Ferreiraella charazata Sigwart, 2025

(SOSA), Senckenberg Ocean Species Alliance, Andrade, Luiz F., Boyko, Christopher B., Brandt, Angelika, Buge, Barbara, Dávila Jiménez, Yasmín, Henseler, Mats, Hernández Alcántara, Pablo, Jóźwiak, Piotr, Knauber, Henry, Marcondes Machado, Fabrizio, Martínez-Muñoz, Carlos A., Momtazi, Farzaneh, Nakadera, Yumi, Qiu, Jian-Wen, Riehl, Torben, Rouse, Greg W., Sigwart, Julia D., Sirenko, Boris, Souza-Filho, Jesser F., Steger, Jan, Stępień, Anna, Tilic, Ekin, Trautwein, Bianca, Vončina, Katarzyna, Williams, Jason D. & Zhang, Junlong, 2025, Ocean Species Discoveries 13 – 27 — Taxonomic contributions to the diversity of Polychaeta, Mollusca and Crustacea, Biodiversity Data Journal 13, pp. e 160349-e 160349 : e160349-

Ferreiraella charazata Sigwart sp. nov.

Materials

Type status: Holotype. Occurrence: catalogNumber: SCSMBC 240287 ; recordedBy: ROV ROPOS on R / V TAN KAH KEE; individualCount: 1; lifeStage: adult; occurrenceID: 1E1FA6C7-42D2-56D6-B5D2-BBC070119095; Taxon: scientificName: Ferreiraella charazata Sigwart ; kingdom: Animalia; phylum: Mollusca; class: Polyplacophora; order: Lepidopleurida ; family: Abyssochitonidae ; genus: Ferreiraella ; specificEpithet: charazata ; taxonRank: species; scientificNameAuthorship: Sigwart; nomenclaturalCode: ICZN; Location: higherGeography: Pacific Ocean; waterBody: Western Pacific Ocean; verbatimDepth: 3003 m; verbatimCoordinates: 21°18.3411N, 119°11.7281E; verbatimLatitude: 21°18.3411N; verbatimLongitude: 119°11.7281E; verbatimCoordinateSystem: degrees decimal minutes; Identification: identifiedBy: Julia D. Sigwart; dateIdentified: 2024; Event: samplingProtocol: remotely operated vehicle (ROV) ROPOS on R / V TAN KAH KEE; eventDate: 9 - May- 18; Record Level: institutionCode: SCSMBC; basisOfRecord: PreservedSpecimen

Type status: Paratype. Occurrence: catalogNumber: SMF 380825 ; recordedBy: ROV ROPOS on R / V TAN KAH KEE; individualCount: 1; lifeStage: adult; occurrenceID: 5EFBBA70-2307-5E1C-A9C9-BC95C0190D7F; Taxon: scientificName: Ferreiraella charazata Sigwart ; kingdom: Animalia; phylum: Mollusca; class: Polyplacophora; order: Lepidopleurida ; family: Abyssochitonidae ; genus: Ferreiraella ; specificEpithet: charazata ; taxonRank: species; scientificNameAuthorship: Sigwart; nomenclaturalCode: ICZN; Location: higherGeography: Pacific Ocean; waterBody: Western Pacific Ocean; verbatimDepth: 3003 m; verbatimCoordinates: 21°18.3411N, 119°11.7281E; verbatimLatitude: 21°18.3411N; verbatimLongitude: 119°11.7281E; verbatimCoordinateSystem: degrees decimal minutes; Identification: identifiedBy: Julia D. Sigwart; dateIdentified: 2024; Event: samplingProtocol: remotely operated vehicle (ROV) ROPOS on R / V TAN KAH KEE; eventDate: 9 - May- 18; Record Level: institutionCode: SMF; basisOfRecord: PreservedSpecimen

