[Invertebrate • 2026] Helobdella viridoclypus • A New free-living Leech Species (Hirudinea: Rhynchobdellida: Glossiphoniidae) from Chiang Mai, Thailand

 

 Helobdella viridoclypus

 K, Trivalairat, P. Trivalairat, Raquib & Purivirojkul, 2026

Emerald-charm leech | ปลิงสร้อยมรกต || 

 RAFFLES BULLETIN OF ZOOLOGY. 74

 Abstract

 A new species of glossiphoniid leech, Helobdella viridoclypus, is described from the northern region of Thailand, representing the first record of the genus Helobdella from the country and Southeast Asia. Its characteristics are similar to those of the type species, H. stagnalis, but can be distinguished by its transparent rice-shaped and triannulated body, cephalisation, a single pair of dark eyes, a smooth dorsal surface without papillae, rich darkgreen pigmentation on the dorsum, six pairs of crop caeca with less developed first pair and unbranched second to sixth pairs (posterior caeca), male and female gonopore separated by a single annulus, and a triangular nuchal scute pointed backwards with yellowish-green colouring around the mid-dorsal region. The phylogenetic relationships of H. viridoclypus, new species, are clarified, showing that it is monophyletic within the stagnalis species-complex clade which includes H. adiastola, H. octatestisaca, H. modesta, and the type species H. stagnalis. The new species is a free-living leech that specifically preys on invertebrates and not on humans. 

Key words. Annelida, Glossiphoniidae, Haementeriinae, jawless leech, freshwater, Huai Tueng Thao Reservoir

Order Rhynchobdellida Blanchard, 1894 

Suborder Glossiphoniiformes Tessler & de Carle, 2018 in Tessler et al., 2018 

Family Glossiphoniidae Vaillant, 1890 

Subfamily Haementeriinae Autrum, 1939 

Genus Helobdella Blanchard, 1896

Diagnosis. Small, two eyes, transparent papillae on segment, nuchal gland or scute on dorsum on VIIIa1/a2, gonopores separated by one annulus, compact salivary glands, crop with less developed first pair and unbranched second to sixth pairs of caeca, liquidosomatophagous (Blanchard, 1896; Sawyer, 1986).

 Helobdella viridoclypus, new species, live holotype (ZRC.ANN.1623).
 A, dorsal view; B, ventral view.

Helobdella viridoclypus, new species

Diagnosis. Rice-shaped, transparent body; cephalisation; a pair of large, distinctly separated, dark eyes on somite III; anterior sucker twice as large as prostomium without pits inside; central mouth in anterior sucker; triangular nuchal scute pointed backward with yellowish-green colouring around mid-dorsal region (VIIa1–a3, annuli 11–13); smooth surface without dorsal papillae; rich dark-green pigmentation on dorsum, particularly around crop caeca; lesser or almost absent pigmentation along crop; one male gonopore on XIIa1/XIIa2 (annuli 26/27); one female gonopore on XIIa2/ a3 (annuli 27/28); six pairs of crop caeca with unbranched posterior caeca; maximum body width wider than anterior and posterior suckers by four and two times, respectively.

 

Etymology. The species epithet refers to the description of the nuchal scute on the neck region, which resembles a shield and is a yellowish green colour. 

The following common names are suggested: “Emerald-charm leech” (English), “Pling soi mor ra kot” (ปลิงสร้อยมรกต) (Thai), and “Der Smaragdt-charm Plattegel” (German).

 Krittiya TRIVALAIRAT, Poramad TRIVALAIRAT, Tashfia RAQUIB and Watchariya PURIVIROJKUL. 2026. Helobdella viridoclypus (Hirudinea: Rhynchobdellida: Glossiphoniidae), A New free-living Leech Species from Chiang Mai, Thailand. RAFFLES BULLETIN OF ZOOLOGY. 74: 124–141. [23 March 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

[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]

[Invertebrate • 2025] Amynthas septuaginta & Metaphire fidelis • Two New Earthworm Species (Oligochaeta: Megascolecidae) from the Mekong River, Thailand

Amynthas septuaginta  Bantaowong & Panha,

in Bantaowong, Chanabun, Nantarat et Panha, 2025. 

  Tropical Natural History. Suppl. 8; 

ไส้เดือนริมโขงบึงกาฬ  ||  DOI: doi.org/10.58837/tnh.25.8.267154 

 facebook.com/BioCHULA

Abstract

Two new earthworm species are described from the Mekong River, Thailand, namely Amynthas septuaginta Bantaowong & Panha, sp. nov. and Metaphire fidelis Bantaowong & Panha, sp. nov. The former is a small Mekong earthworm in the A. aeruginosus species group with two pairs of spermathecal pores in 7/8-8/9. It is mainly distinguished from other Amynthas from the Mekong River by its small size (less than 50 mm), and with no genital markings at the male pore region. The latter is distinguished by having four pairs of spermathecal pores in 5/6-8/9, genital markings paired on xvii, ampulla paddle-shaped, and with diverticulum as a slender tube with a loose loop. Morphological description, taxonomic comments, illustrations, and distribution are provided.

