[Crustacea • 2026] Harcledo toyoshioae • A New Species of Giant-eyed bathypelagic eusirid Amphipod (Amphipoda: Eusiridae) from the western North Pacific

 Harcledo toyoshioae 

 Kodama, Watabe, Nakaguchi & Wakabayashi, 2026

「オオメダマヨコエビ」 DOI: doi.org/10.1080/14772000.2026.2659885

Abstract

Deep-sea visual environments show extreme gradients in light intensity, driving divergence in eye morphology. In the order Amphipoda, such specializations are documented in pelagic hyperiideans, whereas deep-sea Eusiridae remain poorly known. During a bathypelagic survey in Japan, we collected a eusirid amphipod with conspicuously enlarged eyes. Integrative taxonomy, using morphology and four DNA barcoding regions, shows that it represents a new species of the monotypic genus Harcledo Barnard, 1964, described here as Harcledo toyoshioae sp. nov. It is characterized by markedly enlarged eyes that cover most of the lateral head and meet across the dorsal midline, and by a distinctive maxilla 1 armature. Phylogenetic analyses place H. toyoshioae sp. nov. within Eusiridae but leave its relationships to H. curvidactyla unresolved, owing to the lack of sequence data. Comparisons with historical records suggest rapid diversification of eye size within this clade and indicate that it is unlikely to be governed by depth or pelagic–benthic mode alone. We propose that the enlarged eyes are plausibly associated with a pelagic lifestyle in dim mid-water habitats, while noting that this interpretation remains tentative. Our findings highlight visual specializations in deep-sea eusirids and the value of combining new collections, historical literature, and molecular data when reassessing deep-sea taxa.

Key words: bathypelagic, deep sea, Harcledo, Kagoshima, Tanegashima Island, visual specialization

ORDER AMPHIPODA Latreille, 1816

FAMILY EUSIRIDAE Stebbing, 1888

Harcledo Barnard, 1964

 Harcledo toyoshioae sp. nov., paratype female, 18.8 mm, NSMT-Cr 33350, ethanol preserved specimen, photographs for head and pereonites 1–2: A, dorsal view; B, lateral view.

 Harcledo toyoshioae sp. nov., fresh specimens, lateral view:
A, holotype ovigerous female, 21.6 mm, NSMT-Cr 33349; B, paratype female, 18.8 mm, NSMT-Cr 33350.

Harcledo toyoshioae sp. nov.

DISTRIBUTION: Known only from type locality, North Pacific Ocean off Tanegashima Island, Kagoshima, Japan.

HABITAT: Bathypelagic zone (about 1200 m deep).

ETYMOLOGY: The new species is named after TRV Toyoshio Maru. The specific name is a noun in the genitive case.

Masafumi Kodama, Hiroto Watabe, Kazumitsu Nakaguchi and Kaori Wakabayashi. 2026. A New Species of Giant-eyed bathypelagic eusirid Amphipod (Crustacea: Amphipoda: Eusiridae) from the western North Pacific. Systematics and Biodiversity. 24(1); 2659885. DOI: doi.org/10.1080/14772000.2026.2659885 [05 Jun 2026]

[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]

[Mollusca • 2026] Microeledone galapagensis • A New Species of Microeledone (Octopoda: Incirrata) from Galápagos Islands and an amended diagnosis of the Megaleledonidae

 

Microeledone galapagensis 

Voight, Smith, Buglass & Ziegler, 2026

DOI: doi.org/10.11646/zootaxa.5814.4.5 

 

Abstract

The octopod fauna of the deep tropical Pacific Ocean remains poorly known, as is the octopod family Megaleledonidae Taki. A single female megaleledonid specimen collected at 1773 m depth near the equatorial Galápagos island of Darwin is named Microeledone galapagensis sp. nov. This small, squat, short-armed octopod has few arm suckers and gill lamellae. Its lack of a crop diverticulum, ink sac, and anal flaps suggests that it pertains to Thaumeledone. However, its smooth skin, which dorsally is nearly free of pigment, large rachidian tooth, and large funnel organ ally it with the monotypic Microeledone. Its reverse countershading and dense pigmentation on the inner dorsal mantle musculature distinguish this species from Microeledone mangoldi Norman, Hochberg & Boucher-Rodoni, 2004a. This species belies the definition of the Megaleledonidae as large-bodied, Southern Ocean endemics, leading us to revise the family diagnosis. The short arms carrying few suckers in this genus and Thaumeledone are hypothesized to relate to heterochrony, potentially increasing energy available for reproduction and contributing to niche partitioning.