Type status: Paratype. Occurrence: catalogNumber: SMF 380826 ; recordedBy: ROV ROPOS on R / V TAN KAH KEE; individualCount: 1; lifeStage: adult; occurrenceID: B886AD47-B4EF-57D5-B2BD-FBDFA0A0ED69; Taxon: scientificName: Ferreiraella charazata Sigwart ; kingdom: Animalia; phylum: Mollusca; class: Polyplacophora; order: Lepidopleurida ; family: Abyssochitonidae ; genus: Ferreiraella ; specificEpithet: charazata ; taxonRank: species; scientificNameAuthorship: Sigwart; nomenclaturalCode: ICZN; Location: higherGeography: Pacific Ocean; waterBody: Western Pacific Ocean; verbatimDepth: 3003 m; verbatimCoordinates: 21°18.3411N, 119°11.7281E; verbatimLatitude: 21°18.3411N; verbatimLongitude: 119°11.7281E; verbatimCoordinateSystem: degrees decimal minutes; Identification: identifiedBy: Julia D. Sigwart; dateIdentified: 2024; Event: samplingProtocol: remotely operated vehicle (ROV) ROPOS on R / V TAN KAH KEE; eventDate: 9 - May- 18; Record Level: institutionCode: SMF; basisOfRecord: PreservedSpecimen

Type status: Paratype. Occurrence: catalogNumber: SMF 380827 ; recordedBy: ROV ROPOS on R / V TAN KAH KEE; individualCount: 1; lifeStage: adult; occurrenceID: 7AB36057-98EC-5EEA-AE3B-ADFE5E4B24B5; Taxon: scientificName: Ferreiraella charazata Sigwart ; kingdom: Animalia; phylum: Mollusca; class: Polyplacophora; order: Lepidopleurida ; family: Abyssochitonidae ; genus: Ferreiraella ; specificEpithet: charazata ; taxonRank: species; scientificNameAuthorship: Sigwart; nomenclaturalCode: ICZN; Location: higherGeography: Pacific Ocean; waterBody: Western Pacific Ocean; verbatimDepth: 3003 m; verbatimCoordinates: 21°18.3411N, 119°11.7281E; verbatimLatitude: 21°18.3411N; verbatimLongitude: 119°11.7281E; verbatimCoordinateSystem: degrees decimal minutes; Identification: identifiedBy: Julia D. Sigwart; dateIdentified: 2024; Event: samplingProtocol: remotely operated vehicle (ROV) ROPOS on R / V TAN KAH KEE; eventDate: 9 - May- 18; Record Level: institutionCode: SMF; basisOfRecord: PreservedSpecimen

Description

Holotype 18.0 × 8.5 mm, oval. Overall colour of valves light brown, frequently marked with scratches revealing white shell.

Valves rounded, little elevated (dorsal elevation ratio 0.28 in valve III, Fig. 10 A). Head valve semicircular. Intermediate valves slightly recurved, lateral margins rounded, anterior margin concave, posterior margin paralleling anterior margin, apex not projecting. Lateral areas not raised or visibly demarcated. Tail valve as wide as head valve, flattened, mucro central, posterior slope flat (Fig. 10 A, B). Tegmentum smooth, covered with tissue and apical projections from aesthete pores. Aesthetes in bundles of one megalaesthete and approximately six micraesthetes with caps protruding from aesthete openings (Fig. 11 A, C). Aesthete bundles typically in two parallel rows of three micraesthetes, but often irregularly arranged (sometimes 5 or 7 per megalaesthete).

Articulamentum white, well developed, without insertion plate or callus, apophyses moderately narrow, triangular in the intermediate valves and tail valve. Jugal sinus wide and convex.

Central tooth of radula small, bud-like, first (inner) lateral teeth with brush-like projections. Second (major) lateral teeth with flattened, tridentate mineralised cusps. Third uncinal (sweeper) teeth with extremely large and broad, spoon-shaped, but comb-like blade (Fig. 11 B).

Girdle very wide, dorsally densely covered with oblong spicule-scales (up to 80–100 × 15–20 μm). Scales are proximally smooth, suboval in cross section, but include two types: distally tapering to a blunt point or distally stellate with four or six ribs. Ventral side of girdle naked.

Gills 11 on each side ( paratype 3), smaller to the anterior, extending from valve VI to the anus.

Type material

Holotype ( SCSMBC 240287), now disarticulated, consisting of mounts of shell, perinotum and radula; three paratypes ( Paratype 1: SMF 380825; Paratype 2: SMF 380826; Paratype 3: SMF 380827).

Material examined

Only known from the type material.

