taxonID	type	description	language	source
03CB95362205325FBD5AFB85FCBBF899.taxon	materials_examined	Material examined. Korea, Incheon, Incheon Port (37 ° 27 ʹ 00 ʺ N, 126 ° 39 ʹ 22 ʺ E), 24 Oct 2019, Hee-Min Yang. Voucher Number: NIBRIV 0000879588.	en	Min, Hee-Min Yang and Gi-Sik (2022): New record of two marine synchaetid rotifers (Monogononta: Synchaeta) from Korea. Journal of Species Research 11 (3): 174-179, DOI: 10.12651/JSR.2022.11.3.174
03CB95362205325FBD5AFB85FCBBF899.taxon	diagnosis	Diagnosis. Body 285 - 366 μm in length, cone-shaped, and gradually tapering to foot. Apical field wide and flat, with four lateral and dorsolateral styles. Color of auricles and rotatory organ orange. Red eyespot located near mastax. One pair of lateral antennae at the end of the trunk. Foot long, one-fourth of body length, 81 - 85 μm. Pedal glands symmetrical and elongated, each gland with two swollen parts. Length of pedal glands approximately equal to length of foot. Two small toes on the tip of the foot. Toe tips completely separated. Trophi virgate type. Apical rami with frontal hook, one distinct tooth, and serrated inner margin. Fine needle structure on the inner margin of mid-rami. Hypopharynx located in front of needle structure. Manubrium straight with broad lamella. Tip of manubrium knob-shaped. Fulcrum thick and dagger-like. Fulcrum consisted of thick rod on dorsal side with broad lamella on ventral side.	en	Min, Hee-Min Yang and Gi-Sik (2022): New record of two marine synchaetid rotifers (Monogononta: Synchaeta) from Korea. Journal of Species Research 11 (3): 174-179, DOI: 10.12651/JSR.2022.11.3.174
03CB95362205325FBD5AFB85FCBBF899.taxon	distribution	Distribution. Korea (this study), Baltic Sea (Remane, 1929), British Atlantic coast (Galliford, 1946), Gulf of Mexico (Koste, 1981), Peter the Great Bay (Pacific Ocean) (Chernyshev, 2005).	en	Min, Hee-Min Yang and Gi-Sik (2022): New record of two marine synchaetid rotifers (Monogononta: Synchaeta) from Korea. Journal of Species Research 11 (3): 174-179, DOI: 10.12651/JSR.2022.11.3.174
03CB95362205325FBD5AFB85FCBBF899.taxon	discussion	Remarks. Synchaeta grimpei is easily distinguished from other synchaetid species based on the following characteristics: (1) cone-shaped body, (2) wide and flat apical field, (3) indistinct auricles, and (4) long foot with two separated small toes. This species has been recorded from brackish water or marine environments (Hollowday, 2002; Wilke et al., 2019). The Korean specimens were collected in September and October, at a water temperature of 20 - 24 ℃ and salinity of 28.5 - 29.6 ‰. The morphological characteristics of the Korean specimens were generally consistent with those observed in previous studies (Hollowday, 2002; Wilke et al., 2019), except for the number of rami teeth. The descriptions by Koste (1981) and Hollowday (2002) documented the presence of multiple distinct teeth on rami; however, Korean specimens did not have distinct teeth in rami as described by Wilke et al. (2019). This is the second record of S. grimpei from the Pacific Ocean after Chernyshev (2005). Molecular analysis. Partial COI sequences were obtained from five specimens. The intra-specific genetic distances were 0.0 - 1.7 % within the Korean population (627 bp) (GenBank accession numbers: ON 038411 - ON 038415). The genetic distances of Korean and German S. grimpei specimen were 0.4 - 1.2 % (483 bp, Table 1) (GenBank accession numbers: MK 905783 - MK 905785) (Wilke et al., 2020).	en	Min, Hee-Min Yang and Gi-Sik (2022): New record of two marine synchaetid rotifers (Monogononta: Synchaeta) from Korea. Journal of Species Research 11 (3): 174-179, DOI: 10.12651/JSR.2022.11.3.174
03CB953622063259BD34F8FEFBF4FA7D.taxon	materials_examined	Material examined. Korea, Incheon, Incheon Port (37 ° 27 ʹ 00 ʺ N, 126 ° 39 ʹ 22 ʺ E), 31 Mar 2021, Hee-Min Yang. Voucher Number: NIBRIV 0000895436.	en	Min, Hee-Min Yang and Gi-Sik (2022): New record of two marine synchaetid rotifers (Monogononta: Synchaeta) from Korea. Journal of Species Research 11 (3): 174-179, DOI: 10.12651/JSR.2022.11.3.174