Keywords: Amynthas, Metaphire, taxonomy, Mekong River

External and internal morphology of holotype (CUMZ3831) of Amynthas septuaginta sp. nov.,
A. external ventral view; B. internal dorsal view; C. spermathecae. Dark arrow indicates the connection of the spermathecae and spermathecal pore.

 Amynthas septuaginta Bantaowong & Panha, sp. nov. 

ไส้เดือนริมโขงบึงกาฬ

Metaphire fidelis Bantaowong & Panha, sp. nov.

 ไส้เดือนภักดีแม่น้ำโขง

Ueangfa Bantaowong, Ratmanee Chanabun, Nattawadee Nantarat and Somsak Panha. 2025. Description of Two New Earthworm Species (Oligochaeta: Megascolecidae) from the Mekong River, Thailand.  Tropical Natural History. Suppl. 8; 305-312. DOI: doi.org/10.58837/tnh.25.8.267154  [2025-10-20]

  facebook.com/BioCHULA/posts/1348182277097491

[Invertebrate • 2025] Troglobdella guizhouensis • A New Genus and Species of Cave-dwelling Leech (Hirudinea: Salifidae) from China: Taxonomy, Phylogeny, and mitochondrial Genome Characterization

 

Troglobdella guizhouensis  Liu & Nakano, 

in K. Liu, Q. Li, Wu, Lin, H. Li, Nakano et Z. Liu, 2025.

 贵州隐洞蛭  ||  DOI: doi.org/10.3897/zse.101.168628 

 

Abstract

Accurate identification of leech species is critical for biodiversity conservation and evolutionary studies. However, due to the ambiguity and variability of some key characteristics, Salifidae remains a rather poorly known group of Erpobdelliformes. In this study, a new genus of salifid leech, Troglobdella gen. nov., is established, and a new species, Troglobdella guizhouensis sp. nov., is described based on specimens collected from a cave in Guizhou Province, Southwest China. Phylogenetic analyses based on mitochondrial cytochrome c oxidase subunit I (COI) and nuclear 18S rRNA gene sequences reveal that Troglobdella guizhouensis represents a distinct lineage within a clade that also includes the troglobiotic species Shibabdella wulingensis Tang & Liu, 2025, and the terrestrial Odontobdella gaowangjiensis Yin & Liu, 2025, both of which are known from Hunan Province. This suggests that cave-related morphologies in Chinese salifid leeches may have evolved independently. The complete mitochondrial genome of the new species was assembled into a circular molecule of 15,732 bp, comprising 13 protein-coding genes, 22 tRNAs, and 2 rRNAs. This study contributes new insights into the taxonomy, systematics, and mitochondrial architecture of cave-adapted leeches.

Key Words: mitochondrial genome, phylogeny, Salifidae, taxonomy, Troglobdella guizhouensis, troglobiont

Taxonomy

Family Salifidae Johansson, 1910

Troglobdella guizhouensis 
 B. The entrance of the cave; C. A leech living in the puddle.

 Troglobdella Liu & Nakano, gen. nov.

 Troglobdella guizhouensis Liu & Nakano, sp. nov.

Diagnosis. Troglobdella guizhouensis can be distinguished from the other salifid genera as well as other species by the following combination of characters: body milky white with no pigments; without eyes; oral sucker well developed, distinctly laterally expanded; mid-body somites six-annulate; gonopores separated by four annuli; testisacs multiple; pharynx strepsilaematous; lacking preatrial loop of male paired ducts; paired atrial cornua conical, curved laterad; atrium short, globular; ovisacs descending to anterior of somite XIV, then turned several times in each of posterior parts, forming globular mass.

Etymology. The genus name Troglobdella is derived from the Ancient Greek “troglos” meaning “cave” and “bdella” meaning “leech” referring to the genus’ trait to subterranean habitats. We suggest the Chinese formal name as “yǐn dòng zhì shǔ” (隐洞蛭属). The species name “guizhouensis” is based Guizhou Province in China, where the species was discovered, with the suffix “-ensis” indicating geographical origin. We suggest the Chinese formal name as “guì zhōu yǐn dòng zhì” (贵州隐洞蛭).