Type locality

Western Pacific Ocean, South China Sea, 21°18.3411N, 119°11.7281E, at 3003 m depth.

Diagnosis

Animal medium, holotype approximately 18.0 mm long (estimated from curled position). Overall colour brown, frequently marked with scratches revealing white shell. Shell rounded, valves not beaked, mucro of tail valve slightly anterior, tail valve flattened. Tegmentum smooth; aesthetes in bundles of one megalaesthete and six micraesthetes, with protruding caps. Girdle densely covered with oblong spicule-scales, flattened oval in profile. Scales include two types: distally bluntly pointed or stellate. Major lateral teeth of radula with relatively flattened, tridentate cusps. Sweeper teeth large, expanded, comb-like. Eleven gills on each side.

Etymology

From the Latin charazo meaning scratch or engrave, noting the common white scratch marks on the brown dorsal shells in this species (adjective, feminine).

Distribution

Only known from the type locality.

Taxon discussion

Sigwart and Sirenko (2012) provided a dichotomous key to all species of the genus Ferreiraella . The new species has a tail valve most similar to F. plana . In geographic range, F. charazata sp. nov. could be most comparable to F. tsuchidai Saito 2006 , but the intermediate valves are oval in F. tsuchidai and cardioid in F. charazata sp. nov. The tail valve in F. tsuchidai is more oval with a straight postmucronal slope, round in F. plana and, in F. charazata sp. nov., the tail valve is distinctly triangular and the postmucronal area very flat. Specimens of F. charazata sp. nov. and F. tsuchidai frequently host epibiotic tubeworms on their tail valves.

Methods

Individuals of F. charazata sp. nov. were collected in 2018 from sunken wood by remotely operated vehicle (ROV) ROPOS aboard R / V TAN KAH KEE, in the framework of the research programme “ Deep Sea Process and Evolution of the South China Sea ”.

Specimens were photographed using a motorised NIKON SMZ 25 stereomicroscope, equipped with a NIKON Digital Sight 10 camera and stacked with NIKON NIS Elements Basic Research software (v. 5.42. 04). Body size was measured from these photographs using ImageJ software (v. 1.54 g); to estimate body length in curled specimens, a curved line was fitted along the perinotum-plate boundary of lateral-view images and subsequently digitally straightened.

The holotype SCSMBC 240287 was dissected to remove head, tail and representative intermediate valves, the radula and a piece of the perinotum for spicule preparation. Small cuts of the radula and girdle, as well as a fragment of the head valve were cleaned of soft tissue using diluted (max. 50 %) household bleach for a few minutes, carefully rinsed with fresh water and transferred to aluminium SEM stubs with double-sided adhesive carbon tabs, either via air drying (valve fragment, spicules) or following dehydration through a graded ethanol series and subsequent chemical drying by means of hexamethyldisilazane (radula). SEM images were taken with a HITACHI TM 4000 Plus Tabletop scanning electron microscope with (chemically-dried radula) and without (other preparations) gold-palladium coating.

Spicules were measured using scales on SEM images and ImageJ. Images were processed with Adobe Photoshop 2024.

Specimen data for this description were gathered and processed via the Discovery Laboratory of the SENCKENBERG OCEAN SPECIES ALLIANCE.

Repository: Specimens are housed in the South China Sea Marine Biological Collections, Chinese Academy of Sciences, Guangzhou, China ( SCSMBC) and the Senckenberg Research Institute and Natural History Museum Frankfurt ( SMF).

Figures

Figure 10. Ferreiraella charazata Sigwart, sp. nov. A Holotype SCSMBC 240287, valves. From top to bottom: valve I, valve III (anterior view), valve V, valve VIII and valve VIII in lateral view; B Paratype 1 SMF 380825; C In situ photograph of multiple specimens (indicated with arrowheads) on sunken wood, together with other fauna. Scale bars: 2 mm.

Figure 11. Ferreiraella charazata Sigwart, sp. nov., holotype SCSMBC 240287, SEM micrographs. A Aesthete pores, shown from valve I; B Radula; C Aesthete caps, shown from valve IV; D – F Girdle scales (perinotum). All scale bars: 100 μm (A, B, D – F), 25 μm (C).