identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
E3B41256544858E48B4587BACEC19531.text	E3B41256544858E48B4587BACEC19531.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Idas pacificus Wu & Lin & Qiu & Xu & Xing 2025	<div><p>Idas pacificus sp. nov.</p><p>Figs 3 A – G, 4 A – E, 7, 8 A (Idas sp. OTU- 51 mentioned earlier; Idas sp. ESU D, as mentioned by Lorion et al. (2010))</p><p>Materials examined.</p><p>All 23 specimens were collected from a piece of wood by trawling at 460–550 m seabed at 30.7°N, 127.8°E in April 2023.</p><p>Type material.</p><p>Holotype • TIO 2023-1816 B 14 (length: 10.8 mm);  Paratypes • six specimens, TIO 2023-1816 B 9, TIO 2023-1816 B 12, TIO 2023-1816 B 15, TIO 2023-1816 B 24, TIO 2023-1816 B 29, TIO 2023-1816 B 30</p><p>Diagnosis.</p><p>Adult specimens approximately measure 10 mm in length, resembling the general outline of  Idas ghisottii Warén &amp; Carrozza, 1990 from the Mediterranean region. Shells with an H / L ratio of about 0.36 to 0.45, maintaining a consistent overall shape across different sizes, though older individuals are slightly more elongated. Umbo located at approximately the anterior 1 / 7 to 1 / 9 of the shell length. The triangular area, from the posterior margin to the umbo, near the dorsal margin, is covered with bristles that match the external shell surface color. The base of the bristles is triangular in shape.</p><p>Shell morphology.</p><p>Shells 3.2–10.8 mm in length, 1.4–4.1 mm in height (Fig. 3 A – G). Shells thin, olive-yellow, semi-transparent, with prominent concentric growth lines. Shells oval, with straight dorsal margin, slightly incurved ventral outline, and rounded posterior margin. Triangular area near dorsal margin, from posterior margin to umbo, sparsely covered with bristles. Umbo located at approximately the anterior 1 / 7 to 1 / 9, shifting forward with increasing shell size and tilting slightly forward. Hinge plate slender and straight (Fig. 4 A – E). Both inner and outer shell surfaces with pearly luster. Inner shell surface smooth, faint traces of anterior adductor scar and pallial line, difficult to discern under optical microscope. Posterior adductor scar large, nearly circular; anterior adductor scar shallow, curved droplet-shaped (SEM images in Fig. 7 C). Pallial sinus indentation small. Prodissoconch pink, rounded, smooth, ~ 400 µm in diameter.</p><p>Soft tissue anatomy.</p><p>Foot well-developed, approximately 40 % of shell length (Fig. 7). Like  I. macdonaldi, byssal retractors continuous and not divided into posterior and anterior portions (Gustafson et al. 1998). Byssus retractor muscle and pedal retractor muscle fused into a single strand. Cross-section of anterior adductor muscle teardrop-shaped, posterior adductor muscle round. No byssus observed.</p><p>Gill-associated microbes.</p><p>The 13 specimens of  Idas pacificus sp. nov. share 11 common microbial species (Fig. 6), with 7 of these accounting for more than 1 % of the total read abundance. Specifically, three species belong to  Gammaproteobacteria, two to Bacteroidia, and two to Campylobacteria. In addition, genetic diversity among symbionts from different  Idas pacificus sp. nov. specimens is notable, with 11 different SUP 05 cluster genotypes detected among the 13 specimens (Fig. 5). ASV 2 is the most common SUP 05 genotype, dominating in 6 of the specimens where it accounts for over 50 % of all SUP 05 sequences. In the remaining specimens, the predominant SUP 05 genotypes include ASV 4, ASV 10, ASV 96, ASV 144, and ASV 325.</p><p>Habitat and distribution.