Kaiqing Liu, Qing Li, Heqi Wu, Yiquan Lin, Hexiang Li, Takafumi Nakano, Zichao Liu. 2025. A New Genus and Species of Cave-dwelling Leech from China in the family Salifidae: Taxonomy, Phylogeny, and mitochondrial Genome Characterization. Zoosystematics and Evolution. 101(4): 2123-2132. DOI: doi.org/10.3897/zse.101.168628 

[Invertebrate • 2021] Magelona brachypalpata • A Review of the Magelonidae (Annelida: Polychaeta) of Northeast America, including A Description of A New Species and re-descriptions of Magelona riojai and M. sacculata

 

Magelona brachypalpata

Mortimer, Blake & Harrendence, 2021

 DOI: 10.2988/0006-324X-134.1.209  

 twitter.com/CardiffCurator

 

Abstract

A new species of Magelona is described based on collections from off Long Island, New York that are identical to an undescribed species reported by M. L. Jones (1968) from the vicinity of Woods Hole, Massachusetts. The species is herein named (Magelona brachypalpata, new species) and described. The new species belongs to the ‘Magelona mirabilis group,' possessing a rounded prostomium, lacking prostomial horns, and having specialized chaetae on chaetiger nine. The new species is most similar to M. riojai and M. sacculata, both of which are here redescribed. Additionally, a dichotomous identification key to the known magelonid species of the northeastern American coast and a worldwide pictorial identification key to the ‘M. mirabilis' group of magelonids are provided.

Magelona brachypalpata, new species

Kate Mortimer, James A. Blake and Kelsey Harrendence. 2021. A Review of the Magelonidae (Annelida: Polychaeta) of Northeast America, including A Description of A New Species and re-descriptions of Magelona riojai and Magelona sacculata. Proceedings of the Biological Society of Washington. 134(1); 209–242. DOI: 10.2988/0006-324X-134.1.209 

  twitter.com/CardiffCurator/status/1447467272868618242

[Invertebrate • 2025] Amynthas sirindhornae • Cryptic Diversity within the Endemic Mekong Giant Earthworm, Amynthas mekongianus (Cognetti, 1922) (Clitellata: Megascolecidae) across the Lower Mekong River Basin with Descriptions of a New Species

Amynthas sirindhornae Nantarat & Bantaowong,  

in Nantarat, Panha, Chanabun, Inkhavilay et Bantaowong. 2025. 

ไส้เดือนเทพรัตน์แม่น้ำโขง  ||  DOI: doi.org/10.58837/tnh.25.8.267375

Abstract

The Lower Mekong Basin is recognized as a region of remarkable biodiversity. However, it is currently experiencing severe degradation due to rapid economic development and the intensifying effects of climate change. Numerous species, including earthworms, are under increasing threat. In addition, Amynthas mekongianus (Cognetti, 1922) exhibits considerable intraspecific morphological variability, making its identification challenging. Therefore, the study aims to clarify species boundaries within the A. mekongianus complex in the Lower Mekong River Basin using both morphological and molecular approaches. Specimens were collected from multiple sites in the basin, and analyses revealed at least two putative species. Phylogenetic reconstructions (NJ, ML, and BI) together with species delimitation methods (ASAP, GMYC, and bPTP) consistently supported the recognition of two distinct lineages. These lineages differ primarily in body length, segment number, and spermathecae morphology. Accordingly, they are recognized as A. mekongianus sensu stricto and A. sirindhornae Nantarat & Bantaowong, sp. nov., which is formally described herein. This study enhances understanding of the evolutionary complexity and taxonomic status of the group, providing a foundation for future conservation and management strategies in the region.

Keywords: conservation, earthworm, phylogeny, systematics, taxonomy

A. coloration of living Amynthas sirindhornae sp. nov. 
B. surface casting and C. cocoon.

Amynthas sirindhornae Nantarat & Bantaowong, sp. nov.

ไส้เดือนเทพรัตน์แม่น้ำโขง 

Diagnosis.–Elongate and cylindrical body with 419-494 mm length, width 65–70 mm. Four pairs of spermathecal pores at 5/6–8/9, slit-like. Female pores mid-ventral on xiv. Male pores paired, on round placed disc, protuberant, alate on xviii. Spermathecae ellipsoi-dal ampulla, diverticulum long zig zag loops in the same plane. Testis sacs paired in x and xi. Seminal vesicles paired in xi, xii. Prostate glands paired in xvii-xix. Intestinal caecum simple in xxvii–xxiv.

Nattawadee Nantarat, Somsak Panha, Ratmanee Chanabun, Khamla Inkhavilay and Ueangfa Bantaowong. 2025. Cryptic Diversity within the Endemic Mekong Giant Earthworm, Amynthas mekongianus (Cognetti, 1922) (Clitellata: Megascolecidae) Across the Lower Mekong River Basin with Descriptions of a New Species. Tropical Natural History. Suppl. 8; 368-379. DOI: doi.org/10.58837/tnh.25.8.267375  [2025-10-20]

[Paleontology • 2025] Macromyzon siluricus • The First Leech Body Fossil predates estimated hirudinidan origins by 200 million years

 

Macromyzon siluricus 

de Carle​, Iwama, Wendruff, Babcock & Nanglu, 2025

 

