were measured from tentacles, column, actinopharynx, and mesenterial filaments of polyps (specimens examined n=2-4 colonies/species) for both new species. 400x images of the nematocysts were obtained by optical microscope, and measured using the software ImageJ (National Institutes of Health, USA). Nematocyst nomenclature generally followed
Phylogenetic analyses are detailed and were performed on both species in
MTQ Museum of Tropical Queensland, Townsville, Australia.
USNM Smithsonian National Museum of History, Washington D.C., USA
NSMT National Museum of Nature and Science, Tokyo, Japan
RMNH Naturalis Biodiversity Center, Leiden, the Netherlands
MISE Molecular Invertebrate Systematics and Ecology Laboratory, University of the Ryukyus, Nishihara, Okinawa, Japan
Additional data related to both species, including tables, phylogenetic trees, and histological images, are reported in
Diagnosis.Brachycnemic zoanthids with a simple endodermal sphincter muscle (Figure 2) that are only partially sand-encrusted (Figure 1).
Type species. Neozoanthus tulearensis Herberts, 1972
Diagnosis.As for the family above.
Longitudinal section of Neozoanthus caleyi sp. n. specimen HI225 showing endodermal sphincter muscle (=sm). A Light microscope B scanning electron microscope. Both scales =200 µm.
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Figures 2, 3, 5A, Tables 2, S1Type 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).
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 may 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).
Differs from Neozoanthus tulearensis Herberts, 1972 and Neozoanthus uchinasp. 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 (
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.
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 (
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).
This species can close its polyps much more rapidly than those of other zooxanthellate zoanthid genera (Reimer pers. obs).
Comparison of various features of Neozoanthus tulearensis Herberts, 1972, Neozoanthus caleyi sp.n. and Neozoanthus uchina sp. n.
Morphological character | Neozoanthus tulearensis | Neozoanthus uchina sp. n. | Neozoanthus caleyi sp. n. |
Distribution | NE Madagascar | Middle Ryukyu Islands, Okinawa, Japan | Heron Island, Great Barrier Reef, Australia |
Depth | No data | Intertidal to 25 m | 4 to 29 m |
Oral disk color | Greenish-beige to yellow | Light gray-blue, white, rust or deep wine red | Light gray-blue, white, or deep wine red |
Polyp diameter (mm) | 1.5 to 5.0 | 2.2 to 5.1 | 2.3 to 5.0 |
Polyp height (mm) | 2.0 to 12.0 | 2.0 to 8.5 | 2.5 to 3.0 |
Number of tentacles (avg. ± SE) | 38–44 | 32–42 (38±3.0) | 28–40 (33±3.9) |
Cnidae | |||
Column | Microbasic mastigophores | Holotrichs | Holotrichs |
Pharynx | Microbasic mastigophores | Holotrichs, basitrichs, spirocysts | Holotrichs, basitrichs |
Tentacles | Holotrichs, spirocysts | Holotrichs, basitrichs, spirocysts | Holotrichs, basitrichs, spirocysts |
Filaments | Holotrichs, microbasic mastigophores | Holotrichs, p-mastigophores | Holotrichs, basitrichs, p-mastigophores |
Neozoanthus caleyi sp. n. in situ around Heron Island on the Great Barrier Reef, Queensland, Australia. A Specimen HI214 at Sykes Reef, depth=9 m, November 23, 2009 B Close-up of a single polyp showing yellow coloration at base of tentacles; specimen HI145 at Sykes Reef, depth=18 m, November 18, 2009 C Specimen HI231 at Heron Channel, depth=23 m, November 24, 2009 D Uncollected specimen at Heron Channel, depth=approximately 20 m, November 2011. Scales approximately 1 cm. A, B taken by JD Reimer, C, D taken by Gary Cranitch.
Originally listed in Table S1 in
Cytochrome oxidase subunit I: HM991247-HM991257
Mitochondrial 16S ribosomal DNA: HM991230-HM991242
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Figures 1, 4, 5B, Tables 2, 3, S1Holotype, specimen number NSMT-Co1553. Colony of 17 polyps connected by stoloniferous coenenchyme on a rock approximately 4.5 × 3.0 cm. Polyps approximately 2.0–4.4 mm in diameter, and approximately 2.0–5.4 mm in height from 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. Original label.