Mollusca, Thaumeledone, heterochrony, Pacific Ocean, deep sea, posterior salivary gland, ink sac, skin texture

Photos of Microeledone galapagensis sp.  nov. 
in situ (a); on recovery dorsal (b) and ventral (c) (photos by the Science Party of the NA064 cruise); in preservation dorsal (d) and ventral (e) views of entire animal. 

Microeledone galapagensis sp. nov. 

Diagnosis. With the characters of the genus; sheath covering inner dorsal mantle muscles heavily pigmented, internal organs lack pigment, except dots near mantle opening on mantle septum, rectum, and anus; posterior salivary glands medium, ca. 70% of buccal mass length; eyes large, slightly projecting.

Janet R. VOIGHT, Stephanie M. SMITH, Salome BUGLASS and Alexander ZIEGLER. 2026. A New Species of Microeledone from Galápagos Islands and an amended diagnosis of the Megaleledonidae (Octopoda: Incirrata). Zootaxa. 5814(4); 533-549. DOI: doi.org/10.11646/zootaxa.5814.4.5 [2026-05-25]

     

[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]

[Invertebrate • 2026] Dalhousiella yabukii & Leocratides watanabeae • Single Origin and Convergent Host Use of hexactinellid Sponge Symbiosis in Hesionidae (Annelida: Polychaeta) with Descriptions of Two New Deep-sea Species

Dalhousiella yabukii  &  Leocratides watanabeae 

 Jimi, Downey, Mella & Hookabe, 2026

 DOI: doi.org/10.1093/zoolinnean/zlag028  

 x.com/nu_mbl

Abstract

Symbiotic associations between annelids and sponges are widespread and have evolved repeatedly across diverse families. However, their evolutionary history within Hesionidae remains poorly understood. Using the manned submersible Shinkai 6500, we conducted in situ observations and collected hesionid specimens from a hexactinellid sponge on the Getsuyo Seamount, north-west Pacific Ocean. An integrative taxonomic approach combining morphology and molecular phylogenetics revealed that they belong to two new species, Dalhousiella yabukii sp. nov. and Leocratides watanabeae sp. nov. Phylogenetic analyses suggest that sponge symbiosis in Hesionidae originated once, in the common ancestor of Dalhousiella and Leocratides. Nevertheless, the two new species are not each other’s closest relatives; instead, they form independent sister-clades, each including different congeners. Specimens of the two new species inhabited the same sponge host and probably shared similar ecological niches, suggesting convergent ecological specialization toward the limited resource of hexactinellid sponges in the deep sea. Such niche overlap and convergent evolution between closely related symbiotic species have not been previously reported in Hesionidae. Our findings shed new light on the origin and diversification of sponge symbiosis in Hesionidae and highlight the importance of integrative taxonomy and direct in situ observation for understanding deep-sea biodiversity.

Hesionini, taxonomy, symbiosis, Polychaeta, seamount

Dalhousiella yabukii sp. nov.  

Leocratides watanabeae sp. nov. 