DOI: doi.org/10.7717/peerj.19962

Abstract

Clitellata is a major annelid clade comprising oligochaetes (e.g., earthworms) and hirudineans (e.g., leeches). Due to their scant fossil record, the origins of clitellates, particularly Hirudinea, are poorly known. Here, we describe the first leech body fossil, Macromyzon siluricus, gen. et sp. nov., from the Brandon Bridge Formation (Waukesha Lagerstätte). This fossil, which is preserved in exceptional detail, possesses several hirudinean soft-tissue synapomorphies–including a large sucker at the posterior end and sub-divided segments–and phylogenetic analyses resolve Macromyzon siluricus as a stem leech. Its age, 437.5–436.5 Ma, is consistent with early age estimates for the origin of clitellates, and predates molecular-clock-based estimates of hirudinidan origins by at least 200 million years. These findings suggest that the earliest true leeches were marine and that, contrary to prevailing hypotheses, were unlikely to have fed on vertebrate blood.

Macromyzon siluricus gen. et sp. nov. from the Lower Brandon Bridge Formation (Waukesha Lagerstätte), Silurian (Llandovery: Telychian), Waukesha, Wisconsin, USA.
(A) Holotype specimen UWGM 7056. (B) Schematic of the external morphology of Macromyzon siluricus based on the holotype. (C) Detail of the anterior region, dorsal view, showing sexannulate segments with annuli numbered; black arrows indicate putative tubercles. (D) Schematic of the anterior region showing tubercles in light grey and sexannulate segments with annuli numbered. (E) Schematic of segmentation pattern for M. siluricus. Green borders indicate extant Hirudinida introduced for comparison:
(F) Ventral view of Myxobdella sinanensis (Zoological Collection of Kyoto University, specimen KUZ Z1794); photo by T. Nakano. (G) Schematic of Haementeria lutzi (dorsal view) with inset showing the species’ segmentation pattern. This specimen is deposited in the collections of the Museum of Zoology of the University of São Paulo (MZUSP 0026).

Abbreviations: Ca, caudal sucker; S, segment; Tu, tubercles; Tu?, putative tubercles (metameric circular organs). White arrow indicates mid-body torsion, the point of torsion is shown in blue on schematics; breakage in the specimen is indicated in dark grey.

Phylogenetic analyses recover Macromyzon siluricus gen. et sp. nov. as a stem leech.
(C) Life reconstruction of Macromyzon siluricus. Illustration by E. K. Chan.

Phylum: Annelida, Lamarck 1809

Class: Clitellata, Michaelson 1919

Subclass: Hirudinea, Lamarck 1818

Genus: Macromyzon gen. nov.

 Macromyzon siluricus sp. nov.

 

Etymology: Macromyzon (gender: masculine), from Greek, makros, “large” + myzon, “sucker” in reference to the large caudal appendage. The specific epithet refers to the Silurian age of the fossil.

 

Locality: Waukesha Lime and Stone Company, west quarry, north of State Highway 164, Waukesha, Wisconsin, USA.

Stratigraphic occurrence: Lower part of the Brandon Bridge Formation (Silurian: Llandovery, Telychian; Mikulic & Kluessendorf, 1999).

 

Diagnosis: Hirudinean having a vermiform-sublanceolate shape, truncated anteriorly, width expanding toward posterior, reaching maximum width slightly anterior of margin. Posterior margin approximately twice the width of anterior margin. Body segmented, with regularly spaced, sexannulate divisions. Posterior terminates in a large caudal sucker. The genus is monospecific; the diagnosis applies to both genus and species.

 

Danielle de Carle​, Rafael Eiji Iwama, Andrew J. Wendruff, Loren E. Babcock and Karma Nanglu. 2025. The First Leech Body Fossil predates estimated hirudinidan origins by 200 million years. PeerJ. 13:e19962. DOI: doi.org/10.7717/peerj.19962 [October 1, 2025]

[Invertebrate • 2025] Kanchuria tripuraensis & K. priyasankari • Two New Earthworm Species of the Genus Kanchuria Julka, 1988 (Clitellata: Megascolecidae) from Tripura State, North-eastern India

 Kanchuria tripuraensis ...  K. priyasankari 

Narayanan, Paliwal & Julka, 

in Narayanan, Paliwal, Kurien, Nath, ... et Julka, 2025.