</p><p>The  Idas pacificus sp. nov. specimens lived inside holes in a piece of sunken wood. These holes are typically round, each containing only a single individual. Unlike those of  I. iwaotakii and  Idas sinensis sp. nov., the holes occupied by  I. pacificus sp. nov. are black (Fig. 8 A), which may be due to FeS precipitation (Bienhold et al. 2013). This hypothesis is supported by the functional heatmap of the microbes recovered from the gill tissues (Fig. 6 B), which showed that  I. pacificus sp. nov. had a high abundance of sulfur-oxidizing bacteria. Due to the limited samples of  I. iwaotakii and  Idas sinensis sp. nov. and the fact that all analyzed  Idas samples came from the same piece of wood, we could not determine the generality of this phenomenon.</p><p>The type specimens were collected from sunken wood in the East China Sea at depths of approximately 460–550 meters.  Idas pacificus sp. nov. was reported on sunken wood in Philippines and Vanuatu as  Idas sp. ESU D by Lorion et al. (2009), and experimental bones placed in Japanese waters (Lorion et al. 2013). Comparing our DNA barcode data for  Idas pacificus sp. nov. with those available on GenBank indicates that it is conspecific to  Idas sp. ESU D (GenBank Acc. No. HF 545116, EU 702350, EU 350071, EU 702358), with K 2 P distances of 0–0.3 %, being smaller than the inter-specific genetic divergence between other species of  Idas (e. g. 19.8 % between  I. argenteus and  I. washingtonius, and 2.8 % between  I. macdonaldi and  I. modiolaeformis, See Suppl. material 8 for details.). Therefore,  Idas pacificus sp. nov. may be widespread in the Western Pacific, including East China Sea (this study), Santo Island in Vanuatu (Lorion et al. 2009), Bohol Sea (Duperron et al. 2009), and Japanese waters (Lorion et al. 2013), with water depth ranging from 460 to 1764 meters (Duperron et al. 2009; Lorion et al. 2013).</p><p>Etymology.</p><p>Since our comparison with DNA barcode data obtained from GenBank indicates this species to be widely distributed in the Western Pacific, the name  “ pacificus ” was given to the species.</p><p>Remarks.</p><p>Idas pacificus sp. nov. is notably different from  I. iwaotakii, which has a very elongated shape, a sharply pointed posterior margin, and shorter and darker bristles that appear to degrade with increasing size. Bristles are also a key distinguishing feature that separates this species from  I. washingtonius,  I. coppingeri, and  I. indicus . The first two species lack bristles (Murray et al. 1885; Harbo and Gillespie 2021), while  I. indicus has very short bristles and a more pronounced curvature of the ventral outline (Smith 1899).</p></div>	https://treatment.plazi.org/id/E3B41256544858E48B4587BACEC19531	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Pensoft via Plazi	Wu, Qiong;Lin, Yi-Tao;Qiu, Jian-Wen;Xu, Mei Yu;Xing, Bing Peng	Wu, Qiong, Lin, Yi-Tao, Qiu, Jian-Wen, Xu, Mei Yu, Xing, Bing Peng (2025): Two new species of Idas (Bivalvia, Mytilidae) from sunken wood in the East China Sea: description, phylogenetic position and symbionts. Zoosystematics and Evolution 101 (2): 761-778, DOI: 10.3897/zse.101.142007
AE3CA7D7ED9D5480A8FF8EDE5BA769CC.text	AE3CA7D7ED9D5480A8FF8EDE5BA769CC.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Idas sinensis Wu & Lin & Qiu & Xu & Xing 2025	<div><p>Idas sinensis sp. nov.</p><p>Figs 3 H – I, 4 F – G</p><p>Materials examined.</p><p>Two specimens collected from the same piece of sunken wood by trawling from a seabed at a depth of 460–550 m (30.7°N, 127.8°E) in April 2023.</p><p>Type material.</p><p>Holotype • TIO 2023-1816 B 6 (length: 9.3 mm);  Paratype • TIO 2023-1816 B 21 (length: 13.4 mm), with a fractured right valve .