[Cnidaria • 2026] Hemicorallium osmanthogemmum • A New Species of Hemicorallium (Anthozoa: Octocorallia: Coralliidae), along with a revised identification key to species of the genus

Hemicorallium osmanthogemmum

Koido, 2026 

 

DOI: doi.org/10.3897/zookeys.1277.184620 

 

Abstract

A new precious coral species, Hemicorallium osmanthogemmum sp. nov. (Scleralcyonacea, Coralliidae), retrieved from a depth of 550 m in Kochi Prefecture, Japan, is described, and an updated identification key for the genus Hemicorallium is provided. The new species is confirmed as belonging to the genus Hemicorallium based on the presence of nonretractile but contractile autozooids with an ovate-cylindrical shape and sclerites comprising elongated rods, 6–8-radiates and double clubs, with elongated rods present exclusively in the tentacles. Moreover, the species is distinct from all its congeners in that it has orange coenenchyme and a pink axis, with autozooids distributed only on the front side of the branch, forming clusters at the branch tips. These morphological features differ from those of all previously described species of Hemicorallium, and molecular analysis of mitochondrial sequences (16S, ND1, ND2, ND3, ND6, COI, MSH, and IGR1) further corroborates the validity of this new species. This is the first report of Hemicorallium off the coast of Kochi Prefecture, Japan.

Key words: Cnidaria, deep-sea corals, precious coral, Scleralcyonacea, Western Pacific

 

Hemicorallium osmanthogemmum sp. nov. (Holotype: KBF-OA-00436).
 A. ‘‘Front’’ and ‘‘back’’ of colony; B. Branch, showing autozooid (AZ); C. Exposed axis with the coenenchyme removed; D, E. Surface detail of branch, showing autozooid (AZ), siphonozooid (SZ), burrows (Bu), cluster of autozooids (CL), warts on coenenchyme surface (W), and commensal polychaete (Po).

 Scale bars: 50 mm (A); 10 mm (B–E).

Class Octocorallia Haeckel, 1866

Order Scleralcyonacea McFadden, van Ofwegen & Quattrini, 2022

Family Coralliidae Lamouroux, 1812

Genus Hemicorallium Gray, 1867

Hemicorallium osmanthogemmum sp. nov. 

 New Japanese name. Kinmokusei-mizo-sango.

Diagnosis. The colony branches in one plane, and anastomoses are present only where broken branches come into contact with other branches. Autozooids are contracted but not retracted, and they are distributed only on one side of the colony. Spacing is almost absent on the twigs, and clusters are formed at the tips. The axis has no pits beneath the autozooids and is pale pink to pink in colour. Sclerites are predominantly radiate, and double clubs are rare. Warty rods are present only in the tentacles.

 

Tatsuki Koido. 2026. A New Species of Hemicorallium (Anthozoa, Octocorallia, Coralliidae), along with a revised identification key to species of the genus. ZooKeys. 1277: 339-354.  DOI: doi.org/10.3897/zookeys.1277.184620 [20 Apr 2026]

[Cnidaria • 2026] Paraplexaura binyuani • A New Gorgonian (Octocorallia: Acanthogorgiidae) from the Huaguang Atoll, Xisha Islands, South China Sea

 

Paraplexaura binyuani 

You, Xia & Liu, 2026. 

斌源似丛柳珊瑚  ||  DOI: doi.org/10.3390/d18030166 

Abstract

A new shallow-water gorgonian coral species in the family Acanthogorgiidae, Paraplexaura binyuani sp. nov., is described from a specimen collected at Huaguang Atoll in the South China Sea at a depth of 22 m. The new species is distinguished from its congeners by abundant polyp sclerites, predominantly flattened rods, and by the coenenchyme bearing numerous large spindles reaching up to 0.6 mm in length, which are approximately two to three times longer than those reported for most described species of Paraplexaura. Phylogenomic analyses based on ultraconserved elements (UCEs) recover Paraplexaura as monophyletic and place P. binyuani sp. nov. as sister to P. cryptotheca, consistent with its morphological distinctiveness and supporting its recognition as a separate species.

Keywords: Malacalcyonacea; shallow-water coral; taxonomy; morphology; ultraconserved elements

 The external morphology and polyps of Paraplexaura binyuani sp. nov. Holotype, GXTCMU-2025-HT005.
(A,C) in situ; (B) After collection; (D) Frontal view of a branch; (E) Polyps under SEM.

 Scale bars indicate 1 cm in (B), 5 mm in (D), 100 μm in (E).

Paraplexaura binyuani sp. nov.

Etymology. The new species is named after Dr. Binyuan He, principal investigator of the Guangxi Academy of Oceanography, and for his great contribution to benthos research of Guangxi. The Chinese name of the new species is “斌源似丛柳珊瑚”

Distribution and habitat. Known only from the subtidal zone of the Huaguang Atoll on the Chinese coast of the South China Sea with a water depth of 22 m. Colony attached to a rocky substrate.