DOI: doi.org/10.11646/zootaxa.5647.2.1 

 

Abstract 

Eastern Himalaya-Northeastern Hills are the second most earthworm species-rich region in India. Kanchuria Julka, 1988, is a small genus endemic to the north-eastern region of India, with eight known species. Two new species of the genus, namely Kanchuria tripuraensis Narayanan, Paliwal & Julka, sp. nov., and K. priyasankari Narayanan, Paliwal & Julka, sp. nov., are described from materials collected from the Tripura State in North-eastern India. K. tripuraensis sp. nov. is a unique species of the genus, distinguishable from all other known species by having single ventromedian spermathecae in segments 7 and 8. K. priyasankari sp. nov. belongs to the turaensis-species group characterized by three pairs of spermathecal pores. This group has a total of 5 species, including the new species described herein. Among the congeners of the group, K. priyasankari sp. nov. shows close similarity with K. turaensis Julka, 1988. K. priyasankari sp. nov. can be easily differentiated from the K. turaensis by the small body dimensions and characteristics of the spermathecae. The present work provides detailed descriptions of the new species along with photographs and illustrations of the key characters. A key to species of the genus Kanchuria is also provided. With the discovery of two new taxa, the total number of Kanchuria species has gone up to 10, and megadrile worm diversity reported from the Tripura State has increased to 38.

 Annelida, distribution, endemic, Oligochaeta, soil fauna, taxonomy, India

S. Prasanth NARAYANAN, R. PALIWAL, Vijo T. KURIEN, Sabyasachi NATH, Animesh DEY, Subhrajit NANDY, Prithwiraj KAR, Sujata GOLDAR, A.P. THOMAS and J.M. JULKA. 2025. Description of Two New Kanchuria Julka, 1988 (Clitellata: Megascolecidae) Species of Earthworms from Tripura State, North-eastern India.  Zootaxa. 5647(2); 101-116. DOI: doi.org/10.11646/zootaxa.5647.2.1 [2025-06-13]

 facebook.com/PrithwirajKAR58/posts/1341451770281276

Researchgate.net/publication/392631231_two_new_Kanchuria_from_Tripura_NE_India

[Invertebrate • 2024] Erinaceusyllis simonlledoi • A New Species of Erinaceusyllis (Annelida: Syllidae) discovered at A Wood-fall in the eastern Clarion-Clipperton zone, central Pacific Ocean

Erinaceusyllis simonlledoi 

Nilsson, Wiklund, Glover, Bribiesca-Contreras & Dahlgren, 2024  

DOI: doi.org/10.1016/j.dsr.2024.104415

Highlights: 

• A novel polychaete species was discovered on an abyssal wood-fall.

• Its high abundance on degraded wood displays a tolerance to sulfidic environments.

• Morphology and genetics support placement in Erinaceusyllis of the family Syllidae.

• This constitutes the first finding of abundant syllids on a natural wood-fall.

• Sulfide-tolerant syllids in the East Pacific may originate from the same lineage.

Abstract

In the deep sea, organic falls provide temporary localized enrichments of organic matter to the otherwise nutrient-poor abyssal seafloor. Areas where organic falls land become ephemeral patches of increased biodiversity. Often rich in opportunistic species which are tolerant to the sulfidic environment formed from anaerobic breakdown of organic matter. On a wood-fall at abyssal depths in the eastern Clarion-Clipperton Zone, the novel species Erinaceusyllis simonlledoi (Annelida: Syllidae) was discovered in high abundance. This study entails the first description of a novel syllid species found in high density on a naturally occurring organic fall. Phylogenetic position was investigated using three genetic markers (16S, 18S, COI) and morphology was studied through light- and scanning electron microscopy. Genetic data and morphological analysis supported placement in the syllid genus Erinaceusyllis. Distinguishing features were lack of eyes, dorsal brooding of one egg per egg-bearing segment, lack of visible papillae across the body, incomplete fusion of palps, bidentate chaetae, as well as pyriform antennae and tentacular cirri. Erinaceusyllis simonlledoi sp. nov. is highly similar to a species found on hydrothermal vents belonging to the closely related genus Sphaerosyllis. The similarity between the two species, as well as findings of unspecified Sphaerosyllis species in various types of sulfidic habitats evoke questions of a possible syllid lineage adapted to sulfidic environments.

Previous article in issue

 Keywords: Erinaceusyllis, Sphaerosyllis, Wood-falls, Sulfidic habitats, Clarion-Clipperton zone, Abyssal zone

 The piece of wood on which Erinaceusyllis simonlledoi sp. nov. was discovered. In situ image during collection.

Photo: University of Gothenburg.

 Full body light microscopy images of Erinaceusyllis simonlledoi sp. nov. 
 A – Holotype NHM_9029 dorsal view, chaetigers 13–16 on left side removed for DNA extraction. B – NHM_9029 ventral view. C – Paratype NHM_9081A dorsal view. D – Paratype NHM_9070B lateral view, left side. E – NHM9073 dorsal view, 3 posterior chaetigers and pygidium removed for DNA extraction.

 Scale bar: 100 μm. la – lateral antenna; ma – median antenna; tc – tentacular cirrus; dc – dorsal cirrus; ac -anal cirrus; px – pharynx; pr – proventricle.

Systematics

Phylum: Annelida Lamarck, 1802.

Class: Polychaeta Grube, 1850.