Naoto Jimi, Rachel Downey, María Belén Arias Mella and Natsumi Hookabe. 2026. Single Origin and Convergent Host Use of hexactinellid Sponge Symbiosis in Hesionidae (Annelida: Polychaeta) with Descriptions of Two New Deep-sea Species. Zoological Journal of the Linnean Society. 206(3); zlag028. DOI: doi.org/10.1093/zoolinnean/zlag028 [09 March 2026] 

 x.com/nu_mbl/status/2030905993211810299

[Crustacea • 2026] Galathea balasubramaniani • A New Species of the Squat Lobster Genus Galathea Fabricius, 1793 (Decapoda: Galatheidae) from Lakshadweep, India

 

 Galathea balasubramaniani  

Sureandiran, Divya, Naeem, Sundaramanickam & Kumar, 2026 

  DOI: doi.org/10.11646/zootaxa.5757.4.6  

Researchgate.net/publication/400595434

 

Abstract

A new species of galatheid squat lobster, Galathea balasubramaniani sp. nov. is described from Lakshadweep Island, India. The G. balasubramaniani sp. nov. belongs to the ‘G. mauritiana’ group, identified through having a pterygostomian flap with 1 or 2 spines and an uninterrupted mesogastric ridge. This group includes: G. acis Macpherson & Robainas-Barcia, 2015, G. aequata Macpherson & Robainas-Barcia, 2015, G. ahyongi Macpherson & Robainas-Barcia, 2015, G. mauritiana Bouvier, 1914 and G. senta Macpherson & Robainas-Barcia, 2015. The G. balasubramaniani sp. nov. resembles G. mauritiana Bouvier, 1914, but differs based on the presence of an epipod on P1, and P2 with propodus 4.2–4.7 times as long as wide and the merus with the proximal spine reaching or slightly over-reaching the distal margin of the article. Maximum Likelihood analysis of the new species, using mitochondrial genes cytochrome c oxidase (COI) and 16S rRNA also supported the findings and suggests that G. balasubramaniani sp. nov. is closely related to G. mauritiana, with pairwise genetic distances estimated at 6.0–14.3 % (COI) and 3.1–16.9% (16S rRNA).

Crustacea, Arabian Sea, Galatheid squat lobster, Genetic divergence, Indian Ocean, Phylogeny

 Galathea balasubramaniani sp. nov. 
A–H, holotype female, GALGBAL/NBFGR (PCL 2.85 mm); I, paratype male, GALGBAL/NBFGR.2 (PCL 1.88 mm). A, carapace, dorsal view; B, pterygostomian flap, left lateral view; C, right P1, dorsal view; D–F, right P2–4, lateral view; G, maxilliped 3 dorsal view; H, thoracic sternum, ventral view; I right G2, dorsal view. Scale bar for A–F, H = 1 mm, G–I = 0.5 mm.

 Galathea balasubramaniani sp. nov. in live condition, collected from Agatti Island, Lakshadweep. Specimen not preserved.

Galathea balasubramaniani sp. nov.

B. SUREANDIRAN, P.R. DIVYA, U.P. MOHAMMED NAEEM, A. SUNDARAMANICKAM, T.T. AJITH KUMAR. 2026. A New Species of the Squat Lobster Genus Galathea Fabricius, 1793 from Lakshadweep, India (Crustacea: Decapoda: Galatheidae).  Zootaxa. 5757(4); 382-392. DOI: doi.org/10.11646/zootaxa.5757.4.6 [2026-02-09]

 Researchgate.net/publication/400595434_A_new_species_of_Galathea_from_Lakshadweep_India

[Invertebrate • 2025] Taxonomy and Ecological insights into Melinnopsis shinkaiae sp. nov., A Polychaete with a vertical tube from the Daiichi-Kashima Seamount (Northwest Pacific)

 

Melinnopsis shinkaiae 

Jimi, Hookabe, Woo & Fujiwara, 2025

DOI doi.org/10.3800/pbr.20.29 

 

Abstract  

Melinnopsis shinkaiae sp. nov. represents the fifth species of the genus Melinnopsis to be discovered in Japan. The new species was collected using the submersible Shinkai 6500 at 3623 m depth of Daiichi-Kashima Seamount, a locality with relatively unexplored biodiversity. Our in-situ observation revealed that the species inhabits the upper end of a vertical tube built on the seafloor. The species is differentiated from its congeners by combination of the following morphological characteristics: i) the presence of 12 thoracic uncinigers; ii) the absence of a postbranchial dorsal membrane; iii) the arrangement and shape of four pairs of branchiae; iv) thoracic uncini with a small basal tooth on each three teeth above the rostral tooth; v) absence of longitudinal groove in the large buccal tentacle.

