Craspedochiton zefranki Voncina 2025, sp. nov.
Year: 2025
Type: other
Abstract: Craspedochiton zefranki Vončina sp. nov. Materials Type status: Holotype. Occurrence: catalogNumber: MNHN-IM- 2019-34865; recordedBy: leg. Bouchet, Dayrat, Warén & Richer de Forges-IRD; individualCount: 1; lifeStage: adult; preparations: EtOH 100 %, partly disarticulated + SEM stubs with parts of girdle and radula; associatedSequences: GenBank nr PV 664593; occurrenceID: B359911D-085D-512F-8E8E-407151DD3145; Taxon: scientificName: Craspedochiton zefranki Vončina; kingdom: Animalia; phylum: Mollusca; class: Polyplacophora; order: Chitonida; family: Acanthochitonidae; genus: Craspedochiton; specificEpithet: zefranki; scientificNameAuthorship: Vončina; nomenclaturalCode: ICZN; Location: higherGeography: Pacific Ocean; continent: Oceania; country: Solomon Islands; locality: NW San Cristobal; minimumDepthInMeters: 97; maximumDepthInMeters: 223; verbatimLatitude: 10°17'S; verbatimLongitude: 161°43'E; Identification: identifiedBy: Katarzyna Vončina; dateIdentified: 21-04 - 2024; Event: eventDate: 06-10 - 2001; eventRemarks: Expedition: Solomon 1, Station: DW 1840, Ship: Alis; Record Level: institutionCode: MNHN; collectionCode: IM; basisOfRecord: PreservedSpecimen Type status: Paratype. Occurrence: catalogNumber: SMF 380885; recordedBy: leg. Bouchet, Dayrat, Warén & Richer de Forges-IRD; individualCount: 1; lifeStage: adult; preparations: EtOH 100 %; otherCatalogNumbers: MNHN-IM- 2019-35217; occurrenceID: B12459B8-0BC6-59F6-805F-02F09F435567; Taxon: scientificName: Craspedochiton zefranki Vončina; kingdom: Animalia; phylum: Mollusca; class: Polyplacophora; order: Chitonida; family: Acanthochitonidae; genus: Craspedochiton; specificEpithet: zefranki; scientificNameAuthorship: Vončina; nomenclaturalCode: ICZN; Location: higherGeography: Pacific Ocean; continent: Oceania; country: Solomon Islands; locality: NW San Cristobal; verbatimLatitude: 10°17'S; verbatimLongitude: 161°43'E; Identification: identifiedBy: Katarzyna Vončina; dateIdentified: 2024-21 - 04; Event: eventDate: 06-10 - 2001; Record Level: institutionCode: SMF; basisOfRecord: PreservedSpecimen Description Body of small size (holotype: 16 x 10 mm, paratype: 13 x 8 mm), oval, carinated, moderately elevated (quotient of valve II = 0.31), side slopes slightly concave, valves solid, beaked. Tegmentum densely granulated, girdle expanded anteriorly (Fig. 5). Tegmentum ground colouration yellowish, dark orange at the valves edges and jugum, with mostly white pustules and irregular small green maculation; girdle yellow to orange with irregular brownish patches and white blotches around the tufts (Figs 5, 6). Dorsum, despite well-defined jugum, hardly keeled, side slopes straight to slightly convex. Tegmentum densely covered with polymorphic pustules (Figs 6, 7 A – E). Head valve semicircular with rather straight posterior margin, notched in the middle, with five elevated ribs consisting of irregular, elongate pustules, larger towards anterior and side margins of the valve, pustules between the ribs smaller, roundish in the apical region and larger, more elongate towards the margins (Fig. 6 A, G, Fig. 7 A). Intermediate valves roughly rectangular, weakly produced forward at jugal part, the posterior edge of the valve having a central protrusion that extends outwards, creating a small beak, flanked by straight edges on either side (Fig. 6 C, Fig. 7 C). Jugal area with wavy ridges, wedge-shaped, separated from the lateropleural areas. Lateropleural areas moderately elevated with an inconspicuous diagonal ridge consisting of slightly elevated and larger pustules, separating areas with different kind of granulation: anterior part covered with sparsely distributed, small and oval pustules (Fig. 6 C, Fig. 7 B, C) and posterior part with densely arranged, much larger and irregular pustules (Fig. 6 C, Fig. 7 C, D). Tail valve small, almost circular, slightly wider than long, with antemedian flat mucro, straight postmucronal slope; seven inequidistance elevated ribs formed by elevated large pustules correspond to the articulamentum slits; granulation of the tail valve similar to the intermediate valves, with the antemucronal area covered with small oval pustules and the postmucronal area with densely distributed, much larger and elongate pustules (Fig. 6 E, H, Fig. 7 E). Articulamentum strongly developed, creamy-pink, but white in apophyses and under the pleural areas of the intermediate valves. Slit formula: 5 / 1 / 7. Slits deep and wide, smooth, but with distinct dorsal grooves; insertion plates long and wide. Apophyses well-developed, rounded in a head valve, trapezoidal in valve II and very short, but wide, rectangular with rounded edges in tail valve (Fig. 6 B, D, F). Girdle anteriorly expanded, light orange with irregular brownish patches and white blotches around the tufts. Dorsally densely covered with short, flattened spicules, with distinct radial ribs in their upper half – ribs usually not reaching the tip which tends to be tapered and smooth, L: 56–62 μm (mean = 58 μm, n = 10), W: 10–15 μm (mean = 12 μm, n = 10), intermingled with long, randomly, but densely distributed hair-like, smooth long spicules, usually bent, L: 210–420 μm (mean = 318 μm, n = 3), W: 33–42 μm (mean = 37 μm, n = 3) (Fig. 8 A – C); 18 sutural tufts indistinct, consisting of very short (likely broken), thick, straight spicules. Marginal fringe of