Family: Syllidae Grube, 1850.

Genus: Erinaceusyllis San Martín, 2005

Species: Erinaceusyllis simonlledoi sp. nov.

Etymology: The species is named in honor of Dr. Erik Simon Lledo, a member of the group of scientists onboard the Maersk Launcher on the NORI-D 5E biodiversity baseline research expedition of November–December 2021.

Christian L. Nilsson, Helena Wiklund, Adrian G. Glover, Guadalupe Bribiesca-Contreras and Thomas G. Dahlgren. 2024. A New Species of Erinaceusyllis (Annelida: Syllidae) discovered at A Wood-fall in the eastern Clarion-Clipperton zone, central Pacific ocean. Deep Sea Research Part I: Oceanographic Research Papers. 214, 104415. DOI: doi.org/10.1016/j.dsr.2024.104415

 

[Invertebrate • 2024] Perinereis kaustiana • A New Species (Annelida: Nereididae) for the Saudi Arabian Red Sea Region

Perinereis kaustiana 

 Teixeira, Fourreau, Sempere-Valverde & Carvalho, 2024

DOI: 10.3897/zookeys.1196.115260

  twitter.com/ChaoticChloeia

Abstract

Annelid biodiversity studies in the Red Sea are limited and integrative taxonomy is needed to accurately improve reference libraries in the region. As part of the bioblitz effort in Saudi Arabia to assess the invertebrate biodiversity in the northern Red Sea and Gulf of Aqaba, Perinereis specimens from intertidal marine and lagoon-like rocky environments were selected for an independent assessment, given the known taxonomic ambiguities in this genus. This study used an integrative approach, combining molecular with morphological and geographic data. Our results demonstrate that specimens found mainly in the Gulf of Aqaba are not only morphologically different from other five similar Perinereis Group I species reported in the region, but phylogenetic analysis using available COI sequences from GenBank revealed different molecular operational taxonomic units, suggesting an undescribed species, P. kaustiana sp. nov. The new species is genetically close and shares a similar paragnath pattern to the Indo-Pacific distributed P. helleri, in particular in Area III and Areas VII–VIII. Therefore, we suggest it may belong to the same species complex. However, P. kaustiana sp. nov. differs from the latter mainly in the shorter length of the postero-dorsal tentacular cirri, median parapodia with much longer dorsal Tentacular cirri, posteriormost parapodia with much wider and greatly expanded dorsal ligules. Additionally, two new records are reported for the Saudi Neom area belonging to P. damietta and P. suezensis, previously described only for the Egyptian coast (Suez Canal) and are distributed sympatrically with the new species, but apparently not sympatric with each other.

Key words: Gulf of Aqaba, mtCOI-5P, NEOM, north-eastern Red Sea, Polychaeta, Saudi Arabia, taxonomy

Perinereis kaustiana sp. nov. All pictures are from the holotype (NTNU-VM-86011) if not stated otherwise
A anterior end, prostomium, dorsal view B anterior end, prostomium, ventral view C jaws and respective jaw canals (JC), dorsal view D pharynx, maxillary ring (Areas III and IV), ventral view; black arrows, lateral patches with two paragnaths each E pharynx, oral ring (Areas VI), dorsal view F pharynx, maxillary ring (Areas I and II), dorsal view G pharynx, oral ring (Areas VII–VIII), ventral view; black arrows, furrow regions; white arrows, ridge regions H posterior end; white arrows, pygidial Tentacular cirri, paratype (NTNU-VM-86015) I anterior body, tentacular cirri reaching chaetiger 9, paratype (NTNU-VM-86015) J worm’s eyes, right side, paratype (NTNU-VM-86015). Abbreviations: chaet., chaetiger; Pyg., Pygidium. Scale bars: 500 μm (A, B, I); 250 μm (E, F, H); 100 μm (D, G); 125 μm (J); 75 μm (C).

Family Nereididae Blainville, 1818

Genus Perinereis Kinberg, 1865

 Perinereis kaustiana sp. nov.

Diagnosis: Four pairs of tentacular cirri, postero-dorsal one reaching chaetiger 7–9; ratio of DPCL / HL = 3.6×. Eversible pharynx with one pair of dark brown curved jaws with seven or eight denticles; two longitudinal canals emerging from the pulp cavity, both in the mid-section of the jaw. Pharynx consisting of maxillary and oral rings with conical shaped paragnaths. Maxillary ring: Area I = 2 small paragnaths arranged in a longitudinal line. Area II = Cluster of 5–7 small paragnaths. Area III = central patch of nine small paragnaths, lateral patches with two small paragnaths each. Area IV = 13 small paragnaths arranged in wedge shape without any bars. Oral ring: Area V = a triangle of three large paragnaths. Area VI (a+b) = two narrow bar-shaped ...