Keywords: Terebelliformia, taxonomy, Melinnidae, Polychaeta, seamount

Melinnopsis shinkaiae sp. nov.
A–C, in situ observations of tubes. D, a collected tube.
E, drawing of tubes. White arrows indicate tubes.  

Scale bar: B–C, 30 cm; D, 2 cm

 Melinnopsis shinkaiae sp. nov. 

Etymology. The specific name shinkaiae derives from HOV Shinkai 6500, that was used for sampling of the new species. The new Japanese name “Takeuma-kazarigokai” is derived from the vertical tube that evokes “Takeuma,” which refers to Japanese stilts.

Naoto Jimi, Natsumi Hookabe, Sau Pinn Woo and Yoshihiro Fujiwara. 2025. Taxonomy and Ecological insights into Melinnopsis shinkaiae sp. nov., A Polychaete with a vertical tube from the Daiichi-Kashima Seamount (Northwest Pacific). Plankton and Benthos Research. 20(1); 29-35. DOI doi.org/10.3800/pbr.20.29 [February 28, 2025]

[Crustacea • 2026] Leiogalathea samudragiri • A New deep-sea munidopsid squat lobster of the Genus Leiogalathea Baba, 1969 (Decapoda: Anomura: Munidopsidae) from the southeastern Arabian Sea, India

  

Leiogalathea samudragiri  

Tiwari, Padate & Cubelio, 2026

DOI: doi.org/10.1007/s44289-026-00117-5

Abstract

The present study describes a new species of the deep-water munidopsid squat lobster genus Leiogalathea Baba, 1969. Leiogalathea samudragiri sp. nov. resembles L. achates Rodríguez-Flores, Macpherson & Machordom, 2019, L. evander Rodríguez-Flores, Macpherson & Machordom, 2019, and L. laevirostris (Balss, 1913) by the unarmed hepatic margin of the carapace. However, the new species differs from these congeners mainly in having uninterrupted mesogastric and mid-transverse ridges on the carapace and the presence of six transverse ridges on the posterior half of the carapace.

 

Keywords: Anomura, Arabian Sea, New species, Seamount, Taxonomy

Leiogalathea samudragiri sp. nov. Holotype, ovigerous female (IO/SS/ANO/00195; PCL 4.8 mm, CW 3.7 mm).
a carapace, dorsal view, b thoracic sternum, ventral view, c left eye, antennular article 1 and antennal peduncle, ventral view, d left mxp3, lateral view, e right P1, dorsal view, f right P2, lateral view, g right P2 dactylus, lateral view, h right P3, lateral view, i right P4, lateral view

Leiogalathea samudragiri sp. nov. Holotype, ovigerous female (IO/SS/ANO/00195; PCL 4.8 mm, CW 3.7 mm). Dorsal habitus

Leiogalathea samudragiri sp. nov.  

 

 Etymology: The species name is derived from a combination of the Sanskrit “samudra” meaning ocean, and “giri” meaning mountain, which refers to the seamount habitat of this species.

Shivam Tiwari, Vinay P. Padate and Sherine Sonia Cubelio. 2026. A New deep-sea munidopsid squat lobster of the Genus Leiogalathea Baba, 1969 (Decapoda: Anomura) from the southeastern Arabian Sea, India.  Discover Oceans. 3, 6. DOI: doi.org/10.1007/s44289-026-00117-5 [04 February 2026]

[Mollusca • 2025] Taningia silasii • A New Species of Deep-sea Squid Genus Taningia (Cephalopoda: Octopoteuthidae) from the Arabian Sea

Taningia silasii Sajikumar & Sasikumar,

in Sajikumar, Sasikumar, Ameri et Thomas, 2025. 