 

Li You, Fei Xia and Xinming Liu. 2026. A New Gorgonian Paraplexaura binyuani sp. nov. (Cnidaria, Octocorallia, Acanthogorgiidae) from the Huaguang Atoll, Xisha Islands, South China Sea. Diversity. 18(3), 166. DOI: doi.org/10.3390/d18030166 [9 March 2026]

[Cnidaria • 2026] Chrysogorgia pugnioides, Iridogorgia acutisclerita, I. levisquama • Systematics and Biogeography of Chrysogorgiidae (Anthozoa: Octocorallia) from the Indian Ocean: discovery of New Species on Deep-sea Ridges

Iridogorgia acutisclerita Ge, Zhang & Xu,

in Ge, N. Xu, Hu, Tian, Li, Y. Xu, Wang, Zhang et Q. Xu, 2026. 

DOI: doi.org/10.3897/zse.102.182492 

Abstract

Species of the family Chrysogorgiidae are distributed worldwide in deep-sea environments. However, most recorded species of this family were from the Atlantic and Pacific Oceans, with only a few reports from the Indian Ocean, particularly from ridge regions. This study describes three new species and reports two known species from Indian Ocean ridges, integrating morphological and molecular analyses (mtMutS and 28S rDNA). Chrysogorgia pugnioides Ge, Hu & Xu, sp. nov. is characterized by fist-like polyps; warty spindles in tentacles; flat and irregular spindles and elongate scales in the polyp body wall; and slender and smooth scales with toothed to irregular edges in the coenenchyme. Iridogorgia acutisclerita Ge, Zhang & Xu, sp. nov. resembles I. splendens but differs by possessing needles and pointed elongate scales in the polyp body wall. Iridogorgia levisquama Ge, Zhang & Xu, sp. nov. is differentiated from the congeneric I. squarrosa by slender and smooth scales with sharp ends in the polyp body wall and needles with fine wartiness in the tentacles. Parachrysogorgia chryseis and Metallogorgia melanotrichos are reported as new records for the Indian Ocean ridges. These findings expand the known biodiversity and biogeographic range of Chrysogorgiidae in the Indian Ocean ridges.

Key Words: Carlsberg Ridge, Chrysogorgiidae, Ninetyeast Ridge, phylogeny, taxonomy

Chrysogorgia pugnioides Ge, Hu & Xu, sp. nov.  

Iridogorgia acutisclerita Ge, Zhang & Xu, sp. nov. 

Iridogorgia levisquama Ge, Zhang & Xu, sp. nov.

The external morphology of Iridogorgia acutisclerita Ge, Zhang & Xu, sp. nov.
 A. Holotype FIO-IND72-JLBEN22309 in situ; B. Paratype FIO-IND72-JLBEN22402 in situ; C–E. Holotype FIO-IND72-JLBEN22309, paratype FIO-IND72-JLBEN22402, and FIO-IND72-JLBEN225511 after collection;
F. Single polyp under a light microscope; G. Single polyp under SEM; H. A part of the tentacle under SEM; I. A part of the branch under a light microscope; J. A part of the branch with epidermal tissue removed under SEM; K. A part of the branch with epidermal tissue under SEM.

Scale bars: 20 cm (C–E); 1 mm (F, I); 500 μm (G, K); 250 μm (H, J).

 Meiling Ge, Ningxia Xu, Xuying Hu, Xin Tian, Xinlong Li, Yu Xu, Zongling Wang, Xuelei Zhang and Qingzeng Xu. 2026. Systematics and Biogeography of Chrysogorgiidae from the Indian Ocean: discovery of New Species on Deep-sea Ridges. Zoosystematics and Evolution. 102(2): 621-647.  DOI: doi.org/10.3897/zse.102.182492 [07 Apr 2026]

[Cnidaria • 2026] Rhytisma acoronatum, R. calyaceum, R. karibu, ... • Phylogenomics-guided Revision of the Genus Rhytisma Alderslade, 2000 (Octocorallia: Malacalcyonacea: Lemnaliidae), with Descriptions of Six New Sspecies

 

(a, b) Rhytisma karibu sp. nov., 

(c, d) R. acoronatum sp. nov. 

(e, f) R. oblongum sp. nov.

 (c) R. inaequale sp. nov., with expanded polyps 

(d) R. calyaceum sp. nov., with partially expanded polyps 

(e) R. sperkolae sp. nov., polyps partly expanded

Samimi-Namin, Benayahu, Durkin, Ekins, Quattrini & McFadden, 2026

DOI: doi.org/10.1071/IS25068 

Photographs by Y. Benayahu, and M. Ekins.