Etymology: The species designation pays tribute to the King Abdullah University of Science and Technology (KAUST) in Saudi Arabia, a globally recognized graduate-level research institution. This naming honours KAUST’s substantial and enduring contributions to marine science, particularly in advancing our understanding of the Red Sea over the course of more than a decade. Through its dedicated research efforts, KAUST has significantly enriched the scientific community’s knowledge of this unique marine environment.

Marcos A. L. Teixeira, Chloé Julie Loïs Fourreau, Juan Sempere-Valverde and Susana Carvalho. 2024. Two New Records and Description of A New Perinereis (Annelida, Nereididae) Species for the Saudi Arabian Red Sea Region.  ZooKeys. 1196: 331-354. DOI: 10.3897/zookeys.1196.115260

  twitter.com/ChaoticChloeia/status/1774838199384461695

[Invertebrate • 2024] Pectinereis strickrotti • A remarkable New deep-sea nereidid (Annelida: Nereididae) with gills

 

 Pectinereis strickrotti

Villalobos-Guerrero, Huč, Tilic, Hiley & Rouse, 2024

 DOI: 10.1371/journal.pone.0297961

Abstract

Nereidid polychaetes are well known from shallow marine habitats, but their diversity in the deep sea is poorly known. Here we describe an unusual new nereidid species found at methane seeps off the Pacific coast of Costa Rica. Specimens of Pectinereis strickrotti gen. nov., sp. nov. had been observed dating back to 2009 swimming just above the seafloor at ~1,000 m depth but were not successfully captured until 2018. Male epitokes were collected as well as a fragment of an infaunal female found in a pushcore sample. The specimens were all confirmed as the same species based on mitochondrial COI. Phylogenetic analyses, including one based on available whole mitochondrial genomes for nereidids, revealed no close relative, allowing for the placement of the new species in its own genus within the subfamily Nereidinae. This was supported by the unusual non-reproductive and epitokous morphology, including parapodial cirrostyles as pectinate gills, hooked aciculae, elfin-shoe-shaped ventral cirrophores, and elongate, fusiform dorsal ligules emerging sub-medially to enlarged cirrophores. Additionally, the gill-bearing subfamily Dendronereidinae, generally regarded as a junior synonym of Gymnonereidinae, is reviewed and it is here reinstated and as a monogeneric taxon.

 Pectinereis strickrotti gen. nov., sp. nov. male anatomy.
A, B, D-F. Paratype (SIO-BIC A9889), epitokous male: A, whole body of living specimen in dorsal view; B, anterior region of living specimen in dorsal view; D, prostomium of preserved specimen in frontal view; E, posterior end of preserved specimen in dorsal view; F, post-natatory chaetigers and pygidium of preserved specimen in dorsolateral view. C. Holotype (SIO-BIC A9836), epitokous male: anterior region of preserved specimen in dorsal view. Scale bars: A, ~20 mm; B, ~5 mm; C, 5 mm; D, 1 mm; E, 3 mm; F, 0.5 mm. Credits: A, B, Ekin Tilic; C, Tulio Villalobos; D-F, Greg Rouse.

 Pectinereis strickrotti gen. nov., sp. nov. in life.
A, B, D. Several epitokous males swimming near methane seeps of Mound 12 (~1,000 m depth) of the Costa Rica margin and videoed via the submersible DSV Alvin. A. A frame grab from a video taken on Alvin dive 4503 on Feb. 4, 2009. B and D. Frame grabs from video taken on Alvin dive 4987 on Nov. 2, 2018. C. A fragment of an atokous infaunal female was collected at the same depth and locality via sediment pushcore on Alvin dive 4984 on Oct. 30, 2018. A white egg ~350 μm in diameter is visible on the exterior. Scalebar 1 mm. E. An epitokous male swimming near methane seeps of Parrita Scar (~1,000 m depth) of the Costa Rica margin. The specimen was initially caught via slurp with the ROV SuBastian (dive S0218, Jan. 11, 2019) but escaped. Images A, B, D, courtesy of Woods Hole Oceanographic Institute. E, courtesy of Schmidt Ocean Institute.

Family NEREIDIDAE de Blainville, 1818

Subfamily NEREIDINAE de Blainville, 1818

Pectinereis Villalobos-Guerrero, Huč, Tilic, Hiley & Rouse gen. nov. 

Diagnosis: Prostomial anterior region entire. Esophageal caeca absent. Anterior parapodial cirrostyles as comb-like gills. Dorsal cirrostyles attached sub-distally and dorsal ligule attached sub-medially to expanded cirrophores. Notopodial prechaetal, neuropodial postchaetal and inferior lobes present. First two chaetigers without notoacicula. Neuropodial spinigers and falcigers very long, homogomph. Epitoke males divided into four body regions, with distally-bilamellated dorsal cirrophore, elfin-shoe shaped ventral cirrophore, pre-pygidial hooked aciculae, and ensiform spinigers.