</p><p>Diagnosis.</p><p>Shells extremely thin, with internal surface color similar to external surface. Dorsal and ventral margins nearly parallel. Bristles short, brown, mainly concentrated along both sides of ridge in posterior triangular area. Shells resemble those of  I. iwaotakii, but overall outline more elliptical compared to  I. iwaotakii due to more similar anterior and posterior heights.</p><p>Shell morphology.</p><p>Shells 9.3 mm to 13.4 mm in length, 3.1 mm to 3.9 mm in height (Fig. 3 H – I), thin, fragile, deep olive-yellow, semi-transparent, very thin nacreous layer. Highly elongated, elliptical shape with concentric growth lines. Small specimen with rounded anterior and posterior margins; large specimen with broadly triangular posterior margins. Dorsal and ventral margins straight and nearly parallel, with slight incurvature along the ventral outline in larger specimens. Very short, dark brown bristles distributed mainly along the ridge from the posterior margin to the umbo. Umbo extremely anterior. Hinge plate slightly curved, with degenerated anterior hinge teeth (Fig. 4 F – G). Inner shell surface smooth, lacking muscle scars. Prodissoconch pink and rounded.</p><p>Soft tissue anatomy.</p><p>The soft tissue was poorly preserved to allow for detailed examination. However, the foot of the specimen preserved in alcohol was purple.</p><p>Gill-associated microbes.</p><p>Only the gill tissues of the holotype (TIO 2023-1816 B 6) could be used for analysis of symbiotic microbes. Among the bacteria associated with the gill,  Pseudohongiella sp.,  Reichenbachiella sp., and SUP 05 cluster were most abundant, representing 70 %, 9 %, and 7 % of the sequences, respectively (Figs 5, 6 A).</p><p>Habitat and distribution.</p><p>So far, this species has only been found within wood. It is known only from the East China Sea (30.7°N, 127.8°E).</p><p>Etymology.</p><p>The name  sinensis – the Latinized form of China, refers to the type locality, within the Chinese EEZ of the East China Sea.</p><p>Remarks.</p><p>Idas sinensis sp. nov. exhibits a close morphological and phylogenetic relationship with  I. iwaotakii, as both species share an elongated shell shape, characterized by nearly parallel dorsal and ventral outlines, a feature that sets them apart from  Idas species in other clades. The primary difference between these species (for specimens around 1 cm in length) lies in the curvature of the anterior and posterior margins:  Idas sinensis sp. nov. has a more capsule-shaped outline, while  I. iwaotakii has a more triangular profile.</p><p>Additionally, the Mediterranean species  Idas cristiani Fr. Giusti, Mietto &amp; Sbrana, 2012 and  Idas emmae Fr. Giusti, Mietto &amp; Sbrana, 2012 also exhibit an elongated form. However, none of the  Idas sinensis sp. nov. specimens (9.3 mm and 13.4 mm) have anterior hinge teeth, whereas  I. cristiani has 5–6 small teeth below the umbo, and  I. emmae has three. Moreover,  Idas sinensis sp. nov. has sparser bristles compared to  I. cristiani, and its shell (H / L = 0.29–0.33) is higher than that of  I. emmae (H / L = 0.25–0.26) (Giusti et al. 2012).</p></div>	https://treatment.plazi.org/id/AE3CA7D7ED9D5480A8FF8EDE5BA769CC	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Pensoft via Plazi	Wu, Qiong;Lin, Yi-Tao;Qiu, Jian-Wen;Xu, Mei Yu;Xing, Bing Peng	Wu, Qiong, Lin, Yi-Tao, Qiu, Jian-Wen, Xu, Mei Yu, Xing, Bing Peng (2025): Two new species of Idas (Bivalvia, Mytilidae) from sunken wood in the East China Sea: description, phylogenetic position and symbionts. Zoosystematics and Evolution 101 (2): 761-778, DOI: 10.3897/zse.101.142007