DOI: doi.org/10.1007/s12526-025-01576-3

Abstract

A new species of the genus Taningia Joubin, 1931 (family Octopoteuthidae Berry, 1912), is described from the southeastern Arabian Sea, based on a single specimen collected in March 2024 at a depth of 390 m. This new species, Taningia silasii sp. nov., differs from congeners in a combination of traits, including the shape of the funnel-mantle locking cartilage, nuchal-locking cartilage, lower beak morphology, gill lamellae count, and distinct genetic divergence as revealed by phylogenetic analysis of mitochondrial COI and 16S rRNA genes, with uncorrected p-distances of 11.8–12.1% (COI) and 4.3–4.5% (16S rRNA) from T. danae. Phylogenetic trees clearly separate Taningia silasii sp. nov. from Atlantic Ocean lineages of T. danae, supporting its recognition as a distinct species. The genus Taningia appears to represent a species complex, comprising the newly described Indian Ocean lineage and at least two distinct lineages from the Atlantic Ocean. These findings, based on integrated morphological and molecular analyses, highlight hidden diversity within Taningia and expand the known biogeographic range of the genus.

Keywords: Indian octopus squid, Southeastern Arabian Sea, New species, Morphology, Molecular taxonomy

a Dorsal and b ventral view of Taningia silasii sp. nov. from the Arabian Sea,
 dotted lines showing the proportion of aborted arms; right fin (dotted line) proportion extrapolated from left fin

Octopoteuthidae Berry, 1912

Taningia Joubin, 1931

Taningia silasii sp. nov. Sajikumar and Sasikumar

Proposed common name: Indian octopus squid

Sajikumar KK, Geetha Sasikumar, Shijin Ameri and Toji Thomas. 2025.  Description of A New Species of Deep-sea Squid Genus Taningia (Cephalopoda: Octopoteuthidae) from the Arabian Sea. Marine Biodiversity. 55, 107. DOI: doi.org/10.1007/s12526-025-01576-3 [14 November 2025]

New deep-sea ‘Octopus Squid’ discovered in Arabian Sea

CMFRI scientists discover new species of a rare octopus squid; Named after eminent marine biologist Dr E. G. Silas

https://www.pib.gov.in/PressReleasePage.aspx?PRID=2192497&reg=3&lang=2

[Mollusca • 2025] Clione japonica • A New cryptic Species of Clione (Gastropoda: Gymnosomata) in deep waters of the Japan Sea (East Sea) and shallow waters of the southern Okhotsk Sea

 

Clione japonica

Tomoyasu, Hiroshi & Jing, 2025

DOI: doi.org/10.1016/j.japb.2025.10.002

Abstract

We describe a new cryptic species of Clione from intermediate and deep waters of the Japan Sea (East Sea) and from shallow coastal waters of the southern Okhotsk Sea. Diagnosis is based on a suite of stable morphological traits—particularly laterally extended foot lobes and a broader central radular tooth—with c oxidase subunit I (COI) data providing supplementary support. Maximum likelihood analyses of the COI dataset resolved two sister clades: specimens from the Japan Sea (East Sea) occurred only in the clade that also contains the new species, whereas specimens from the southern Okhotsk Sea occurred in both. In contrast, Automatic Barcode Gap Discovery, applied to the same alignment, recovered a single molecular operational taxonomic unit (MOTU) consistent with shallow divergence and the lack of a clear barcode gap. As COI distances from C. okhotensis Yamazaki & Kuwahara, 2017, are modest, we rely primarily on morphology and reciprocal monophyly for species recognition, with COI data playing a supplementary role. We hypothesize that hydrographic structure and Late Quaternary isolation of the Japan Sea (East Sea) shaped this lineage, and that its occurrence in the Okhotsk Sea reflects transport by regional water masses. The new species highlights hidden diversity in pelagic pteropods and the role of semi-enclosed seas in fostering regional differentiation.

Keywords: Clione, COI gene, gymnosomata, Japan Sea (East Sea), taxonomy

  The new species Clione japonica sp. nov., holotype (SMRZ M20):
A, front view; B, dorsal view; C, right-side view; D, left-side view

<scale bars: 2 mm (A–D)>.