03CB953622063259BD34F8FEFBF4FA7D.taxon	diagnosis	Diagnosis. Head large and wide. Apical field strongly convex. One tubular antenna on the center of apical field, tip of antenna with tuft. Four long styles present on apical field. Lateral auricles large, directed semi-cau- dally. Two small eyespots located near mastax. Head and trunk distinctly separated by wrinkled neck. Trunk cylindrical, tapered to posterior end. Longitudinal fold present on trunk. Lateral antennae at posterior third of trunk. Foot short, 60 - 65 μm in length. Pedal glands symmetrical and approximately the same length as the foot. Two small, separated toes on the foot. Total length 410 - 460 μm. Trophi virgate. Rami with frontal hook and several distinct teeth. One spine on middle of frontal hook. Each side of ramus teeth separated into two groups: three to four teeth on apical group and two teeth on basal group. Hypopharynx wide and crown-shaped. Manubrium straight and simple, with broad lamella. Fulcrum thick, machete-shaped.	en	Min, Hee-Min Yang and Gi-Sik (2022): New record of two marine synchaetid rotifers (Monogononta: Synchaeta) from Korea. Journal of Species Research 11 (3): 174-179, DOI: 10.12651/JSR.2022.11.3.174
03CB953622063259BD34F8FEFBF4FA7D.taxon	distribution	Distribution. Cosmopolitan.	en	Min, Hee-Min Yang and Gi-Sik (2022): New record of two marine synchaetid rotifers (Monogononta: Synchaeta) from Korea. Journal of Species Research 11 (3): 174-179, DOI: 10.12651/JSR.2022.11.3.174
03CB953622063259BD34F8FEFBF4FA7D.taxon	discussion	Remarks. The external morphological characteristics of Korean S. vorax specimens were most similar to the original description by Rousselet (1902). The trunk shape of the Korean specimens and the original description were slender and cylindrical, whereas those of Lie-Pettersen (1905) and Wilke et al. (2019) were plump and wineglass-shaped. In terms of trophi morphology, several variations were recorded in rami teeth. Wilke et al. (2019) reported that S. vorax has no distinct teeth and only a serrated plate. However, descriptions from Rousselet (1902), Lie-Pettersen (1905), and Arndt et al. (1990) indicated that the rami teeth of S. vorax possess several distinct teeth. The rami of the Korean specimen contained one frontal hook and distinctly large teeth. The teeth are divided into two groups as indicated in the ‘ Diagnosis’ section, with each ramus containing three to four teeth on the apical group and two teeth on the basal group. The rami teeth formula of the Korean specimen was similar to that of S. curvata Lie-Pettersen, 1905, described by Arndt et al. (1990). However, the two species are clearly distinguished by morphological characteristics such as the tubular apical antenna and the number of eyespots. Synchaeta vorax was recorded as a eurythermal species in a previous study (Hollowday, 2002), and the Korean specimen was collected from November to March, at a water temperature of 5 - 10 ℃ and a salinity of 26.0 - 29.3 ‰. Molecular analysis. Partial COI sequences were obtained from five specimens. The intra-specific genetic distances were 0.0 - 1.1 % within the Korean population (657 bp) (GenBank accession numbers: ON 038419 - ON 038423). The genetic distances between the Korean and German S. vorax specimens were 11.1 - 12.4 % (621 bp, Table 2) (GenBank accession numbers: MK 905832 - MK 905842) (Wilke et al., 2020). These genetic distances were unusually large within the same species, even if they were in different population. Recently, as molecular analysis has been introduced to the rotifer research, cryptic species have been identified in various species (GarcÍa-Morales and ElÍas-Gutiérrez, 2013; Obertegger et al., 2014; Papakostas et al., 2016; Kordbacheh et al., 2017; 2018). Most of the cryptic species are morphologically indistinguishable and have large genetic distance. In this regard, we reconfirmed the external and trophi characteristics of the Korean S. vorax specimens, and found no significant dif- ference from the previously known morphological characteristics. For the accurate assessment of biodiversity, the problem of cryptic species must be solved, and for this, it is considered that additional studies on biogeographical, ecological, and reproductive are needed in addition to morphological analysis.	en	Min, Hee-Min Yang and Gi-Sik (2022): New record of two marine synchaetid rotifers (Monogononta: Synchaeta) from Korea. Journal of Species Research 11 (3): 174-179, DOI: 10.12651/JSR.2022.11.3.174