 

The genus Rhytisma Alderslade, 2000 (Octocorallia: Malacalcyonacea: Lemnaliidae), formerly comprising four nominal species (R. fulvum, R. fuscum, R. monticulum and R. rubiginosum), is revised using an integrative approach. We combine morphological and phylogenomic data for newly collected and historical specimens. A neotype is designated for R. fulvum and a lectotype for R. fuscum to stabilise the application of these names. Six new species are described from the Indo-Pacific: R. acoronatum sp. nov., R. calyaceum sp. nov., R. oblongum sp. nov., R. inaequale sp. nov., R. karibu sp. nov. and R. sperkolae sp. nov. Species delimitation is supported by discrete combinations of morphological characters – particularly those of the tentacle and polyp sclerites – as well as multi-locus DNA barcoding and phylogenomic analyses of conserved elements (UCE and exon loci). Our findings highlight the diagnostic value of tentacle sclerites and reveal extensive species-level diversity that was previously obscured by insufficient morphological examination. The revised genus currently comprises 10 valid species, many of which display restricted geographic distributions, reflecting patterns of regional endemism in Indo-Pacific octocoral assemblages. These results underscore the importance of integrative taxonomy in uncovering hidden biodiversity.

 

Keywords: biogeography, DNA barcoding, endemism, Indo-Pacific, integrative taxonomy, neotype, soft corals, species delimitation, taxonomic revision, ultraconserved elements

Underwater images of Rhytisma species in their respective type localities.
(a, b) Rhytisma fulvum yellow colour and grey colour morphs, polyps partly expanded
(c) R. inaequale sp. nov., with expanded polyps (d) R. calyaceum sp. nov., with partially expanded polyps
(e) R. sperkolae sp. nov., mat morphology reflects underlying irregular reef substrate, polyps partly expanded. (f) R. monticulum with expanded polyps.

Photographs by (a–c, e) Y. Benayahu, (d, f) M. Ekins.

Underwater images of Rhytisma species in their respective type localities.
(a, b) Rhytisma karibu sp. nov., growing on seagrass blades and reef substrate (c, d) R. acoronatum sp. nov. (e, f) R. oblongum sp. nov. 

Photographs by (a, b, e, f) Y. Benayahu, and (c, d) M. Ekins.

Rhytisma acoronatum sp. nov., R. calyaceum sp. nov., 

R. oblongum sp. nov., R. inaequale sp. nov., 

R. karibu sp. nov. and R. sperkolae sp. nov. 

Kaveh Samimi-Namin, Yehuda Benayahu, Kathleen M. Durkin, Merrick Ekins, Andrea M. Quattrini and Catherine S. McFadden. 2026. Phylogenomics-guided Revision of the Genus Rhytisma Alderslade, 2000 (Octocorallia: Malacalcyonacea: Lemnaliidae), with Descriptions of Six New Sspecies. Invertebr Syst. 40(3); IS25068. DOI: doi.org/10.1071/IS25068   [30 March 2026]

[Cnidaria • 2025] Iridogorgia curva & I. chewbacca • Unexpected Diversity of the Genus Iridogorgia in the tropical western Pacific with Descriptions of Two New Species [Studies on western Pacific Gorgonians (Anthozoa: Octocorallia: Chrysogorgiidae). Part 2]

 

Iridogorgia chewbacca 

Y. Xu, Watling, Zhan & K. Xu, 2025

  

DOI: doi.org/10.11646/zootaxa.5689.3.3 

manoa.hawaii.edu

Abstract

Species of the genus Iridogorgia Verrill, 1883 are typical deep-sea organisms, characterized by monopodial and spiral axis with a brilliant iridescence. Utilizing an integrated morphological-molecular approach, twelve specimens of Iridogorgia obtained from the tropical western and central Pacific were described as two new species I. curva sp. nov. and I. chewbacca sp. nov., and four known species. Additionally, I. fontinalis Watling, 2007 and I. splendens Watling, 2007 are two new recorded species in the Western Pacific Ocean. Iridogorgia verrucosa Xu, Zhan & Xu, 2021 and I. squarrosa Xu, Zhan, Li & Xu, 2020 are described again. There are currently fourteen species of Iridogorgia with twelve species in the Pacific. Among them, ten species were found in the tropical western Pacific, showing a high diversity. This study indicates the direction of growth (clockwise or counter-clockwise) is not a useful taxonomic character for Iridogorgia species identification. Phylogenetic analyses, based on both mtMutS-cox1 and 28S rDNA sequences, substantiated the taxonomic designation of the new species, I. chewbacca sp. nov. However, the mtMutS and mtMutS-cox1 showed very limited usefulness for species delimitation and inner relationship inference of most Iridogorgia species, while the 28S rDNA showed much higher level of genetic variation.

deep sea, morphology, phylogeny, seamount, taxonomy

Iridogorgia chewbacca 

YU XU, LES WATLING, ZIFENG ZHAN and KUIDONG XU. 2025. Studies on western Pacific Gorgonians (Anthozoa: Octocorallia: Chrysogorgiidae). Part 2: Unexpected Diversity of the Genus Iridogorgia in the tropical western Pacific with Descriptions of Two New Species. Zootaxa. 5689(3); 451-486. DOI: doi.org/10.11646/zootaxa.5689.3.3  [2025-09-04]

Chewbacca coral: New deep-sea species spotted in waters off Hawai‘i, Mariana Trench

https://manoa.hawaii.edu/news/article.php?aId=14141

[Crustacea • 2023] Lebbeus cultrirostris & L. kexuei • Integrative Taxonomy reveals Two New Species of Lebbeus (Decapoda: Thoridae) from Seamounts in NW Pacific, and Questions the Validity of the Genus Paralebbeus

 Lebbeus cultrirostris

Wang, Sha & Sun, 2023

DOI: doi.org/10.1016/j.dsr.2023.104044 

Highlights: 

• Two new species were described.