Family CLIONIDAE Rafinesque, 1815

Genus Clione Pallas, 1774

Clione japonica sp. nov.  

Diagnosis. Body with three ciliated rings (anterior, mid-body, tail region). No space between head tentacles and mouth. Lateral foot lobes ellipsoidal and extending outward. Visceral mass bright orange to red, occupying much of the anterior body (Figure 2, Figure 3B). Radula with broad central tooth and protruding lateral expansions (Figure 4, Figure 5).

Etymology. The species name japonica refers to the location of first discovery, the Japan Sea (East Sea).

Distribution. Known from deep waters of the Japan Sea (East Sea) (JSPW and JSIW) and shallow waters of the southern Okhotsk Sea.

 Yamazaki Tomoyasu, Shimada Hiroshi and Zhang Jing. 2025. A New cryptic Species of Clione (Gastropoda) in deep waters of the Japan Sea (East Sea) and shallow waters of the southern Okhotsk Sea. Journal of Asia-Pacific Biodiversity. In Press, DOI: doi.org/10.1016/j.japb.2025.10.002 [7 November 2025]

[Ichthyology • 2025] Sayonara flavolineata • A New Deep-water anthiadid perchlet (Perciformes: Anthiadidae) from Vietnam

 Sayonara flavolineata

Tang, Vo & Gill, 2025

  RAFFLES BULLETIN OF ZOOLOGY. 73; 

  facebook.com/TVictorCN

Abstract

 A new species of deep-water anthiadid perchlet, Sayonara flavolineata, is described from seven specimens collected off Nha Trang, southeastern Vietnam. Based on morphological features, it is assigned to a recently resurrected genus Sayonara Jordan & Seale, 1906, a former junior synonym of Plectranthias. Sayonara flavolineata, new species is distinctive in having yellow and reddish orange stripes when fresh, a horizontal dusky stripe in the middle of spinous dorsal fin, and a slightly concave dorsal profile of the head. It is further distinguished from other anthiadids by the following combination of characters: dorsal-fin rays X, 15; pectoral-fin rays 15–16; branched caudal-fin rays 8+7; lateral-line scales 31–35; circumpeduncular scales 12; predorsal scales extending anteriorly to posterior nostrils; body scales bearing basal cteni; scales present on maxilla, infraorbital, and mandibles; presence of trisegmental pterygiophores in both dorsal and anal fins; and two supraneurals. We updated and revised the record of species previously classified under Plectranthias in Vietnam. Including the new species, five species are now known from Vietnam and are reclassified to recently resurrected genera including Sayonara, Xenanthias, and Zalanthias.

Key words. taxonomy, species diversity, Plectranthias

Fresh colouration of Sayonara flavolineata, new species.
 A, holotype, OIM-E.55852 (field code: Q.01204-2), 101.1 mm SL; B, paratype, NMMB-P 41621 (field code: Q.01204-1), 107.9 mm SL.

Photos by Q. V. Vo.

CHI-NGAI TANG, QUANG VAN VO & ANTHONY C. GILL. 2025. Sayonara flavolineata (Perciformes: Anthiadidae), A New Deep-water anthiadid perchlet from Vietnam.  RAFFLES BULLETIN OF ZOOLOGY. 73; 698–708.

  facebook.com/TVictorCN/posts/25309871345346161

[Cnidaria • 2025] Endolobactis simoesii (Cnidaria: Actiniaria) • A New Species of Sea Anemone from the Yucatán Peninsula, Mexico