Etymology: This genus is named by combining the Latin word pectinis (= ‘comb’) with the name of the type genus of the family, Nereis. The name emphasizes the pectinate (i.e., comb-like) parapodial cirrostyles (gills) in the first anterior chaetigers formed by digitiform filaments. The gender is feminine, as the stem genus-group name.

Pectinereis strickrotti Villalobos-Guerrero, Huč, Tilic, Hiley & Rouse sp. nov.

Etymology: The species is named in honor of Bruce Strickrott, Group Manager and lead submersible pilot of the DSV Alvin (Woods Hole Oceanographic Institution), who chased these worms for many years before finally skillfully succeeding in their capture.

  

Tulio F. Villalobos-Guerrero, Sonja Huč, Ekin Tilic, Avery S. Hiley and Greg W. Rouse. 2024. A remarkable New deep-sea nereidid (Annelida: Nereididae) with gills. PLoS ONE. 19(3): e0297961. DOI: 10.1371/journal.pone.0297961

[Invertebrate • 2024] Megascolex jeyporeghatiensis & M. quadripapillatus • Two New Species of the Genus Megascolex Templeton, 1844 (Clitellata: Megascolecidae) from the Eastern Ghats of Odisha State, India

Megascolex jeyporeghatiensis Narayanan & Paliwal,
M. quadripapillatus Narayanan & Paliwal, 

in Naik, Narayanan, Palita, Thomas et Paliwal, 2024.

DOI: 10.11646/zootaxa.5424.5.5

Abstract

Two new earthworm species of Megascolex Templeton, 1844, M. quadripapillatus Narayanan & Paliwal, sp. nov. and M. jeyporeghatiensis Narayanan & Paliwal, sp. nov. are described from the under-explored Eastern Ghats Hills of Odisha state in Peninsular India. They belong to a group of species characterized by two pairs of spermathecal pores in intersegmental furrows 7/8/9, holandric, seminal vesicles in segments 9 and 12, absence of penial setae and calciferous glands. Megascolex ratus Cognetti, 1911, M. pumilio Stephenson, 1916 and the two new species described here are the members of this group. Megascolex quadripapillatus sp. nov. and M. jeyporeghatiensis sp. nov. occur in deciduous forests with brownish gravel-loamy soils. Here we provide the detailed description of the external and internal characteristics of the new species along with the illustrations of the key characters. With the new findings, the range of Megascolex genus has been extended further north in the less explored Eastern Ghats Hills of India. With this discovery, the total number of Megascolex species has increased to 70, of which 34 are found in India.

Annelida, biodiversity, endemic, Oligochaeta, Peninsular India, taxonomy  

Ayusmita Naik, S. Prasanth Narayanan, Sharat Kumar Palita, A.P. Thomas and R. Paliwal. 2024. Two New Species of the Genus Megascolex Templeton, 1844 (Clitellata, Megascolecidae) from the Eastern Ghats of Odisha State, India.  Zootaxa. 5424(5); 569-580. DOI: 10.11646/zootaxa.5424.5.5

[Invertebrate • 2019] Polyodontes kuroshio • A New Species of Polyodontes (Annelida: Acoetidae) from Western Japan

  

Polyodontes kuroshio

Jimi, Tomioka, Orita & Kajihara, 2019

DOI  10.12782/specdiv.24.275 

 twitter.com/alciopidae

Abstract
Acoetid polychaetes were collected from shallow waters off Kochi Prefecture and Wakayama Prefecture, Japan. The specimens could be assigned to the genus Polyodontes Blainville, 1828, but are different from all the known species of the genus by the following characters: ommatophores with short neck; palps with minute papillae; parapodia without branchiae; the acicular neurochaetae always lacking aristae and having hairs only on a small area of their subdistal end; and antennae with brown dots. They are herein morphologically described as a new species and a partial 658-bp COI sequence as a DNA barcode is provided for future taxonomic studies.

Keywords: Kuroshio coastal region, marine invertebrates, North West Pacific, taxonomy

Polyodontes kuroshio sp. nov., NMST-Pol H-764 (holotype), live specimen, dorsal view.

Polyodontes kuroshio sp. nov. 

[New Japanese name: kurobuchi-bouseki-urokomushi]

 Etymology. This species is named after the Biological Institute on Kuroshio. The holotype from Sukumo was collected by the first author who received funding by the institution. The specific name is a non-declensive noun.

Distribution. This species is known from off Otsuki (Kochi Prefecture) and Hatakejima island (Wakayama Prefecture), Japan, Northwest Pacific


Naoto Jimi, Shinri Tomioka, Ryo Orita and Hiroshi Kajihara. 2019. A New Species of Polyodontes (Annelida: Acoetidae) from Western Japan. Species Diversity. 24: 275–279. DOI  10.12782/specdiv.24.275
  twitter.com/alciopidae/status/1199141243319570432