• The validity of Paralebbeus was examined.

• Paralebbeus should be synonymized with Lebbeus.  

Abstract

During two expeditions to Caroline Plate seamounts and Zhenbei seamount in the NW Pacific, three Paralebbeus (we list Paralebbeus as a synonym of Lebbeus herein) specimens are sampled. Two of them are recognized as new to science herein after carefully morphological observations. L. cultrirostris sp. nov. collected with the keratoisidid coral at a depth of 866 m is characterized by the smooth rostrum, and the telson having three pairs of dorsolateral spines. L. kexuei sp. nov. collected at a depth of 796–1510 m is characterized by the rostrum only bearing two dorsal spines, and the carpus of pereopod 2 having two articles equal in length. Morphological characters and generic analysis of mitochondrial COI and 16 S rRNA genes using maximum likelihood, Bayesian inference, and pairwise uncorrected p-distances indicated that all species of Paralebbeus Bruce and Chace (1986 should be transferred into genus Lebbeus White, 1847.

 

Keywords: Decapoda, Paralebbeus, Lebbeus, New species, Deep sea

Superfamily Alpheoidea Rafinesque, 1815

Family Thoridae Kingsley, 1879

Genus Lebbeus White, 1847

 Lebbeus cultrirostris sp. nov., not ovigerous female holotype, cl 10.1 mm, pcl 7.6 mm, MBM 287552.
A, photographed immediately after sampling on Zhenbei seamount, by Wei Jiang; B, the keratoisidid coral collected by ROV “Faxian”, and the red arrow points to this new species.

  Lebbeus cultrirostris sp. nov.

 

 Etymology: From the Latin cultr (= knife) and rostr (= rostrum), referring to the shape of the rostrum of the species.

Lebbeus kexuei sp. nov. 

Etymology: The species name is derived from the oceanographic vessel “Kexue” of Institute of Oceanology, Chinese Academy of Sciences, which contributed substantially to biological studies of seamounts in Caroline Plate.

Yanrong Wang, Zhongli Sha and Shao'e Sun. 2023. Integrative Taxonomy reveals Two New Species of Lebbeus (Decapoda: Thoridae) from Seamounts in NW Pacific, and Questions the Validity of the Genus Paralebbeus. Deep Sea Research Part I: Oceanographic Research Papers. 197; 104044. DOI: doi.org/10.1016/j.dsr.2023.104044 

[Cnidaria • 2025] Neoanthomastus stellatus, Anthomastus sphaericus, Pseudoanthomastus ornatus, ... • Mushroom Soft Corals (Octocorallia: Coralliidae) From Seamounts in the Tropical Northwestern Pacific: Morphology and Phylogenetic Analysis Reveal a New Genus and Six New Species

 

Neoanthomastus stellatus gen. et sp. nov., N. elongatus gen. et sp. nov., 
Anthomastus sphaericus sp. nov., A. tongi sp. nov., 
Pseudoanthomastus ornatus sp. nov., and P. applanatus sp. nov.

Y. Li, J. Li & Xu, 2025 

DOI: doi.org/10.1155/jzs/4177670

Abstract

Mushroom soft corals in the subfamily Anthomastinae are among the most remarkable octocorals found in the deep sea, characterized by their capitate or mushroom-shaped red colonies and large autozooids. To date, their species diversity remains largely unknown due to limited research, and their phylogenetic relationships have yet to be explored. Based on samples collected from four seamounts in the tropical Northwestern Pacific, we establish a new genus and six new species within Anthomastinae: Neoanthomastus stellatus gen. et sp. nov., Neoanthomastus elongatus gen. et sp. nov., Anthomastus sphaericus sp. nov., Anthomastus tongi sp. nov., Pseudoanthomastus ornatus sp. nov., and Pseudoanthomastus applanatus sp. nov. We transfer four species of Anthomastus with the siphonozooids extending into the stalk to the new genus Neoanthomastus, and four additional species of Anthomastus to Pseudoanthomastus. A dichotomous key to all five known genera and 43 species of Anthomastinae is provided. Meanwhile, we utilize the concatenated nucleotides of 13 mitochondrial protein-coding genes (PCGs), the full-length coding regions of the mitochondrial MutS gene (mtMutS) and the barcodes of partial mtMutS to elucidate the phylogenetic relationships among all the five genera (Anthomastus, Bathyalcyon, Heteropolypus, Pseudoanthomastus, and Neoanthomastus gen. nov.) and available species of Anthomastinae. The phylogenetic trees constructed from the three types of sequences suggest a hierarchical relationship where Neoanthomastus gen. nov. and Pseudoanthomastus form a clade that clusters with Bathyalcyon, which in turn with Heteropolypus, and finally with Anthomastus, all with high nodal supports. We also identify a second species in octocorals that lack the unique mtMutS. The study reveals a high diversity of mushroom soft corals and underscores the need for further systematic and zoogeographic research.