Endolobactis simoesii

 González-Muñoz, Rodríguez, Durán-Fuentes & Acuña, 2025

DOI: doi.org/10.11646/zootaxa.5722.3.5

Abstract

A new genus and species of sea anemone belonging to the family Actiniidae, Endolobactis simoesii gen. et sp. nov., is described. A comprehensive description is provided, including information on its external and internal anatomical features, cnidome, and size ranges and distribution of cnidae, accompanied by images of live specimens and their histological characteristics. The most distinctive feature of E. simoesii gen. et sp. nov. is the frond-like marginal projections located on exclusively endocoelic lobes. This contrasts with other genera in Actiniidae that exhibit similar marginal projections, which are commonly referred to as a “marginal ruff.” In addition, E. simoesii gen. et sp. nov. has more mesenteries proximally than distally. These and other differences between E. simoesii gen. et sp. nov. and other genera within Actiniidae with similar features are discussed in detail. With the inclusion of E. simoesii gen. et sp. nov., the number of documented sea anemone species along the Mexican Atlantic coast increases to 24.

 

Coelenterata, Actiniidae, sea anemone, Endolobactis simoesii

 Endolobactis simoesii gen. et sp. nov.

Ricardo GONZÁLEZ-MUÑOZ, Estefanía RODRÍGUEZ, Jefersón DURÁN-FUENTES and Fabián H. ACUÑA. 2025. Endolobactis simoesii gen. et sp. nov. (Cnidaria: Actiniaria), A New Species of Sea Anemone from the Yucatán Peninsula, Mexico.  Zootaxa. 5722(3); 391-407. DOI: doi.org/10.11646/zootaxa.5722.3.5 [2025-11-20]

[Invertebrate • 2025] Acanthotrochus verruciosseous • A New abyssal Species of Acanthotrochus (Holothuroidea: Apodida) from the Aleutian Trench, North Pacific Ocean

 

 Acanthotrochus verruciosseous

Ogawa, Chen & Sigwart, 2025

DOI: doi.org/10.5343/bms.2025.0092 

 x.com/squamiferum

 

A new species of the rarely seen myriotrochid holothurian genus Acanthotrochus, Acanthotrochus verruciosseous sp. nov., is described from 5272 to 5325 m deep in the Aleutian Trench, North Pacific Ocean. The new species is morphologically clearly separated from three valid congeners based on acanthotrochid-type wheel ossicles bearing multiple low knobs on the inner and outer rims as well as the outward teeth. The outer, concave side of the acanthotrochid-type wheels also form inward-pointing protrusions at the base of spokes at the inner rim edge. These ossicle features have never been observed in the three described species. Acanthotrochus has a global distribution, in the North Atlantic, Indian Ocean, and Antarctica, with a maximum depth of 3320 m. Our discovery is the first record of Acanthotrochus from the North Pacific and from the lower abyssal zone, which greatly extends the known geographic and bathymetric range of Acanthotrochus. Partial mitochondrial 16S ribosomal DNA sequences from the type specimens of A. verruciosseous sp. nov. are clearly separated from the type species of the genus, Acanthotrochus mirabilis Danielssen and Koren, 1881.

Acanthotrochus verruciosseous sp. nov.

 Ogawa, Akito; Chen, Chong and Sigwart, Julia D. 2025. A New abyssal Species of Acanthotrochus (Holothuroidea: Apodida) from the Aleutian Trench, North Pacific Ocean. Bulletin of Marine Science. DOI: doi.org/10.5343/bms.2025.0092 

 x.com/squamiferum/status/2001017902213079083

[Ichthyology • 2025] Branchenchelys megacephala • A New Genus and Species of ilyophine eel (Anguilliformes: Synaphobranchidae: Ilyophinae) from the Arabian Sea, western Indian Ocean

Branchenchelys megacephala

Tighe & Kodeeswaran, 2025

 DOI: doi.org/10.11646/zootaxa.5722.4.6  

 Researchgate.net/publication/397839726 

facebook.com: Paramasivam Kodeeswaran

 

Abstract

A new genus and species of ilyophine eel, Branchenchelys megacephala, is described based on five specimens collected in the Arabian Sea, western Indian Ocean. The new genus is distinguished from all other ilyophine genera by its relatively large head with large gill openings and a very large branchial chamber with an increased number of branchiostegal rays and hypertrophied gill filaments.