Paratypes (all from Japan): Paratype 1. Specimen number USNM 1194728. Collected from Teniya, Nago, Okinawa, at 1 to 2 m by JDR, September 5, 2008. Paratype 2. Specimen number RMNH Coel 40098. Collected from Manza, Onna, Okinawa I., Japan, at 25 m by JDR, 1 September, 2008.
Type locality. Japan, Okinawa Prefecture, Okinawa Island: Nago City, Teniya, 26.563832°N, 128.140822°E, in small cracks on reef flat at 1 to 2 m depth, 5 September 2008, J.D. Reimer (JDR) leg.
Other material (all from Japan, coll. JDR unless noted): Teniya, Okinawa I., Okinawa, MISE 545, 546, 549 (n=3), 1-2 m 5 September 2008; Yona, Okinawa I., Okinawa, MISE 560, 13 m, coll. JDR and Takuma Fujii (TF), 24 September 2008; Teniya, Okinawa I., Okinawa, MISE 1092, 1093 (n=2), intertidal - 1 m, 1 July 2008; Tinyuhama, Korijima I., Okinawa, MISE 1115, 1116 (n=2), 24 m, 28 December 2008; Omonawa, Tokunoshima I., Kagoshima, MISE 1400, 9 m, 9 March 2010; San, Tokunoshima I., Kagoshima, MISE 1401, 1402 (n=2), 10-12 m, 10 March 2010; Zampa, Okinawa I., Okinawa, MISE 1403, at unknown depth, 29 August 2008 (see also Table 2); Tebiro Beach, Amami-Oshima I., Kagoshima, MISE MO-100, 10 m, coll. Masami Obuchi, 16 March 2011.
Size: Polyps in situ approximately 2.2-5.1 mm in diameter when open, and approximately 2-8.5 mm in height.
Morphology: Neozoanthus uchina sp. n.has 32 to 42 (average 38±3.0, n=24 polyps on 9 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, rust red, or transparent, often with black, white, or fluorescent blue bands or patterning (Figure 4). No bractae are visible, and all specimens were 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 4). Oral disks may be a variety of colors, such as light gray-blue, white, rust or deep wine red. Occasionally, white or light blue dots may be seen on the oral disk in regular circular patterns, and the oral opening (mouth) is often white or cream 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 consisted of tens to <100 polyps, connected by stolons with no well-developed coenenchyme.
Cnidae: Basitrichs and microbasic p-mastigophores (often difficult to distinguish), holotrichs (large and small), spirocysts (see Table S1, Figure 5).
Differs from Neozoanthus tulearensis Herberts, 1972 and Neozoanthus caleyi sp. n. with regards to distribution (Ryukyu Archipelago as opposed to Madagascar and southern Great Barrier Reef, respectively), coloration (yellow observed in some Neozoanthus caleyi sp. n.), and tentacle count (Neozoanthus tulearensis = 38 to 44 tentacles, Neozoanthus caleyi sp. n. = average 33±3.9 tentacles). The two new Neozoanthus species’ tentacle counts are statistically significant (t-test, p<0.001). Often polyps are much taller (to 8.5 mm) than Neozoanthus caleyi sp. n. (to 3.0 mm), although height ranges overlap (Table 3). The two new Neozoanthus species mt 16S rDNA sequences differ by three base pairs (
Neozoanthus uchina sp. n.is currently the only partially encrusted zoanthid described from the Ryukyu Archipelago.
Named for the Okinawan dialect word for Okinawa, “uchina”, the prefecture where this species was first found. Noun in apposition.
Specimens from the Ryukyu Archipelago were found at depths from the intertidal zone to 25 m. Despite repeated surveys focused on zoanthids, no Neozoanthus uchina sp. n.have been found further north on Yakushima Island or mainland Japan, nor further south in the Miyako and Yaeyama Islands of southern Okinawa, and it may be that this species is limited to a subtropical distribution in the Middle Ryukyu Islands. Additionally, despite surveys, thus far no specimens have been reported from neighboring Taiwan (
Neozoanthus uchina 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. Preference for such environments may be related to its encrustation patterns. Colonies were almost always found in cracks and holes in rocks partially exposed to light, and usually not in locations completely exposed to light. Most colonies were relatively small, consisting of tens (not hundreds) of polyps, with polyps spread out and connected by thin stolons (Figure 4).