Keywords: Anthomastus, Anthomastinae, deep sea, mitochondrial DNA, mtMutS, new taxa

Morphology of Neoanthomastus gen. nov. and six new species of Anthomastinae.
(A–C) A. sphaericus sp. nov., same specimen in situ (A) and in preservation (B, C). (D, E) A. tongi sp. nov. in situ and in preservation.
(F, G) N. stellatus gen. et sp. nov. in situ and in preservation. (H, I) N. elongatus gen. et sp. nov. in situ and in preservation.
(J–M) P. ornatus sp. nov., same specimen in situ (J) and in preservation (K–M), arrows indicate small autozooids of capitulum margin. (N–P) P. applanatus sp. nov., same specimen in situ (N, O) and in preservation (P). au, autozooids; o, oocytes; si, siphonozooids.

 Scale bars = 10 mm (B, C, E), 20 mm (G, I, K, M), 5 mm (L), and 50 mm (P).

 

Neoanthomastus stellatus gen. et sp. nov., N. elongatus gen. et sp. nov., 

Anthomastus sphaericus sp. nov., A. tongi sp. nov., 

Pseudoanthomastus ornatus sp. nov., and P. applanatus sp. nov. 

Yang Li, Junyuan Li, Kuidong Xu. 2025. Mushroom Soft Corals (Octocorallia: Coralliidae) From Seamounts in the Tropical Northwestern Pacific: Morphology and Phylogenetic Analysis Reveal a New Genus and Six New Species. Journal of Zoological Systematics and Evolutionary Research. DOI: doi.org/10.1155/jzs/4177670 [30 March 2025] 

[Cnidaria • 2025] Parasphaerasclera mcfaddenae • A New Soft Coral Species (Octocorallia: Scleralcyonacea: Parasphaerascleridae) from the Gulf of Mexico

 Parasphaerasclera mcfaddenae

Quattrini, Morrissey & McCartin, 2025.  

 

DOI: doi.org/10.11646/zootaxa.5601.3.8

 

Abstract

A new species of soft coral, Parasphaerasclera mcfaddenae (Octocorallia: Scleralcyonacea: Parasphaerascleridae), is described from mesophotic hardbottom habitats of the Gulf of Mexico, western North Atlantic Ocean. Previously, this family was only known from the tropical Indo-Pacific and South Africa; therefore, we extend the distribution of the family Parasphaerascleridae into the North Atlantic Ocean. This diminutive species differs from other parasphaerasclerids by a capitate growth form, non-retractile polyps, and presence of tuberculated spindles. Notably, this species was also detected in environmental (e)DNA samples from locations where it was not physically collected, highlighting the importance of both eDNA for biodiversity surveys as well as specimen collections for building comprehensive reference databases for eDNA analyses.

Coelenterata, Parasphaerasclera, Scleralcyonacea, North Atlantic Ocean, eDNA, mesophotic reef

 Parasphaerasclera mcfaddenae sp.  nov. 
A) in situ image of two colonies,  B) in situ image of  the holotype prior to ROV collection, and C) image of holotype under the microscope with a 1 cm scale bar.

Parasphaerasclera mcfaddenae sp. nov. 

Andrea M. QUATTRINI, Declan MORRISSEY and Luke J. MCCARTIN. 2025. A New Soft Coral Species from the Gulf of Mexico (Octocorallia: Scleralcyonacea: Parasphaerascleridae). Zootaxa. 5601(3); 545-557. DOI: doi.org/10.11646/zootaxa.5601.3.8 [2025-03-10]

[Cnidaria • 2024] Pseudopterogorgia nanjiensis • A New gorgonian (Octocorallia: Gorgoniidae) from the Nanji Islands, China

 Pseudopterogorgia nanjiensis Sun, Xu & Zhan,

in Sun, Y. Xu, K. Xu, Chen, Xie et Zhan, 2024.  

DOI: 10.3897/zookeys.1213.126841

Abstract

Members of the genus Pseudopterogorgia Kükenthal, 1919 are widely distributed in shallow water of the Indo-West Pacific. During an investigation of benthic biodiversity in the subtidal zone surrounding the Nanji Islands in the East China Sea, two specimens of Pseudopterogorgia were collected and described as a new species based on an integrated morphological-molecular approach. Pseudopterogorgia nanjiensis sp. nov. is most similar to P. fredericki Williams & Vennam, 2001 in the irregular branching form and indistinct scaphoids, but differs by the coenenchymal sclerite content of distinct capstans and a few warty spindles and radiates (vs. mostly warty spindles and a few capstans), and a purplish colony (vs. white, pink to deep rose). Molecular phylogenetic analyses, based on the mtMutS-COI gene sequences, delineated a monophyletic clade encompassing all assessed Pseudopterogorgia species. Within this clade, P. nanjiensis sp. nov. showed a close phylogenetic affinity with both P. fredericki and P. australiensis Ridley, 1884.