elongate, rounded, straight and point-ended spicules (some spicules striated), L: 322–347 μm (mean = 340 μm, n = 3), W: 37–50 μm (mean = 42 μm, n = 3) (Fig. 8 D). Ventral spicules densely arranged, tiled, polymorphic, very elongate to oval with a clear zonation. The anterior and middle part of hyponotum covered with longitudinally densely striated, flattened scale-like spicules, L: 75–120 μm (mean = 87.6 μm, n = 7), W: 40–75 μm (mean = 53.4 μm, n = 7) (Fig. 9 A). The posterior part of hyponotum covered with elongate, flattened, sharply pointed or slightly tapered and deeply striated spicules, L: 170 μm, W: 30 μm, n = 1, (Fig. 9 B). Mantle fold with smooth, flat, elongated scales at the edges (L: 800 μm, W: 200 μm, n = 1) and very long, straight, deeply striated spicules, L: 451–553 μm (mean = 499 μm, n = 8), W: 21–44 μm (mean = 32.5 μm, n = 8), intermingled with similar, but much shorter spicules (up to 250 μm), more abundant closer to the interior part of the mantle fold (Fig. 9 C – F). Radula of holotype small, ca. 3 mm in length, with 46 rows of teeth, of which 40 are matured. Central tooth subrectangular, the apical edge is very thin and folded, which gives it a bicuspid look, with wide base and tapering towards the top, the antero-lateral corner of the centro-lateral tooth is obtuse and smooth, thin. First lateral tooth elongate, major lateral tooth robust, with tricuspid head, denticles pointed, of similar size (Fig. 7 F). Gills merobranchial, six ctenidia per side. Type material Holotype (MNHN-IM- 2019-34865) now partly disarticulated; parts of girdle and radula on two SEM stubs and the vial with the specimen stored in 96 % ethanol; and one paratype (SMF 380885) stored in 96 % ethanol. Material examined Only known from the type material. Type locality Solomon Islands, NW San Cristobal, 10°17'S, 161°43'E, 97–223 m depth. Diagnosis Chitons of small size, up to 15 mm, body oval, girdle expanded anteriorly; colour of the tegmentum yellowish, mottled with dark orange and green; girdle yellow to orange with brownish maculation and white patches around the tufts. Valves carinated, moderately elevated, densely covered with pustules. Head valve with five distinct ribs, tail valve almost circular, mucro antemedian, flat. Perinotum covered with short, ribbed spicules and scattered with hair-like long spicules; hyponotum covered with scale-like, deeply striated spicules and very long thin spicules on the mantle fold. Etymology The specific epithet zefranki is a masculine adjective formed from the name of Hosea Jan "Ze” Frank, an online performance artist known for his wit, creativity and humorous approach to scientific knowledge in the YouTube series TRUE FACTS. The name honours his influential contributions to internet culture and the vision he has brought to the SENCKENBERG OCEAN SPECIES ALLIANCE as a member of its advisory board. Distribution At present known only from its type locality, the Solomon Islands. Taxon discussion Morphological discussion The genus Craspedochiton consists of 14 currently accepted species and five of them belong to Thaumastochiton - group Thiele, 1909 (Schwabe and Els 2019) which is characterised by the uplifted posterior mucro and unslitted callus in the tail valve. As Craspedochiton zefranki sp. nov. has antemedian positioned mucro, it surely does not belong to this group. The new species can be immediately distinguished from the rest of the species belonging to the same genus by its roundish insertion plates in the head valve (in all other species they are rectangular). Additionally, below there are provided more detailed differences between the new species and other Craspedochiton reported from the similar geographic range. C. zefranki sp. nov. differs from: Craspedochiton elegans (Iredale & Hull, 1925) by sculpture of the valves (small, fine pustules in C. elegans vs. much larger, coarser pustules in C. zefranki sp. nov.), by the shape of the tail valve (rhomboidal in C. elegans vs. roundish in C. zefranki sp. nov.), position of the mucro (in posterior third and elevated in C. elegans vs. antemedian and flat mucro in C. zefranki sp. nov.); Craspedochiton hystricosus Kaas, 1991 by the sculpture of the valves (much finer, smaller pustules, roundish or elongate vs. much larger, irregular, but squarish in C. zefranki sp. nov.), longitudinal ridges in the pleural area of the intermediate valves (present in C. hystricosus vs. absent in C. zefranki sp. nov.), position of mucro (more posteriorly located in C. hystricosus vs. antemedian in C. zefranki sp. nov.), ridges on the head valves (only weakly indicated in C. hystricosus v
Authors: (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
Institutions: Senckenberg Research Institute and Natural History Museum Frankfurt/M, University of Łódź, Hofstra University, Goethe University Frankfurt, Muséum national d'Histoire naturelle, Universidad Nacional Autónoma de México, Instituto de Ciencias del Mar y Limnología, Universidade Estadual de Campinas (UNICAMP), Hong Kong Baptist University, Scripps Institution of Oceanography, University of California San Diego, Zoological Institute, Universidade Federal de Pernambuco, University of Vienna, Senckenberg - Leibniz Institution for Biodiversity and Earth System Research, Chinese Academy of Sciences, Institute of Oceanology
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7091346563
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