This species can close its polyps much more rapidly than species of other zooxanthellate zoanthid genera (Reimer pers. obs).
Originally listed in Table S1 in
Cytochrome oxidase subunit I: HM991243-HM991246
Mitochondrial 16S ribosomal DNA: HM991227-HM991229
Neozoanthus uchina sp. n. in situ. A Partially closed polyps showing lack of encrustation at oral end B Colonies of two different color morphotypes C Close-up of polyps of the same color morphotype as on the left in B) D Polyps showing variation in oral disk color where the dorsal directive is located. Scales approximately 1 cm. A to D images taken by Masaru Mizuyama, September 20, 2010, in the lower intertidal zone at Kamomine, Tokunoshima, Kagoshima, Japan, specimens uncollected E Colony MISE MO-100 in situ on March 16, 2011 at Tebiro Beach, Amami-oshima, Kagoshima, Japan. Image taken by Masami Obuchi.
Cnidae of Neozoanthus caleyi sp. n. and Neozoanthus uchina sp. n. from the tentacles, pharynx, and filaments showing their relative size. Type abbreviations: Sp=spirocysts, H=holotrichs, LH=large holotrichs, SH=small holotrichs, B=basitrichs, SH?=potential small holotrichs, pM=p-mastigophores. Size and frequency data are given in Table S1.
As stated previously (
Both new species in this study were found in areas notable for their strong currents. Both species, although zooxanthellate, were found in areas somewhat sheltered from direct sunlight, unlike many Zoanthus and Palythoa spp. The sand encrustation plus Neozoanthus species’ preference for cracks and overhangs may have led to their lack of discovery in both Australia and Japan until 2008-2009 (
Neozoanthus caleyi sp. n. possesses Symbiodinium (=zooxanthellae) of subclade C1 sensu
As mentioned in the species’ descriptions, for now it appears that both Neozoanthus uchina sp. n. and Neozoanthus caleyi sp. n. have subtropical distributions, as no colonies were found to regions directly north (both species) or directly south (Neozoanthus uchina sp. n.) of their distribution. However, due to their small size and preference for semi-cryptic microhabitats, we cannot discount the possibility that there are further populations of both species that await discovery. Furthermore, it is known there are unidentified Neozoanthus species in Indonesia (Reimer & Hoeksema, unpublished data), and specimens are needed to complete work on these.
Two new species of Neozoanthus from the Pacific are formally described, one from the Great Barrier Reef and one from the Middle Ryukyu Islands.
The discovery of these two species (detailed in
We recommend the utilization of the combination of both molecular results (
The author thanks the following people at the University of the Ryukyus (UR): Dr. Mamiko Hirose (now Ochanomizu U.) for histology help, and Dr. Frederic Sinniger (now JAMSTEC), Masami Obuchi (now Biological Institute on Kuroshio) and Masaru Mizuyama for specimens, distribution information, and in situ images. On the Great Barrier Reef, the Census of Coral Reef Ecosystems (CReefs) Australia Project, and in particular Dr. Julian Caley and Shawn Smith (both AIMS) are thanked for sampling help, and Gary Cranitch (AIMS) for images. CReefs was a field project of the Census of Marine Life. Dr. Bert Hoeksema (Naturalis Biodiversity Center) and Julian Sprung are thanked for information on Neozoanthus in the central Indo-Pacific. This study was funded in part by the Japan Society for the Promotion of Science, and the Rising Star Program and the International Research Hub Project for Climate Change and Coral Reef/Island Dynamics at UR. The third author was supported in part by the Japan Society for the Promotion of Science. Specimens from Australia were collected under Great Barrier Reef Marine Park Authority permit #G32313.1 and Queensland Fisheries permit # 95152. Two anonymous reviewers’ comments greatly improved the manuscript.
Types, relative abundance and sizes of cnidae in Neozoanthus uchina sp. n. and Neozoanthus caleyi sp. n. (doi: 10.3886/zookeys.246.3886.app) File format: Microsoft Word Document (doc).
Explanation note: Table S1 Types, relative abundance and sizes of cnidae in Neozoanthus uchina sp. n. and Neozoanthus caleyi sp. n.