Key words: Anthozoa, COI, Malacalcyonacea, morphology, mtMutS, new species, phylogeny, taxonomy, 28S rDNA

Phylum Cnidaria Hatschek, 1888

Subphylum Anthozoa Ehrenberg, 1834

Class Octocorallia Haeckel, 1866

Order Malacalcyonacea McFadden, van Ofwegen & Quattrini, 2022

Family Gorgoniidae Lamouroux, 1812

Genus Pseudopterogorgia Kükenthal, 1919

The external morphology and polyps of Pseudopterogorgia nanjiensis sp. nov.
  A holotype in situ B holotype after collection C paratype after fixation D part of branch under a light microscope E single polyp aperture under a light microscope F sclerites under a light microscope G coenenchyme under SEM H single dissolved polyp aperture under a light microscope.

Scale bars: 2 cm (B); 3 cm (C); 2 mm (D); 0.2 mm (E); 0.1 mm (F, G, H).

 Pseudopterogorgia nanjiensis Sun, Xu & Zhan, sp. nov.

 

Diagnosis: Colony non-pinnate and purplish. Branches divided dichotomously and irregularly, nearly in one plane. Polyp retracted and forming a small and oval-shaped protrusion. Sclerites in polyps small flat rodlets, colorless and rare to absent in numbers. Sclerites in coenenchyme red, mostly capstans, a few radiates and warty spindles, and rare scaphoids. Capstans have two whorls of tubercles and blunt ends with irregular arrangements of complex tubercles. Radiates and immature sclerites with two whorls of projections, spindles with 4–8 whorls of tubercles, and scaphoids with similar ornamentation of tubercles on both convex and concave sides.

Tingzai Sun, Yu Xu, Kuidong Xu, Shun Chen, Shangwei Xie and Zifeng Zhan. 2024. A New gorgonian Pseudopterogorgia nanjiensis sp. nov. (Cnidaria, Octocorallia, Gorgoniidae) from the Nanji Islands, China. ZooKeys. 1213: 237-249. DOI: doi.org/10.3897/zookeys.1213.126841

[Crustacea • 2021] Caprella nojimaensis • A New Species of the Genus Caprella (Amphipoda: Caprellidae) Collected from a Gorgonian at 1497 m Depth off Boso Peninsula, Central Japan

 

 Caprella nojimaensis 

 Takeuchi, Shiraishi & Mimori, 2021

DOI: 10.12782/specdiv.26.225

 twitter.com/Species_Divers

Abstract

Caprella nojimaensis sp. nov. (Crustacea: Amphipoda: Caprellidae), inhabiting the gorgonian Calcigorgia gracilis Matsumoto, van Ofwegen, and Bayer, 2019, is described based on a specimen from 1497 m depth in the Nojima Submarine Canyon, off Boso Peninsula, central Japan. The species is closely related to C. gracillima Mayer, 1890, but differs from the latter in gnathopod 2 being positioned near the anterior margin of pereonite 2 and in the presence of paired small mid-dorsal projections on pereonites 2 and 5. The body colour of live material is pale pink, with mouth parts and gnathopod 2 fringed with darker pink, revealing protective colouration that matches that of the host gorgonian. The clinging behaviour in situ is “upright” as recorded by the remotely operated vehicle Hyper-Dolphin, and the presence of dense swimming setae on antenna 2 suggests that the caprellid feeds by filtering material suspended in the bathyal zone.

Keywords: Amphipoda, bathyal depth, Caprella, new species, off Boso Peninsula, protective colouration

 Caprella nojimaensis sp. nov., holotype, mature female, 20.69 mm body length, NSMT-Cr 29015, photographed at the cold laboratory of Tokyo Sea Life Park (Edogawa-ku, Tokyo, Japan).

 Four individuals of  Caprella nojimaensis sp. nov. (red arrows) attached to the gorgonian and on rock and surrounding sediment at around 1500 m depth in the Nojima Submarine Canyon, off Boso Peninsula, central Japan.

 Caprella nojimaensis sp. nov. (yellow arrow), holotype, mature female, 20.69 mm body length, NSMT-Cr 29015, attached to the gorgonian Calcigorgia gracilis Matsumoto, van Ofwegen, and Bayer, 2019 at 1497 m depth; Nojima Submarine Canyon, off Boso Peninsula, central Japan.

Order Amphipoda Latreille, 1816 

Family Caprellidae Leach, 1814 

Genus Caprella Lamarck, 1801 

Caprella nojimaensis sp.nov. 

Etymology. The specific name nojimaensis is derived from the name of the collection site of the new species, Nojima Submarine Canyon. 