Pisces, Teleostei, taxonomy, Branchenchelys megacephala

 

Kenneth A. TIGHE and Paramasivam KODEESWARAN. 2025. A New Genus and Species of ilyophine eel (Anguilliformes: Synaphobranchidae: Ilyophinae) from the Arabian Sea, western Indian Ocean. Zootaxa. 5722(4); 555-569. DOI: doi.org/10.11646/zootaxa.5722.4.6 [2025-11-21]

 Researchgate.net/publication/397839726_A_new_genus_and_species_of_Anguilliformes_Synaphobranchidae_from_the_Arabian_Sea_western_Indian_Ocean

facebook.com/kodyvenkat/posts/4305402499679734

[Ichthyology • 2025] Genome-wide Pphylogeny reshapes our Understanding of the Evolution of Deep-sea Dragonfishes, bristlemouths, viperfishes, and allies (Stomiiformes)

Stomiiformes phylogeny

in Chang, Heiple, Hays, Melendez-Vazquez, Lee, Frable, Pogonoski, Martinez, Betancur-R et Arcila, 2025. 

DOI: doi.org/10.1186/s12862-025-02453-0 

Abstract

Background: 

The evolutionary relationships within Stomiiformes, a diverse order of deep-sea fishes dominating the mesopelagic and bathypelagic zones, remain contentious due to conflicting morphological and molecular evidence. These fishes, comprising 464 species across four traditionally recognized families (Gonostomatidae, Sternoptychidae, Phosichthyidae, and Stomiidae), exhibit remarkable adaptations such as bioluminescence, ultra-black pigmentation, and extreme jaw morphologies. Their global abundance and ecological significance, including contributions to the biological carbon pump, underscores the need to resolve their phylogeny amid escalating threats from climate change and human activities.

Results: 

We conducted the most comprehensive phylogenomic analysis of Stomiiformes to date, integrating 936 nuclear loci from 60 species and an expanded dataset of 135 species with mitochondrial sequences from publicly available repositories such as the Barcode of Life Data Systems (BOLD) database. We used maximum likelihood and coalescent-based approaches to assess family monophyly and relationships, including extensive quality control to address contamination in public databases. Our analyses reveal unstable tree topologies and complex evolutionary histories that challenge traditional classifications, while our quality control analyses identified 29% of BOLD sequences as misidentified or contaminated, emphasizing rigorous curation for deep-sea taxa. Congruent with a recent taxonomic treatment of Stomiiformes, the families Phosichthyidae and Gonostomatidae exhibit polyphyly and paraphyly, respectively, while subfamilies within Stomiidae are extensively non-monophyletic, leading us to recommend their abandonment. We propose the recognition of eight monophyletic families: Vinciguerriidae, Diplophidae, Gonostomatidae, Yarrellidae, Ichthyococcidae, Phosichthyidae, Sternoptychidae, and Stomiidae, supported by robust molecular and morphological evidence.

Conclusions: 

This revised classification reflects the morphological and ecological diversity of Stomiiformes, aligning with their evolutionary diversification in the deep sea. Our phylogenomic framework resolves longstanding systematic uncertainties and highlights the power of genome-wide data in tackling taxonomically challenging clades. These findings provide a foundation for understanding deep-sea fish diversification and assessing the potential ecBMC Ecology and Evolution  Article

Genome-wide phylogeny reshapes our understanding of the evolution of deep-sea dragonfishes, bristlemouths, viperfishes, and allies (Stomiiformes)

Keywords: Mesopelagic Fishes, Taxonomic Classification, Morphological Diversity

 

Solomon Chang, Zach Heiple, Delson Hays, Fernando Melendez-Vazquez, Casey Lee, Benjamin W. Frable, John Pogonoski, Christopher M. Martinez, Ricardo Betancur-R  and Dahiana Arcila. 2025. Genome-wide Pphylogeny reshapes our Understanding of the Evolution of Deep-sea Dragonfishes, bristlemouths, viperfishes, and allies (Stomiiformes). BMC Ecol Evo. 25, 111. DOI: doi.org/10.1186/s12862-025-02453-0 [21 October 2025]