Ichiro Takeuchi, Momoko Shiraishi and Ryosuke Mimori. 2021. A New Species of the Genus Caprella (Crustacea: Amphipoda: Caprellidae) Collected from a Gorgonian at 1497 m Depth off Boso Peninsula, Central Japan. Species Diversity. 26(2); 225-233. DOI: 10.12782/specdiv.26.225

 twitter.com/Species_Divers/status/1436221455482589191

[Cnidaria • 2023] Anthomastus nanhaiensis, new species, and Bathyalcyon robustum Versluys, 1906, Two mushroom Soft Corals (Octocorallia: Coralliidae) from Zhenbei Seamount in the South China Sea

Anthomastus nanhaiensis   

 Li & Xu, 2023

 RAFFLES BULLETIN OF ZOOLOGY. 71 

 Abstract

 Members of the subfamily Anthomastinae Verrill, 1922, commonly known as mushroom soft corals, are some of the most typical examples of octocorals in the deep sea. However, their diversity and spatial distribution in the northwestern Pacific are poorly known. Here, two species of mushroom soft corals were obtained from the Zhenbei Seamount in the South China Sea, one described as Anthomastus nanhaiensis, new species, and the other identified as Bathyalcyon robustum Versluys, 1906. Anthomastus nanhaiensis is characterised by highly tuberculated double spheroids, clubs and spindles in capitulum and stalk, and the absence of sclerites from neck zone of anthocodial wall. It is the first species of Anthomastus Verrill, 1878 recorded from the South China Sea, and the second one known from the northwestern Pacific. Bathyalcyon robustum Versluys, 1906 is a remarkable octocoral originally reported from the western Pacific by having a single large autozooid, a peculiar feature within the subfamily Anthomastinae Verrill, 1922. We describe its live morphology for the first time and the detailed structure of sclerites, particularly the rodlets in pharynx and the multiradiates in tentacles, which can be used to distinguish the monotypic genus Bathyalcyon Versluys, 1906 from Anthomastus Verrill, 1878 (vs. platelets in pharynx and the absence of multiradiates in tentacles).

Key words. Anthomastinae, Scleralcyonacea, Anthozoa, dimorphic, taxonomy, deep sea

TAXONOMY: 

Class Octocorallia Haeckel, 1866 

Order Scleralcyonacea McFadden, van Ofwegen & Quattrini, 2022 

Family Coralliidae Lamouroux, 1812 

Subfamily Anthomastinae Verrill, 1922 

Anthomastus Verrill, 1878 

 

Morphology of the holotype of Anthomastus nanhaiensis, new species.
 A, the animal in situ; B, an autozooid; C, the colony in top view; D, the colony in lateral view; E, the longitudinal section of the colony, showing large cavities of autozooids (au) and small cavities of siphonozooids (arrows).

Scale bars = 1 mm (B), 10 mm (C‒E).

Anthomastus nanhaiensis, new species

Diagnosis. Anthomastus with capitate-shaped colony divided into a spherical capitulum and an inconspicuous stalk. Polyps dimorphic. Autozooids sterile, large, retractile, 92 in number. Siphonozooids fertile, minute, scattered among autozooids and forming a continuous layer. Sclerites including rods, platelets, highly tuberculated double spheroids, clubs and spindles. Anthocodial wall devoid of sclerites.

Etymology. The specific name nanhaiensis refers in Chinese to the South China Sea, the type locality of the species.

Yang Li and Kuidong Xu. 2023. Anthomastus nanhaiensis, new species, and Bathyalcyon robustum Versluys, 1906, Two mushroom Soft Corals (Octocorallia: Coralliidae) from Zhenbei Seamount in the South China Sea. RAFFLES BULLETIN OF ZOOLOGY. 71: 669–680. 

https://lkcnhm.nus.edu.sg/publications/raffles-bulletin-of-zoology/volumes/volume-71/

[Cnidaria • 2023] Aliena parva • An Enigmatic New Octocoral Species (Anthozoa: Octocorallia: Malacalcyonacea) from Isla del Coco National Park, Costa Rica

Aliena parva 

Breedy, McFadden & Cortés, 2023

 DOI: 10.3897/zookeys.1169.100576

Abstract

Aliena parva gen. et sp. nov. is described from Cocos Island, Costa Rica. The species was found at various islets and rocky outcrops north and northwest of the island, 20–30 m in depth. The genus is characterised by polyps, retracting into calyces, that form thin encrusting mats extending on dead or live substrates. Sclerites are mostly asymmetrical spindles. Anthocodial rods are arranged in points, not forming a collaret. Colonies and coenenchymal sclerites are red, and polyps are transparent. Using an integrative taxonomic approach, we found the new genus to morphologically and genetically differ from all other described taxa. The molecular phylogenetic analyses provide strong support for the placement of this new genus in the family Pterogorgiidae. Morphologically it is unlike any of the other members of this family, necessitating an amendment to the diagnosis of Pterogorgiidae. Like several other known taxa of octocorals with encrusting growth forms, Aliena gen. nov. appears to have evolved from a gorgonian ancestor by loss of an internal skeletal axis. It is the first member of Pterogorgiidae to be reported from the eastern Pacific, contributing further to the knowledge of marine biodiversity in the eastern tropical Pacific and to the octocoral biodiversity of Cocos Island in particular.

Key words: Biodiversity, new genus, new species, oceanic island, soft corals, taxonomy

Aliena parva gen. nov. et sp. nov.
A holotype, MZUCR 3679 B polyps, partially retracted showing anthocodial sclerites C polyp mounds.

(Photographs by Fiorella Vásquez, University of Costa Rica.)

Colonies in situ. A Manuelita Afuera, panoramic view of the wall, 25 m deep. (photograph by Anuar Patjane) B–D Manuelita Canal, 25 m deep (photographs by Avi Klapfer).

Systematics

SubPhylum Anthozoa Ehrenberg, 1831

Class Octocorallia Haeckel, 1866

Order Malacalcyonacea McFadden, van Ofwegen & Quattrini, 2022

Family Pterogorgiidae McFadden, van Ofwegen & Quattrini, 2022

Genus Aliena gen. nov.

 Diagnosis: Colonies are encrusting mats of irregular shape, consisting of clusters of 3–25 polyps that may be interconnected by thin coenenchymal extensions forming bridge-like bands between them. Colonies lack an axis. Polyps are retractile into calyces that are covered by a dense layer of small sclerites producing a granular appearance. Coenenchyme is thin without differential sclerite layers. Coenenchymal sclerites are mostly red asymmetrical spindles with simple tubercles and irregular ends. Anthocodial sclerites are mostly red flat rods, with serrated or prickly borders and sparse thorns on the surface, and spine-like rods. They are arranged “en chevron”, forming points but not a collaret. Flat rods form longitudinal rows along the polyp body. Tentacular sclerites are mostly yellow, biscuit-like rods. Colonies are dark red in life and maintain that colour in ethanol.

Type species: Aliena parva sp. nov. by original designation.

Etymology: Alienus (L) foreign, strange, not related. The generic name refers to the unexpected appearance or unnoticed presence of a new shallow-water taxon. It also alludes to its surprising phylogenetic relationship to a group of gorgonian octocorals, a relationship not predicted by its morphology. Gender feminine.

 Aliena parva sp. nov.

Etymology: Parvus (L), in allusion to the small size of the polyps. Gender feminine: parva.

Colonies in situ with modified tentacle, January 2022.
A Manuelita Canal, 25–30 m deep B Roca Sucia, 25 m deep.

 Odalisca Breedy, Catherine S. McFadden and Jorge Cortés. 2023. An Enigmatic New Octocoral Species (Anthozoa, Octocorallia, Malacalcyonacea) from Isla del Coco National Park. ZooKeys. 1169: 317-331.  DOI: 10.3897/zookeys.1169.100576

[Cnidaria • 2022] Pseudumbellula scotiae • When Distant Relatives look too Alike: A New Family, Two New Genera and A New Species of Deep-sea Umbellula-like Sea Pens (Anthozoa, Octocorallia, Pennatulacea)

Pseudumbellula scotiae

 López-González & Drewery, 2022

 publish.CSIRO.au/IS

Abstract

Among octocorals, colonies of the deep-sea pennatulacean genus Umbellula Gray, 1870 are some of the most instantly recognizable forms. Historically however, species identification in this genus has been usually based on few morphological characters with very little knowledge of associated intraspecific variability. This fact, combined with the very limited access to these deep-sea organisms, has resulted in numerous uncertainties about the true characters that should be used in species determination and recognition of synonyms and questionable species. Recent phylogenetic analyses based on mitochondrial and nuclear DNA markers has shown to be an excellent complementary source of information to morphological examination, being able to detect incongruent taxonomic assignments in classifications based only on morphological characters. Molecular analyses can reveal the presence of paraphyletic or polyphyletic groupings of taxa, which may then be the subject of further research integrating morphological and molecular techniques. This paper addresses the existence of a set of specimens initially assigned to the genus Umbellula Gray, 1879, but which have been shown to be distantly related to its type species Umbellula encrinus (Linné, 1758) based on molecular phylogenetic hypotheses. Phylogenetic analyses based on four genetic markers, three mitochondrial (mtMutS, ND2, Cox1) and one nuclear (28S), validates the definition of a new family (Pseudumbellulidae fam. nov.) and two new genera (Pseudumbellula gen nov., and Solumbellula gen. nov.). These analyses also justify the segregation of some of the morphological characters previously included in the diagnosis of the genus Umbellula and its monotypic family Umbellulidae Kölliker, 1880. Moreover, a new species, Pseudumbellula scotiae sp. nov. is described and illustrated with material from the North Eastern Atlantic and compared with its congeners. Additionally, the well-known but atypical species Umbellula monocephalus Pasternak, 1964 is transferred and described here as Solumbellula monocephalus (Pasternak, 1964) comb. nov., based on both molecular data and morphology.

 

 

Pablo López-González and Jim Drewery. 2022. When Distant Relatives look too Alike: A New Family, Two New Genera and A New Species of Deep-sea Umbellula-like Sea Pens (Anthozoa, Octocorallia, Pennatulacea).  Invertebrate Systematics. publish.CSIRO.au/IS/justaccepted/IS21040